ALBERT

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Xihao Pan, Gancheng Zuo, Ting Su, Siyao Cheng, Yufan Gu, Xiaoliang Qi, Wei Dong〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Magnetic particle is a promising class of materials to absorb harmful contaminants for their easy collecting property with magnetic response. Here, we report a novel kind of polycarboxylic magnetic polydopamine sub-microspheres (Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@PDA-COOH) facilely synthesized by coating polydopamine (PDA) onto the surface of magnetic nanocrystal clusters (Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉). Then the sub-microspheres were modified with mercaptosuccinic acid (MSA) to have polycarboxylic groups on their surface. Fourier transform infrared spectroscopy (FT-IR) was used to demonstrate the desired chemical structure. The unique morphology and particle size distribution were confirmed by Transmission electron microscopy (TEM). Malachite green (MG) was used as a model to test the adsorption capacity of the magnetic sub-microspheres. Besides, factors such as initial MG concentration, initial solution pH, and contact time were systematically studied for this adsorption process. Results showed that the maximum adsorption capacity of Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@PDA-COOH could reach up to 331.0162 mg/g (MG/ sub-microspheres), much higher than that of Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@PDA. The adsorption kinetics and adsorption isotherms could be well described by pseudo-second-order kinetic model and Freundlich isothermal model. Moreover, Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@PDA-COOH sub-microspheres can retain the high adsorption ability after five using-cycles. Therefore, the synthesized Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@PDA-COOH can be a high-efficiency adsorbent in the field of wastewater treatment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718313177-ga1.jpg" width="296" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