Facultad de Ciencias Físico-Matemáticas, Universidad Autónoma de Sinaloa, Av. de las Américas y Blvd. Universitarios, Cd. Universitaria, 80000 Culiacán, Sinaloa, Mexico.
CONACYT-Instituto de Física de la Universidad Autónoma de San Luis Potosí, Álvaro Obregón 64, 78000 San Luis Potosí, San Luis Potosí, Mexico.
J Chem Phys. 2018 Apr 21;148(15):154703. doi: 10.1063/1.5024553.
The capacitive compactness has been introduced very recently [G. I. Guerrero-García et al., Phys. Chem. Chem. Phys. 20, 262-275 (2018)] as a robust and accurate measure to quantify the thickness, or spatial extension, of the electrical double layer next to either an infinite charged electrode or a spherical macroion. We propose here an experimental/theoretical scheme to determine the capacitive compactness of a spherical electrical double layer that relies on the calculation of the electrokinetic charge and the associated mean electrostatic potential at the macroparticle's surface. This is achieved by numerically solving the non-linear Poisson-Boltzmann equation of point ions around a colloidal sphere and matching the corresponding theoretical mobility, predicted by the O'Brien and White theory [J. Chem. Soc., Faraday Trans. 2 74, 1607-1626 (1978)], with experimental measurements of the electrophoretic mobility under the same conditions. This novel method is used to calculate the capacitive compactness of NaCl and CaCl electrolytes surrounding a negatively charged polystyrene particle as a function of the salt concentration.
最近 [G. I. Guerrero-García 等人，物理化学化学物理 20, 262-275 (2018)] 引入了电容紧致度作为一种稳健且精确的度量标准，用于量化无限带电电极或球形大离子附近的双电层的厚度或空间延伸。我们在这里提出了一种实验/理论方案，用于确定球形双电层的电容紧致度，该方案依赖于计算电动电荷和大粒子表面的相关平均静电势。这是通过数值求解胶体球周围的点离子的非线性泊松-玻尔兹曼方程并匹配相应的理论迁移率来实现的，理论迁移率由 O'Brien 和 White 理论 [J. Chem. Soc.， Faraday Trans. 2 74, 1607-1626 (1978)] 预测，实验测量在相同条件下的电泳迁移率。这种新方法用于计算带负电荷的聚苯乙烯颗粒周围的 NaCl 和 CaCl 电解质的电容紧致度作为盐浓度的函数。
