Key laboratory of the Three Gorges Reservoir Region's Eco-Environment, State Ministry of Education, Chongqing University, Chongqing, 400045, China; National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing, 400045, China.
Key laboratory of the Three Gorges Reservoir Region's Eco-Environment, State Ministry of Education, Chongqing University, Chongqing, 400045, China; National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing, 400045, China.
Carbohydr Polym. 2018 Feb 1;181:327-336. doi: 10.1016/j.carbpol.2017.10.089. Epub 2017 Oct 26.
A multifunctional carboxylate-rich magnetic chitosan flocculant (Mag@PIA-g-CS) was prepared through surface graft copolymerization on magnetite particles. The effect of monomer molar ratio, initiator and pre-neutralized degree on polymerization rate was determined. Various analytical methods were applied to characterize Mag@PIA-g-CS, exhibiting the successful grafting of polymers, good magnetic feature and core-shell structure. The kinetic process of Ni(II) and malachite green (MG) flocculation by Mag@PIA-g-CS reached equilibrium within <60min with the optimal uptake rate of 98.3% and 87.4%, and exhibited satisfactory removal effect in wide pH range (4.0-8.0 for Ni(II), 5.0-10.0 for MG). Mag@PIA-g-CS exhibited superior flocculation performance over chitosan magnetic flocculant (Mag@CS). The pH-dependent behavior, rapid responsiveness and sensitivity to ionic strength in batch flocculation tests indicated the distinct effect of ionic groups. Moreover, sweeping action of linear molecular chains facilitated further flocculation. Mag@PIA-g-CS showed high stability in extreme environments, and can be easily regenerated and separated.
通过在磁铁矿颗粒表面接枝共聚合成了一种多功能羧酸根丰富的磁性壳聚糖絮凝剂（Mag@PIA-g-CS）。确定了单体摩尔比、引发剂和预中和度对聚合速率的影响。采用各种分析方法对 Mag@PIA-g-CS 进行了表征，表明聚合物成功接枝，具有良好的磁性和核壳结构。Mag@PIA-g-CS 对 Ni(II)和孔雀石绿（MG）的絮凝动力学过程在 <60min 内达到平衡，最佳吸附率分别为 98.3%和 87.4%，并在较宽的 pH 范围内（Ni(II)为 4.0-8.0，MG 为 5.0-10.0）表现出良好的去除效果。Mag@PIA-g-CS 的絮凝性能优于壳聚糖磁性絮凝剂（Mag@CS）。在批量絮凝试验中，pH 依赖性、快速响应性和对离子强度的敏感性表明离子基团的明显影响。此外，线性分子链的扫动作用促进了进一步的絮凝。Mag@PIA-g-CS 在极端环境下表现出高稳定性，且易于再生和分离。
