Madill Evan A W, Garcia-Valdez Omar, Champagne Pascale, Cunningham Michael F
Department of Chemical Engineering, Queen's University, Kingston, ON K7L 3N6, Canada.
Department of Civil Engineering, Queen's University, Kingston, ON K7L 3N6, Canada.
Polymers (Basel). 2017 Aug 26;9(9):394. doi: 10.3390/polym9090394.
Chitosan was chemically functionalized with poly(diethylaminoethyl methacrylate) (PDEAEMA) using a grafting to approach to produce a CO₂-responsive material for adsorbing metals from wastewater streams. A need for improved economical and greener approaches to recover heavy metals from wastewater streams exists due to increasing resource scarcity. Chitosan is currently used as an adsorbent for heavy metals but suffers from some properties that can be disadvantageous to its effectiveness; it is difficult to effectively disperse in water (which limits available surface area) and to regenerate. We set out to improve its effectiveness by grafting CO₂-responsive tertiary amine containing polymers onto the chitosan backbone, with the goals of preparing and assessing a new type of adsorbent based on a novel concept; using carbon dioxide switchable polymers to enhance the performance of chitosan. PDEAEMA chains prepared by nitroxide-mediated polymerization were grafted onto chitosan functionalized with glycidyl methacrylate. In carbonated water, the grafted chitosan displayed improved dispersibility and exhibited a Ni(II) adsorption capacity higher than several other chemically functionalized chitosan variants reported in the literature with the regenerated material having a higher capacity than all physical and chemical derivatives reported in the literature. The results of this study validate the continued development of this material for applications in heavy metal removal and recovery from wastewater streams.
采用接枝法将壳聚糖与聚（甲基丙烯酸二乙氨基乙酯）（PDEAEMA）进行化学功能化，以制备一种用于从废水流中吸附金属的CO₂响应材料。由于资源稀缺性日益增加，需要改进从废水流中回收重金属的经济且更环保的方法。壳聚糖目前用作重金属吸附剂，但存在一些对其有效性不利的性质；它难以在水中有效分散（这限制了可用表面积）且难以再生。我们着手通过将含CO₂响应叔胺的聚合物接枝到壳聚糖主链上来提高其有效性，目标是基于一个新颖的概念制备和评估一种新型吸附剂；使用二氧化碳可切换聚合物来提高壳聚糖的性能。通过氮氧自由基介导聚合制备的PDEAEMA链被接枝到用甲基丙烯酸缩水甘油酯功能化的壳聚糖上。在碳酸水中，接枝的壳聚糖显示出改善的分散性，并且表现出比文献中报道的其他几种化学功能化壳聚糖变体更高的Ni(II)吸附容量，再生材料的容量高于文献中报道的所有物理和化学衍生物。本研究结果验证了该材料在从废水流中去除和回收重金属方面持续开发的可行性。
