Mechanism of diffusiophoresis with chemical reaction on a colloidal particle.

Seki, Tomotaka; Okuzono, Tohru; Toyotama, Akiko; Yamanaka, Junpei · Phys Rev E · 2019

basic_science · Level V

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Abstract

A mechanism for diffusiophoresis of a charged colloidal particle undergoing surface chemical reaction is proposed. A theoretical model is constructed to describe the dynamics of the particle and the surrounding solution of a weak electrolyte. Theoretical analysis and numerical simulations of the model reveal that phoretic motion of the particle emerges in response to a concentration gradient of electrolyte. The concentration gradient breaks the spherical symmetry of the surface charge distribution, which gives rise to a net force on the particle and leads to directional motion of the particle.