包合作用降低十六烷基三甲基溴化铵在黏土上的吸附

Reduction of Clay Adsorption of Cetyl Trimethyl Ammonium Bromide by Inclusion Complexation

固定十六烷三甲基溴化铵（CTAB）浓度为0．15mmol／L，改变辟环糊精（β-CD）浓度，测定了β-CD／CTAB混合水溶液30℃时的表面张力，由表面张力升高段与稳定段的拐点，求出水溶液中β-CD-CTAB包合物的包合比为1．53：1。通过红外光谱确认了该包合物的存在。测定不同浓度的该包合物溶液与钠基蒙脱土相互作用8小时后的表面张力，由CTAB溶液表面张力～溶液浓度曲线求得吸附后包舍物溶液中CTAB浓度，取为吸附平衡浓度，并计算蚴在钠基蒙脱土上的吸附量，构建包合物溶液中CTAB的吸附等温线，与采用相同方法求得的CTAB的溶液吸附等温线相比，CTAB的饱和吸附量降低75％。讨论了有关的机理。此结果为阳离子表面活性剂用作驱油剂提供了新思路。图7参7。

The surface tension of β-cyclodextrin （β-CD）/cetyl trimethyl ammonium bromide （CTAB） mixed aqueous solution was measured at 30℃ with varying CTAB concentration at constant β-CD concentration 0.15 mmol/L and the stoichiometric ratio of the host-guest, β-CD-CTAB, inclusion complex was determined from the inflection point of surface tension curve from raising section to steady section, being of 1.53 ： 1. The inclusion complex was confirmed structurally by IR-spectrometry. For a series of inclusion complex solution of varying concentration after adsorption of CTAB from solution onto Na-montmoriUonite performed at 30℃ in 8 hrs, their surface tension was measured, corresponding CTAB concentration remaining in solution was found by using a surface tension vz CTAB concentration curve and was taken as as orption-desorption equailibrium CTAB concentration and thus the adsorption amount of CTAB on rnontmoriUonite was found and an adsorption isotherm for CTAB from its inclusion complex solution was constructed. The saturation adsorption on this isotherm was by 75 % lower than that of CTAB from its single solution found by a similar way. The mechanisms involved were discussed. This experimental result might serve as a way of using cationic surfaetants in EOR.