Horozov T, Arnaudov L
Laboratory of Thermodynamics and Physico-Chemical Hydrodynamics, Sofia University, Faculty of Chemistry, 1 James Bourchier Ave., Sofia, 1126, Bulgaria
J Colloid Interface Sci. 2000 Feb 1;222(1):146-155. doi: 10.1006/jcis.1999.6530.
The adsorption kinetics of Triton X-100 and Triton X-405 at solution/air and solution/hexane interfaces is studied by the recently developed fast formed drop technique. The dynamic interfacial tension of Triton X-100 and Triton X-405 solutions against hexane has been measured without preequilibration of the water and oil phases. It is found that the dynamic interfacial tension of Triton X-100 solutions passes through a minimum. This strange behavior is attributed to partial solubility of the surfactant in hexane. Such minima of the dynamic interfacial tension of Triton X-405 solutions have not been observed, which correlates well with the solubilities of both surfactants in hexane reported in the literature. The dynamic surface tension of solutions of both surfactants and the dynamic interfacial tension of Triton X-405 solutions are interpreted by the Ward and Tordai model for diffusion controlled adsorption. It is shown that proper interpretation of the experimental data depends on the type of isotherm used. More consistent results are obtained when the Temkin isotherm is used instead of the Langmuir isotherm. The results obtained with Triton X-100 at the solution/air interface confirm that the adsorption of this surfactant occurs under diffusion control. The adsorption of Triton X-405 at solution/air and at solution/hexane interfaces seems to occur under diffusion control at short periods of time, but under mixed (diffusion-kinetic) control at long periods of time. A hypothesis is drawn to explain this phenomenon by changes in the shape of the large hydrophilic heads of Triton X-405 molecules. Copyright 2000 Academic Press.
采用最新开发的快速形成液滴技术，研究了Triton X - 100和Triton X - 405在溶液/空气以及溶液/己烷界面的吸附动力学。在水相和油相未预先平衡的情况下，测量了Triton X - 100和Triton X - 405溶液与己烷之间的动态界面张力。发现Triton X - 100溶液的动态界面张力会经过一个最小值。这种奇怪的行为归因于表面活性剂在己烷中的部分溶解性。未观察到Triton X - 405溶液动态界面张力的这种最小值，这与文献中报道的两种表面活性剂在己烷中的溶解度很好地相关。两种表面活性剂溶液的动态表面张力以及Triton X - 405溶液的动态界面张力，都用Ward和Tordai扩散控制吸附模型来解释。结果表明，对实验数据的正确解释取决于所使用的等温线类型。使用Temkin等温线而非Langmuir等温线时，能得到更一致的结果。在溶液/空气界面用Triton X - 100得到的结果证实，这种表面活性剂的吸附是在扩散控制下发生的。Triton X - 405在溶液/空气和溶液/己烷界面的吸附，在短时间内似乎是在扩散控制下发生，但在长时间内是在混合（扩散 - 动力学）控制下发生。提出了一个假设，通过Triton X - 405分子大亲水头部形状的变化来解释这一现象。版权所有2000年，学术出版社。
