Wu Liang, Zhang Xingrong, Chen Long, Zhang Huan, Li Chengbi, Lv Yin, Xu Yisheng, Jia Xin, Shi Yulin, Guo Xuhong
Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University Shihezi 832003 P. R. China
State Key Laboratory of Mineral Processing Beijing 102628 China.
RSC Adv. 2018 Jan 3;8(3):1274-1280. doi: 10.1039/c7ra12798g. eCollection 2018 Jan 2.
A pH-responsive amphoteric starch derivative (PRAS) bearing dual functional groups (amino and carboxyl groups) was prepared through etherification of starch with 2-chloro-4,6-diglycino-[1,3,5]-triazine. PRAS exhibits a reversible pH-response property in aqueous solution. The attractive property of PRAS is that it could be used as an effective flocculant for heavy metal-ion ( Cu(ii) and Zn(ii)) removal from wastewater by changing pH. The transition of hydrophobicity-hydrophilicity would produce shrinkage of the polymer matrix, facilitating the release of heavy-metal ions from the saturated flocculant. As an ideal flocculant PRAS displayed outstanding stability and reproducibility, whose remove rate for Cu(ii) and Zn(ii) remained at 93% and 91% after three flocculation/regeneration cycles.
通过淀粉与2-氯-4,6-二甘氨酰基-[1,3,5]-三嗪的醚化反应制备了一种带有双官能团（氨基和羧基）的pH响应性两性淀粉衍生物（PRAS）。PRAS在水溶液中表现出可逆的pH响应特性。PRAS的吸引人之处在于，通过改变pH值，它可以用作从废水中去除重金属离子（Cu(ii)和Zn(ii)）的有效絮凝剂。疏水性-亲水性的转变会导致聚合物基质收缩，促进饱和絮凝剂中重金属离子的释放。作为一种理想的絮凝剂，PRAS表现出出色的稳定性和可重复性，在三个絮凝/再生循环后，其对Cu(ii)和Zn(ii)的去除率分别保持在93%和91%。
