ALBERT

Beschreibung: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 493〈/p〉 〈p〉Author(s): Shivshankar Chaudhari, MinKyoung Baek, YongSung Kwon, MinYoung Shon, SeungEun Nam, YouIn Park〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Surface modification of a halloysite nanotube (HNT) was performed by piranha etching of the HNT surface to generate hydrophilic moiety on the surface. The HNT and surface-modified HNT (MHNT) were embedded in polyvinyl alcohol/polyvinyl amine (PVA/PVAm) membranes. Surface modification of the HNT was confirmed using X-ray photoelectron spectroscopy, Fourier transform infrared, and transmission electron microscopy analyses. The 5 wt% MHNT-embedded membrane showed the best pervaporation performance (flux = 0.13–0.031 kg/m〈sup〉2〈/sup〉 h and separation factor = 427–93,313) among all membranes at 40 °C with 80–90 wt% of isopropanol (IPA) in the feed solution. Up to 5 wt% loading of HNT and MHNT in the membrane, the flux decreased, while the separation factor increased and subsequently decreased continuously with further HNT and MHNT loading. This was attributed to the hydrophilicity arising from HNT inclusion in the membranes. The membrane performance was evaluated under various pervaporation-operating conditions. Based on the solution diffusion model, with increase in water content, flux increased, while separation factor decreased. The temperature dependence of flux followed the Arrhenius equation. The energy of activation for the permeation of water (25.99 kJ/mol) was less than that of IPA (143.49 kJ/mol for the 5 wt% MHNT-loaded membrane at an 85 wt% of feed IPA composition). Overall, the pervaporation data suggested that the presence of MHNT in the PVA/PVAm membrane benefited pervaporation dehydration.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219320379-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 492〈/p〉 〈p〉Author(s): Naofumi Ohtsu, Yuma Hirano, Kaho Yamaguchi, Kako Yamasaki〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A titanium oxide layer containing a small amount of Ni can be formed on a NiTi surface through anodization when using HNO〈sub〉3〈/sub〉 as an electrolyte. In this study, the effect of different HNO〈sub〉3〈/sub〉 concentrations on the surface characteristics of the alloy, including hydrophilicity, Ni-ion release, and antibacterial efficacy, was investigated. An oxide layer was fabricated, in which tiny pores were generated by pitting corrosion. The layer thickness and pore size varied with the concentration of the HNO〈sub〉3〈/sub〉 electrolyte. The hydrophilicity of the NiTi surface was dramatically improved through anodization owing to the formation of the oxide layer. The layer formed was expected to serve as a corrosion protection barrier; however, the Ni release rate from the anodized surface was higher than that of an untreated surface due to the generation of pores. The Ni release rate from the anodized surfaces varied depending on the electrolyte concentrations used, owing to the balance between the layer thickness and pore size. Ni ion release was advantageous from the view of antibacterial efficacies; the efficacies of NiTi alloy against 〈em〉E. coli〈/em〉 and 〈em〉S. aureus〈/em〉 were actually enhanced by anodization. Ni ion release was not beneficial with regards to allergenic reaction and cytotoxicity; the Ni ion release rate decreased rapidly when the alloy was soaked in a simulated body fluid. Thus, we concluded that anodization in HNO〈sub〉3〈/sub〉 is one possible approach to fabricate ideal NiTi medical devices with excellent antibacterial performance and biosafety.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 493〈/p〉 〈p〉Author(s): Pingan Zhang, Aimin Pang, Gen Tang, Jianru Deng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this article, Molecular dynamics (MD) simulation were applied to investigate the adsorption behavior and mechanism of neutral polymeric bonding agents (NPBA) in nitrate ester plasticized polyether (NEPE). The simulation results indicate that due to the strong van der Waals (vdW) force interaction, NPBA has the highest binding energy with RDX compared to PEG and nitrate plasticizer. Then, the influences of temperature on the compatibility of nitrate plasticizer and two polymers, NPBA and PEG, were studied. The results show that PEG can dissolve in nitrate plasticizer over a wide range of temperature, while the compatibility of NPBA and nitrate plasticizer decrease with the reducing of temperature. Moreover, the adsorption behavior of the NPBA on RDX surface in nitrate plasticizer was investigated. The results demonstrate that the NPBA chains can penetrate through nitrate plasticizer, adsorb on the RDX surface, and form a compact protection layer, which prevents the bonding interface from nitrate plasticizer damage. Our researches afford a microscopic insight into the mechanism of NPBA, and can be helpful to the NPBA molecular and NEPE formulation design.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219320513-ga1.jpg" width="303" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 492〈/p〉 〈p〉Author(s): A. Dulmaa, H. Vrielinck, S. Khelifi, Diederik Depla〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Copper oxide thin films are grown by reactive magnetron sputter deposition. To define the parameter space to obtain CuO films, the influence of the oxygen partial pressure, the total pressure, and the discharge current was investigated on the phase formation. A clear change from pure copper, over cuprite (Cu〈sub〉2〈/sub〉O), and paramelaconite (Cu〈sub〉4〈/sub〉O〈sub〉3〈/sub〉) to tenorite (CuO) thin films with increasing oxygen partial pressure was observed using X-ray diffraction and Fourier transform infrared spectroscopy. The main driving force defining the phase composition is the oxygen partial pressure, while the influence of the total pressure, and the discharge current is minimal. A clear condition to obtain phase pure CuO films could be defined based on the measured discharge voltage. Both the domain size, and the Bragg peak position for pure CuO thin films can be correlated to the negative ion bombardment during film growth.〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 493〈/p〉 〈p〉Author(s): Yun Kon Kim, Sungjun Kim, Yonghwan Kim, Kyeonghui Bae, David Harbottle, Jae W. Lee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Selective removal of 〈sup〉137〈/sup〉Cs and 〈sup〉90〈/sup〉Sr from aqueous environments is essential for the volume reduction and ultimate safe storage of nuclear waste. This study introduces a facile one-pot hydrothermal synthesis of Dual-cation form of TitanoSilicate (DTS, M〈sub〉3〈/sub〉HTi〈sub〉4〈/sub〉O〈sub〉4〈/sub〉(SiO〈sub〉4〈/sub〉)〈sub〉3〈/sub〉, M = Na〈sup〉+〈/sup〉 and K〈sup〉+〈/sup〉) for the effective and simultaneous removal of Cs〈sup〉+〈/sup〉 and Sr〈sup〉2+〈/sup〉. DTS showed enhanced adsorption capacities (469 mg/g for Cs〈sup〉+〈/sup〉 and 179 mg/g for Sr〈sup〉2+〈/sup〉) and the adsorption kinetics were extremely fast with around 98% and 〉99% removal achieved within 1 min from a dilute Cs〈sup〉+〈/sup〉 and Sr〈sup〉2+〈/sup〉 solution, respectively. Moreover, DTS indicated the superior selectivity for both Cs〈sup〉+〈/sup〉 and Sr〈sup〉2+〈/sup〉 due to the dual-cation incorporation in the structure. In groundwater, the distribution coefficients (K〈sub〉d〈/sub〉 at V/m = 1000 mL/g) for DTS were high for both Cs〈sup〉+〈/sup〉 (1 ppm, 2.9 × 10〈sup〉5〈/sup〉 mL/g) and Sr〈sup〉2+〈/sup〉 (1 ppm, 1.0 × 10〈sup〉5〈/sup〉 mL/g), and even in seawater DTS maintained a Cs〈sup〉+〈/sup〉 (1 ppm) K〈sub〉d〈/sub〉 value as high as 4.9 × 10〈sup〉4〈/sup〉 mL/g. Remarkably, DTS is synthesized as a membrane with graphene oxide for continuous removal of the radionuclides, which is extremely beneficial to purifying a large volume of contaminated water.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219320446-ga1.jpg" width="455" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 493〈/p〉 〈p〉Author(s): Sreejith Karthikeyan, Sehyun Hwang, Mandip Sibakoti, Timothy Bontrager, Richard W. Liptak, Stephen A. Campbell〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Thin-film photovoltaic research based on ternary or quaternary absorber materials has mainly concentrated on copper (indium/gallium) diselenide, CuIn〈sub〉x〈/sub〉Ga〈sub〉1-x〈/sub〉Se〈sub〉2〈/sub〉 (CIGS). This material has demonstrated exceptional energy conversion efficiencies. By altering the In/Ga ratio the band gap can be varied from 1.02 eV (for CuInSe〈sub〉2〈/sub〉) to 1.68 eV (for CuGaSe〈sub〉2〈/sub〉). However, research from leading groups showed that cells have maximum efficiency at or below 1.35 eV. This paper reports the challenges of using aluminium alloyed CIGS deposited with a single step co-evaporation method. Adding aluminium is found to reduce the bulk trap state density for wide gap devices. However, it created significant safety issues when compared to conventional CIGS co-evaporation deposition systems. The release of H〈sub〉2〈/sub〉Se when moisture comes in contact with aluminium selenide was resolved by placing exhaust lines at various places of the deposition chamber. A single phase CIAGS device with a bandgap of 1.30 eV was prepared using a co-evaporation method. The fabricated solar cell devices with CIAGS absorber layers and resulted in a photoconversion efficiency of 10.3%. A progressive rapid thermal annealing at various temperature resulted in a 10% increase in the overall efficiency at 300 °C. The efficiencies were reduced when the RTA temperature increased above 300 °C.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉SEM image of device cross section based on CIAGS absorber layer.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219320148-ga1.jpg" width="410" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 492〈/p〉 〈p〉Author(s): Beleta Bolvardi, Javad Seyfi, Iman Hejazi, Maryam Otadi, Hossein Ali Khonakdar, Seyed Mohammad Davachi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Oil spill accidents and industrial oily wastewater are threatening all living species in the ecological system. Development of materials with special wettability for oil/water separation has been the subject of many researches. Herein, superhydrophobic and superoelophilic nanocomposite coatings, based on titanium dioxide (TiO〈sub〉2〈/sub〉) nanoparticles and polydimethylsiloxane (PDMS), were applied on metal meshes with different pore sizes (25 and 100 μm). Morphological analysis revealed that adding PDMS, as a binder, significantly changes the surface structure of the coatings. For 100 μm-sized meshes, PDMS causes a two-tier roughness whereas a uniform and finely packed single-scale nanostructure was formed for 25 μm-sized meshes upon PDMS addition. Exceedingly high content of nanoparticles was found to impose a detrimental influence on uniformity of morphology. All the samples exhibited superhydrophobicity; however, their mechanical durability results were significantly diverse. PDMS introduction was found to impose a substantial improvement in abrasion resistance. Oil/water separation experiments revealed that the mesh with smaller pore size exhibited a more efficient separation while a much shorter separation time and higher flux could be achieved by the mesh with larger pore size. In addition, the mesh with smaller pore size exhibited a more abrasion resistant coating which could be more beneficial in real-life applications.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 493〈/p〉 〈p〉Author(s): De-Cai Guo, Chun-Shui Sun, Wei Wu, Zhong-Shuai Wu, Jing Gao, Nan Su, Jian Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The fabrication of nanocarbons possessing ultrathin graphitic structure and ultrahigh nitrogen doping simultaneously remains challenging so far. Herein, we develop a novel and versatile strategy to prepare ultrahigh nitrogen-doped hierarchical porous carbon with ultrathin graphitic framework (NHPCs), through the Schiff-base reaction of melamine and terephthalaldehyde in the presence of lithium oxide, as high-performance anodes for rechargeable lithium ion batteries. During one-pot solid-phase interface reaction, Li〈sub〉2〈/sub〉O was used to absorb the in-situ generating H〈sub〉2〈/sub〉O enhancing the formation of Schiff-based networks and LiOH was in-situ obtained, which can be used as active agent to increase the BET surface areas of final carbons. The obtained NHPCs present 3D hierarchical honeycomb-like morphology, ultrahigh nitrogen content up to 12.2 wt%, large specific surface area of 1260 m〈sup〉2〈/sup〉 g〈sup〉−1〈/sup〉. These unique structural properties allowed for fast ion diffusion and rapid electron transport, and offered enriched active sites for lithium storage. NHPCs presented a high reversible capacity of 880 mAh g〈sup〉−1〈/sup〉 at 100 mA g〈sup〉−1〈/sup〉 even after 100 cycles, and exceptional rate capability with 301 mAh g〈sup〉−1〈/sup〉 at 3000 mA g〈sup〉−1〈/sup〉, outperforming most reported nano‑carbons. Therefore, this strategy will open a new way to prepare heteroatom-doped porous carbons with a controllable hierarchical structure, for high-performance energy storage.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Nitrogen-doped hierarchical porous carbon with ultrathin graphitic framework was prepared by the novel method of one-pot solid phase in situ templated synthesis strategy shows superior high electrochemistry performance for lithium-ions storage.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219319166-ga1.jpg" width="433" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 492〈/p〉 〈p〉Author(s): Liwei Wang, Huiyun Tian, Han Gao, Fazheng Xie, Kang Zhao, Zhongyu Cui〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Passivation behavior and surface chemistry of 304 stainless steel in alkaline solution with different HCO〈sub〉3〈/sub〉〈sup〉−〈/sup〉/CO〈sub〉3〈/sub〉〈sup〉2–〈/sup〉 concentrations are studied with a combined electrochemical and XPS analytical investigation. Cathodic and anodic reactions are inhibited and accelerated, respectively, attributed to the depletion of acceptable oxygen and variation of passive film properties. Increasing HCO〈sub〉3〈/sub〉〈sup〉−〈/sup〉/CO〈sub〉3〈/sub〉〈sup〉2–〈/sup〉 concentration does not alter the bilayer structure but leads to an intensification in electric field strength and composition changes including enrichment of oxidized Cr, increase of Fe(II)/Fe(III) ratio, and decrease of OH〈sup〉−〈/sup〉/O〈sup〉2–〈/sup〉 ratio of the film. Meanwhile, the film thickness is reduced and the point defect density is increased due to the enhanced film dissolution. High HCO〈sub〉3〈/sub〉〈sup〉−〈/sup〉/CO〈sub〉3〈/sub〉〈sup〉2–〈/sup〉 concentration increases the critical chloride concentration of 304 SS in alkaline solution, attributed to the inhibition of the localized acidification within the pits and suppression of the stable pit development.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 492〈/p〉 〈p〉Author(s): Rong Zhang, Liancheng Wang, Xi Yang, Zheng Tao, Xiaobo Ren, Baoliang Lv〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The surface chemistry of catalyst plays a vital role in the catalytic process. And the effects of surface groups of porous boron nitride (〈em〉p〈/em〉-BN) on the hydrogenation reaction have not been studied in detailed. In this work, two main surface species of Co/〈em〉p〈/em〉-BN catalyst were tuned thermally and their roles on the hydrogenation reaction were discriminated by α, β-unsaturated aldehyde hydrogenation reaction. The surface B〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O content decreased at higher reduction temperature and the cobalt phase changed from CoO to the mixture of CoO and Co0. The Co/〈em〉p〈/em〉-BN-500 exhibited the highest selectivity to C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉O hydrogenation. And its turnover frequency (TOF) of 13.2 h〈sup〉−1〈/sup〉 is close to the optimal value of reported cobalt catalysts. When the reaction proceeds, hydrogenation rate of C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉O increases but that of C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉C decreases gradually, thus a surface groups variation was expected at the initial period. Further in-situ FTIR spectra showed the band intensity of edge N〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉H increases as the adsorption proceeds at 50°С but it decreases as the temperature rise to 200°С, in combined with the shift of C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉O adsorption peak, a intermolecular hydrogen bond between edge N〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉H and the terminal C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉O group was suggested, which account for the better selectivity to C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉O than C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉C.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219320045-ga1.jpg" width="490" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 493〈/p〉 〈p〉Author(s): Jin-hua Ren, Yu-ting Huang, Kai-wen Li, Jie Shen, Wan-yu Zeng, Chu-ming Sheng, Jing-jing Shao, Yan-bing Han, Qun Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Tm〈sup〉3+〈/sup〉 doped SnO〈sub〉2〈/sub〉 semiconductor thin films were prepared by RF magnetron sputtering method. The doping effects of rare-earth thulium on the crystal structures, optical properties, chemical compositions, surface morphologies of tin-oxide thin films, together with the electrical properties of the corresponding SnTmO thin film transistors (TFTs), were investigated. SnTmO semiconductor thin films with polycrystalline structures feature a wide bandgap of over 3.8 eV. XPS results reveal the typical photoelectron signals of Sn〈sup〉4+〈/sup〉 and Tm〈sup〉3+〈/sup〉. Smaller crystallite size and more grain boundaries can be formed in doped SnO〈sub〉2〈/sub〉 samples which may be responsible for the degradation of device mobility. It was found that the electrical properties of SnO〈sub〉2〈/sub〉 TFTs can be modulated by Tm〈sup〉3+〈/sup〉 incorporation. The appropriate Tm〈sup〉3+〈/sup〉 doping concentration is around 1.6 at.% within our experimental conditions. The optimized field-effect mobility, subthreshold swing, threshold voltage, on-off current ratio and the interface trap density are 5.5 cm〈sup〉2〈/sup〉 V〈sup〉−1〈/sup〉 s〈sup〉−1〈/sup〉, 0.618 Vdec〈sup〉−1〈/sup〉, −2.3 V, 5 × 10〈sup〉7〈/sup〉 and 6.7 × 10〈sup〉11〈/sup〉 cm〈sup〉−2〈/sup〉, respectively. Stability measurements show threshold voltage shifts of 12.3 V and −11.7 V in PBS and NBS process respectively. This study may provide useful understandings on rare-earth doped SnO〈sub〉2〈/sub〉 semiconductors.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219320367-ga1.jpg" width="399" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 492〈/p〉 〈p〉Author(s): Meng Chen, Yifu Zhang, Yanyan Liu, Jiqi Zheng, Changgong Meng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fabrication of a novel electrode material with efficient storage mechanism is a desirable strategy to build a better supercapacitors. Herein, a novel intercalation pseudocapacitance material, VO(OH)〈sub〉2〈/sub〉/CNT binary composite with cross-linked structure, is first successfully synthesized by a facile one-step hydrothermal method. This composite combines the intrinsic positive traits of each component, in which the synergistic efforts greatly enhance to achieve a considerable electrochemical performance. In the three-electrode system, VO(OH)〈sub〉2〈/sub〉/CNT composite electrode exhibits a capacitance of 256 F·g〈sup〉−1〈/sup〉 (512C·g〈sup〉−1〈/sup〉) at 0.5 A·g〈sup〉−1〈/sup〉 within the wide potential range of −0.8–1.2 V. More remarkably, the VO(OH)〈sub〉2〈/sub〉/CNT-based flexible symmetric supercapacitor delivers a high energy density of 32.08 Wh·kg〈sup〉−1〈/sup〉 at a power density of 63.65 W·kg〈sup〉−1〈/sup〉 in a large operating voltage of 2.2 V. As well as, it performs a well cycling stability that the capacitance retention is about 90% after 3000 cycles. For the factual application measurement, two devices in series can light red LED for 5 min after charging 100 s. This work enriches the exploration of vanadium oxyhydroxides' pseudocapaicitance performance, which is of great significance to the future application of vanadium oxyhydroxides in energy storage.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉VO(OH)〈sub〉2〈/sub〉/CNT electrode material with cross-linked structure performs the excellent intercalation pseudocapacitance. VO(OH)〈sub〉2〈/sub〉/CNT flexible SSC device can deliver a high energy density of 32.08 Wh·kg〈sup〉−1〈/sup〉 at a power density of 63.65 W·kg〈sup〉−1〈/sup〉 in a large operating voltage of 2.2 V. And after charging for 100 s, two devices in series can light red LED for 5 min.