官能团化MCM-41在分离低碳醇-水混合物中的应用

采用一步法水热合成了介孔材料氯丙基官能团化的MCM-41(Cl(CH2)3-MCM-41)、氨丙基官能团化MCM-41(NH2(CH2)3-MCM-41)、甲基官能团化MCM-41(CH3-MCM-41)和氯丙基官能团化硅胶,并考察了它们作为气相色谱固定相分离低碳醇-水混合物的情况。实验结果表明,Cl(CH2)3-MCM-41能够分离低碳醇-水混合物中的各组分,随水、甲醇、乙醇、异丙醇、正丁醇极性的减小,各分子与Cl(CH2)3-MCM-41的作用力增强,保留时间延长。氯丙基官能团化硅胶、NH2(CH2)3-MCM-41)和CH3-MCM-41均不能分离低碳醇-水混合物,表明介孔材料规则的孔道结构、表面嫁接基团等对低碳醇-水混合物的分离有重要影响。同时考察了Cl(CH2)3-MCM-41的氯丙基负载量对低碳醇-水混合物分离效果的影响,结果表明,当氯丙基的摩尔分数为15%时,分离效果最佳。

Applications of Functionalized MCM-41 to Separation of Lower Alcohols-Water Mixture

Chloropropyl-modified MCM-41,aminopropyl-modified MCM-41,methyl-modified MCM-41 and chloropropyl-modified silica were separately prepared by one step hydrothermal method and used as stationary phases of gas chromatographic columns for separation of lower alcohols-water mixture.Chloropropyl-modified MCM-41 is good in high efficiency for separation.The separation order is highly consistent with polarity of lower alcohols and water.With decreasing of alcohol polarities,the attraction between stationary phase and alcohols increase gradually and retention time prolong.Chloropropyl-modified silica,aminopropyl-modified MCM-41 and methyl-modified MCM-41 failed to meet the aim.The fact illustrates that ordered nano-pores and organic groups incorporated to the supports greatly affect the separation.Optimal loading of chloropropyl groups on pore wall of MCM-41 was also investigated.When mole fraction of chloropropyl groups anchored onto pore wall of MCM-41 is 15%,its separation efficiency is the highest.