The Study Of Imidazle Ionic Liquids Adsorpted By Mesoprous Silica Adsorbent

With the advancement of industrialization process of ionic liquids, it not only brings the development of science and technology, but also causes a series of environmental problems, meanwhile its processing technology has been obtained extensive research of scholars both in domestic and overseas. Traditional removal methods of ionic liquids have some limitations, such as the removal effect of low concentration ionic liquid is not ideal, while it can be effectively solved by adsorption. The mesoporous silica is a novel adsorption material owing to its uniform and easily-controlled pores, high surface area, easily-modified surface at the present. So the mesoporous silica is used as the adsorbent for imidazole ionic liquid adsorption study by a series of characterization methods in this article,which mainly contains three parts as following:Use CTAB and P123 as template agents prepared MCM-41 and SBA-15 mesoporous silica materials respectively. It was found that the adsorption of [Bmim]Cl reached equilibrium around approximately 150 min by them; With increasing of the dose of adsorbent, it’s adsorption capacity fell sharply; The process is exothermic reaction, that heating is not benefite with it; The result of the equilibrium adsorption isotherm model fitting the data shows that Langmuir and Freundlich model can both effectively describe the adsorption behavior in [Bmim]Cl,and the maximum adsorption capacity of MCM-41 and SBA-15 are 56.24 mg/g and 336.70 mg/g respectively. It can be inferred that the larger of the silica channels’ diameter, the higher of the adsorption quantity in ionic liquids, when the reactions do not contain chemical adsorption.SBA-15 C used to be the adsorbent of [Bmim]Cl and [Bmim]OH ionic liquids by grafting carboxyl onto the surface of SBA-15. The results found that its pore diameters and volumes were decrease as the space were occupied by organic groups which compared with SBA-15. These two kinds of ionic liquids adsorption equilibrium time was also 150 min with SBA-15 C. Temperature has significantly influence on adsorption that the higher temperature could reduce the adsorption quantity. Because of the carboxyl on the SBA-15C’ surface had chemical action with the hydroxyl of [Bmim]OH that it made SBA-15 C has a better adsorption effect on [Bmim]OH instead of [Bmim]Cl, and the maximum of the former was up to 313.48 mg/g already.A kind of mixed template agent(CTAB and Brij97) was used to synthesis the Worm-like mesoporous silica CB, which was applied to the study of the adsorption effects with different length of alkyl chains of imidazole ionic liquids. The [Pmim]Cl, [Bmim]Cl, [Pnmim]Cl, [Omim]Cl and [PhCH2mim]Cl were used as adsorbates in this article, and the experimental results showed that CB reached adsorption equilibrium in a very short of time to the several kinds of ionic liquids. At the temperature of 35℃, it catched the maximum adsorption quantity of each ionic liquid. Analoging the experimental datas, CB showed the best adsorption effect on [Pnmim]Cl.