Singh Rajesh, Adhikari R, Cates M E
DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, United Kingdom.
J Chem Phys. 2019 Jul 28;151(4):044901. doi: 10.1063/1.5090179.
At the surfaces of autophoretic colloids, slip velocities arise from local chemical gradients that are many-body functions of particle configuration and activity. For rapid chemical diffusion, coupled with slip-induced hydrodynamic interactions, we deduce the chemohydrodynamic forces and torques between colloids. For bottom-heavy particles above a no-slip wall, the forces can be expressed as gradients of a nonequilibrium potential which, by tuning the type of activity, can be varied from repulsive to attractive. When this potential has a barrier, we find arrested phase separation with a mean cluster size set by competing chemical and hydrodynamic interactions. These are controlled, in turn, by the monopolar and dipolar contributions to the active chemical surface fluxes.
在自泳胶体的表面，滑移速度源于局部化学梯度，这些梯度是粒子构型和活性的多体函数。对于快速化学扩散，再加上滑移诱导的流体动力相互作用，我们推导出了胶体之间的化学流体动力和扭矩。对于位于无滑移壁上方的底部较重的粒子，这些力可以表示为非平衡势的梯度，通过调整活性类型，该势可以从排斥变为吸引。当这个势存在一个势垒时，我们发现相分离被阻止，平均簇尺寸由竞争的化学和流体动力相互作用设定。这些相互作用又由活性化学表面通量的单极和偶极贡献所控制。