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219320057-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 492〈/p〉 〈p〉Author(s): Lan Chen, Xinzhou Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Owing to the layer-by-layer deposition characteristic of fused deposition modeling (FDM) process, parts produced via FDM have typical low surface quality and do not satisfy the requirements for end-use applications. Therefore, it is necessary to improve the surface quality of parts produced via FDM. In this study, laser polishing technology was employed to enhance the surface quality of aluminum fiber/polylactide acid (Al/PLA) composite parts produced via FDM. The surface roughness, surface morphology, dynamic mechanical properties, and tensile properties were investigated. With optimal polishing parameters, the laser polishing process removed the defects formed during the FDM process. The surface roughness was reduced from the initial value of 5.64 μm to 0.32 μm (〈em〉Ra〈/em〉). The dynamic mechanical analysis (DMA) results showed that there was a remarkable improvement in the storage modulus (〈em〉E〈/em〉′), loss modulus (〈em〉E〈/em〉"), and glass transition temperature of Al/PLA composite specimens after laser polishing. The re-melted and polished surface of the specimens also led to improvement in the tensile strength and Young's modulus. Lastly, the fracture morphologies were observed, and the possible strengthening mechanism was also discussed. These results indicate that laser polishing can be an efficient method for the surface polishing of FDM-printed parts.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219319786-ga1.jpg" width="273" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 492〈/p〉 〈p〉Author(s): Sher Bahadar Khan, Kalsoom Akhtar, Esraa M. Bakhsh, Abdullah M. Asiri〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A facile, cheap and efficient system has been developed for selective detection and removal of 4-nitrophenol. Herein, cerium oxide-copper oxide (CeO〈sub〉2〈/sub〉-Cu〈sub〉2〈/sub〉O) and CeO〈sub〉2〈/sub〉-Cu〈sub〉2〈/sub〉O/chitosan (CeO〈sub〉2〈/sub〉-Cu〈sub〉2〈/sub〉O/CH) nanocomposites were coated on glassy carbon electrode to evaluate their electrochemical behavior toward 4-nitrophenol via cyclic voltammetry. The response of coated electrodes toward 4-nitrophenol were remarkable, in which the reduction peak current of 4-nitrophenol was increased as compared to bare electrode. This specifies that such nanocomposites significantly boost the electrochemical reduction of 4-nitrophenol and therefore, we demonstrated that the nanocomposites exhibit outstanding selectivity and sensitivity toward 4-nitrophenol detection. The effects of different parameters including pH and scan rate were tested. The reduction peak current of 4-nitrophenol is proportionate with its concentration in the range 74–375 μM, and the correlation coefficient was 0.998. The detection limit is 2.03 μM (S/N = 3). This simplistic system was effectively implemented to the detection of 4-nitrophenol in real water samples, with reasonable recovery values (92.5–99.85%). Furthermore, we demonstrated that the nanocomposite displays an excellent catalytic ability for the transformation reaction of 4-nitrophenol to 4-aminophenol by NaBH〈sub〉4〈/sub〉. Such a system could be applicable for diverse applications in catalysis, sensing and environmental sciences.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S016943321931921X-ga1.jpg" width="271" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 492〈/p〉 〈p〉Author(s): Wang Li, Xin Shen, Rong Zeng, Jian Chen, Weiming Xiao, Shunmin Ding, Chao Chen, Rongbin Zhang, Ning Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The interaction of the metal and support in copper-ceria oxide catalysts has been proven to have extremely favorable effects on catalytic performance in CO oxidation. Therefore, how to construct more copper-ceria interfaces becomes the key to improve the catalytic activity. Herein, we developed a facile approach to prepare copper-ceria nanosheets with high concentration of interfacial active sites (active copper species sites and oxygen vacancies) using GO as a sacrificial template. Notably, GO was used as an excellent platform to grow precursors of both the Cu and Ce on its surface. Then, transfer them to metal oxides nanosheets by calcination. The CuCe-GO-X catalysts were characterized by SEM, TEM, In situ DRIFT, AFM, XRD, XPS, H〈sub〉2〈/sub〉-TPR and Raman spectra and applied in CO oxidation. The results demonstrate that CuCe-GO-600 nanosheets catalyst with about 10 nm thickness shows a higher concentration of oxygen vacancies (7.79%) and active copper species sites (2756 μmol g〈sup〉−1〈/sup〉) in the interface of copper-ceria than those of other CuCe-GO-X catalysts. Moreover, CuCe-GO-600 displays a highest catalytic activity (complete conversion at 90 °C with a space velocity of 54,000 mL (h g〈sub〉cat〈/sub〉)〈sup〉−1〈/sup〉).〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219320276-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): Yadan Guo, Chenxi Li, Yiqin Guo, Xuegang Wang, Xiaomeng Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Graphitic carbon nitride (g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉) is a new type of nonmetal polymeric semiconductor photocatalyst for removal of pollutants. To overcome the low BET surface and the low electron–hole recombination rate of the g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 photocatalysts, we successfully synthesized g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Na-bentonite composites using an ultrasonic-assisted method. The XRD showed that the composite was composed of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 and Na-bentonite. The analyses of TEM and XPS indicated that graphite carbon nitride was successfully intercalated on Na-bentonite via the ultrasonic-assisted strategy, and the g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Na-bentonite nanocomposites presented remarkable light absorption capacities and mesoporous structure observed by UV–vis DRS and BET method. In addition, the as-prepared composites can be used for the photocatalytic removal of single RhB or Cr(VI), and the efficiencies of the Cr(VI) reduction are increased from 53.2% to 88.6% in RhB/Cr(VI) mix-system. Superior stability and high efficiencies of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Na-bentonite composites were also exhibited for up to 4 cycles. The photocatalytic enhancement was due to the strong adsorption and the higher charge separation efficiency of as-prepared g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Na-bentonite composites.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719306065-ga1.jpg" width="219" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): Lifeng Chen, Zhen Qian, Liang Li, Meilong Fu, Hui Zhao, Lipei Fu, Gang Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Water production is getting worse along with the continuous water injection in the reservoir with fracture, but common hydrogels cannot be successfully applied for water shutoff due to its poor resident ability in fracture. In this work, an interpenetrating network hydrogel has been developed innovatively by polyvinyl alcohol (PVA) fiber and common polyacrylamide (PAM) hydrogel. Plugging ability, long-term thermal stability and the interaction between PVA fiber and hydrogel were detailedly studied. Results show that PVA fiber is beneficial to the stability of the PAM hydrogel, and the syneresis rate can be decreased from 30% to 3% on the 120〈sup〉th〈/sup〉 day. PVA fiber accelerates the hydrogel gelation, and the high concentration of fiber leads to good hydrogel strength. PVA fiber increases the amount of the bound water in hydrogel, leading the hydrophilcity increase of hydrogel. An interpenetrating network is formed on the micrometer level, resulting from the three-group crosslinking among polymer, cross-linker and fiber. Compared with common PAM hydrogel, the interpenetrating network hydrogel has better water shutoff effect and EOR performance. Core flow experiment and micromodel test show that the interpenetrating network hydrogel forms an effective bridge in fracture, and it is hard to be moved due to the water washing. The introduction of fiber to hydrogel is an innovative research, which not only improves the water shutoff effect of hydrogel in fracture, but also provides reference to increase the performance of drilling fluid, fracturing solution and EOR polymer utilized in petroleum engineering.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Micropresentation of synergistic effect of PVA fiber on PAM solution (A, B) and hydrogel (C, D).〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719305928-ga1.jpg" width="252" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): Krzysztof Kolman, Zareen Abbas〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Molecular dynamics (MD) simulations provide molecular level information about the interaction of organic molecules with the solid surfaces. There has been much development of this method to simulate the interaction of organic molecules with neutral surfaces but relatively less information is available regarding the interactions with charged surfaces. In this study we have developed MD model for the charged silica surface and have investigated the interactions of different benzoic acid derivatives with the charged silica surface in pure and saline water at acidic, neutral and basic pH. The investigated molecules were 2,3-dihydroxybenzoic acid (23DHBA), 3,4-dihydroxybenzoic acid (34DHBA), 1,2,4-benzenetricarboxylic acid (BTCA) and phthalic acid (PHTHA). To simplify the analysis of results, three different simulation systems were considered. Clustering simulations showed how molecules aggregate in solution, pulling simulations provided quantitate information regarding the interactions of single molecule with the silica surface, whereas adsorption simulations focused on the adsorption of multiple molecules on the surface. In general, at pH 2–3, all investigated molecules were clustering and were attracted towards the surface. At pH 7, due to arising electrostatic repulsion, the interactions became weaker which prevented 23DHBA, 34DHBA and BTCA from clustering, however, they continued to adsorb on the silica surface. The adsorption of 23DHBA and 34DHBA decreased significantly at pH 9–10 due to electrostatic repulsion between the molecules and charged silica surface, while BTCA adsorbed slightly stronger due to interactions with ions close to the surface. PHTHA molecules behaved differently by clustering stronger and adsorbing weaker at higher pH. The results of MD simulations presented in this work by using pulling and adsorption approaches provide possibility to compare the results with experimental data.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719301748-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): José G. Parra, Héctor Domínguez, Yosslen Aray, Peter Iza, Ximena Zarate, Eduardo Schott〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Structural characteristics, interfacial distribution and molecular interactions of the components of the CO〈sub〉2〈/sub〉(gas)/SDS/water/SDS/CO〈sub〉2〈/sub〉(gas) systems as a function of the CO〈sub〉2〈/sub〉(gas)/water interface coverage by the SDS surfactant to different amounts of the CO〈sub〉2〈/sub〉 were studied with molecular dynamics simulations and the NVT ensemble. Initially, the repulsive nonbonding parameter between the water oxygen and CO〈sub〉2〈/sub〉 oxygen was adjusted to improve the prediction of the solvation free energy, solubility of the CO〈sub〉2〈/sub〉 gas in water and the behavior of the CO〈sub〉2〈/sub〉(gas)/SDS/water/SDS/CO〈sub〉2〈/sub〉(gas) systems at molecular level. Our results show that the stability of the studied foams can be improved incrementing of the vapor/water interface coverage with the SDS surfactant and the amount of CO〈sub〉2〈/sub〉 in the system. With the highest interface coverage, the sulfate group has a molecular array more compact at the interface. Furthermore, CO〈sub〉2〈/sub〉 gas have a reduction of the diffusion across of the hydrocarbon chains to the water layer with an increment of the number of CO〈sub〉2〈/sub〉 molecules in the system, indicating a behavior more hydrophobic of the CO〈sub〉2〈/sub〉 gas. The tendencies obtained of the simulations are consistent with the reported experimental results.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719305989-ga1.jpg" width="239" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): M. Jinish Antony, C. Albin Jolly, K. Rohini Das, T.S. Swathy〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report here the synthesis of polyaniline (PANI) nanomaterials using sodium bis (2-ethylhexyl) sulfosuccinate (AOT) micelles assisted chemical oxidative interfacial polymerization. We have employed two interfaces (chloroform-water and hexane-water) and two oxidizing agents (ammonium persulfate and ferric chloride). The anionic surfactant sodium bis (2-ethylhexyl) sulfosuccinate (AOT) forms normal micelles in aqueous solution and reverse micelles in hydrophobic solvents like hexane or chloroform. The factors influencing the properties and morphologies of polyaniline nanomaterials such as monomer: surfactant ratio, monomer: oxidant ratio, types of interfaces and oxidants used have been studied. Powder X-ray diffraction of the polyaniline nanomaterials have revealed that polyaniline samples were semi-crystalline in nature. Morphology of polyaniline samples studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) have revealed that most of the polyaniline nanomaterials synthesized using ferric chloride possess spherical nature, whereas polyaniline samples synthesized using ammonium persulfate (APS) possess short nanofibers especially at lower aniline/AOT mole ratio in feed (12.5–6.5). The four probe electrical conductivity of the samples were found to be of the order of 1.8 × 10〈sup〉−1〈/sup〉 to 8.6 × 10〈sup〉−1〈/sup〉 S/cm. Thermal stability of the polyaniline samples recorded by thermogravimetric analysis (TGA) have revealed that polyaniline samples were thermally stable up to 275 °C for 10% weight loss. Interfacial polymerization of aniline monomer using reverse micelles of AOT in hexane phase and ammonium persulfate as oxidizing agent in aqueous phase have been proved to be efficient method for the synthesis of short polyaniline nanofibers.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719306090-ga1.jpg" width="316" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): Feng Zhao, Shibin Wang, Xin Shen, Jianchun Guo, Yuxuan Liu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Inhibiting acid-rock reaction rate is an important key in the field of acid fracturing. Based on the acid-rock reaction mechanism and the performance characteristics of surfactant, the surfactant is applied to cover the rock surface for forming an adsorption layer, which can keep H〈sup〉+〈/sup〉 from contacting the surface of rock during acid fracturing. In this paper, a series of cationic Gemini surfactants with different hydrophobic chain length are synthesized (C〈sub〉n〈/sub〉-4-C〈sub〉n〈/sub〉, n = 12, 14, 16).The surface tension, adhesion work, and AFM are used to investigate the effect of hydrophobic chain length and concentration of surfactant on surface activities, adsorption morphology and adsorption capacities. The static acid-rock reaction rate is measured and the surface of the rock plate is digitally characterized by 3D scanning. The results show that Gemini surfactants have the high surface activities. It can be recognized from AFM that as the length of the carbon chain increases, the aggregation of Gemini surfactants on the surface to form micelles becomes more and more obvious, resulting in a decrease in the density and area of the adsorption. However there are few differences for adsorption capacities. Therefore, 12-4-12 can restart H〈sup〉+〈/sup〉 most efficiently. This conclusion is proved by static acid-rock reaction. In addition, H〈sup〉+〈/sup〉 only reacted with the rock from the micro fractures of the adsorption layer formed by 12-4-12, the surface morphology of the rock plate after etching is the best rugged. In conclusion, it is believed that using the Gemini surfactant to form an adsorption layer on the rock surface is a new approach for inhibiting acid rock reaction rate and has great potential in oil field application.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Inhibiting acid-rock reaction rate is an important key in the field of acid fracturing. The morphology of the surfactant on the rock controls the rate between acid and rock. The properties of the different chain length surfactant form different layered structure on the substrate. 12-4-12 can play an efficacious role to adsorb on the rock surface to prevent H〈sup〉+〈/sup〉 from contacting the surface of rock.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719306119-ga1.jpg" width="295" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): Zhao Mu, Jianhao Hua, Sai Kumar Tammina, Yaling Yang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In current investigation, we synthesized a new Cu, N co-doped carbon dots/Ag〈sub〉3〈/sub〉PO〈sub〉4〈/sub〉 (Cu, N-CDs/Ag〈sub〉3〈/sub〉PO〈sub〉4〈/sub〉) nanocomposite by one-step thermolysis and precipitation method. In addition, we evaluated the activity of Ag〈sub〉3〈/sub〉PO〈sub〉4〈/sub〉 and Cu,N-CDs/Ag〈sub〉3〈/sub〉PO〈sub〉4〈/sub〉 nanomaterials in degrading an environmental pollutant called neutral red under visible radiations. Compared to the pure Ag〈sub〉3〈/sub〉PO〈sub〉4〈/sub〉, Cu, N-CDs/Ag〈sub〉3〈/sub〉PO〈sub〉4〈/sub〉 had shown high degradation efficiency by more than 25% and shown good recyclability. The synthesized nanocomposite was characterized by XRD, HRTEM, FT-IR, Raman and XPS techniques. The optical property of Cu, N-CDs/Ag〈sub〉3〈/sub〉PO〈sub〉4〈/sub〉 nanocomposite was examined with UV–vis DRS (Diffuse Reflectance Spectroscopy). And the excellent photocatalytic performance of this Cu, N-CDs system was ascribed to the increased conversion of ·O〈sub〉2〈/sub〉〈sup〉−〈/sup〉 under visible light irradiations and effective separation of electron-hole pairs, results in inhibited photocorrosion of the system. Also, this nanocomposite could successfully degrade the neutral red dye (mention the concentration) about 95.5% under LED irradiations within 60 min.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719306193-ga1.jpg" width="222" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): Juan David Beltrán, Camilo Eduardo Sandoval-Cuellar, Katherine Bauer, María Ximena Quintanilla-Carvajal〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Liposomes are spherical vesicles which can be used as encapsulation systems for transporting and releasing many biocomposites which can be affected by conditions in the gastrointestinal tract; such affectation means that the dominant degradation mechanisms and the factors influencing such degradation must be identified by means of digestion studies. This study was thus aimed to evaluate the physical stability and intestinal digestibility of nanoliposomes (NLs) produced by microfluidization (MF) and ultrasound (US) for high oleic palm oil (HOPO) encapsulation. A standardized 〈em〉in vitro〈/em〉, three-stage (〈em〉i.e.〈/em〉 oral, gastric and intestinal) static model of the gastrointestinal tract was used which had been published by the INFOGEST research network. No statistically significant changes were observed concerning any of the properties regarding stability during the oral phase; however, both types of NL studied here became destabilized during the gastric phase by environmental conditions, such as acid pH and high ion concentration. This was reflected by increased average particle size, the polydispersity index and the Z potential. Decreased particle size was observed during intestinal digestion regarding both technologies compared to gastric phase. MF-produced NLs were larger than US-produced ones during this phase. Intestinal enzymes degraded the system’s triglycerides, leading to 116.04 ± 2.62%w MF and 80.39 ± 2.26%w US free fatty acid release.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719305862-ga1.jpg" width="389" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): Chengwei Wang, Lili Ma, Qingkun Wen, Baoxiang Wang, Rongjiang Han, Chuncheng Hao, Kezheng Chen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, an electrorheological (ER) fluid containing titanium oxide@ H〈sub〉2〈/sub〉Ti〈sub〉2〈/sub〉O〈sub〉5〈/sub〉 nanotube core/shell nanocomposite was prepared via the combination of hydrothermal and solvo-thermal method. The morphological evolution was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. Furthermore, the structural characteristics of the as-obtained core/shell nanoparticles were confirmed by x-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) and nitrogen adsorption measurements respectively. Titanium oxide@H〈sub〉2〈/sub〉Ti〈sub〉2〈/sub〉O〈sub〉5〈/sub〉 nanotube core/shell nanocomposite is showed to possess tube-like and core-shell structure and enhanced ER properties under external electric fields.