Hsu J P, Lin S H, Tseng S
Department of Chemical Engineering, National Taiwan University, Taipei, Republic of China.
J Theor Biol. 1996 Sep 21;182(2):137-45. doi: 10.1006/jtbi.1996.0148.
The electrophoretic mobility of a particle covered by a membrane in an a:b electrolyte solution is modeled theoretically. The membrane, which simulates the surface of a biological cell, is ion-penetrable, and carries homogeneously distributed negative fixed charges. An approximate expression for the electrophoretic mobility is derived. Based on the results of numerical simulation, we conclude the following: (1) The absolute Donnan potential increases with the concentration of the fixed charges C0, but decreases with the ionic strength I. (2) The greater the valence of cation alpha, the lower the absolute potential distribution. (3) The greater the C0, the greater the absolute mobility of a particle, magnitude of mu, and the greater the friction coefficient of the membrane phase gamma, the smaller the magnitude of mu. (4) A large I or a large a leads to a small magnitude of mu. (5) The greater the ratio (permittivity of solution/permittivity of membrane phase), the smaller the magnitude of mu. (6) For a large gamma, magnitude of mu decreases with the thickness of membrane d under the condition of constant amount of fixed charges. However, if gamma is sufficiently small, the variation of magnitude of mu as a function of d exhibits a maximum. The classic result of Smoluchowski for the electrophoretic mobility of a rigid particle can be recovered as a limiting case of the present model.
理论上对在a:b电解质溶液中被膜覆盖的粒子的电泳迁移率进行了建模。该膜模拟生物细胞表面，具有离子渗透性，并带有均匀分布的负固定电荷。推导了电泳迁移率的近似表达式。基于数值模拟结果，我们得出以下结论：(1) 绝对唐南电位随固定电荷浓度C0的增加而增加，但随离子强度I的增加而降低。(2) 阳离子价数α越大，绝对电位分布越低。(3) C0越大，粒子的绝对迁移率μ的大小越大，膜相的摩擦系数γ越大，μ的大小越小。(4) 大的I或大的a导致μ的大小小。(5) （溶液介电常数/膜相介电常数）的比值越大，μ的大小越小。(6) 对于大的γ，在固定电荷量恒定的条件下，μ的大小随膜厚度d的增加而减小。然而，如果γ足够小，μ的大小随d的变化会出现最大值。刚性粒子电泳迁移率的经典斯莫卢霍夫斯基结果可作为本模型的极限情况得到。
