BROWNIAN DYNAMICS SIMULATION OF DIFFUSION-LIMITED POLYMERIZATION OF RODLIKE MOLECULES - ISOTROPIC TRANSLATIONAL DIFFUSION

Rigid rodlike polymers have considerable technological importance due to their excellent mechanical properties. The polymerization kinetics of such condensation polymers are qualitatively different from flexibl e polymers, and exhibit significant slowing at the later stages of the reaction. This is due to the slow rotational diffusion of the molecul es to an appropriate configuration for reaction. In this work we have carried out Brownian dynamics (ED) simulations to obtain the effective rate constant for reaction between rodlike molecules in the presence of diffusional limitations. The theory of Northrup et nl. [J. Chem. Ph ys. 80, 1517 (1984)] for pairwise ED simulation of reactions is extend ed to the case of rodlike molecules assuming isotropic translational d iffusion. The computed results are compared to exact analytical predic tions. Good agreement between computation and theory is obtained over a wide range of parameter values. (C) 1997 American Institute of Physi cs.