Abstract
Colloids driven by phoresis constitute one of the main avenues for the design of synthetic microswimmers. For these swimmers, the specific form of the phoretic and hydrodynamic interactions dramatically influences their dynamics. Explicit solvent simulations allow the investigation of the different behaviors of dimeric Janus active colloids. The phoretic character is modified from thermophilic to thermophobic, and this, together with the relative size of the beads, strongly influences the resulting solvent velocity fields. Hydrodynamic flows can change from puller-type to pusher-type, although the actual flows significantly differ from these standard flows. Such hydrodynamic interactions combined with phoretic interactions between dimers result in several interesting phenomena in three-dimensional bulk conditions. Thermophilic dimeric swimmers are attracted to each other and form large and stable aggregates. Repulsive phoretic interactions among thermophobic dimeric swimmers hinder such clustering and lead, together with long- and short-ranged attractive hydrodynamic interactions, to short-lived, aligned swarming structures.Graphic
Highlights
Colloids driven by phoresis constitute one of the main avenues for the design of synthetic microswimmers
We extend the study of thermophobic dimeric swimmers [28] to further investigate various dimeric geometries and densities for thermophobic dimers and for thermophilic dimers
Note that the averages of vc/|vs| and ni · nj in Fig. 7 are underestimated, since they consider all clusters of a certain size, namely random clusters formed as a consequence of random collisions and aligned structures formed as consequence of the combination of phoretic and hydrodynamic interactions
Summary
When many phoretic colloidal swimmers come together, their dynamic collective behavior shares many properties with other systems of active particles, and displays specific and varied characteristics. There already exist various methods to perform simulations of active matter which account for the effects of propulsion, thermal fluctuations, hydrodynamics, and phoretic interactions [29,30,31,32,33]. Most of these models neglect one or various of the previous contributions or consider them as independent from each other [34,35]. Hydrodynamic interactions have already shown to affect the phase behavior of systems
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
