炭气凝胶微球的凝胶化机理

The gelation mechanism of carbon aerogel spheres

以间苯二酚和甲醛为原料,溴化十六烷三甲基铵为催化剂,通过反相悬浮聚合法成功制备了炭气凝胶微球。研究了反应体系的黏度、酸度、温度以及反应中间产物紫外光谱的变化情况,探讨该凝胶反应的作用机理。结果表明:凝胶反应是一个酚醛缩合过程,其反应历程可以分为线性缩聚、交联、胶粒生长和宏观凝胶化四个阶段。

Carbon aerogel （CA） spheres were prepared by an inverse phase suspension polymerization of resorcinol and formaldehyde （RF） monomers with hexadecyl trimethyl ammonium bromide as catalyst. The gelation mechanism of RF gel was investigated by analyzing the changes of viscosity, pH, temperature and the UV spectra of the as-formed sol. Results indicate that the gelation of resorcinol and formaldehyde is a condensation polymerization, which can be divided into four stages including linear condensation, cross-linking, growth of colloidal particles and macroscopic gelation.