纳米硅胶多孔层毛细管气相色谱柱的原位溶胶-凝胶法制备及其应用

采用原位溶胶-凝胶法在毛细管内壁上合成出均匀的纳米硅胶多孔层,对纳米硅胶颗粒进行了形貌表征,同时考察了不同反应条件下合成的纳米硅胶的比表面积、孔容和孔径的变化规律。先采用含氢硅油高温键合固化硅胶层，然后用无机盐淋洗钝化毛细管色谱柱,制备出纳米多孔层硅胶毛细管色谱柱。考察了所制备的纳米多孔层硅胶毛细管色谱柱对挥发性氟氯烃、水中氯代烃、含硫化合物以及低碳烃的分离特性。结果表明:所制备的纳米多孔层硅胶毛细管色谱柱具有良好的分离能力、一定的抗水性、稳定的色谱保留特性和良好的制柱重复性。

In-Situ Sol-Gel Preparation of Nano Silica Porous Layer Capil-lary Columns and Their Applications in Gas Chromatography

A new method is described to prepare nano silica porous layer columns by using in-situ sol-gel synthesis technology. By the interaction of ethyl acetate and water glass solution, the nano silica was synthesized on the inner surface of fused silica capillary. The influence of reaction conditions on the morphology surface area, pore volume and pore size was investigated. The experimental results demonstrate that when the mole ratio of ethyl acetate to silica was 0.82, the particle size of the superfine silica powder was in the range of 25-50 nm, the BET specific surface area was 420 (m~2/g), and the total pore volume was 0.68 (cm~3/g). The nano silica porous layer on the inner surface of fused silica capillary was formed by bonding reactions through cross-linked polysiloxane chains, and deactivated by 1 g/L KCl. The column shows sufficient selectivity, stable retention performance, proper resistance to water, good reproducibility, and (unique) activity. The column is suitable for the analysis of chlorofluorocarbons, halohydrocarbons, sulfur compounds, and light hydrocarbons C_1-C_4.