The hindrance created by the induced electric filed on the sedimentation of a charged colloid in an aqueous media is studied through numerical modeling. The colloid is considered to be hydrophobic, sedimenting under gravity or a centrifugal force (generalized gravity). The deformation of the charge cloud around the colloid induces an electric field, which generates electrical dipole force on the colloid. The sedimentation velocity is governed by the balance of an electric force, hydrodynamic drag, and gravitational force. Governing equations based on the first principle of electrokinetics is solved numerically through a control volume approach. The dependence of the sedimentation velocity on the electrical properties and slip length of the colloid is investigated. The sedimentation velocity of the charged colloid is slower than the corresponding uncharged particle and this deviation magnifies as the charge density as well as particle slip length is increased. An enhanced g‐factor creates a size dependency of the charged colloids. The induced sedimentation field is obtained to analyze the electrokinetics. Surface hydrophobicity enhances the sedimentation velocity, which in turn manifests the induced sedimentation field. However, the sedimentation velocity of a charged hydrophobic colloid is lower than the corresponding uncharged hydrophobic particle and this deviation manifests as slip length is increased.

中文翻译：

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广义重力场下带电疏水刚性胶体在水介质中的沉降

通过数值模拟研究了感应电场对水介质中带电胶体沉降的阻碍。胶体被认为是疏水的，在重力或离心力（广义重力）下沉降。胶体周围电荷云的变形会引起电场，从而在胶体上产生电偶极子力。沉降速度由电力、流体动力阻力和重力的平衡控制。基于电动力学第一原理的控制方程通过控制体积方法进行数值求解。研究了沉降速度对胶体电性能和滑移长度的依赖性。带电胶体的沉降速度比相应的不带电粒子慢，并且这种偏差随着电荷密度和粒子滑移长度的增加而扩大。增强型g因子产生带电胶体的尺寸依赖性。获得诱导沉降场以分析电动力学。表面疏水性提高了沉降速度，进而表现出诱导沉降场。然而，带电疏水胶体的沉降速度低于相应的不带电疏水颗粒，这种偏差表现为滑移长度增加。