TY  - JOUR
A1  - Shin, Jaeoh
A1  - Cherstvy, Andrey G.
A1  - Metzler, Ralf
T1  - Self-subdiffusion in solutions of star-shaped crowders: non-monotonic effects of inter-particle interactions
T2  - New journal of physics : the open-access journal for physics
N2  - We examine by extensive computer simulations the self-diffusion of anisotropic star-like particles in crowded two-dimensional solutions. We investigate the implications of the area coverage fraction phi of the crowders and the crowder-crowder adhesion properties on the regime of transient anomalous diffusion. We systematically compute the mean squared displacement (MSD) of the particles, their time averaged MSD, and the effective diffusion coefficient. The diffusion is ergodic in the limit of long traces, such that the mean time averaged MSD converges towards the ensemble averaged MSD, and features a small residual amplitude spread of the time averaged MSD from individual trajectories. At intermediate time scales, we quantify the anomalous diffusion in the system. Also, we show that the translational-but not rotational-diffusivity of the particles Dis a nonmonotonic function of the attraction strength between them. Both diffusion coefficients decrease as the power law D(phi) similar to (1 - phi/phi*)(2 ... 2.4) with the area fraction phi occupied by the crowders and the critical value phi*. Our results might be applicable to rationalising the experimental observations of non-Brownian diffusion for a number of standard macromolecular crowders used in vitro to mimic the cytoplasmic conditions of living cells.
KW  - anomalous diffusion
KW  - crowded fluids
KW  - stochastic processes
Y1  - 2015
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/38449
SN  - 1367-2630
VL  - 17
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  -