Self-Propulsion Mechanism of Active Janus Particles in Near-Critical Binary Mixtures

Self-Diffusiophoresis of Janus Particles in Near-Critical Mixtures.

We theoretically study the self-propulsion of a laser-heated Janus particle in a near-critical water-lutidine mixture, and we relate its velocity v_{p} and squirmer parameter β to the wetting properties of its two hemispheres. For nonionic surface forces, the particle moves the active cap at the front, whereas a charged hydrophilic cap leads to backward motion, in agreement with the experiment....

Geometric tuning of self-propulsion for Janus catalytic particles

Catalytic swimmers have attracted much attention as alternatives to biological systems for examining collective microscopic dynamics and the response to physico-chemical signals. Yet, understanding and predicting even the most fundamental characteristics of their individual propulsion still raises important challenges. While chemical asymmetry is widely recognized as the cornerstone of catalyti...

Solvation effects in near-critical binary mixtures.

A Ginzburg-Landau theory is presented to investigate solvation effects in near-critical polar fluid binary mixtures. Concentration dependence of the dielectric constant gives rise to a shell region around a charged particle within which solvation occurs preferentially. As the critical point is approached, the concentration has a long-range Ornstein-Zernike tail representing strong critical elec...

Self - assembly of dielectric Janus particles

Submitted for the MAR14 Meeting of The American Physical Society Self-assembly of dielectric Janus particles HUANXIN WU, ERIK LUIJTEN, Northwestern University — We consider dielectrically heterogeneous Janus particles, spherical colloids with a dielectric mismatch between their two hemispheres. When such particles are suspended in solution, this mismatch leads to different polarization charges ...

Temperature and pressure studies of dielectric permittivity in near-critical binary mixtures