A molecular simulation study on adsorption of acetone/water in mesoporous silicas modified by pore surface silylation
A molecular simulation study on adsorption of acetone/water in mesoporous silicas modified by pore surface silylation
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DOI：
10.1252/jcej.38.999
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发表时间：
2005-12-01
影响因子：
0.8
通讯作者：
Nakano, M
中科院分区：
文献类型：
--
作者：
Furukawa, S;Nishiumi, T;Nakano, M
两种类型的分子模拟技术已被用于研究表面改性对具有六方均匀孔结构的介孔二氧化硅中丙酮/水吸附的影响：NVT系综分子动力学技术与熔融淬灭算法模拟非硅烷化介孔二氧化硅（011表面模型）和完全甲硅烷基化的中孔二氧化硅（FS表面模型），以及用于计算吸附等温线的μ VT-系综定向偏置蒙特卡罗方法。一个很好的协议之间获得的模拟和实验纯丙酮和水的吸附在298 K的非硅烷化和硅烷化的介孔二氧化硅。丙酮和水的等逸度混合物的平衡吸附密度计算的OH和FS表面模型，通过指定的混合物的气相或液相。在FS表面模型中，从液体混合物中的吸附获得了相当大的分离因子，7300，虽然吸附量相当小，这解释了为什么通过高度硅烷化的介孔二氧化硅膜的渗透蒸发是有效的有机/水混合物的分离。
Two types of molecular simulation techniques have been utilized to investigate surface modification effects on adsorption of acetone/water in mesoporous silicas with a hexagonal uniform pore structure: the NVT-ensemble Molecular Dynamics technique with the melt-quench algorithm for modeling a nonsilylated mesoporous silica (an 011 surface model) and a fully silylated mesoporous silica (an FS surface model), and the mu VT-ensemble Orientational-Bias Monte Carlo method for calculating adsorption isotherms. A good agreement was obtained between simulations and experiments for adsorption of pure acetone and water at 298 K on non-silylated and silylated mesoporous silicas. Equilibrium adsorption densities of the equi-fugacity mixture of acetone and water are calculated for the OH and FS surface models, by specifying either the gas or the liquid phase for the mixture. A considerably large separation factor, 7300, was obtained for the adsorption from a liquid mixture in the FS surface model, though the adsorption amount was rather small, which explains why the pervaporation through highly silylated mesoporous silica membranes was effective for separation of organic/water mixtures.