摘要
以纯硅酸溶液为研究体系,采用紫外/分光光度仪、傅立叶红外光谱仪(FT-IR)分别表征溶液吸光度与凝胶基团,探究纯硅酸溶液的聚合行为,探讨实验条件对纯硅酸胶凝时间的影响。结果表明:在没有金属离子的干扰下,纯硅酸溶液胶凝曲线最高点出现在p H=1.10附近,p H升高,导致硅酸溶胶的形成速率减小,引起溶液吸光度增加;p H<2.27时,随着p H升高,纯硅酸聚合的氧联作用所占比例增加,聚合活化能升高,p H>2.27时,聚合以氧联作用为主,活化能保持在最大值;随着p H升高,纯硅酸凝胶中Si-O-Si反对称收缩振动吸收峰发生红移,是由胶体结构单元[Si O4]4+聚合度的降低导致。
Taking the pure silicic acid solution as research system, the absorbance of pure silicic acid solution and the functional groups of the silica gel were separately characterized by spectrophotometer and IR spectra. The po- lymerization behavior of pure silicic acid solution was studied, and the effect of experimental conditions on its gel time was investigated. It shows that the maximum gel time of pure silicic acid occurs at pH=l. 10. The formation rate of silicic acid sol decreases with the increasing of pH value. The polymerization activation energy of pure si- licit acid increases with the pH value rising as pH 〈 2.27 and keeps to a maximum as pH 〉 2.27. The structural unit of pure silicic acid sol particles is [SiO4]4＋ and the polymerization degree of [SiO4]4＋ decreases with the in- creasing ofpH value. The antisymmetric vibration absorption peak of Si-O-Si moves to lower wavenumbers for the polymerization degree decrease.
出处
《安徽工业大学学报（自然科学版）》
CAS
2015年第4期343-347,共5页
Journal of Anhui University of Technology（Natural Science）
基金
安徽省科技厅项目(1506c085003)
2014年马鞍山市科技计划
关键词
纯硅酸溶液
活化能
胶体
凝胶
聚合
pure acid solution
activation energy
colloid
gel
polymerization