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571930617X-ga1.jpg" width="235" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 30 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 492〈/p〉 〈p〉Author(s): Yuexin Liu, Yanzhong Wang, Huiqi Wang, Peihua Zhao, Hua Hou, Li Guo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Due to the large specific surface area and potential redox sites, metal organic frameworks (MOFs) are considered as a promising electrode material for supercapacitors. However, the low electrical conductivity of MOFs impedes their application in supercapacitors. Here, the NiCo-MOF/acetylene black composites were facily fabricated by an ultrasonic method, in which acetylene black was uniformly distributed between NiCo-MOF nanosheets and formed a conductive network, thus improving the electrical conductivity of NiCo-MOF as well as hindering their aggregation. The as-obtained NiCo-MOF/acetylene black composites exhibit high specific capacitance of 916.1 F g〈sup〉−1〈/sup〉, remarkable rate capability and cycling stability compare to the pure NiCo-MOF. In addition, an asymmetrical supercapacitor were also constructed, which achieved a maximum energy density of 33.84 Wh kg〈sup〉−1〈/sup〉 at a power density of 750 W kg〈sup〉−1〈/sup〉 and good cycling stability with 85.25% of initial capacitance after 5000 cycles.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉The sheet-like NiCo-MOF/AB nanocomposite is synthesized via an ultrasonic method. The NiCo-MOF/AB composites exhibit a high specific capacitance of 916.1 F g〈sup〉−1〈/sup〉 at 1 A g〈sup〉−1〈/sup〉. The assembled asymmetric supercapacitors show high energy density of 33.84 Wh kg〈sup〉−1〈/sup〉 with a power density of 750 W kg〈sup〉−1〈/sup〉, and the capacitance retention remains 85.25% after 5000 cycles at 5 A g〈sup〉−1〈/sup〉, indicating the excellent cycling stability.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219319646-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 492〈/p〉 〈p〉Author(s): Yanting Yang, Liangguo Yan, Jing Li, Jingyi Li, Tao Yan, Meng Sun, Zhiguo Pei〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Three TiO〈sub〉2〈/sub〉 and Zn-Al-layered double hydroxide composites, denoted LDH-TiO〈sub〉2〈/sub〉 composites, were prepared using the sol–gel method and characterized utilizing scanning and transmission electron microscopy with energy dispersive spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, X-ray diffraction, N〈sub〉2〈/sub〉 adsorption–desorption, X-ray photoelectron spectroscopy, photocurrent, photoluminescence and electrochemical impedance spectroscopy techniques. The characterization results illustrated that TiO〈sub〉2〈/sub〉 was attached onto the surface of LDH and the sizes of both TiO〈sub〉2〈/sub〉 and LDH particles were in the nanoscale range. The combination of LDH and TiO〈sub〉2〈/sub〉 promoted the photogenerated electron–hole transfer and separation. The removal abilities of the LDH-TiO〈sub〉2〈/sub〉 composites for Cr(VI) were evaluated using the synergistic adsorption and photocatalytic method. The adsorption percentages of the three LDH-TiO〈sub〉2〈/sub〉 composites for 20.0 mg/L Cr(VI) solutions ranged between 26% and 75%, and upon ultraviolet irradiation, the total removal percentages rapidly increased to approximately 100%. The removal efficiency for Cr(VI) depended on the TiO〈sub〉2〈/sub〉 contents of the LDH-TiO〈sub〉2〈/sub〉 composites. Increasing the TiO〈sub〉2〈/sub〉 percentage resulted in decrease in the adsorption capacities and increase in the photocatalytic removal ratios. The kinetic and isothermal data well fitted the pseudo-second-order and Langmuir equations, respectively. The high removal efficiencies suggested that the composites were suitable for the treatment of Cr(VI)-containing wastewater.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219319555-ga1.jpg" width="361" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 491〈/p〉 〈p〉Author(s): Zhenjiang Li, Xiaomei Wang, Xuehua Wang, Yusheng Lin, Alan Meng, Lina Yang, Qingdang Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Non-noble metal catalysts for photo/electrocatalytic water splitting are quite feasible for solving the problems of growing energy demand and environmental pollution. In this paper, noble-metal free Mn-Cd-S@amorphous-Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉 hybrid catalyst (MCS@a-Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉) with bifunctionality of photocatalytic hydrogen evolution and electrocatalytic OER is designed and prepared by simple hydrothermal method. The characterization results show that Mn-Cd-S was composed of cubic manganese sulfide and manganese doped cadmium sulfide, and amorphous Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉 coating on the surface of Mn-Cd-S. The resultant Mn-Cd-S@amorphpus-Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉 catalyst presents good stability and a high photocatalytic H〈sub〉2〈/sub〉 evolution rate of 12,069.27 μmolh〈sup〉−1〈/sup〉 g〈sup〉−1〈/sup〉. Besides, both Mn-Cd-S and Mn-Cd-S@amorphpus-Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉 show good OER property with overpotential of 333 mV. Mn-Cd-S@amorphpus-Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉 shows more favorable kinetics than that of Mn-Cd-S for OER. Moreover，the mechanism of the enhanced photo/electrocatalytic performance is investigated in detail. This work provides references for developing the catalysts with both photocatalytic and electrocatalytic properties.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉The Mn-Cd-S@amorphous-Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉 hybrid catalyst (MCS@a-Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉) was composed of cubic MnS, Mn doped CdS, and amorphous Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉 coated on the surface of MCS. MCS@a-Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉 possesses excellent photocatalytic H〈sub〉2〈/sub〉 evolution rate of 12,069.27 μmolh〈sup〉−1〈/sup〉 g〈sup〉−1〈/sup〉 and good electrocatalytic OER overpotential of 333 mV.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219316216-ga1.jpg" width="449" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 492〈/p〉 〈p〉Author(s): Shujuan Zhang, Li Liu, Jieyu Yang, Yiqing Zhang, Zhengrui Wan, Liqun Zhou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Well-dispersed trimetallic Pd-Ru-Bi alloy nanoparticles (NPs) were successfully embedded in the three-dimensional (3D) rGO/MOF-199 by a facile hydrothermal and in situ impregnation-reduction method. Among the mono-, bi- and tri-metal@rGO/MOF-199 electrocatalysts, the trimetallic PdRuBi@rGO/MOF-199 exhibited the highest catalytic activity and durability towards ethylene glycol oxidation reaction (EGOR) under the alkaline condition, as high as 213.93 mA cm〈sup〉−2〈/sup〉, is about 7.23 times higher than that of commercial Pd/C. The outstanding electrocatalysis oxidation performance of the PdRuBi@rGO/MOF-199 is attributed to the unique 3D structures with trimetallic composition and strong synergistic effects of Pd, Ru and Bi nanoalloys that providing plenty of interfaces and achievable reaction active sites. Furthermore, the introduction of GO in MOF-199 matrix conduces to the superior electron transfer and large surface area, which are beneficial to improve the catalytic ability of the catalyst. The study on the new composites offers a conception and applicable way to develop the advanced Pd-based electrocatalysts for high performance direct ethylene glycol fuel cells.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 492〈/p〉 〈p〉Author(s): Chao Peng, Fanlin Zeng, Bin Yuan, Youshan Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Several nanoindentation MD simulations were conducted to investigate the indentation size effect (ISE) of Polystyrene (PS) and Polyethylene (PE) at nano-scale using different indenters and loading rates. A strain gradient elasticity model in which the ISE is related to the Frank energy caused by finite bending stiffness and neighboring interactions of chains was imported to describe the ISE in this work. Two large-scale molecular substrates for PS and PE were constructed to compare the ISE performance during indentation simulations. The spherical indenter was firstly considered, and an uptrend of the calculated hardness and modulus with increasing indenter radius was found for both PS and PE. A conical indenter consisting of 25 virtual rigid spheres used in LAMMPS was designed. Considering different tip sizes and loading rates, indentation simulations using these conical indenters were conducted. The uptrend of hardness curves at the initial indentation stage was also found in conical cases. Through fitting the hardness curves, the strengthening effects of tip size and loading rate were certified, especially for PS. At nano-scale, the dominant effect of benzene ring component on ISE performance was confirmed. The downtrend of ISE was found to exist at nano-scale for PE although it was not obviously found in experimental cases and the contributing factors for this kind of ISE were discussed.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219318859-ga1.jpg" width="475" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 492〈/p〉 〈p〉Author(s): Zhaoxi Chen, Li Qiao, Julien Hillairet, Yuntao Song, Viviane Turq, Peng Wang, Raphael Laloo, Jean-Michel Bernard, Kun Lu, Yong Cheng, Qingxi Yang, Caroline Hernandez〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Compounding Au-Ni with carbon (C) lubricants is a feasible approach to improve its mechanical properties and wear performance. In this study, 3.5 μm-thick Au-Ni/C nanocomposite coatings with a low residual stress on CuCrZr substrates by magnetron sputtering were developed. Face-centered cubic and hexagonal close-packed stacking structures were both confirmed in the composite coatings based on transmission electron microscopy and X-ray diffraction analyses. Amorphous C (a-C) was confirmed to be the structure of C in the composite coatings, and its graphitization transition with an increase in the C content was validated by X-ray photoemission spectra and Raman spectroscopy. By compounding 0.88 wt% a-C, the hardness of the Au-Ni/a-C coating reached 400 HV, which is twice higher than that of the Au-Ni coating. The electrical resistivity of the Au-Ni/a-C coating is relatively stable with an increase in the a-C content. As graphitization occurred on the wear track, the produced composite coatings showed a minimum wear rate of 2.2 × 10〈sup〉−6〈/sup〉 mm〈sup〉3〈/sup〉/N·m under atmospheric conditions, which is half that of the Au-Ni reference coating. Under vacuum, the wear performance of the produced Au-Ni/a-C composite coatings was similar to that of the Au-Ni reference coating.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S016943321931966X-ga1.jpg" width="335" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 492〈/p〉 〈p〉Author(s): Zehra Irem Yildiz, Tamer Uyar〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The free-standing and fast-dissolving nanofibrous films from inclusion complexes (ICs) of paracetamol with two different cyclodextrins, hydroxypropyl-beta-cyclodextrin (HPβCD) and sulfobutylether-beta-cyclodextrin (SBE-β-CD) were produced through electrospinning without using polymer matrix. The morphology of the nanofibers (NFs) was uniform and bead-free as confirmed by scanning electron microscopy imaging. The chemical, structural and thermal characteristics of the electrospun paracetamol/CD-IC NFs were investigated by X-ray diffractometry, Fourier transform infrared spectroscopy, differential scanning calorimetry, thermal gravimetric analyzer and proton nuclear magnetic resonance. The aforementioned methods indicated the successful formation of ICs of paracetamol with both CD types (HPβCD and SBE-β-CD). Besides, paracetamol/CD-IC NFs exhibited different features and properties from pristine paracetamol. For instance, the crystalline state of pristine paracetamol was transformed into amorphous state by CD-IC NFs formation which is important for the water-solubility increment of the drug molecules. Moreover, thermal studies indicated that paracetamol became thermally more stable in CD-IC NFs. The molar ratio of paracetamol:CD was found as ~0.85:1.00 for paracetamol/HPβCD-IC NFs and ~0.80:1.00 for paracetamol/SBE-β-CD-IC NFs. The dissolution behavior of paracetamol/CD-IC nanofibrous films was examined by exposing them to water. The electrospun paracetamol/CD-IC nanofibrous films showed fast-dissolving character in water due to the CD-ICs formation and high surface area of nanofibrous structure.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219319464-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): Jincheng Mao, Jizhen Tian, Wenlong Zhang, Xiaojiang Yang, Heng Zhang, Chong Lin, Yang Zhang, Zhaoyang Zhang, Jinzhou Zhao〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Gemini cationic surfactants, which have two cationic surfactant molecules connected by a spacer, have received increased attention in recent years as very good thickeners for clean fracturing fluids. We synthesized four Gemini cationic surfactants with three, four, five, and six methylene groups in the spacers. Salts can promote micelle aggregation of viscoelastic surfactants (VESs) and affect their performance and we used potassium chloride (KCl) to study the performance differences of the surfactants with different spacer lengths. The results showed that the surfactant with three methylene groups in its spacer had the lowest critical micelle concentration, and when combined with KCl in solution, it had the best salt tolerance and apparent viscosity in KCl concentrations ranging from 0.2 wt% to 2.6 wt%. In addition, the solution also exhibited an excellent viscoelasticity and a tighter network microstructure, which was confirmed by SEM observation and oscillatory measurement. We conducted rheological measurements for the four Gemini cationic surfactant fracturing fluid formulations with a shear rate of 170 s〈sup〉−1〈/sup〉 at up to 100 °C. The solution with KCl and the surfactant with the shortest spacer had distinctly superior rheological properties, and its viscosity could be maintained above 58 mPa.s after 120 min. Finally, we did proppant suspension tests, gel breaking property tests, and core matrix permeability damage rate tests on the four optimized fracturing fluid systems. The solution prepared by KCl and the surfactant with the shortest spacer was found to have the most favorable properties for fracturing fluids. These results demonstrate that decreasing the spacer length of a Gemini cationic surfactant leads to better performance in fracturing fluids.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉The effect of counter-ion salt (KCl) concentrations on 21-(3,4,5,6)-21 surfactants that the surfactant solutions were transparent at low salt concentrations, but with increasing counter-ion concentrations above a peak viscosity, the phase separation occurred in all surfactant solutions. Meanwhile, this also shows that increasing the number of carbon atoms on the spacer of the surfactants lead to a greater sensitivity to the phase separation phenomenon.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719306016-ga1.jpg" width="227" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Ehsan Rahimi, Ali Kosari, Saman Hosseinpour, Ali Davoodi, Henny Zandbergen, Johannes M.C. Mol〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, we report on a combined microscopic, analytical and electrochemical characterization of the nanoscopic passive layer on a tungsten‑molybdenum-containing super duplex stainless steel. We used scanning transmission electron microscopy/energy dispersive X-ray spectroscopy, scanning Kelvin probe force microscopy, scanning tunneling spectroscopy, and Mott–Schottky electrochemical impedance spectroscopy analysis to correlate the local chemical composition and electronic properties of passive layers on austenite and ferrite phases. The passive layer on the ferrite phase contains a higher amount of Mo, W, and Cr, which accommodates a higher nobility of ferrite and a higher local energy of the band gap compared to those on the austenite. The two aforementioned phases exhibit a different composition and semi-conductive properties of their passive layers leading to dissimilar local corrosion susceptibility. These findings are of pivotal importance in further studies of austenite and ferrite phase resolved corrosion resistance of duplex stainless steel demanding a dedicated alloying strategy.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324316-ga1.jpg" width="296" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Shan-Shan Guan, Sha-Sha Ke, Fei-Fei Yu, Hong-Xiang Deng, Yong Guo, Hai-Feng Lü〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉By means of density functional theory-based spin polarized first-principles computations, we systematically investigate the stable geometry, total energy, magnetic and electronic properties of 3d transition metal (TM) atoms substituted and adsorbed on monolayer (ML) Janus MoSSe. We first identify the most stable binding sites and their corresponding total energies as well. The results show that the most stable adsorption site is above the Mo atoms in the S atom side. It is found that the TM atoms substitution and adsorption do not destroy the stability of ML Janus MoSSe. Our calculations predict the magnetism could be induced in ML Janus MoSSe by the substitution of Cr, Mn, Fe, Co, and Ni atoms, respectively. However, for the adsorbed case, only Cr, Mn, Fe, and Co atoms could induce magnetism in the MoSSe substrate. We found that the band structures of Janus MoSSe can be efficiently modified by doping it with TM atoms (adsorbed or susbtitutionally located in the Janus MoSSe monolayer). Our investigation indicates that TM atoms-doped ML Janus MoSSe has a potential application for spintronics and optoelectronics.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324894-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Shawei Tang, Yaoyu Zhang, Hongshan San, Jin Hu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Controlling the corrosion rate of magnesium alloys is the critical way to demonstrate their excellent performance in the practical application, it is imperative to design and construct a surface to allow better expeditions adaptation to the application environment. A hydrophobic coating with a good adhesion to the substrate is required. In this study, calcium myristate coating, cerium myristate coating and calcium/cerium myristate mixed coating were fabricated respectively on the surface of AZ31 magnesium alloy by a one-step electrodeposition. The coating characteristics were studied. The corrosion behavior of the coated samples was investigated and the corrosion mechanism was also discussed. The results showed that all three coatings exhibited hydrophobicity with little difference. The presence of Ce ions in the electrolyte promoted the formation of the corresponding coating, and the Ce coating with cracks had the maximum thickest and a poor adhesion to the substrate The Ca coating and Ca/Ce mixed coating presented a good adhesion to the substrate. Compared with the single myristate coatings, the mixed coating exhibited improved corrosion performance. The EIS evolution reveals that the protection effect of the coatings gradually decreases during the immersion process, which is caused by the formation of porous hydrated coating on the surface.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324249-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Sumit Bera, P. Behera, A.K. Mishra, M. Krishnan, M.M. Patidar, R. Venkatesh, V. Ganesan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Microwave-assisted solvothermal route has been followed to synthesize Sb〈sub〉2〈/sub〉Te〈sub〉3〈/sub〉 nanomaterial. The morphology and topography of the material have been studied in FESEM and AFM measurements respectively. The optical band gap of the material is found to be ~ 0.25 eV as measured in IR spectroscopy. Temperature dependent resistivity of the nanostructure shows thermal activation behavior in the high temperature region as well as it follows 3D Variable Range Hopping mechanism in the moderate temperature region. Electron-electron interaction and quantum interference dominated upturn in the resistivity is observed at T 〈 24 K. Low field magnetoconductivity (MC) shows disorder induced weak localization (WL) which makes over to weak antilocalization (WAL) at T ≥ 4 K. MC after post annealing of the sample shows WAL behavior at T 〈 4 K also. Quantum correction to the low field magnetoconductivity of the material follows Hikami-Larkin-Nagaoka (HLN) equation. The obtained parameters of the HLN equation indicate that the system follows the 2D conduction mechanism and presence of a single conduction channel at low temperature. High field MR exhibits linear and positive magnetoresistance (LPMR) which suggests the survival of robust topological surface state conduction in the nanostructured bulk Sb〈sub〉2〈/sub〉Te〈sub〉3〈/sub〉 topological insulator.