Maurya Saurabh Kumar, Gopmandal Partha P, De Simanta, Ohshima H, Sarkar Sankar
Physics and Applied Mathematics Unit, Indian Statistical Institute, Kolkata 700108, India.
Department of Mathematics, National Institute of Technology Durgapur, Durgapur 713209, India.
Langmuir. 2021 Jan 19;37(2):703-712. doi: 10.1021/acs.langmuir.0c02805. Epub 2021 Jan 7.
This article presents a theoretical study on the electrokinetics of concentrated suspension of charge-regulated soft particles under a weak electric field and low potential assumptions. The inner core of the undertaken particle is "semisoft" in nature, which allows ion penetration while the fluid cannot flow within it, and the outer soft polymeric shell allows the flow of the ionized fluid. In addition, the inner core and the outer polyelectrolyte layer (PEL) bear pH-regulated basic and acidic functional groups, respectively. The Poisson-Boltzmann equation-based mathematical model was adopted here for electric potential. The fluid flow across the electrolyte medium and PEL is governed by the Stokes equation and the Darcy-Brinkman equation, respectively. The Kuwabara's unit cell model ( 522-527) was invoked to observe the effect of the interaction between the neighboring particles in a concentrated suspension. A first order perturbation technique was used to determine the mean electrophoretic mobility of the undertaken soft particles in a concentrated suspension. The effect of pH and concentration of bulk electrolyte, electrohydrodynamic properties of both the inner core and PEL, on the mean electrophoretic mobility has been studied extensively. In addition, the results have been presented for the neutralization factor that measures the fraction of fixed charges neutralized by the mobile counterions.
本文在弱电场和低电势假设下，对电荷调节软颗粒浓悬浮液的动电现象进行了理论研究。所研究颗粒的内核本质上是“半软”的，允许离子渗透但流体不能在其中流动，而外部软聚合物壳允许电离流体流动。此外，内核和外部聚电解质层（PEL）分别带有pH调节的碱性和酸性官能团。这里采用基于泊松 - 玻尔兹曼方程的数学模型来描述电势。电解质介质和PEL中的流体流动分别由斯托克斯方程和达西 - 布林克曼方程控制。调用桑原的单胞模型（522 - 527）来观察浓悬浮液中相邻颗粒间相互作用的影响。采用一阶微扰技术来确定所研究软颗粒在浓悬浮液中的平均电泳迁移率。广泛研究了pH值、本体电解质浓度、内核和PEL的电流体动力学性质对平均电泳迁移率的影响。此外，还给出了衡量被移动反离子中和的固定电荷分数的中和因子的结果。
