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〉