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324511-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Meixuan Li, Huiyuan Wang, Yun Zhu, Di Tian, Ce Wang, Xiaofeng Lu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉It is extremely necessary to develop high-performance noble-metal-free hydrogen evolution reaction (HER) electrocatalysts applied over the whole pH values to replace expensive Pt-based catalysts. Herein, a typical metal-semiconductor heterostructure with metallic Mo and Mo〈sub〉2〈/sub〉C nanoparticles encapsulated in nitrogen-doped carbon nanofibers (N-CNFs) is fabricated via the pyrolysis of electrospun polyacrylonitrile (PAN)/cellulose acetate (CA)/bis(acetylacetonato)dioxomolybdenum (MoO〈sub〉2〈/sub〉(acac)〈sub〉2〈/sub〉) nanofibers. The unique porous and channel-rich structure of Mo/Mo〈sub〉2〈/sub〉C/N-CNFs can be manipulated by varying the mass ratio of polyacrylonitrile and cellulose acetate, leading to the exposure of abundant active centers and the acceleration of rapid mass transport. In addition, the synergetic effect among metal and semiconductor as well as the excellent conductivity of the N-CNFs result in excellent HER activity and stability over a wide pH range. To achieve the current density of 10 mA cm〈sup〉−〈/sup〉〈sup〉2〈/sup〉, the optimized Mo/Mo〈sub〉2〈/sub〉C/N-CNFs exhibit overpotentials of 175, 162 and 294 mV in 0.5 M H〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉, 1 M KOH and 0.1 M phosphate buffer solution (PBS), respectively. This work provides a feasible approach to synthesize high-performance and economical hydrogen evolution electrocatalysts at all pH values for renewable energy-related applications.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Mo/Mo〈sub〉2〈/sub〉C encapsulated in nitrogen-doped carbon nanofibers as efficient heterojunction electrocatalysts for hydrogen evolution reaction have been developed.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324699-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 20 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Zechen Liu, Yangchao Xia, Qingteng Lai, Maoyan An, Yinfei Liao, Yongtian Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this investigation, a mixed collector (MC) of dodecane and n-valeric acid was used to improve low rank coal flotation. Fourier transformation infrared spectroscopy (FTIR) measurements and contact angle measurements were conducted to explain flotation responses. Furthermore, using a molecular dynamics (MD) simulation, the changes of water/collector (dodecane or MC)/coal systems were studied before and after adsorption to indicate the absorption behavior and mechanism. The results showed that a better flotation performance of low-rank coal was obtained using the MC compared to a conventional collector of dodecane. The hydroxyl (-OH) or carbonyl (C = O) or carboxyl (COOH) migration of the coal with the MC was stronger than that with dodecane as a solo collector, and the MC can enhance the hydrophobicity and lipophilicity of the coal surface. MD simulation results revealed the adsorption behavior of the MC on low-rank coal surfaces. Dodecane was mainly adsorbed on the hydrophobic surface of coal, and n-valeric acid was more inclined to act on the oxygen-containing functional group of coal, i.e., a hydrophilic surface. The mobility of = dodecane molecules on the coal surface was reduced owing to the presence of n-valeric acid, which increased the lipophilicity and hydrophobicity of the low-rank coal surface, thus attracting dodecane molecules of the MC and restricting their movement, and accelerating the departure of water molecules from the low-rank coal surfaces. There was also a higher interaction energy between the MC and low-rank coal. The simulation results are in good agreement with the measured results; this effectively explains the flotation results.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308283-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Xing-An Luo, Pei Zhao, Hai Zhang, Shu-Yi Feng, Ke-Xian Chen, Zhong-Xiu Chen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Dietary macromolecules are often used for food formulation. Most of the published literature usually focuses on a certain polysaccharide reducing lipid digestion, but the non-specific physical effects such as the excluded volume effect of the surrounding macromolecules, which will possibly enhance the hydrolysis of lipids, is rarely discussed. As the influence of polysaccharides on the gastrointestinal fate of α-tocopherol acetate (VE-A) encapsulated in emulsion have not been conducted so far, in this research, we study the effect of crowded medium created by polysaccharides (Ficoll400) on the hydrolysis of VE-A and its bioaccessibility. The results show that the presence of Ficoll400 increased the bioaccessibility and conversion of VE-A 1.6 times that of a dilute buffer. An enzyme-catalyzed kinetic reaction rate of VE-A hydrolysis is increased up to 3.5 times. Both the improved thermodynamic conversion yields and kinetic rates of the hydrolysis of the VE-A emulsion was further observed in a synthetic macromolecule PEG2000 medium. This research improves our understanding of the crowding effect of macromolecules on VE-A/lipid emulsion digestion.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308258-ga1.jpg" width="323" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Zili Zhang, Zhuji Jin, Jiang Guo, Xiaolong Han, Qing Mu, Xianglong Zhu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Yttrium aluminum garnet (Y〈sub〉3〈/sub〉Al〈sub〉5〈/sub〉O〈sub〉12〈/sub〉, YAG) crystal is widely used for laser applications. However, due to its high hard and brittle nature, high surface quality and high material removal rate (MRR) are difficult to be achieved. In this study, to solve the problem, a novel CMP slurry was developed, which contains 8 wt% ZrO〈sub〉2〈/sub〉 abrasives, 5 wt% Na〈sub〉2〈/sub〉SiO〈sub〉3〈/sub〉·5H〈sub〉2〈/sub〉O, 0.3 wt% MgO and deionized water. After polishing, the surface roughness and MRR achieved 0.08 nm Ra and 34 nm/min respectively. The reaction mechanism during polishing was elucidated based on the results of grazing incidence small angle X-ray diffraction (GIXRD) and X-ray photoelectron spectroscopy (XPS). The results show that AlOOH and YOOH generated from hydration reaction react with Si–OH in Na〈sub〉2〈/sub〉SiO〈sub〉3〈/sub〉 aqueous solution to form soft andalusite and yttrium silicate, then MgO combines with andalusite to produce montmorillonite. All soft products are removed mechanically by ZrO〈sub〉2〈/sub〉 abrasives, obtaining the ultra-smooth surface of YAG crystal.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323980-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Eunseok Oh, Sangwoo Lim〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Dissolution of the high dose ion-implanted photoresist which has carbonized C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉C cross-linked crust layer was demonstrated by using nitrate-infused superheated water. The ion-implanted photoresist was partially dissolved in pure superheated water at 200 °C, but the crust layer was not dissolved. The dissolution of the ion-implanted photoresist was greatly improved with the addition of nitrate compounds, such as HNO〈sub〉3〈/sub〉, Zn(NO〈sub〉3〈/sub〉)〈sub〉2〈/sub〉, Cu(NO〈sub〉3〈/sub〉)〈sub〉2〈/sub〉 and Fe(NO〈sub〉3〈/sub〉)〈sub〉3〈/sub〉, to the superheated water. In particular, the ion-implanted photoresist was completely dissolved when the nitrate-infused aqueous solution produced H〈sup〉+〈/sup〉 concentrations higher than 1 × 10〈sup〉−5〈/sup〉 M and NO〈sub〉3〈/sub〉〈sup〉−〈/sup〉 concentrations higher than 0.0156 M. When H〈sup〉+〈/sup〉 and NO〈sub〉3〈/sub〉〈sup〉−〈/sup〉 ions were sufficiently present in superheated water, NO〈sub〉2〈/sub〉, which is very reactive with carbon, was produced. Based on the 〈em〉in〈/em〉-〈em〉situ〈/em〉 spectroscopic analysis, it was suggested that the cleavage of the C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉C bond between the aromatic rings and the backbone chains in the crust structure by NO〈sub〉2〈/sub〉 initiated the dissolution reaction. Additionally, 4-nitrophenol, aliphatic compounds and 〈em〉trans〈/em〉-4,4-azodiphenol were produced and then they were decomposed to the 4-aminophenol and other gases. Therefore, it was concluded that H〈sup〉+〈/sup〉, NO〈sub〉3〈/sub〉〈sup〉−〈/sup〉, and NO〈sub〉2〈/sub〉 in superheated water were the key species to dissolve the crust layer and the bulk ion-implanted photoresist.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324754-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 20 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Ping Ding, Serafim Bakalis, Zhibing Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Foaming in high viscous and non-Newtonian aqueous phase is generally difficult to be realised. In this work, a surfactant (Sodium Linear Alkylbenzene Sulphonate with alkyl chain lengths varying from C10 to C16) named LAS paste mixed with a co-polymer solution of acrylic acid and maleic acid denoted by Polymer solution was used to generate foam under conditions of sparging without or with agitation, which aims to be used as a coating material of detergent powders. The foam structure/morphology, bubble size, gas holdup and liquid drainage in such surfactant-copolymer system were investigated. It was found that two different types of foam were generated: 1) dispersed spherical air bubbles in highly viscous mixtures of LAS paste and Polymer solution with median size d50 in a range of 20 – 50 μm and gas holdup of 0.20 - 0.44 depending on LAS concentration, 2) bubbles with polyhedral structure in a mixture of LAS paste and Polymer solution diluted with water and size d50 = 7.0 ± 0.4 mm and gas holdup of 0.93 ± 0.05. The generated foam structures depended on the energy input, air superficial velocity, surfactant concentration and the liquid viscosity. Besides, they even depended on liquid mixing procedures before the foam was generated, resulting from different transfer rates from LAS paste phase to Polymer solution. The comparison of foam behaviours in such complex system and in single-phase liquid was made. For dispersed spherical bubbles, the median size has been correlated to energy input whilst for bubbles with polyhedral structure the characteristic size has been predicted by considering the balance between their buoyancy and viscous forces generated in the system. Based on the results, the mechanism of foam stabilisation is proposed.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308052-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Jae Seo Lee, Sang Jin Lee, Seok Bin Yang, Donghyun Lee, Haram Nah, Dong Nyoung Heo, Ho-Jin Moon, Yu-Shik Hwang, Rui L. Reis, Ji-Hoi Moon, Il Keun Kwon〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Titanium implants (Ti) have been widely used in several medical fields. In clinical practice, Ti can become contaminated with bacteria through a variety of mechanisms. This contamination can lead to implant failure and serious infections. In this study, we aimed to develop a new, hybrid Ti with good biocompatibility and antibacterial properties by immobilizing ceftazidime (CFT) onto the Ti surface through polydopamine (PDA) and polyethyleneimine (PEI) chemistry. Hybrid Ti was confirmed by assessing the cell proliferation of human adipose-derived stem cells using a cell counting. The biofilm formation across the Ti surface of two bacterial strains associated with nosocomial infections, 〈em〉Pseudomonas aeruginosa〈/em〉 and methicillin-resistant 〈em〉Staphylococcus aureus〈/em〉, was evaluated by scanning electron microscopy. The viability of the bacteria exposed to Ti surface was evaluated by cell counting. Our results clearly demonstrate that the bacterial biofilm formation as well as bacterial viability was significantly reduced on the hybrid Ti as compared to the control, Ti alone. Collectively, the Ti surface was successfully modified to form the hybrid Ti exhibiting good biocompatibility and antibacterial properties through PDA, PEI, and CFT grafting. Within the limitations of this 〈em〉in vitro〈/em〉 study, we conclude that the hybrid Ti may be useful for successful implant treatment.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324729-ga1.jpg" width="292" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Denis Music, Damian M. Holzapfel, Felix Kaiser, Erik Wehr〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Using molecular dynamics based on density functional theory, interaction of aspartic acid (C〈sub〉4〈/sub〉H〈sub〉7〈/sub〉NO〈sub〉4〈/sub〉) with room-temperature thermoelectrics Bi〈sub〉2〈/sub〉Te〈sub〉3〈/sub〉, SnSe, MgAgSb, and TiO〈sub〉2〈/sub〉 alloyed with V is investigated. Aspartic acid is a common amino acid in mammals, decorating a cell membrane, and hence relevant for biocompatibility. Ti(0001), Zn(0001), Pd(111), Pb(111), and Cu(111) surfaces are employed to gauge such interactions, yielding an approximate adsorption energy threshold of −0.060 eV atom〈sup〉−〈/sup〉〈sup〉1〈/sup〉. Based on this threshold, Bi〈sub〉2〈/sub〉Te〈sub〉3〈/sub〉(0001) and SnSe(001) are rendered inert, while MgAgSb(001) and TiO〈sub〉2〈/sub〉(001) alloyed with V are proposed to be biocompatible. An aspartic acid molecule undergoes a non-dissociative adsorption on MgAgSb(001). The interaction of aspartic acid with TiO〈sub〉2〈/sub〉(001) alloyed with V is characterized by deprotonation of a carboxyl group, a subsequent Ti〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O interfacial bond formation, and a reaction of an amino functional group with Ti. Short covalent-ionic bonds across these interfaces support the findings. These results may inspire future research on self-powered biomedical devices.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219325139-ga1.jpg" width="354" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Natalya Sankova, Viktoriya Semeykina, Ekaterina Parkhomchuk〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, we have studied the growing mechanism of polystyrene microspheres with a small amount of cross-linking agent (0.2–2 wt%) during dispersion polymerization (DP) in 1-butanol in presence of PVP-40 steric stabilizer. Scanning electron microscopy and dynamic light scattering showed that particles take anomalous form at first several hours due to the growth predominantly by homo- and hetero-coagulation mechanism. The duration of the coagulation process is estimated to be of about a minute. Understanding of the mechanism of particle formation in the above systems will help to overcome the problem of irreproducibility, control the preparation of anisotropic particles during DP and extend the application of these particles.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307332-ga1.jpg" width="496" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Sen-Yan Zhong, Xue-Qing Gong〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cerium dioxide (CeO〈sub〉2〈/sub〉) has a wide range of applications in the field of heterogeneous catalysis. Different facets can be exposed at CeO〈sub〉2〈/sub〉 nanomaterials with different morphologies, and these facets can exhibit very different catalytic activities. Previous studies focusing on the activities of various CeO〈sub〉2〈/sub〉 facets largely relied on the calculated energetics such as surface energies and oxygen vacancy formation energies, and the activities of the low-index CeO〈sub〉2〈/sub〉 surfaces obtained in these ways follow the order (110) 〉 2 × 1 reconstructed (110) 〉 (111). In this work, in order to more thoroughly examine the surface physicochemical properties, we used a combination of molecular dynamics (MD) and density functional theory calculations to systematically study the mobilities of different oxygen atoms on the three CeO〈sub〉2〈/sub〉 surfaces under relatively high temperatures. The O mobilities have been studied by means of MD trajectories as well as the coordination number analysis. The results indicate that the exposed unsaturated O atoms at reconstructed CeO〈sub〉2〈/sub〉(110)-2 × 1 can exhibit extraordinary mobilities, and they also suggest that besides the bonding strength, the distribution patterns of surface O atoms might be able to affect their activities as well.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): A.A. Nayl, A.I. Abd-Elhamid, Ahmed A. El-Shanshory, Hesham M.A. Soliman, El-Refaie Kenawy, H.F. Aly〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A hierarchically porous structure composite (sponge-GO) is prepared by eco-friendly and a simple immersing of a local sponge in a good dispersed GO aqueous media. Where, appropriated weight of the sponge washed several times with distilled-water and ethanol, then immersed in GO suspended solution (3 mg/mL) and left to absorb all GO suspension. The resulted sponge-GO was dried at 70 °C for 72 h. and characterized by SEM, FTIR, Raman, TGA, and EDS. The characterization results indicate that GO sheets perfectly contact with the sponge Skelton network. The fabricated sponge-GO used as a filtration device in a laboratory made continuous filter system. Methylene blue (MB) is used as a chemical contaminant in wastewater to study the adsorption ability of our system. The parameters affecting on the sorption processes as, composite dose, concentration of dye, solution pH, temperature and NaCl dose were studied. The isotherm models, Langmuir, Freundlich and Tempkin, explained that the organic contaminate prefers to adsorbed as a monolayer with high sorption efficiency q〈sub〉e〈/sub〉 = 19.60 mg g〈sup〉−〈/sup〉〈sup〉1〈/sup〉. It is evident that this filter material possesses good capability and stability. The experimental studies illustrated that sponge-GO can be reused. The breakthrough curve, Yoon–Nelson model and comparison study were also investigated.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324730-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Francielle C.F. Marcos, José M. Assaf, Reinaldo Giudici, Elisabete M. Assaf〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A mesoporous zirconia (ZrO〈sub〉2〈/sub〉) series was synthesized by reflux and hydrothermal methods using Pluronic (P-123) as a surfactant. Characterizations by XPD showed that the ZrO〈sub〉2〈/sub〉 prepared 〈em〉via〈/em〉 reflux consisted of only tetragonal crystalline phase when compared with that obtained by hydrothermal treatment, which was formed by tetragonal and monoclinic phases. The addition of the surfactant had a positive influence on the specific surface area and mesoporous structure ordering of ZrO〈sub〉2〈/sub〉, regardless of the method of synthesis. The surface interaction of H〈sub〉2〈/sub〉/CO〈sub〉2〈/sub〉 mixture with the ZrO〈sub〉2〈/sub〉 samples exhibited some dissimilarity due to the unlike surface acidic-basic features of the tetragonal and monoclinic phases. 〈em〉In-situ〈/em〉 DRIFTS experiments revealed that the species adsorbed on the zirconia prepared by the reflux method were bidentate bicarbonate, ionic bicarbonate, bidentate carbonate, and polydentate carbonate, whereas the adsorption on the zirconia prepared by refluxing method led to increased intensity of the broadband characteristic of bidentate carbonate and the appearance of two new bands typical of bidentate carbonate and bidentate bicarbonate. After subsequent switching off CO〈sub〉2〈/sub〉, it was observed that the carbonate species (1550 cm〈sup〉−〈/sup〉〈sup〉1〈/sup〉) strongly interacted with the zirconia surface and required high energy amount to be desorbed, which was in good agreement with the CO〈sub〉2〈/sub〉-TPD profile. This suggests that these carbonates are not active species when the reaction is carried out at 200 °C.