Diffusiophoretic motion of an isolated charged porous sphere

摘要: Diffusiophoretic motion, the migration of a colloidal particle in response to an externally applied solute concentration gradient, is investigated theoretically this study for isolated charged porous sphere suspended unbounded medium electrolyte solution. The treated as Brinkman with uniformly distributed fixed charge density. resulted general electrokinetic equations adopting full nonlinear Poisson equation are solved numerically pseudo-spectral method based on Chebyshev polynomials. In particular, convection contribution ion flux taken into account properly well. Key parameters interest examined their respective effect motion. mobility much smaller than analytical prediction neglecting convection-induced double layer polarization effect, which by far most important factor determining A less may actually move faster highly one due effect. Visual demonstration provided. Formation separate axisymmetric vortex flow be responsible observation that reverse its direction motion across threshold permeability. This implies polyelectrolyte (like protein or DNA) assuming random coil conformation tango back and forth it makes gyrations diffusiophoretic