Projects per year
Abstract
We report Monte Carlo simulations of the dynamics of a "chucker," a colloidal particle that emits smaller solute particles from its surface, isotropically and at a constant rate k(c). We find that the diffusion constant of the chucker increases for small k(c), as recently predicted theoretically. At large k(c), the chucker diffuses more slowly due to crowding effects. We compare our simulation results to those of a "point particle" Langevin dynamics scheme in which the solute concentration field is calculated analytically, and in which hydrodynamic effects arising from colloidsolvent surface interactions can be accounted for in a coarsegrained way. By simulating the dragging of a chucker, we obtain an estimate of its apparent mobility coefficient which violates the fluctuationdissipation theorem. We also characterize the probability density profile for a chucker which sediments onto a surface which either repels or absorbs the solute particles, and find that the steady state distributions are very different in the two cases. Our simulations are inspired by the biological example of exopolysaccharideproducing bacteria, as well as by recent experimental, simulation and theoretical work on phoretic colloidal "swimmers.". (C) 2010 American Institute of Physics. [doi: 10.1063/1.3428663]
Original language  English 

Article number  204904 
Pages (fromto)   
Number of pages  10 
Journal  The Journal of Chemical Physics 
Volume  132 
Issue number  20 
DOIs  
Publication status  Published  28 May 2010 
Keywords
 colloids
 diffusion
 Monte Carlo methods
 nonlinear dynamical systems
 solutions
 MICROBIAL EXOPOLYSACCHARIDES
 XANTHOMONASCAMPESTRIS
 XANTHAN PRODUCTION
 MONTECARLO
 TRANSPORT
 PARTICLES
 MOTILITY
 MOVEMENT
 FORCES
 GROWTH
Projects
 1 Finished

Edinbugrh Soft Matter and Statistical Physics Programme Grant Renewal
Cates, M., Poon, W., Ackland, G., Clegg, P., Evans, M., MacPhee, C. & Marenduzzo, D.
1/10/07 → 31/03/12
Project: Research