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324687-ga1.jpg" width="352" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): U. Chaitra, A.V. Muhammed Ali, Alison E. Viegas, Dhananjaya Kekuda, K. Mohan Rao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The present work explores the capability of undoped and aluminium doped zinc oxide thin films for the detection of low concentration of Sulphur dioxide gas (SO〈sub〉2〈/sub〉). Highly transparent undoped and aluminium-doped ZnO thin films were successfully deposited using sol-gel spin coating technique. The influence of various concentrations of aluminium (Al) doping on structural, morphological, optical and electrical properties has been studied. The Al doping affected the crystallinity of the films as evident from the X-ray diffraction (XRD) studies. The Atomic force microscope (AFM) and the Field emission scanning electron microscope (FESEM) studies depict the wrinkled structure of the thin films. The transparency of the deposited films was revealed by the UV–Visible characterization. Electrical characterization showed a variation in the conductivity with varying aluminium concentration which influences the gas sensing performance of the thin films. The 2 at.% aluminium doped ZnO thin films exhibited a higher sensitivity of 70% for 3 ppm of SO〈sub〉2〈/sub〉 gas which is below the threshold value limit. For comparison, NH〈sub〉3〈/sub〉 gas sensing of the grown films was also studied.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Xiaobo Nie, Wei Jiang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A facile method is introduced to tune the aggregate morphologies of ABC triblock copolymer in selective media by combining the self-assembly and hydrogen bonding. Poly(styrene)-〈em〉block〈/em〉-poly(1,4-butadiene)-〈em〉block〈/em〉-poly(2-vinyl pyridine), abbreviated for PS-〈em〉b〈/em〉-PBd-〈em〉b〈/em〉-P2VP and used as an ABC triblock copolymer, self-assembles in toluene and methanol mixture to form discoid micelles with PBd as the disk containing part of PS domains in the core, other PS as bumps and P2VP as corona, respectively. When oleic acid (OA) is added in the assembly system, supramolecular polymer PS-〈em〉b〈/em〉-PBd-〈em〉b〈/em〉-P2VP(OA) is prepared by the hydrogen bonding between OA and P2VP of triblock copolymer. As a result, biscuit-like and mushroom-like micelles are formed with assistance of hydrogen bonding. Interestingly, the biscuit-like and mushroom-like micelles can transform reciprocally by fission and fusion mechanism through varying the volume ratio of toluene and methanol. Thus, it provides a simple and convenient approach to control the aggregate morphologies of block copolymers by tuning the hydrogen bonding and selective solvent content. The multicompartment micelles from ABC triblock copolymer may present potential applications in drug delivery, targeting, catalysis and others.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308271-ga1.jpg" width="247" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Yang Xiang, Ming Jiang, Haiyan Xiao, Kaijian Xing, Xinxin Peng, Sa Zhang, Dong-Chen Qi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, a density functional theory method is employed to investigate the surface charge transfer doping of diamond by chromium trioxide (CrO〈sub〉3〈/sub〉) with high electron affinity. Superior surface charge transfer of the hydrogenated diamond surface is demonstrated using CrO〈sub〉3〈/sub〉 as an electron acceptor. The charge density difference and Bader charge analysis reveal that the electrons are transferred from the diamond surface to CrO〈sub〉3〈/sub〉 molecule, leading to the formation of two-dimensional hole gas, and the holes left in the diamond surface increase the conductivity of the diamond surface. The analysis of electronic structure indicates that areal hole density as large as 9.85 × 10〈sup〉13〈/sup〉cm〈sup〉−2〈/sup〉 for CrO〈sub〉3〈/sub〉-doped diamond surface can be achieved. Besides, the optical absorption near infrared region of the hydrogenated diamond surface is greatly enhanced upon CrO〈sub〉3〈/sub〉 doping, which implies that this CrO〈sub〉3〈/sub〉-doped diamond surface is a promising candidate for optoelectronic materials. The present study provides an in-depth theoretical understanding of the formation of two-dimensional hole gas on diamond surface induced by a new transition metal oxide, and predicts that the CrO〈sub〉3〈/sub〉-doped diamond surface may have important implications in electronic and optoelectronic devices.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324018-ga1.jpg" width="294" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Hao Lai, Jiushuai Deng, Shuming Wen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Although dodecylamine (DDA) is a conventional collector for the flotation of smithsonite, the interaction mechanism between DDA and smithsonite is still unclear. In this study, time-of-flight secondary ion mass spectrometry (ToF-SIMS) and principal component analysis (PCA) were used to investigate the surface products of smithsonite with DDA adsorption before and after sulfidization. The spectra analysis showed that the organic peaks C〈sub〉x〈/sub〉H〈sub〉y〈/sub〉〈sup〉+〈/sup〉, CN〈sup〉−〈/sup〉, and CNO〈sup〉−〈/sup〉 dominate the spectra of the smithsonite samples, eclipsing the inorganic peaks and DDA-related peaks. PCA analysis effectively identified the spectral differences between the different samples, indicating that DDA hardly interacted with the hydrated smithsonite surface; the zinc‑sulfur complex on the sulfidized smithsonite surface existed in the form of Zn〈sub〉a〈/sub〉S〈sub〉b〈/sub〉O〈sub〉c〈/sub〉H〈sub〉d〈/sub〉; DDA was chemisorbed on the sulfidized smithsonite surface and may occur in the form of N-S-Zn, N-Zn-S, or Zn-N-S bonds.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S016943321932495X-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Rashed Md. Murad Hasan, Olivier Politano, Xichun Luo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The nanoelectrode lithography has been strengthened in recent years as one of the most promising methods due to its high reproducibility, low cost and ability to manufacture nano-sized structures. In this work, the mechanism and the parametric influence in nanoelectrode lithography have been studied qualitatively in atomic scale using ReaxFF MD simulation. This approach was originally developed by van Duin and co-workers to investigate hydrocarbon chemistry. We have investigated the water adsorption and dissociation processes on Si (100) surface as well as the characteristics (structure, chemical composition, morphology, charge distribution, etc.) of the oxide growth. The simulation results show two forms of adsorption of water molecules: molecular adsorption and dissociative adsorption. After breaking the adsorbed hydroxyls, the oxygen atoms insert into the substrate to form the Si–O–Si bonds so as to make the surface oxidized. The influence of the electric field intensity (1.5–7 V/nm) and the relative humidity (20–90%) on the oxidation process have also been discussed. Nevertheless, the results obtained from the simulations have been compared qualitatively with the experimental results and they show in good agreements. Variable charge molecular dynamics allowed us to characterize the nanoelectrode lithography process from an atomistic point of view.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Shuai Li, Zhe Chen, Xingchen Ling, Jingjiao Cao, Qian Wang, Yu Zhou, Jun Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉High surface energy of noble metal clusters (NMCs) with sub-nanometer size (〈2 nm) endows their remarkable catalytic activity but naturally increases the risk of deactivation due to aggregation or oxidation. As a result, it is challengeable to construct efficient and stable naked NMCs. Herein, we reported the solvothermal synthesis of polyhedral oligomeric silsesquioxane (POSS) based porous ionic polymers with large surface areas, tunable pore structures and abundant ionic sites that resemble the structure of traditional ionic liquids. A series of highly dispersive and stable NMCs (Pd, Pt, Ru and Rh) were generated on these polymers by modulating their polyoxometalate (POM) anions, attributable to their robust framework and ion-exchange property. These organic cations paired POM anions are found to provide versatile strong interaction towards noble metal species, responsive for the formation and stabilization of NMCs. The obtained Pd clusters effectively catalyzed the solvent-free oxidation of benzyl alcohol with atmospheric dioxygen (O〈sub〉2〈/sub〉), affording a high yield of 97% and a huge turnover number (TON) that exceeded 639 times of commercial Pd/C catalyst. The catalyst also exhibited pleasurable reusability and broad substrate compatibility.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S016943321932447X-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Zhen Niu, Tong Yue, Wenjihao Hu, Wei Sun, Yuehua Hu, Zhenghe Xu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Graphene/α-MnO〈sub〉2〈/sub〉 nanocrystals hybrid aerogel (GMA) was designed for catalytic ozonation of rhodamine B (RhB) solution in this study. A novel method was proposed to synthesize this hybrid aerogel in an isopropanol-water system, in contrast to the conventional reaction of potassium permanganate with graphene aerogel, which destroyed the desired structure of graphene. Characterization of the synthesized GMA was carried out by XRD, SEM, TEM, Raman, and BET. It was found that GMA had a porous structure and the needle-like α-MnO〈sub〉2〈/sub〉 nanocrystals were doped in the graphene aerogel uniformly. Based on the FTIR and XPS analysis, the α-MnO〈sub〉2〈/sub〉 was found to covalently bond with graphene aerogel. The removal efficiency of both RhB and COD was found to be in the following order of Blank〈 GA 〈 SMA (silica wool with nano MnO〈sub〉2〈/sub〉 deposited on it) 〈 GMA(I) 〈 GMA(II) 〈 GMA(III). The degradation rate constant (〈em〉k〈/em〉) of RhB ozonation catalyzed by GMA was determined to be 1.2–2.3 times higher as compared with that by UV/Ozone. The enhanced catalytic activity of GMA could be attributed to the high dispersibility of the α-MnO〈sub〉2〈/sub〉 nanocrystals on graphene and the abundant mesopores (r 〈 40 nm) in GMA. The higher electron cloud density of the Mn atoms, when supported by graphene aerogel, promoted the generation of HO〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉 radicals, thereby resulting in better decomposition performance of GMA than UV/Ozone systems.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323827-ga1.jpg" width="311" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 20 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Badr M. Thamer, Ali Aldalbahi, Meera Moydeen A, Abdullah M. Al-Enizi, Hany El-Hamshary, Mandeep Singh, Vipul Bansal, Mohamed H. El-Newehy〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Activated electrospun carbon nanofibers (A-ECNFs) with micro/mesoporous structures and high surface areas (1615 m〈sup〉2〈/sup〉 g〈sup〉-1〈/sup〉) were prepared using an electrospinning technique followed by carbonization and alkali activation. The adsorption of Congo red (CR) and methylene blue (MB) dyes by A-ECNFs from aqueous solutions was investigated and compared with those of pristine ECNFs. The textural characteristics and morphology of the prepared pristine and activated ECNFs were characterized using various techniques. The adsorption performance was found to be associated to the surface area, porosity, and surface charges of the prepared adsorbents; the nature and molecular size of the dyes; and the pH and temperature of the solution. Six nonlinear isotherm models were applied to analyze the adsorption equilibrium data, and the results showed that the adsorption behavior could be appropriately described using the Redlich–Peterson isotherm model. The kinetic results for the adsorption of CR and MB onto A-ECNFs were fitted reasonably well to the Elovich model and were fitted by a pseudo-second order (PSO) model onto the pristine ECNFs. According to the thermodynamic results, the adsorption of CR and MB onto the A-ECNFs was endothermic and spontaneous. In addition, the reusability of the A-ECNFs was evaluated over five adsorption-desorption cycles.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308234-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Min Zheng, Lei Wei, Jing Chen, Qiang Zhang, Jiaqiang Li, Shang Sui, Geng Wang, Weidong Huang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel physical model for the selective laser melting (SLM) was proposed, providing insights into the surface morphology evolution in the pulsed SLM process. Both Marangoni effect and recoil pressure, which were the prevailing driving forces for the melt flow, were incorporated in the model. It was found that the melt track was characterized by regular fish scale patterns in pulsed remelting process, due to the periodic variation of the molten pool, while the melt track exhibited with a smooth surface under a continuous laser mode. The effect of the exposure time on the surface morphology was also investigated during pulsed SLM process. It was shown that the longer exposure time could produce greater recoil pressure and sufficient molten liquid, leading to a more congested fish scale patterns. The surface defects such as distortions and breakups were strongly associated with the distribution characteristics of the powders. The partially melted particles which attached to the melt flow were the main reasons to the formation of distortions. And the formation the breakups could be attributed to the local lacking of the powders. The simulated results were in good agreement with the experimental results.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Hitomi Kobara, Kaoru Nakatsuka, Akihiro Wakisaka〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Size selected synthesis of gold nanoparticle (AuNP) was carried out by use of an ultra-fine liquid droplet as a reaction field. The ultra-fine liquid droplets were generated by electrospraying in a liquid medium. The electrospraying in the liquid medium had a great advantage over the conventional electrospraying in the air. The size of electrosprayed liquid droplets can be varied with the supplied electric voltage beyond the range of the electrospraying in the air. When the AuNPs synthesis through the chemical reduction of Au〈sup〉3+〈/sup〉 was carried out by use of this electrospraying in the liquid medium for the mixing of Au〈sup〉3+〈/sup〉 solution and the reducing agent solution, the size of AuNPs was controlled by the supplied electric voltage. Two types of reaction field equipped with a single and double electrospray nozzles were designed to be demonstrated.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉The size distribution of gold nanoparticles was controlled in the ultra-small reaction field generated by the electrospray in a liquid medium.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308246-ga1.jpg" width="440" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Beschreibung: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Kenji Aramaki, Misaki Fujii, Yuichi Sakanishi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉One of the major drawbacks of ionic-surfactant-based wormlike micelles (WLMs) is their poor low-temperature stability, which severely limits their application. Generally, an ionic surfactant with a linear C12–C16 alkyl chain has a Krafft point around or above room temperature. Therefore, there is a demand for ionic-surfactant-based WLMs with greater lowtemperature stability. Silicone surfactants have flexible hydrophobic chain structures. Hence, they are expected to be suitable candidates for WLMs that can be stable at low temperatures. Sodium trimethylsilyl tetra(dimethylsiloxane) decyl sulfate (Si〈sub〉5〈/sub〉C〈sub〉10〈/sub〉SO〈sub〉4〈/sub〉Na) and benzyltrimethylammonium chloride (BTAC) were used as surfactant and electrolyte, respectively, to obtain the WLM system with desired properties. No precipitation of surfactant crystals was observed in the WLM system obtained in this study when temperature was decreased to as low as 0 °C, indicating excellent low-temperature stability. Steady rheological measurements on the viscous solutions show shear thinning corresponding nearly to a power law relation (viscosity ∝ [shear rate]〈sup〉−1〈/sup〉). Zero shear viscosity (〈em〉η〈/em〉〈sub〉0〈/sub〉) increased with increase in 〈em〉R〈/em〉, reaching a maximum at around 〈em〉R〈/em〉 = 0.3 and decreasing thereafter. Oscillatory shear measurements for the viscoelastic samples, formed around the maximum-viscosity composition, show that the storage modulus (〈em〉G′〈/em〉) and the loss modulus (〈em〉G′′〈/em〉), with respect to the oscillation frequency (〈em〉ω〈/em〉), cross each other and fit the Maxwell model very well in the low-〈em〉ω〈/em〉 region. The normalized Cole-Cole plot of 〈em〉G′′〈/em〉 / 〈em〉G′′〈/em〉〈sub〉max〈/sub〉 against 〈em〉G′〈/em〉 / 〈em〉G′′〈/em〉〈sub〉max〈/sub〉 was obtained as a semicircle centered at 〈em〉G′〈/em〉 / 〈em〉G′′〈/em〉〈sub〉max〈/sub〉 = 1, as is typical for WLM systems.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308295-ga1.jpg" width="356" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: Available online 20 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Jian Xiao, Honglin Luo, Haiyong Ao, Yuan Huang, Fanglian Yao, Quanchao Zhang, Yizao Wan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Although recombinant human bone morphogenetic protein-2 (rhBMP-2) has been widely applied for bone regeneration, finding an ideal delivery system with optimal dose and minimal side effects is still a challenge. In this context, a novel mesoporous bioactive glass nanotubular (MBG-NT) scaffold loaded with rhBMP-2 was developed using a template-assisted sol-gel method. The obtained MBG-NT scaffold showed a notable 3D network structure and the nanotubes had an outer diameter of approximately 45 nm and a wall thickness of 15 nm. X-ray photoelectron spectroscopy (XPS) certified that the rhBMP-2 was successfully loaded into the MBG-NT scaffold with a quantity of 184.3 〈strong〉±〈/strong〉 5 ng mg〈sup〉-1〈/sup〉, and the MBG-NT scaffold exhibited a sustained release of rhBMP-2 for 28 days due to the presence of mesoporous structures. Moreover, the rhBMP-2-loaded MBG-NT scaffold exhibited enhanced proliferation, alkaline phosphatase (ALP) activity and osteogenic-related gene expression of human bone marrow stromal cells (hBMSCs) when compared to bare MBG-NT scaffold. We believe that the rhBMP-2-loaded MBG-NT scaffold can be a promising scaffold for regeneration of large bone defects.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571930826X-ga1.jpg" width="285" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Yunhui Wang, Qiang Wu, Jianing Mao, Shuixin Deng, Rui Ma, Jiaoyan Shi, Jiaoyang Ge, Xin Huang, Lan Bi, Jie Yin, Shanling Ren, Gang Yan, Zhihong Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Recently, a novel layered two-dimensional carbon nanomaterial was synthesized named triphenylene-graphdiyne (TpG). The acetylenic ring and triphenylene are included in primitive cell of this structure. In this work, many different strategies have been adopted to investigate hydrogen storage capacity of Li- and Ca-decorated pristine and B-doped TpG by first-principles calculations. The maximum three H〈sub〉2〈/sub〉 molecules are captured around every one Li atom by Li-decorated on the acetylenic ring only for TpG. The hydrogen storage gravimetric capacity of 8.17 wt% with an approximate ideal average H〈sub〉2〈/sub〉 adsorption energy of 0.18 eV/H〈sub〉2〈/sub〉. Moreover, both acetylenic ring and triphenylene are decorated by Li and two H〈sub〉2〈/sub〉 molecules are adsorbed for each Li atom. The hydrogen storage capacity reaches to 9.70 wt% with an ideal average hydrogen adsorption energy of 0.27 eV/H〈sub〉2〈/sub〉. After two C atoms are doped by B atoms, two more Li atoms are introduced to the triphenylene. Here, maximum 20 H〈sub〉2〈/sub〉 molecules are adsorbed on Li-decorated B-doped TpG. The hydrogen storage capacity reaches to 8.77 wt%, with ideal average hydrogen adsorption energy of 0.24 eV/H〈sub〉2〈/sub〉. Four H〈sub〉2〈/sub〉 molecules can be adsorbed effectively by Ca-decorated pristine TpG with the average hydrogen adsorption energy of 0.19 eV/H〈sub〉2〈/sub〉. We also calculated the H〈sub〉2〈/sub〉 storage of Ca-decorated B-doped TpG and 5.51 wt% of gravimetric with ideal average hydrogen adsorption energy of 0.25 eV/H〈sub〉2〈/sub〉 can be obtained. Our calculation indicates that the Li- and Ca-decorated B-doped TpG and Li-decorated pristine TpG can be a very promising material for reversible hydrogen storage.