黑膜厚度与膜表面张力关系的研究

用微干涉测量技术直接测定楔压等温线，研究了电解质浓对阳离子表面活性剂ＴＴＡＢ在浓度大于cmc时形成黑膜厚度的影响及膜表面张力与溶液表面张力之间的差别，结果显示，黑膜厚度取决于楔压和电解质浓度，随着楔压的增加，液膜厚度减少至一定程序后几乎保持不变，表明膜类型的转化是阶跃式的，而电解质屏蔽了液膜两个表面电荷层是的排斥作用，故电解质浓度增加，液膜厚度变小，由楔压等温线得出的膜表面张力的结果说明一般黑膜的表面张力与溶液的表面张力并无明显差别。

Studies on the Relation of Black Film Thickness and Film Tension

This paper covers the method of direct measurement of the disjoining pressure isotherm for sing, isolated foam films stabilized with TTAB above cmc by microinterferometric technique. It has been studied that the relation of disjoining pressure and film thickness, and the difference between the surface tension of solution and that of the common black film under different liquid film thickness conditions. The experimental results show that common black film thickness depends on the disjoining pressure and electrolytic concentration. At a low disjoining pressure, the film thickness decreases with the increase of the disjoining pressure. At a high disjoining pressure, the film thickness decreases slightly with the increase of the disjoining pressure. This signifies that the transition between black films is jumping. The electrolyte can reduce the interaction forces between two charged monolayers of film and thin the film, so the equilibrium thickness of film decreases with increasing electrolyte concentration of the solution from which they are formed. The surface tension of common black film calculated from the disjoining pressure isotherm is slightly different from the surface tension of solution.