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研究了三种摩尔质量大体相同而脱乙酰度分别为93%、78%和62%的甲壳素-壳聚糖在pH=3～6范围内对皂土悬浮液的絮凝性质,并与非离子型絮凝剂聚丙烯酰胺作了比较,证明含自由氨基的甲壳素-壳聚糖在酸性溶液中形成阳离子聚电解质后.对带负电的皂土悬浮颗粒有很好的絮凝能力.通过对上述三种聚合物的絮凝能力、在皂土颗粒表面的吸附量等测定,认为絮凝中桥连机制起了主导作用,但聚合物所带正电荷则有利于被皂土颗粒所吸附,电中和还降低了颗粒间的静电排斥,这都对桥连絮凝起了促进作用.聚丙烯酰胺分子在水中不带电,故当介质pH 升高使皂土颗粒双电层变厚时,絮凝能力迅速下降.
The flocculation properties of three bentonite suspensions at pH = 3 ~ 6 were studied for three kinds of chitin-chitosan with the same molar mass and 93%, 78% and 62% deacetylation respectively. Flocculant polyacrylamide was compared to prove that free amino-containing chitin - chitosan in acidic solution to form a cationic polyelectrolyte on the negatively charged bentonite suspended particles have good flocculation capacity.Through the above three The flocculation ability of polymers, adsorption on the surface of bentonite particles, etc., suggest that bridging mechanism plays a leading role in the flocculation. However, the positive charge of the polymer is favored by the bentonite particles, Reduce the electrostatic repulsion between the particles, which all play a role in promoting the bridging flocculation.Polyacrylamide molecules are not charged in water, so when the pH of the medium is increased so that the double layer of bentonite particles becomes thick, the flocculation ability drops rapidly.