Petru Poni Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda, 41A, 700487 Iasi, Romania.
J Hazard Mater. 2011 Sep 15;192(3):1009-16. doi: 10.1016/j.jhazmat.2011.06.002. Epub 2011 Jun 12.
New thermosensitive polysaccharide (P-g-pNIPAAm) was synthesized by graft-polymerization of p(N-isopropylacrylamide) (pNIPAAm) onto pullulan (P) using Ce(IV) ion as initiator. The grafted polysaccharide was characterized by FT-IR and (1)H NMR spectroscopy and elemental analysis. Its flocculation efficiency was studied in a clay suspension, in comparison with p(NIPAAm) homopolymer, as a function of the polymer dose, temperature and settling time. The thermosensitive polysaccharide could induce clay particle flocculation both below and above the lower critical solution temperature (LCST), but the process was more effective above the LCST. A lower value of the residual turbidity at the optimum polymer dose and a wider flocculation window were recorded at temperature above the LCST. The floc size distribution and surface morphology revealed bigger size flocs when the flocculation was performed above the LCST. The re-dispersion effect was negligible for the flocs obtained in the presence of P-g-pNIPAAm.
新型温敏多糖（P-g-pNIPAAm）通过 Ce(IV) 离子引发的 p(N-异丙基丙烯酰胺)（pNIPAAm）接枝到普鲁兰（P）上合成。通过傅里叶变换红外光谱（FT-IR）和（1）H 核磁共振光谱（NMR）以及元素分析对接枝多糖进行了表征。研究了其在粘土悬浮液中的絮凝效率，与 p(NIPAAm) 均聚物进行了比较，考察了聚合物剂量、温度和沉降时间的影响。该温敏多糖在低于和高于低临界溶液温度（LCST）下均能诱导粘土颗粒絮凝，但在 LCST 以上时，该过程更为有效。在 LCST 以上的温度下，在最佳聚合物剂量下的残余浊度值较低，絮凝窗口较宽。通过测量絮体的尺寸分布和表面形态，发现在 LCST 以上时形成的絮体更大。在 P-g-pNIPAAm 存在下获得的絮体几乎没有再分散作用。