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322366-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Jin Wang, Long Fan, Xuemin Wang, Tingting Xiao, Liping Peng, Xinming Wang, Jian Yu, Linhong Cao, Zhengwei Xiong, Yajun Fu, Chuanbin Wang, Qiang Shen, Weidong Wu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The properties of graphene vary with the number of layers, thus determining its usefulness in different applications. Consequently, it is important to develop a method for precisely controlling the number of layers for various application demands. In this study, high quality monolayer graphene was successfully prepared using pulsed laser deposition. Meanwhile, the growth of monolayer and bilayer graphene can be controlled by adjusting the laser energy density. Raman spectra show that high quality monolayer films grew at a laser energy density of 5.66 J/cm〈sup〉2〈/sup〉 and bilayer graphene films grew at a laser energy density of 8.49 J/cm〈sup〉2〈/sup〉. X-ray photoelectron spectroscopy indicate that the main chemical state of carbon is the sp〈sup〉2〈/sup〉 hybrid state, and the maximum atomic ratio of sp〈sup〉2〈/sup〉 and sp〈sup〉3〈/sup〉 results from the sample with laser energy density of 5.66 J/cm〈sup〉2〈/sup〉. Scanning electron microscope images show that monolayer graphene is connected by small sheets with different sizes, and the largest graphene sheet reaches 20 μm. High resolution transmission electron microscope images and selected area electron diffraction patterns show that graphene samples are highly crystalline and yield significant layer information. UV–Vis spectra indicate that the transmittance through monolayer and bilayer graphene at 550 nm are 96.93% and 95.05%, respectively. Ultraviolet photoelectron spectroscopic measurements show that the work function of graphene ranges from 3.72 eV to 4.76 eV; the variation in the work function is related to growth defects. Finally, the relationship between the structure of the graphene films and laser energy density are investigated in detail, and these results indicate that the controllable growth of graphene can be achieved by adjusting the laser energy density. This means that a suitable laser energy density is conducive to defining an equilibrium between diffusion and condensation of carbon atoms, which is crucial to the growth of high-quality monolayer and bilayer graphene. It is expected that this study might be facilitate the preparation of graphene-based composite films and devices.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322123-ga1.jpg" width="221" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Yuxiang Wang, Qianqian Shangguan, Dingni Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The droplet anisotropic wetting on chemically heterogeneous stripe-patterned substrates after impact is studied by using many-body dissipative particle dynamics in this work. After a low-velocity impact on substrates with different length ratio (ratio of stripe width to the initial droplet size) and Cassie area fraction, the droplet can show various shapes and contact angles in parallel and orthogonal directions to the stripes. The elongation of the droplet can be increasingly evident when increasing the length ratio. Also, the contact angles at both directions follow the Cassie-Baxter predicted values well at low length ratio while deviate from them at high length ratio. Both the capillary and kinetic effects have a significant influence on the anisotropic wetting. When impact with higher velocity, the droplet leaves some residues on the hydrophilic stripes of the substrates. Surprisingly, the residues for substrates with certain length ratio (≤0.316) are distributed in circular regions with almost identical radii, indicating the spreading stages of them are independent on the surface properties and dominated by the kinetic effect. When the droplet reaches a stable state, the main body shows anisotropic wetting behavior, indicating the capillary effect dominates the wetting instead of the kinetic effect at the retraction stage.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322494-ga1.jpg" width="282" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Peiman Xu, Jinming Zhang, Zhifeng Ye, Yiyi Liu, Tianlun Cen, Dingsheng Yuan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Tailoring low-cost electrocatalysts with high activity and good stable for hydrogen evolution reaction (HER) is vital to energy harvesting and storage. Herein, Co doped Ni〈sub〉0.85〈/sub〉Se nanoparticles supported on reduced graphene oxide (Co〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Ni〈sub〉0.85〈/sub〉Se/RGO) were synthesized by a facile one-step hydrothermal method. As expected, the resulting hybrid materials effectively inhibit the aggregation of nanoparticles and possess the enhanced intrinsic conductivity, leading to exposure of more active sites and the faster electron transport. And then these beneficial effects enable Co〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Ni〈sub〉0.85〈/sub〉Se/RGO efficient HER catalytic activity in both acid and basic electrolytes, achieving small overpotentials of 148 and 128 mV at a current density of 10 mA cm〈sup〉−〈/sup〉〈sup〉2〈/sup〉 in 0.5 M H〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉 and 1.0 M KOH, respectively.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322676-ga1.jpg" width="327" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Xuefei Wang, Jingchao Yu, Can Fu, Tianyi Li, Huogen Yu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Composite semiconductor photocatalysts with hollow structures can present excellent photocatalytic performance by combining the advantages of composite photocatalyst and hollow structures. However, it is a great challenge to develop a facile synthetic route to realize the composite hollow nanostructures. In the paper, AgCl/TiO〈sub〉2〈/sub〉 composite hollow octahedra were synthesized by a facile self-templated method via the direct addition of Ag〈sub〉2〈/sub〉O octahedron template into TiCl〈sub〉4〈/sub〉 ethanol solution. In the case, AgCl and TiO〈sub〉2〈/sub〉 nanoparticles can be simultaneously formed to construct the shell of hollow octahedra along with the alcoholysis and hydrolysis of TiCl〈sub〉4〈/sub〉 and the reaction of releasing H〈sup〉+〈/sup〉 and Cl〈sup〉−〈/sup〉 ions with Ag〈sub〉2〈/sub〉O template. Obviously, the synthetic method showed some advantages of economic reaction steps and uniform component distribution. After AgCl/TiO〈sub〉2〈/sub〉 is illuminated by visible light, partial Ag metal can form in the sample due to the photosensitive property. Further photocatalytic results indicated that the Ag/AgCl/TiO〈sub〉2〈/sub〉 hollow octahedron photocatalyst exhibited excellent photocatalytic activity and stability of performance. Importantly, the present Ag〈sub〉2〈/sub〉O self-template method was also extended for the synthesis of other hollow octahedra such as AgCl/Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉, AgCl/SnO〈sub〉2〈/sub〉 and AgCl. Thus, the present work may provide new insights into design and synthesis of other hollow octahedron photocatalysts.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322573-ga1.jpg" width="479" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Ling Zhang, Xijian Liu, Min Zhang, Haikuan Yuan, Lijuan Zhang, Jie Lu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We present here a novel, simple, low cost and green synthetic strategy for unique core-shell structured Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@C-MoO〈sub〉2〈/sub〉-Ni composites without using extra reducing agent. The Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@C-MoO〈sub〉2〈/sub〉-Ni composites exhibited better catalytic performance (reduction of 4-nitrophenol to 4-aminophenol) than previous common catalysts because highly dense satellite Ni nanoparticles firmly distributed on the porous carbon spheres. In addition, the Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@C-MoO〈sub〉2〈/sub〉-Ni composites can be used as a pollutant remover due to fast adsorption rate and high adsorption capacity for dye in water. More importantly, owing to high magnetic susceptibility, the Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@C-MoO〈sub〉2〈/sub〉-Ni composites show excellent performance for recyclable use by magnetic separation. Thus, the Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@C-MoO〈sub〉2〈/sub〉-Ni composites have great potential as an ideal catalyst and adsorbent due to facile and green synthesis method, good stability, excellent recyclability, nontoxic and low cost properties.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322925-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Xingwen Zhou, Wei Guo, Jian Fu, Ying Zhu, Yongde Huang, Peng Peng〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Efficient manufacturing of composite structure is one of the key challenges in the fabrication of flexible devices. Laser direct writing provides a solution due to its area selectivity, controllability and rapid processing. In this study, one-step patterning of Cu/Cu〈sub〉〈em〉x〈/em〉〈/sub〉O structure with tunable composition on flexible substrate has been realized with laser direct writing on Cu precursor film. An integrated humidity sensor that combines a Cu〈sub〉〈em〉x〈/em〉〈/sub〉O-rich porous sensing structure with a conductive Cu-rich structure has been fabricated. The one-step-written device showed high sensitivity to human breathing. This work highlights the promise of this one-step mask-less laser writing as an efficient, rapid and low-cost composite structure fabrication process for flexible devices.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219321956-ga1.jpg" width="415" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Mehdi D. Esrafili, Mehdi Vatanzadeh〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A dispersion-corrected density functional theory study is performed about reaction pathways and energy barriers of NO reduction by CO over Si-coordinated nitrogen doped graphene (SiN〈sub〉4〈/sub〉-Gr). The results indicate that NO molecule can be stably chemisorbed over the Si atom of SiN〈sub〉4〈/sub〉-Gr due to the favorable hybridization of Si-3p and NO-2π* states. The coadsorption of NO molecules to form absorbed (NO)〈sub〉2〈/sub〉 species is proved to be the initial step for the reduction of NO molecules over the title surface. The energy barriers for the (NO)〈sub〉2〈/sub〉 → N〈sub〉2〈/sub〉O + O* reaction are in the range of 0.38–0.60 eV, which seem to be overcome at ambient condition. According to our findings, NO reduction over SiN〈sub〉4〈/sub〉-Gr is a thermodynamically favored process at a relatively wide range of temperatures.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322536-ga1.jpg" width="265" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Youssef Berro, Saber Gueddida, Sébastien Lebègue, Andreea Pasc, Nadia Canilho, Mounir Kassir, Fouad El Haj Hassan, Michael Badawi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The upgrading of lignin-derived bio-oils involves a HydroDeOxygenation (HDO) reaction through either the Hydrogenation (Hyd) or the Direct DeOxygenation (DDO) route, the latter limiting hydrogen consumption. Herein, dispersion-corrected DFT has been used to evaluate the adsorption behavior of phenol (as a representative model of bio-oils) and two by-products (water and CO) over various crystalline and amorphous silica surfaces to evaluate their potential selectivity (DDO/Hyd) and efficiency (low inhibiting effect) for HDO processing. Phenol can adsorb through three modes, flat π-interaction, flat O-interaction or perpendicular O-interaction. All crystalline surfaces show a preference for the flat π-interaction, which is expected to promote the Hyd route. Over amorphous surfaces the flat O-interaction dominates, and a very specific and strong interaction (around −120 kJ/mol) was found on SiO〈sub〉2〈/sub〉-3.3 and SiO〈sub〉2〈/sub〉-2.0 surfaces where the phenol molecule loses its aromaticity, which is very promising for its degradation under catalytic conditions. In addition, this makes those surfaces very efficient to adsorb selectively phenol in presence of water and CO. Remarkably, on all silica surfaces, the interaction energy of CO is nearly negligible, which makes them more attractive for HDO process compared to sulfide catalysts with respect to the inhibiting effect criteria.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉High adsorption selectivity of phenol vs CO and H〈sub〉2〈/sub〉O on amorphous silica.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322524-ga1.jpg" width="237" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): A.C. Bouali, E.A. Straumal, M. Serdechnova, D.C.F. Wieland, M. Starykevich, C. Blawert, J.U. Hammel, S.A. Lermontov, M.G.S. Ferreira, M.L. Zheludkevich〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This work reports a novel approach for growing layered double hydroxide (LDH) films on any plasma electrolytic oxidation (PEO) coated AA2024 independently of the nature of the PEO coating. The specific PEO coating chosen to carry out this work is considered to be not suitable for direct LDH growth because of phase composition and morphological features. In this paper, we describe a new methodology that consists of covering the PEO coating with a thin layer of aluminum oxide based xerogel as the source of aluminate ions for subsequent in-situ LDH growth. X-ray diffraction (XRD) and scanning electron microscope (SEM) images showed a successful formation of LDHs on the surface. An improvement in terms of active corrosion protection was also demonstrated by electrochemical impedance spectroscopy (EIS) and scanning vibrating electrode technique (SVET).〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219321531-ga1.jpg" width="473" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): M.S.M. Shukri, M.N.S. Saimin, M.K. Yaakob, M.Z.A. Yahya, M.F.M. Taib〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The effect of CO and NO adsorption on graphene (pristine, vacancy and doped) were investigated for structural and electronic properties. The sensitivity of palladium (Pd) doped graphene toward small gas molecules CO and NO have been investigated by using DFT calculation within Generalized Gradient Approximation (GGA) as implemented in DMol〈sup〉3〈/sup〉 and CASTEP. The density of states, the most stable adsorption site and adsorption energy of these small gas molecules on vacancy graphene and Pd-doped vacancy graphene are thoroughly discussed. It is found that Pd doping significantly enhances the strength of interaction between adsorbed molecules and the modified substrates. The most stable adsorption site for CO and NO on all graphene sheets are identified and reported. The results present the potential of vacancy graphene and Pd-doped vacancy graphene for molecules sensor application.〈/p〉〈/div〉 〈div〉 〈h6〉Novelty〈/h6〉 〈p〉〈/p〉 〈dl〉 〈dt〉•〈/dt〉 〈dd〉〈p〉The novelty of this paper is the doping of Pd on vacancy graphene surface could enhance the adsorption energy of CO and NO gas molecules.〈/p〉〈/dd〉 〈dt〉•〈/dt〉 〈dd〉〈p〉Besides, most of the studies not using Pd on vacancy graphene to study its effect on small molecules.〈/p〉〈/dd〉 〈/dl〉 〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322743-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Li Quan, Xuelian Yu, Tao Wang, Wenchao Yin, Jianqiao Liu, Lin Wang, Yihe Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The rational design of non-noble-metal electrocatalysts for oxygen reduction reaction (ORR) with both excellent activity and robust stability still remains a key challenge nowadays. Herein, N-doped carbon wrapped Co nanoparticles core-shell nanostructures grafted on carbon nanotubes (Co@NC@CNTs) were achieved by a simple pyrolysis process using ZIF-67 and CNTs as precursors. Most importantly, this unique structure of Co@NC@CNTs is beneficial to increase the contact area of N-doped carbon and Co, inhibit the aggregation of Co@NC core-shell nanoparticles and protect the Co from dissolution, thus improving the electrocatalytic performance and stability for ORR. As a result, the well-defined Co@NC@CNTs electrocatalyst exhibits excellent ORR activity with a high onset potential, half-wave potential and limited current density, comparable to the commercial Pt/C in alkaline electrolyte. Furthermore, the Co@NC@CNTs electrocatalyst presents outstanding electrochemical durability and methanol tolerance in comparison with Pt/C. This strategy will open a new avenue toward the development of nonprecious high-performance ORR catalysts.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219321932-ga1.jpg" width="410" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Razieh Zahedi, Zahra Asadi, Fahimeh Dehghani Firuzabadi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel heterogeneous catalyst was developed via the immobilization of a copper complex by covalent anchoring of the ligand on the surface of magnetic nano particles. The catalyst was characterized by various techniques including Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron micrograph (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), a vibrating sample magnetometer (VSM) and inductively coupled plasma (ICP) spectroscopy. The prepared catalyst demonstrated high catalytic activity, stability, reproducible dispersibility, and recycability in the O-arylation reactions. Moreover, the catalyst could be easily recovered under the outside magnetic field and reused without noticeable decreasing in its catalytic performance upon five consecutive runs.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307162-ga1.jpg" width="271" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Akram Abbasi, Arijit Bose〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The high electrical conductivity of multilayer graphene (MLG) and their sheet like morphology results in a low percolation threshold, and makes it an attractive filler for inducing electrical conductivity in an insulating polymer at small filler loadings. However, strong van der Waals forces between the flat faces of multilayer graphene cause agglomeration, making it difficult to disperse them in a polymer. The loading required for forming a percolating network of these MLGs then increases dramatically, and the advantage of their sheet-like morphology is lost. To enhance the dispersion of MLGs, carbon black nanoparticles (CB) were added as secondary fillers to a polystyrene (PS) matrix containing 2.5 vol% MLG. The electrical conductivity of the composite increased from 10〈sup〉−9〈/sup〉 S/m with no CB to 10〈sup〉-4〈/sup〉 S/m with 1.5 vol% CB, asymptoting to 10〈sup〉3〈/sup〉 S/m at ∼12 vol% CB. Using Raman spectroscopy and wide-angle X-ray diffraction, we confirmed that the CB particles act as dispersion aids and prevent MLG restacking, reducing agglomeration and enhancing dispersion of the MLG sheets in PS. This leads to an increase of several orders of magnitude in electrical conductivity.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307150-ga1.jpg" width="269" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Jiaoyuan Lian, Suxia Zheng, Cong Liu, Zhongbin Xu, Xiaodong Ruan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We propose a co-flowing step emulsification strategy for the on-line control of micro-droplet generation. The effects of four parameters including wall contact angle, plateau length, channel distance and diameter are investigated numerically and experimentally in this study. The results indicate that the wall contact angle, whose applicable range can be expanded to 90°–180° by co-flow, is critical to droplet formation. The effect of the plateau length on droplet generation is reduced by the co-flow, and the droplet diameter is almost independent of the plateau length, which ranges from 0.7 to 1.5 mm. In addition, the droplet diameter increases significantly with increasing channel distance and diameter. Combining these results with those of our previous study, we derived an explicit equation for droplet diameter prediction. The predicted droplet diameter based on this equation has good agreement with the simulation and experimental results. Furthermore, we proposed a coefficient 〈em〉α〈/em〉 as a function of physical and dimensional parameters to predict the regimes and modes in the co-flowing step emulsification process. The conclusion of this study not only provides an important reference for the design and improvement of step emulsification chips, but also offers a new idea and a scientific basis for tuneable monodisperse micro-droplet production.