铝离子与聚硅酸的相互作用

本文应用核磁共振技术及化学分析方法研究了铝离子与聚硅酸之间的相互作用情况;借助于微电泳技术测定了含铝离子的聚硅酸絮凝剂在不同pH值条件下水解沉淀物的表面ζ电位变化情况;借助于透射电镜手段及静置观察方法考察了铝离子含量对聚硅酸胶凝作用的影响。实验结果表明,聚硅酸对铝离子具有一定的螯合(络合)和吸附作用,但二者之间不存在定量的作用关系,而是聚硅酸对铝离子的作用量随着铝离子含量的增加而增加。铝离子影响聚硅酸的胶凝时间,适量的铝离子的存在可延长聚硅酸的胶凝时间。聚硅酸的存在影响铝离子在不同pH值下的水解沉淀物的ζ电位值,使得达到零电位状态时的pH值向低pH值方向移动。

INTERACTION BETWEEN ALUMINIUM ION AND POLYSILICIC ACID

Pclysilicic acid containing aluminium ion is a new flocculant. The inte-raction between aluminium ion and polysilicic acid is studied with two methods, involving nuclear magnetic resonance, and chemical analysis, respectively. The particle size of silica sols is observed by transmission electron microscope(TEM). The effect of aluminium ion on the time of gelation of polysilicic acid is investigated. The Zeta potential ?of hydrolyzate of polysilicic acid containing aluminum ion under different pH value is measured. The experimental results indicate that there is bond action between aluminium ion and polysilicic acid. The rate of polymerization of polysilicic acid increases in the present of appropriate amount of aluminium ion. Polysilicic acid has a influence on the Zeta potential ?of hydrolysis precipitate product of aluminium sulfate. Compared with the hydrolysis precipitate product of aluminium sulfate, that of polysilicic acid containing aluminium ion, in which Al3+/SiO2 molar ratio is 1.0, gives zero Zeta potential in lower pH value.