气相SiO_2在硫酸介质中的胶凝作用  

Gelation of fumed silica in sulfuric acid medium

作　　者：郑欧[1,2] 蔡晓祥[2] 万南红[1] 

机构地区：[1]福州大学化学化工学院化学系,福建福州350108 [2]超威电源有限公司新能源技术研究院,浙江长兴313100

出　　处：《蓄电池》2012年第1期7-11,共5页Chinese LABAT Man

基　　金：福州大学科技发展基金(2008-XQ-09)资助项目;福州大学人才基金(XRC-0820)资助项目

摘　　要：本文考察了气相SiO2在硫酸中的凝胶化行为,包括了相图的绘制,气相SiO2分散表观粒径(d)、气相SiO2质量分数()和温度(T)对气相SiO2在硫酸中分散体系的凝胶时间的影响(tgel)。在给定的温度下,当分散体系中气相SiO2与H2SO4两者的质量分数满足关系式(/%).(/%)≥96时,体系才有可能生成凝胶;、、T的增大以及d的增大均缩短了体系的胶凝时间,此外tgel与T之间关系满足Arrenhinus公式lntgel=lnK+Ea/RT(其中K为常数,Ea为凝胶的表观活化能),在考察的温度范围内求得Ea为值35.6 kJ/mol,从动力学方面证明了温度的升高加速了气相SiO2在硫酸中的凝胶作用。Abstract： In this paper, the gelation behavior of fumed silica in sulfuric acid medium was studied, which included the phase diagrams and the effects on gelled time （tgel）, such as the apparent size of Si02 （d）, content of fumed silica （WSiO2）, temperature （7）, and so on. The results showed that at 25 ℃, when the concentrations of both SiO2 and H2SO4 satisfied the relations （WSiO2/%）·（WH2SO/%） 〉196, the SiOJH2SO4dispersion is possible to form gel. The gelled time of SiOJH2S04 dispersion would be shorted with the value increase of d, WSiO2, WH2SO4 and T respectively. In addition, the relationship between tgel and T satisfied Arrenhinus formula, and the value of Ea is 35.6 kJ/mol in the temperature range of the investigation, so that it was justified from the dynamic field that the increased temperature would accelerate the gelation of fumed silica in sulfuric acid.

关 键 词：气相SiO2 凝胶时间 表观活化能 胶体电解液 

分 类 号：TQ133.3[化学工程—无机化工]