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307216-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Biao Zhang, Xiaojuan Li, Yang Zhao, Hua Song, Huan Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Oxygen doped mesoporous graphitic carbon nitride(O-mpg-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉) was innovatively prepared through facile two-step synthesis and characterized through different characterization tools, such as XRD、SEM、XPS etc. These characterizations confirm that the as-prepared sample has separated plate-like structure with lots of gaps and oxygen atoms have been successfully doped into them. Evaluated by photodegradation of Rhodamine B and Methyl Orange, the O-mpg-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 photocatalyst exhibits higher photocatalytic degradation efficiency, which is attributed to the added active spots, shorter electronic transmission distance and wider range of light absorption. In addition, the photocatalytic activity of the as-prepared catalysts didn’t decrease significantly after five photodegradation cycles, showing a high photocatalytic stability.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Oxygen doped mesoporous g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 was firstly prepared by a facile calcination-solvothermal method and exhibits excellent photocatalytic degradation performance, which is ascribed to the change of morphology and intrinsic electronic structure.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307241-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Wenjie Liu, Kun Yuan, Peipei Liu, Ming Chen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this article, magnetically responsive catalysts were successfully synthesized by host-guest chemistry and self-assembly strategy. Firstly, β-cyclodextrin (β-CD) was bound directly to the surface of core/shell magnetic Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@C (MFC) using chemical bonding methods. Then, in view of the host-guest recognition, p-aminothiophenol (pATP) was captured by β-CD to form inclusion complex on the surface of MFC. Lastly, pre-synthesized gold, silver, platinum nanoparticles (AuNPs, AgNPs, PtNPs) could be adsorbed on the surface of MFC@β-CD-pATP through self-assembly strategy to fabricate ternary composites MFC@β-CD-pATP@metal nanoparticles. Catalytic reduction reaction of methylene blue using NaBH〈sub〉4〈/sub〉 as reducing agent evaluates the catalytic performance of three as-prepared magnetic nanocomposites. MFC@β-CD-pATP@AuNPs catalyst showed the fast catalytic reaction rate constant. Significantly, we have explored the separation of magnetic supports and novel metal nanoparticles under mild conditions. This strategy will become a green and environmental way for highly efficient separation of precious metals catalysts, and recycle and reuse of catalyst carriers.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307174-ga1.jpg" width="362" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Piero De Leonardis, Francesco Cellesi, Nicola Tirelli〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We explored a versatile enzyme nanoencapsulation process based on the synthesis of silica gel nanoparticles, decorated with a dense hydrophilic poly(glycerol monomethacrylate) (PGMMA) shell for biological and therapeutic applications. These hybrid enzyme-SiO〈sub〉2〈/sub〉-polymer nanoparticles were obtained through an aqueous sol-gel process, followed by the adsorption of cationic macroinitiators by electrostatic complexation. Surface-initiated Atom Transfer Radical Polymerisation (ATRP) was applied to obtain a dense hydrophilic (protein repellent) PGMMA layer of tunable size, under conditions which are compatible with the nanoencapsulation of horseradish peroxidase. The sol-gel synthetic procedure, the composition and molecular weight of the macroinitiators, the polymer adsorption and purification methods, and the final ATRP conditions, were optimised to control the properties of these nanoparticles, in terms of particle size, Z-potential, PGMMA decoration, while preserving enzymatic activity.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307228-ga1.jpg" width="489" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈p〉Enzyme-SiO〈sub〉2〈/sub〉-polymer nanoparticle obtained by enzyme (HRP) nanoencapsulation in silica gel nanoparticles, adsorption of a cationic macroinitiator, and final polymer shell generation (PGMMA) by ATRP.〈/p〉 〈/div〉

Beschreibung: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): F. Salerni, D. Orsi, E. Santini, L. Liggieri, F. Ravera, L. Cristofolini〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉We employ Diffusing Wave Spectroscopy (DWS) to characterize microscopic structure, internal dynamics and rheological properties of a paradigmatic emulsion formed by water and dodecane stabilized by the anionic surfactant Sodium Dodecyl Sulfate (SDS).〈/p〉 〈p〉We focus on ageing and stability in the regime of low surfactant concentration, well below the Critical Micellar Concentration (CMC). In the long-time ageing regimes differentiate in stable and unstable, depending on surfactant concentration. For the stable case, ageing affects the dynamics following a power law with an exponent independent on surfactant concentration, presumably related to the late stages of the water drainage process. On the contrary, at constant ageing, the dependence of the dynamics from surfactant concentration shows a slowdown, corresponding to a maximum in the bulk shear mechanical modulus, around 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si25.svg"〉〈mo〉[〈/mo〉〈mi〉S〈/mi〉〈mi〉D〈/mi〉〈mi〉S〈/mi〉〈mo〉]〈/mo〉〈mo〉=〈/mo〉〈mn〉2〈/mn〉〈mi〉m〈/mi〉〈mi〉M〈/mi〉〈/math〉 which is reminiscent of a similar maximum found by drop tensiometry in the dilational modulus of the single interface.〈/p〉 〈p〉This suggests a consistent picture of the mechanisms (de)stabilizing the emulsion, explained in terms of elementary process at the interface. These results show furthermore that DWS can be a reliable diagnostic for the study of the aging and of the mechanical properties of concentrate emulsions. This might be relevant to control stability of emulsions when a low concentration of surfactant is desired, e.g. for economical or environment reasons.〈/p〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719301876-ga1.jpg" width="334" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Huijian Ye, Xuanhe Zhang, Chunfeng Xu, Lixin Xu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The polymer film capacitor has been widely applied in electronics and stationary power system due to the large power density and graceful dielectric reliability. The current requirements for flexible film capacitor are mainly on the development of polymer nanocomposite with high energy density and charge-discharge efficiency during applied electric field. Here we employed the fluoro hyperbranched polyethylene-graft-poly(trifluoroethyl methacrylate) (HBPE-〈em〉g〈/em〉-PTFEMA) copolymer to exfoliate the boron nitride nanosheets (BNNSs) in low-boiling-point solvent, and then, the flexible poly(vinylidene fluoride-trifluoroethylene) (P(VDF-CTFE)) nanocomposite film incorporated with BNNSs was prepared by the simple solution casting. The stable BNNSs dispersion was obtained with assistance of fluoro hyperbranched copolymer as the stabilizer, which was adsorbed on the nanosheets via the noncovalent CH-π interaction against aggregation. The presence of fluoro segments improves the compatibility of BNNSs/P(VDF-CTFE) nanocomposite, which contributes to the large interfacial polarization. The energy density in 0.4 wt% nanocomposite achieves 6.8 J/cm〈sup〉3〈/sup〉 with charge-discharge efficiency of 66% at 300 MV/m, which is ascribed to the large content of electroactive phase and the enhanced interfacial polarization. The fluoro hyperbranched copolymer functionalized BNNSs/P(VDF-CTFE) nanocomposite film exhibits high electric storage capability as well as lightweight feature and flexibility, which is benefit to potential applications for portable and implantable electrical devices where both the weight and size are primary concerns.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571930723X-ga1.jpg" width="287" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Mohammad M. Hassan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, multifunctional wool fabrics were produced by treating them with silver (Ag) nanoparticles in a single-stage treatment using trisodium citrate (TSC) as a reducing and capping agent. The effects of treatment parameters, such as Ag〈sup〉+〈/sup〉 concentration, pH, temperature and time on the colour strength, antibacterial and antistatic properties, and UV radiation absorption by the treated fabric were carried out. It was found that the wool fabric treated with Ag nanoparticles formed by using Ag〈sup〉+〈/sup〉 concentration of less than 1.11% on the weight of wool fibres produced very pale shade. The colour strength and UV radiation absorption capacity of the treated wool fibres increased with an increase in the concentration of Ag〈sup〉+〈/sup〉, and Ag〈sup〉+〈/sup〉 to citrate anion ratio, and also with a decrease in the treatment pH. The treatment temperature had a great effect on the colour strength of the treated fabrics and the size of Ag nanoparticles. The colour strength increased from 1.59 for the fabric treated at 55 °C to 7.74 for the fabric treated at 95 °C. The surface resistance of the treated wool fibres decreased with an increase in the concentration of Ag〈sup〉+〈/sup〉, while the colour fastness to washing decreased for the fabric treated at a higher pH. The treated fibres showed excellent antibacterial activity, UV radiation absorption capacity, and also very good antistatic properties along with an excellent colourfastness to washing. Moreover, the developed treatment is highly durable to washing as after 20 washes the treated fibres lost their colour and antibacterial activity only marginally.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308076-ga1.jpg" width="415" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: Available online 17 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Yixing Wang, Taijun He, Mengyun Liu, Jianqi Ji, Yu Dai, Yang Liu, Longbo Luo, Xiangyang Liu, Jiaqiang Qin〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fast and efficient oil-water separation materials under harsh conditions become urgent requirement for eliminating destruction of environment from offshore oil spill, oily wastewater produced in industry and life. Here, we designed and prepared polyimide (PI) aerogel with strong hydrogen bond by introducing benzimidazole structure. The hydrogen bond increases the intermolecular interactions to overcome the expansion force and capillary force during ice crystal growth and sublimation. The obtained PI aerogel has a mutually interleaved sheet three-dimensional network structure of thin pore walls (about 85 nm), interconnected pores and tortuous channels with a low shrinkage (about 7.8%). Moreover, due to the high hydrophobicity and morphological characteristics, the PI aerogel can be used for oil-water separation continuously under different harsh conditions, such as high viscosity oil (above 570 mPa·s), oil in cold/hot water (0 °C/120 °C), corrosive solution and emulsion. The separation efficiency and maximum oil flux can reach 99. 9% and 14320 L·m〈sup〉-2〈/sup〉 h〈sup〉-1〈/sup〉, respectively. Because of their fast and efficient oil-water separation performance in harsh environments, this PI aerogel shows great potential in the field of petroleum, municipal and industrial wastewater treatment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307976-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: Available online 13 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Junmei Tian, Zhijia Zhu, Baojiang Liu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Photocatalysts with heterojunctions had attracted much attention in the field of photocatalysis due to their strong charge separation and transfer capabilities. In this work, a novel Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉/MWCNTs Z-scheme photocatalyst was firstly prepared by one-step hydrothermal method. A series of characterization results showed that the ternary flower-like Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉/MWCNTs photocatalyst was successfully synthesized. The photocatalytic property of Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉/MWCNTs composite was evaluated by photo-degradation of reactive blue 19 (RB-19) dye under visible light irradiation. The results manifested that Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉/MWCNTs composite presented the better photocatalytic property than pure Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉 and Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉. Additionally, in the photocatalytic process free radical and hole scavenging experiments indicated that h〈sup〉+〈/sup〉 and ·O〈sub〉2〈/sub〉- played an indispensable role. Finally, possible mechanisms for the photocatalytic enhancement of the composite were put forward.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307861-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Chao Zhang, Siyao Liu, Shuangxi Li, Yue Tao, Panpan Wang, Xinyue Ma, Lanzhou Chen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The magnetic chitosan microspheres immobilized 〈em〉Aspergillus sydowii〈/em〉 (MCMAs) was prepared and characterized by SEM, BET, XRD and VSM analyses, and used to adsorb Cu(II) from aqueous solution under different influence factors such as contact time, initial Cu(II) concentration and biosorbent dose. Characterization results showed that MCMAs had large specific surface area and were rapidly separated from aqueous solution by using an adscititious magnetic field. Batch adsorption experiments showed that Cu(II) adsorption capacity of MCMAs was up to 119.21 mg g〈sup〉−l under the optimal condition. The CO, OH and NH〈/sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉 groups played an important role in Cu(II) chelation observed from FTIR spectra. Cu(II) adsorption onto MCMAs was well described by pseudo-second-order kinetics and Langmuir isotherm, and the adsorption process involved surface and intra-particle diffusion. In addition, MCMAs showed good recyclable efficiency after four adsorption-desorption cycles.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308015-ga1.jpg" width="334" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Suvendu Manna, Snigdha Prakash, Papita Das〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This article presents the process of synthesizing a value added product from a carbonaceous industrial waste. For this a carbonaceous industrial waste was coated with graphene oxide (GO) and then thermally activated at 800 °C. The GO and the GO-coated biochar were characterized with atomic force microscope, raman spectroscope, fourier transform infrared spectroscopy, field-emission scanning electron microscope, x-ray Diffraction and transmission electron microscope. This GO-coated biochar was then utilized to investigate removal capacity of phenol present in wastewater. The data indicated that the GO-coated biochar showed better phenol removal efficacy then that of the GO itself. The isotherm analysis indicated that the data could be described best with Langmuir isotherm indicating that the phenol separation was a monolayer surface adsorption. The kinetic analysis indicated that the phenol separation process was followed by pseudo second order kinetics. Also, it was evident from the intra-particle diffusion kinetic analysis that diffusion plays a significant role in phenol separation. From thermodynamic analysis it was evident that the phenol separation process was endothermic as well as spontaneous in nature. The GO-coated biochar showed better separation efficacy in the presence of salt.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308064-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Yong-li Yan, Qi Xi, Christian-chibuike Una, Bing-cheng He, Chun-sheng Wu, Long-long Dou〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉The serious fingering and nonuniform injectivity profile of acid liquid result from the features of heterogeneity in most carbonate reservoir, leading to a poor effect on the acidizing process. In the present contribution, for the first time, we report a novel diversion acidizing strategy that uses acid-rock reaction between the acidizing fluid itself and carbonate core to produce CO〈sub〉2〈/sub〉 at supercritical state. Under the action of a mixture of foaming agent and stabilizer contained in this working fluid, a CO〈sub〉2〈/sub〉 foamed acid fluid is in-situ formed in the acidizing layer, which would play a diverting role in carbonate matrix acidizing operations. Experiments on in-situ formation of CO〈sub〉2〈/sub〉 microfoams (emulsions) were performed utilizing a visible acid-rock reaction simulation device and a self-made high pressure and temperature foam generator. A series of divided-flow experiments were undertaken by the core displacement setup.〈/p〉 〈p〉Results based on these experiments indicate that with 0.5% SDBS as a foaming agent and 0.15% CMC as a stabilizing agent, the supercritical CO〈sub〉2〈/sub〉 microfoams (emulsions) could be created in-situ in the process of acidizing through the carbonate reservoirs. The foamed acid has the accumulating and plugging effects, with divided-flow selectivity not only in the parallel cores of oil saturation and water saturation, but also in the parallel cores of different permeability. This foamed acid fluid could provide better diversion acidizing operations for heterogeneous carbonate formation. Finally, the mechanism of this novel diversion acidizing technology was uncovered in detail. It is suggested that the whole working process is actually an interface effect in the dynamic system of gas/liquid/solid multiphase fluid. Such findings are potentially important for a better understanding on the mechanisms of in-situ formation of CO〈sub〉2〈/sub〉 foamed acid and its self-diversion. Looking out to the future, our report attempts to provide a new and efficient technology for the improvement of acid stimulation in the carbonate reservoirs.〈/p〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉A novel diversion acidizing technology using in-situ microfoams to meet the challenge of serious fingering and poor backflow of acid liquid existing in application of diverting acid technology in heterogeneous formations. This technology uses a chemical reaction between conventional acid and carbonate cores to produce CO〈sub〉2〈/sub〉 at supercritical state. Under the action of a mixture of foaming agent and stabilizer, a CO〈sub〉2〈/sub〉 foam fluid was in-situ formed, which would play a diverting role in carbonate matrix acidizing operations. It is suggested that the whole working process is actually an interface effect in the dynamic system of gas/liquid/solid multiphase fluid.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307757-ga1.jpg" width="200" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Beschreibung: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Tao Ma, Haishun Feng, Hairong Wu, Zhe Li, Jiatong Jiang, Derong Xu, Ziyu Meng, Wanli Kang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Gemini surfactant has a good application prospect in the field of enhanced oil recovery (EOR) due to the advantages of high interfacial activity, low critical micelle concentration (CMC) and good wettability alteration. In this paper, ethylenediamine, sodium 2-bromoethanesulphonate and fatty alcohol polyoxyethylene ether are used as raw materials to synthesize a new kind of anionic-nonionic gemini surfactant which hydrophilic group consists of two parts nonionic and anionic groups through a mild reaction of amination. The surface tension, interfacial tension, wettability and oil displacement of the synthesized anionic-nonionic gemini surfactants were evaluated. Parameters of surfactant the saturated adsorption amount 〈em〉Γ〈/em〉〈sub〉max〈/sub〉 and the minimum molecular occupied area 〈em〉A〈/em〉〈sub〉min〈/sub〉 were calculated. The structures of the optimal product were characterized by IR and 〈sup〉1〈/sup〉H-NMR. The results showed that the critical surface tension of the synthesized anionic-nonionic gemini surfactant was as low as 28.94 mN/m, and the critical micelle concentration was 4.9 × 10〈sup〉−5〈/sup〉 mol/L. An interfacial tension between the aqueous solution of 600 mg/L optimal surfactant and Dagang crude oil was 0.0804 mN/m. 1500 mg/L aqueous solution can reduce the surface contact angle of lipophilic low permeability core from 144.5° to 71.5°. The anionic-nonionic gemini surfactant (1000 mg/L; 0.4 PV) can improve oil displacement efficiency by 7.03%. The current study opens a new pathway for designing enhancing oil recovery applicable gemini surfactants with excellent performance, wide source of raw materials and low dosage.