| 介孔SiO2气凝胶的常压干燥制备研究 |
| Synthesis of Mesoporous Silica Aerogels via Ambient Pressure Drying |
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| 摘要: 以廉价的水玻璃为硅源，用乙醇(EtOH) / 三甲基氯硅烷(TMCS) / 庚烷(Heptane)溶液对湿凝胶进行改性，采用一种新的常压干燥工艺合成了SiO2气凝胶。通过TMCS与乙醇、湿凝胶孔隙水及Si-OH基团之间的反应，使湿凝胶的溶剂交换和表面改性得以在一步完成。所合成的SiO2气凝胶为轻质透明的块状固体，密度为0.128～0.136 g·cm-3，孔隙率93.8%～94.2%。利用FTIR、SEM、TEM和BET吸附对气凝胶的微观结构、形貌和性质进行了研究。结果表明，气凝胶为海绵状结构，粒子直径和孔径分布均匀，比表面积559～618 m2·g-1，表面带有较多的Si-CH3基团，呈现出明显的疏水性。 |
| 关键词: 水玻璃 常压干燥 SiO2气凝胶 溶剂交换-表面改性 |
| 基金项目: |
| Abstract: Using cheap waterglass as silica source, silica aerogels were synthesized via a novel fast ambient drying by using EtOH / TMCS / Heptane solution for modification of the wet gel. One-step solvent exchange and surface modification of wet gel were accomplished by reaction of trimethylchlorosilane (TMCS) with ethanol, pore water and Si-OH group in the wet gel. The synthesized silica aerogel was a light and crack-free solid, with a density of 0.128～0.136 g·cm-3 and porosity of 93.8%～94.2%. The microstructure, morphology and properties of the aerogels were studied by FTIR, SEM, TEM and BET measurement. The results indicate that silica aerogels exhibit a sponge structure with narrow particle and pore size distribution. The specific surface area of silica aerogels is in the range of 559～618 m2·g-1. Strong hydrophobicity is the characteristics of silica aerogel, and there is obvious Si-CH3 group on the surface of silica aerogel. |
| Keywords: waterglass ambient pressure drying silica aerogel solvent exchange / surface modification |
| 投稿时间：2005-04-02 修订日期：2005-07-19 |
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| 史非,王立久,刘敬肖,曾淼.介孔SiO2气凝胶的常压干燥制备研究[J].无机化学学报,2005,21(11):1632-1636. |
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