Diffusiophoresis of a sphere along the axis of a cylindrical pore

The diffusiophoresis of a charged spherical particle along the axis of an uncharged cylindrical pore filled with an electrolyte solution is analyzed theoretically. The influence of chemiphoresis, which includes two types of double-layer polarization, and that of electrophoresis arising from the difference in the diffusivities of the ionic species on the diffusiophoretic behavior of the particle are discussed. We have underlined the important difference between two cases: the first is a possibility for a particle to migrate to the low concentration side at low surface potentials (∼25 mV) along the axis of a cylindrical pore, while the second is that this migration occurs at high surface potentials (∼150 mV) in the case of a sphere in a spherical cavity.

Diffusiophoresis of a charged spherical particle along the axis of a cylindrical pore subject to an applied concentration gradient ∇n0.Figure optionsDownload high-quality image (36 K)Download as PowerPoint slide