Simulation of Diffusion in Two-Dimensional Crowded Media

In classical diffusion the mean‐square displacement increases linearly with time but in crowded media anomalous diffusion may occur, in which the mean‐square displacement is proportional to a non‐integral power of time for some or all times. The diffusion rate of a particle motion obstructed by obstacles depends on the size, number, and mobility of the obstacles. The aim of this paper is to simulate diffusion processes in two‐dimensional square lattices with obstacles and to analyze how the anomalous diffusion exponent depends on the concentration, size and mobility of the obstacles.