DIFFUSION IN A FLUCTUATING RANDOM GEOMETRY

A theoretical analysis is presented of the self-diffusion of a particle in a disordered and fluctuating one-dimensional geometry. A general result is obtained, showing how geometrical fluctuations enhance the rate of diffusion measured in a laboratory-fixed frame. This result is relevant for understanding molecular transport in certain complex fluids and biological systems. Explicit results are given for three different dynamic models, illustrating how diffusion measurements can be used to extract information about the orientational distribution and dynamics of segments of polymers or wormlike micelles in isotropic solutions and liquid-crystalline phases.