CTAB在硅胶表面吸附引起的润湿性变化和模拟驱油

用椭圆偏振法测定溴代十六烷基三甲胺（CTAB）水溶液在光滑的二氧化硅膜片上的吸附，其结果符合两阶段模型，即在不同浓度下发生单分子层和近似双分子层的吸附，并与其表面润湿性变化的数据吻合.用改进的Washburn方程测量改性硅胶粉末的润湿性, 研究了CTAB水溶液在硅胶粉末表面上吸附引起的润湿性变化.并由此探讨了CTAB水溶液在硅胶粉末表面的润湿性,表面活性剂的临界胶束浓度（CMC）与表面含油粉末脱油率的关系，对在非超低界面张力条件下通过改变固/液界面润湿性提高原油采收率作了实验探讨.

Wettability Changes by CTAB Adsorption at Surfaces of SiO2 Film or Silica Gel Powder and Mimic Oil Recovery

The adsorption of cetyl trimethylammonium bromide (CTAB) at a smooth surface of SiO2 film was determined by ellipsometry. The result is in agreement with a two steps model. Its monolayer and bilayer adsorption occurred at different concentrations. The adsorption is consistant with the wettability change of the film surface. The wettability of a silica gel powder was determined by a modified Washburn equation expressed as contact angles. The interfacial tension (γ) between the dodecane and the dilute CTAB aqueous solution was obtained using the pendant method. The relationship between the wettability of the powder surface, the critical micelle concentration (CMC) of CTAB and the mimic oil recovery of the resident oil on the powder surface has been explored. It has been found that good residual oil could be achieved by surface wettability changes at normal interfacial tensions (100～102 mN?m－1) and no formation of emulsion (see Table 4).