有盐体系中pH值对硅酸聚合度的影响  

Effect of pH on Polymerization Degree of Silica in Salt System

作　　者：王梅[1] 李辽沙[1] 金霞[1] 李洪花[1] 

机构地区：[1]安徽工业大学安徽省冶金与资源综合利用重点实验室,安徽马鞍山243002

出　　处：《安徽工业大学学报（自然科学版）》2007年第2期143-145,149,共4页Journal of Anhui University of Technology（Natural Science）

基　　金：安徽省自然科学基金项目(050450105)

摘　　要：研究在镁、铝盐存在的环境下,硅酸溶液pH值与所制备的白炭黑比表面积的关系,并探讨相应条件下硅酸的聚合机理。发现:当pH<3.9时,随pH升高,硅酸聚合度减小,且Al3+,Mg2+与高聚硅酸表面硅羟基配位能力减弱,生成的白炭黑比表面积逐渐增大;在pH≈3.9时,聚合度达到最小值;pH>3.9时,Al3+,Mg2+水解,各产物离子的羟基配位能力未达饱和,易与硅酸之间发生配位使聚合度逐渐增大,白炭黑比表面积减小,这种趋势随pH进一步增大而逐步减弱。The relationship between pH of the salt system, which contains silica, Al^3＋ and Mg^2＋, and the specific surface area of silica white was investigated, and the polymerization degree of silica white was discussed. It was discovered that the polymerization degree of silica white decreased as pH was increased when pH 〈3.9. Simultaneously, the specific surface area was decreased due to the weak ability to form complex of Al^3＋ or Mg^2＋. with surface hydroxyl groups of the high polymeric silica. When pH 〉3.9, the hydroxyl of ions, produced by hydrolysis of Al^3＋and Mg^2＋, was prone to react with silica because of their superfluous ability to form complex, which made the polymerization degree increase. The reaction trend was weaken as pH was increased. Therefore the polymerization degree of silica was reached minimum when pH ≈ 3.9.

关 键 词：白炭黑 比表面积 聚合度 PH值 有盐体系 

分 类 号：TB321[一般工业技术—材料科学与工程]