Long-time diffusion and energy transfer in polydisperse mixtures of particles with different temperatures

Abstract

Evidence suggests that the transport rate of a passive particle at long timescales is enhanced due to interactions with the surrounding active ones in a size-and composition-dependent manner. The collisions generate additional friction on the particle while, on top of that, for nonequilibrium (active) systems, the collisions can also lead to an exchange of energy between different types of particles. Accordingly, the long-time diffusion coefficient of a tagged particle is shaped by the interplay between the effective friction and the energy transfer. Using a system of particles with different temperatures, we probe these effects in dilute solutions and derive long-time friction and self-diffusion coefficients as functions of volume fractions, sizes and temperatures of particles. Remarkably, we show that both viscosity and energy flux display a nonlinear dependence on size. The simplicity of our formalism allows to discover various interesting scenarios that can be relevant for biological systems.

Spontaneous propulsion of an isotropic colloid in a phase-separating environment

“…Among the different perspectives opened by the present work, it will be particularly interesting to study: (i) such colloids in inhomogeneous environments or under confinement [24], which will affect the polarization of the solute particles around the colloid and its propulsion; (ii) the effect of hydrodynamic interactions, which have been shown to have a dramatic effect on the collective dynamics of active colloids [25][26][27]; (iii) situations where the phase separation is not driven by interparticle interactions but by mixing particles in contact with different thermostats [28][29][30][31].…”

Nanorheology of active-passive polymer mixtures is topology-sensitive

“…Discussion and conclusions -Active matter [21] and, in particular, active polymers [12] are an emergent research field in modern soft matter. By employing the twodiffusivities dynamic model introduced and studied in the recent works [13,33,41,45], we have shown that the way nanoprobes diffuse in active-passive polymer mixtures depend on the architecture of the chains. In linear solutions activity disrupts the clustering of nanoprobes seen under purely passive conditions, while in ring solutions the tendency is quite the opposite with nanoprobes separating away from the active polymer component (Fig.…”