Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP 91501-970, Porto Alegre, RS, Brazil.
Langmuir. 2012 Jan 17;28(2):1304-8. doi: 10.1021/la204036e. Epub 2011 Dec 28.
A theory, based on a modified Poisson-Boltzmann equation, is presented that allows us to calculate the excess interfacial tension of an electrolyte-oil interface accurately. The chaotropic (structure-breaking) ions are found to adsorb to the water-oil interface as the result of large polarizability, weak hydration, and hydrophobic and dispersion interactions. However, kosmotropic (structure-making) anions as well as potassium and sodium ions are found to be repelled from the interface. The adsorption of I(-) and ClO(4)(-) is found to be so strong as to lower the interfacial tension of the water-oil interface, in agreement with the experimental data. The agreement between the calculated interfacial tensions and the available experimental data is very good. The theory is used to predict the interfacial tensions of six other potassium salts, for which no experimental data is available at the moment.
提出了一种基于修正的泊松-玻尔兹曼方程的理论，该理论可以准确地计算电解质-油界面的过剩界面张力。发现离液剂（破坏结构的离子）由于较大的极化率、弱水合作用以及疏水性和分散相互作用而吸附在油水界面上。然而，发现同离子（结构形成离子）以及钾离子和钠离子被排斥离开界面。发现 I(-) 和 ClO4(-) 的吸附非常强，从而降低了油水界面的界面张力，与实验数据一致。计算的界面张力与现有实验数据之间的一致性非常好。该理论用于预测目前尚无实验数据的另外六种钾盐的界面张力。
