Computer simulations of colloids far from equilibrium

Dnr:

SNIC 2017/1-92

Type:

SNAC Medium

Principal Investigator:

Joakim Stenhammar

Affiliation:

Lunds universitet

Start Date:

2017-03-06

End Date:

2018-04-01

Primary Classification:

10603: Biofysik

Secondary Classification:

10304: Den kondenserade materiens fysik

Webpage:

http://www.physchem.lu.se/people/postdocs/stenhammar/?L=3

Allocation

Abstract

This project concerns different aspects of colloidal suspensions driven out of equilibrium either internally (so-called "active matter") or by an external electric field. Within the first subproject we will study fluid-mediated collective effects in dense and semidilute suspensions of motile microorganisms (typically bacteria and algae) using Lattice-Boltzmann simulations. In particular, these suspensions are known to exhibit hydrodynamic instabilities leading to so-called "bacterial turbulence", a phenomenon which is currently not understood even at a basic level. We will also study the observed enhanced diffusion of passive particles in such suspensions, which is important to mass transport in biological systems (e.g. in bioreactors and the oceans). The second sub-project concerns field-assisted self-assembly of anisotropic colloidal particles into advanced structures. It has recently been showed that the interplay between electrostatic interactions induced by applying an alternating electric field to a suspension of polarisable colloids will lead to the self-assembly of non-trivial structures such as nanotubes, sheets and crystals. In this project we will study the mechanisms behind such processes, focusing in particular on the complex interactions stemming from many-body polarisation effects.