Advanced Materials: TechConnect Briefs 2015Advanced Materials TechConnect Briefs 2015

Polymers Chapter 9

SRD-MD modelling of hydrodynamic interactions in colloidal systems: playing between computational cost and resolution

A.M.K. Laganapan, A. Videcoq, M. Cerbelaud, M. Mouas, M. Bienia, R. Ferrando
Science of Ceramic Processing and Surface Treatments (SPCTS), France

pp. 552 - 555

Keywords: simulations, rheology, shear viscosity, percolation

A ubiquitous problem that has always been a subject of intensive research is the role played by hydrodynamic interactions (HI’s) in several fundamental problems in colloid rheology and aggregation kinetics. However, the high computational demand that is often associated with HI’s modelling presents a huge challenge. Even with the computer power that is available today, a full molecular dynamics simulation is still unsustainable. Meanwhile, there is a diverse number of technological applications that call for a means to address this limitation. To that end, we use a hybrid Stochastic Rotation Dynamics - Molecular Dynamic method, which can provide a compromise between computational efficiency and molecular dynamics resolution. We present our SRD-MD simulation results in two parts. The first one is modelling of the rheological behaviour of colloidal suspensions. We successfully reproduce, both qualitatively and quantitatively, the divergence of the suspension viscosity from linear behaviour when HI’s are properly included. The second part deals with the aggregation kinetics of colloidal suspensions. We show that HI’s speed up the aggregation process of colloids and slow down the reorganization of the clusters formed. Consequently, we demonstrate that the probability of percolation is higher for systems with HI's in comparison with systems without.