UMDIJ-Facultad de Ciencias, Universidad Nacional Autónoma de México Campus Juriquilla, 76230 Querétaro, Mexico.
Instituto Politécnico Nacional, CICATA, Querétaro, Qro., Mexico.
Adv Colloid Interface Sci. 2017 Sep;247:178-184. doi: 10.1016/j.cis.2017.07.018. Epub 2017 Jul 21.
The Gibbs Adsorption Isotherm equation is a two-dimensional analogous of the Gibbs-Duhem equation, and it is one of the cornerstones of interface science. It is also widely used to estimate the surface excess concentration (SEC) for surfactants and other compounds in aqueous solution, from surface tension measurements. However, in recent publications some authors have cast doubt on this method. In the present work, we review some of the best available surface tension experimental data, and compare estimations of the SEC, using the Gibbs isotherm method (GIM), to direct measurements reported in the literature. This is done for both nonionic and ionic surfactants, with and without added salt. Our review leads to the conclusion that the GIM has a very solid agreement with experiments, and that it does estimate accurately the SEC for surfactant concentrations smaller than the critical micellar concentration (CMC).
吉布斯吸附等温方程是吉布斯-杜汉姆方程的二维类似物，是界面科学的基石之一。它也被广泛用于通过表面张力测量来估计表面活性剂和其他化合物在水溶液中的表面过剩浓度（SEC）。然而，在最近的一些出版物中，一些作者对这种方法提出了质疑。在本工作中，我们回顾了一些可获得的最佳表面张力实验数据，并比较了使用吉布斯等温线法（GIM）估算 SEC 的结果与文献中报道的直接测量结果。这是针对带有和不带有加盐的非离子和离子表面活性剂进行的。我们的综述得出的结论是，GIM 与实验非常吻合，并且它可以准确估计 SEC 对于小于临界胶束浓度（CMC）的表面活性剂浓度。