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307885-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Zengzi Wang, Runtao Hu, Gaihuan Ren, Gongrang Li, Shangying Liu, Zhenghe Xu, Dejun Sun〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The application of conventional alkalis (NaOH or Na〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉) in alkali/surfactant/polymer (ASP) flooding is rather limited due to their intrinsic drawbacks, including precipitating during injection into formation water with a high divalent ion concentration and enhancing the dispersibility of clays (e.g., montmorillonite (MMT) or kaolinite) in water, which lead to damage to reservoir formations and bring about difficulties in treating produced fluids. Here, we propose polyetheramine D 230 as an alternative alkali to avoid these problems. D 230 is a diamine linked by poly(oxypropylene) backbones. Interfacial tension and emulsification measurements proved that D 230 can neutralize the acidic components in crude oil to generate surface-active soaps, which facilitate oil emulsification in water. Contact angle measurements indicated that an oil-contaminated quartz surface treated with D 230/SP blends was successfully altered from oil-wet to water-wet. Sand pack flooding measurements demonstrated that a D 230/SP injection was able to mobilize 19.23% of the original oil in place (OOIP) after thorough water flooding. Rheograms of alkali/polymer blends showed a reduced impact of D 230 on viscosity. Static bottle tests indicated that no precipitation occurred after D 230 was injected into formation water with a high Ca〈sup〉2+〈/sup〉 concentration. Colloidal stability measurements of clay dispersions suggested that D 230 can inhibit clay dispersibility. As an alternative alkali in ASP flooding, D 230 not only facilitates enhanced oil recovery (EOR) but also solves problems such as precipitation, high biotoxicity, reduced fluid viscosity and enhanced clay dispersibility brought about by conventional inorganic and organic alkalis. These advantages make D 230 an eco-friendly choice as an alkali for ASP flooding.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308088-ga1.jpg" width="362" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Mohsin Ali Marwat, Bing Xie, Yiwei Zhu, Pengyuan Fan, Kai Liu, Meng Shen, Malik Ashtar, Suwadee Kongparakul, Chanatip Samart, Haibo Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The sandwich-structured barium titanate/poly(ether imide) (BT/PEI) nanocomposites are fabricated layer-by-layer, with outer two insulation layers (ILs) for high breakdown strength and a middle polarization layer (PL) for high dielectric constant, using solution casting technique. Consequently, the sandwich-structured BT/PEI nanocomposites with optimum BT NPs concentration in ILs and PL showed tremendously enhanced discharge energy density (〈em〉U〈/em〉〈sub〉e〈/sub〉) of 5.7 J/cm〈sup〉3〈/sup〉, which is ∼256% and ∼307% higher than the pristine PEI (with 1.6 J/cm〈sup〉3〈/sup〉) and its single-layered counterpart, i.e., 9 wt.% BT/PEI (with 1.4 J/cm〈sup〉3〈/sup〉), respectively. The similar sandwich structure also displayed a significantly higher discharge efficiency of ∼62% at very high electric field. In addition, the high-temperature hysteresis loops for optimal sandwich structure nanocomposites revealed considerably high-temperature endurance until 150 °C at 200 MV/m. The present work paves the way for using sandwich-structured linear nanocomposites in thermally stable energy storage devices.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307903-ga1.jpg" width="267" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Sabrina Matos de Carvalho, Carolina Montanheiro Noronha, Cleonice Gonçalves da Rosa, William Gustavo Sganzerla, Ismael Casagrande Bellettini, Michael Ramos Nunes, Fabiano Cleber Bertoldi, Pedro Luiz Manique Barreto〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Natural antioxidants can be incorporated into polymers to the production of active packaging, preventing the formation of off-flavors and undesirable textures in foods, increasing the foods shelf life. In this study was developed polymeric films based on poly (vinyl alcohol) (PVA) incorporated with 30, 50 and 70% of solid lipid nanoparticles entrapped α-tocopherol. PVA films were produced by the casting technique and characterized by their physicochemical, morphological, thermal and antioxidant characteristics. PVA films with nanoparticles demonstrated higher hydrophilic compared to the control film. Thermal analysis of the films showed that nanoparticles incorporation has changed the structure, decreasing the crystallinity. Moreover, films with solid lipid nanoparticles entrapped α-tocopherol demonstrated a higher antioxidant capacity, and the α-tocopherol controlled release confirmed the possibility of its use as active packaging to application in food conservation.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307812-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: Available online 19 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Yudai Chizawa, Yayoi Miyagawa, Mao Yoshida, Shuji Adachi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Mayonnaise is a preferred dressing that is routinely used in many regions. Distribution of products containing frozen mayonnaise is highly desirable due to the development of cold chain and changing lifestyle. However, freezing and thawing of mayonnaise result into separate oil and aqueous phases. A detailed mechanism of this phenomenon is still unknown. In this study, the destabilization of frozen emulsions, using rapeseed, safflower, olive, rice bran, and soybean oils as the oil phase was examined, in which these oil phases crystallize at lower temperature than the aqueous one. The vegetable oils exhibit different crystallization behavior. Irrespective of the type of vegetable oil, it was found that smaller the difference between the storage temperature and the melting point of the oil, which was estimated from the fatty acid composition, quicker was the destabilization of the emulsion prior to the growth of the oil crystal. We consider that the change in the crystallization process of the oil phase increases the energy at the oil–water interface and destabilizes the emulsion.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571930812X-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Yong Nam Ahn, Sung Hoon Lee, Sang Yoon Oh〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The adsorption mechanism and the structural features of perfluoropolyether (PFPE)-containing layers from silane-functionalized derivate (SPFPE) on hydroxylated glassy silica surfaces are systematically investigated by utilizing density functional theory and molecular dynamics simulations. It is found that each individual SPFPE molecule tends to be chemisorbed on the silica surface by forming a single siloxane bond regardless of the number of reactive branches in the functional end group of the SPFPE molecules. We also reveal that the formation of multiple siloxane bonds between a single SPFPE molecule and the hydroxylated silica surfaces is hindered by not only the constraint on geometrical optimization of the absorbed molecule but also the pre-existing hydrogen bonds between adjacent hydroxyl groups on the surfaces. With a structural analysis, the adsorption orientation of SPFPE molecules is predicted as parallel to the silica surface, which induces low surface coverage (~0.31 molecules/nm〈sup〉2〈/sup〉) and sub-nano thickness (~8 Å) of the absorbed PFPE-containing layer. These adsorption characteristics are distinct from those of self-assembled monolayers consisting of fluorocarbon or hydrocarbon molecules. We believe that the fundamental understanding of adsorption mechanism and molecular morphology of the PFPE-containing layers demonstrated in this study can contribute to developing new advanced anti-fouling materials with improved mechanical property.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324961-ga1.jpg" width="456" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): K. Niranjan, P. Kondaiah, G. Srinivas, Harish C. Barshilia〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel spectrally selective tandem stack of W/WAlSiN/SiON/SiO〈sub〉2〈/sub〉 was deposited on stainless steel 304 and silicon substrates using a four-cathode reactive unbalanced magnetron sputtering system. The coatings were deposited by sputtering of W, Al and Si targets in Ar, Ar + N〈sub〉2〈/sub〉, Ar + N〈sub〉2〈/sub〉 + O〈sub〉2〈/sub〉, and Ar + O〈sub〉2〈/sub〉 plasmas. The process parameters were optimized by studying the optical properties of the individual layers using UV-VIS-NIR spectrophotometer and Fourier transform infrared spectroscopy measurements. The high spectral selectivity of the tandem stack was achieved by varying the reactive gas flow rates of N〈sub〉2〈/sub〉 and O〈sub〉2〈/sub〉 and thickness of individual layers. In the tandem stack, W layer acts as an IR reflector, WAlSiN acts as the main absorber layer, SiON, and SiO〈sub〉2〈/sub〉 layers act as anti-reflecting layers. The tandem stack was designed based on graded refractive indices of individual layers with a double layer anti-reflection coating. The tandem stack exhibits superior spectral selectivity with a high solar absorptance of 0.955 in the broadband solar spectrum region and low thermal emissivity of 0.10 in the infrared region. The coating was found to be thermally stable up to 600 °C in vacuum for 200 h under cycling heating conditions.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Xiaoshuo Liu, Zhengyang Gao, Cheng Wang, Mingliang Zhao, Xunlei Ding, Weijie Yang, Zhao Ding〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As important parts of simultaneous removal of multiple pollutants in flue gas, catalytic oxidation of Hg〈sup〉0〈/sup〉 and adsorption removal of SO〈sub〉3〈/sub〉, Pb species and As〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 on the surface of (Fe,Co)@N-GN catalyst were systematically investigated in this work, using density functional theory. As a result, we found (Fe,Co)@N-GN not only showed great performance on Hg〈sup〉0〈/sup〉 oxidation, but also exhibited outstanding removal capacity for SO〈sub〉3〈/sub〉, Pb species and As〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 molecules. Besides, PDOS and EDD analysis were carried out and the result indicated that electron transfer and orbit hybridization played key roles in gas adsorption. In addition, thermodynamics analysis further evidenced (Fe,Co)@N-GN was a qualified sorbent under 550 K, and competitive analysis suggested that the adsorption order of pollution gas was determined by adsorption energy, rather than the volume fraction of corresponding gases in flue gas. We hoped this work can not only lay a foundation for theoretical investigation of Hg〈sup〉0〈/sup〉 oxidation, but also provide an important guideline for simultaneous removal of multiple pollutants released from coal-fired power plants.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324833-ga1.jpg" width="254" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Zhigang Mou, Hui Zhang, Zeman Liu, Jianhua Sun, Mingshan Zhu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Photocatalysis, as a green chemical technology for the removal of antibiotics, has attracted great interest recently. This study proposed a facile one-step hydrothermal process to fabricate ultrathin two dimensional (2D) BiOCl/nitrogen-doped graphene quantum dots (BiOCl/NGQDs) composites. Compared to pure BiOCl, the BiOCl/NGQDs composites exhibited enhancement in both adsorption and photodegradation for antibiotic ciprofloxacin (CIP). The optimized content of NGQDs was 6.9% and this optimized composite showed a degradation efficiency of 82.5% within 60 min under visible-light irradiation, which was considerably better than that of pure BiOCl (34.9%). Meanwhile, most of CIP was efficiently mineralized into CO〈sub〉2〈/sub〉, H〈sub〉2〈/sub〉O and other inorganic products, as revealed by a total organic carbon (TOC) removal efficiency of 95.5% within 5 h. The improved photocatalytic activity was attributed to excellent adsorption capability, enhanced visible-light response and efficient separation of the photoinduced electron-hole pairs in BiOCl/NGQDs composite. The active species trap experiments and electron spin resonance revealed that 〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉O〈sub〉2〈/sub〉〈sup〉−〈/sup〉 and hole mainly participated in the CIP degradation process. Such an effective strategy to design ultrathin 2D composite photocatalysts would provide a new approach for application in wastewater purification.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324523-ga1.jpg" width="371" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Iwan Susanto, Chi-Yu Tsai, Fachruddin, Tia Rahmiati, Yen-Ten Ho, Ping-Yu Tsai, Ing-Song Yu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In the report, the growth of GaN films on the two-dimension molybdenum disulfide (2D MoS〈sub〉2〈/sub〉) and c-sapphire 〈em〉via〈/em〉 plasma-assisted molecular beam epitaxy (MBE) was investigated. Two kinds of MoS〈sub〉2〈/sub〉 layers were prepared by pulsed laser deposition (PLD) and chemical vapor deposition (CVD) techniques. Three different surface conditions were designed for the growth of GaN films. GaN thin films in the form of polycrystalline were successfully grown on the surface of MoS〈sub〉2〈/sub〉 layers. From the surface analysis, CVD technique provided an amorphous and rougher MoS〈sub〉2〈/sub〉 surface for the MBE growth. On the contrary, PLD supplied a better in-plane and smoother surface for GaN growth which included more stability of surface chemical composition, higher crystallinity and better near-band-edge emission property. To compare with the growth on c-Sapphire, however, the van der Waals expitaxial growth of single-crystalline GaN films on sp〈sup〉2〈/sup〉 bonded 2D MoS〈sub〉2〈/sub〉 is still a challenge. The growth of GaN films on sp〈sup〉3〈/sup〉 bonded c-sapphire still performed the best results in the report. In summary, we demonstrate better growth of GaN thin films on 2D MoS〈sub〉2〈/sub〉 surface provided by PLD. The hetetrostructure of 3D GaN on 2D MoS〈sub〉2〈/sub〉 semiconductors could be useful in the future applications of electronic and optoelectronic devices.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Kyung Pyo Hong, Kyu Hyun Lee, Jungtae Nam, Kyoung Soo Kim, Sung Hee Kim, Boram Kim, Kisoo Kim, Jin Sung Park, Jun Young Lee, Taehwan Jeong, Young Jae Song, Jun Yeon Hwang, Jae Boong Choi, Seungmin Cho, Keun Soo Kim, Hyeongkeun Kim〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The present study investigates the atomic layer deposition (ALD) of an Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 film on graphene atop copper with water vapor (H〈sub〉2〈/sub〉O), oxygen plasma (O〈sub〉2〈/sub〉 plasma) and ozone (O〈sub〉3〈/sub〉) serving as oxidants. With water vapor as an oxidant, surface-sensitive deposition results in significant differences in growth on single layer graphene (SLG) and multilayer graphene (MLG). Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 completely covers areas of SLG, while virtually no Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 is deposited on areas of MLG. The MLG areas are removed by O〈sub〉2〈/sub〉 plasma, and exposed copper areas are oxidized. Information about MLG, including the location, size, and density, can be determined by employing optical microscopy. Scanning electron microscopy (SEM), Raman spectroscopy, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) are used to confirm the validity of the surface-selective deposition of Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 on graphene grown on copper. We developed a process to distinguish SLG and MLG on copper. The characterization results were fed back to the synthesis conditions, and we confirmed that high-quality SLG can be grown on copper almost devoid of MLG. This characterization technique is suitable for large-area graphene (up to meter scale graphene), and can be utilized as feedback for growth and process conditions to ensure high-quality graphene.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324110-ga1.jpg" width="380" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Jae-Yup Kim, Woonhyuk Baek, Soyoung Kim, Gumin Kang, Il Ki Han, Taeghwan Hyeon, Minwoo Park〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Extensive studies have been performed to improve the environmental stability of perovskite solar cells (PSCs) with the use of inorganic charge transport layers (CTLs). However, for 〈em〉n〈/em〉-i-〈em〉p〈/em〉 structures, it is difficult to deposit 〈em〉p〈/em〉-type inorganic nanocrystals onto perovskites to form the CTLs because they are usually prepared in polar solvents. In this regard, hydrophobic nanoparticles dispersed in nonpolar solvents would be beneficial for their deposition onto the perovskites, thus leading to the formation of a hole transport layer (HTL). In this work, we report on the preparation of monodispersed CuIn〈sub〉1.5〈/sub〉Se〈sub〉3〈/sub〉 (CISe) quantum dots (QDs) (diameter = 4 nm) for the design of PSCs based on all-inorganic CTLs. By means of efficient hole injection and transfer process through the CISe-HTLs, impressive power conversion efficiencies (PCEs) of 13.72% and 12.19% for active areas of 0.12 cm〈sup〉2〈/sup〉 and 1.0 cm〈sup〉2〈/sup〉 are achieved, respectively, and the devices exhibit hysteresis-less behaviors. Furthermore, the devices show excellent PCE retentions of 89.2% and 74.9% after 30 d relative to their initial values at relative humidity of 25% and 50%, respectively. The hydrophobic QDs effectively suppress the penetration of moisture such that the device maintains its stability in humid environments.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Mohammad Amin Razmjoo Khollari, Mohammad Ghorbani, Abdollah Afshar〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Preparing a selective, efficient, and low-cost solar absorber is one of the main challenges in solar to thermal energy conversion. In this paper, black electroless Ni〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉P (ENi-P) solar absorber has been fabricated, and the effect of nanoporous TiO〈sub〉2〈/sub〉 antireflection layer (ARL) on its optical and corrosion properties has been investigated. The optimum black coating was obtained by blackening in 9 M nitric acid solution at 50 °C for 40 s, in which a solar absorptance of 99.3% was achieved. Deposition of TiO〈sub〉2〈/sub〉 ARL increased the solar absorptance of coating to 99.7% and addition of 0.8 g Pluronic F127 (F127) as pore former, further increased this value to 99.9% and solar-to-heat efficiency of the coating from 78.1 to 78.7%. F127 added coatings exhibited elongated and irregularly shaped pores with dimensions of a few tens of nanometers. Also, deposition of TiO〈sub〉2〈/sub〉 ARL decreased the corrosion current density (i〈sub〉corr〈/sub〉) of black ENi-P coating in 3.5 wt% NaCl solution from 20 to 4 μA/cm〈sup〉2〈/sup〉. The results of this work indicate that the TiO〈sub〉2〈/sub〉 deposited black ENi-P coating can be a suitable choice for black coating applications.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Reduction in unwanted light reflection from black ENi-P solar absorber by deposition of TiO〈sub〉2〈/sub〉 ARL that leads to increase in solar-to-heat conversion efficiency.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324298-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Leijie Sun, Manman Ding, Jie Li, Li Yang, Xun Lou, Zijian Xie, Wenfeng Zhang, Haixin Chang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Two dimensional layered materials show great potential in memristor applications. MoTe〈sub〉2〈/sub〉 shows unique properties and is an important 2D material. However, MoTe〈sub〉2〈/sub〉- based memristor has been rarely studied so far. Herein, a facile method is developed to control phase in large area MoTe〈sub〉2〈/sub〉 and MoTe〈sub〉2-x〈/sub〉O〈sub〉x〈/sub〉/MoTe〈sub〉2〈/sub〉 heterostructures by precursor thickness in chemical vapor deposition. The memristive behavior of MoTe〈sub〉2〈/sub〉 is highly influenced by phase and oxidization states in MoTe〈sub〉2-x〈/sub〉O〈sub〉x〈/sub〉/MoTe〈sub〉2〈/sub〉 heterostructures. The original 2H and 1 T’ MoTe〈sub〉2〈/sub〉 doesn't have memristive property while the surface oxidized 2H-MoTe〈sub〉2〈/sub〉 based MoTe〈sub〉2-x〈/sub〉O〈sub〉x〈/sub〉/MoTe〈sub〉2〈/sub〉 heterostructures behave excellent and stable memristive behavior for at least 3000 cycles. 1 T’ -MoTe〈sub〉2〈/sub〉 based heterostructures still show no memristive behavior. In addition, we compare the effect of metal electrode (Ag electrode and Al electrode) on heterostructures based memristor. The pulse tests about memristor from oxidized 2H-MoTe〈sub〉2〈/sub〉 based heterostructures show a good mimic of biological synapses in neuromorphic system.〈/p〉〈/div〉 〈/div〉