Solvent-induced molecular gel formation at room temperature and the preparation of related gel-emulsions  

作　　者：JING Ping YAN JunLin CAI XiuQin LIU Jing HU BaoLong FANG Yu 

机构地区：[1]Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education [2]School of Chemistry and Chemical Engineering, Shaanxi Normal University

出　　处：《Science China Chemistry》2013年第7期982-991,共10页中国科学（化学英文版）

基　　金：supported by the Natural Science Foundation of China(20927001, 91027017 and 21273141);by the "13115" project of Shaanxi Province (2010ZDKG-89);supported by"Program for Changjiang Scholars and Innovative Research Team in University" of China (IRT1070)

摘　　要：The gelation behaviors of four recently reported amphiphilic cholesteryl derivatives (1, 2, 3 and 4) have been evaluated. It was found that the gel formation process can be controlled by introduction of water at room temperature. Addition of water to an acetone solution of 4 immediately results in the system becoming turbid, and a gel subsequently forms within a few minutes. Interestingly, 4 is a super-gelator for a mixed solvent of acetone and water at room temperature, in particular when their volume ratio is close to 1:1 at which the critical gelation concentration (CGC) is 0.06% (w/v). It was found that the introduction of water favors the formation of gel networks, and the gel possesses smart and reversible thixotropic properties. FTIR and 1H NMR spectroscopy confirmed that hydrogen bonding is one of the main driving forces for the gelation of the solvents. XRD demonstrated that 4 self-assembled into a layered structure within the acetone-water mixed solvent gel. Furthermore, 1 and 2 can be used as excellent stabilizers for gel emulsions of alkanes and water. The maximum of the dispersed phase, water, in one of the gel-emulsions can be as high as 97% (v/v).The gelation behaviors of four recently reported amphiphilic cholesteryl derivatives （1, 2, 3 and 4） have been evaluated. It was found that the gel formation process can be controlled by introduction of water at room temperature. Addition of water to an acetone solution of 4 immediately results in the system becoming turbid, and a gel subsequently forms within a few minutes. Interestingly, 4 is a super-gelator for a mixed solvent of acetone and water at room temperature, in particular when their vol- ume ratio is close to 1：1 at which the critical gelation concentration （CGC） is 0.06% （w/v）. It was found that the introduction of water favors the formation of gel networks, and the gel possesses smart and reversible thixotropic properties. FTIR and 1H NMR spectroscopy confirmed that hydrogen bonding is one of the main driving forces for the gelation of the solvents. XRD demonstrated that 4 self-assembled into a layered structure within the acetone-water mixed solvent gel. Furthermore, 1 and 2 can be used as excellent stabilizers for gel emulsions of alkanes and water. The maximum of the dispersed phase, water, in one of the gel-emulsions can be as high as 97% （v/v）.

关 键 词：low-molecular mass gelators （LMMGs） CHOLESTEROL gel emulsion super-gelation 

分 类 号：O648.23[理学—物理化学]