KINETIC LAWS AT THE COLLAPSE TRANSITION OF A HOMOPOLYMER

We present results from numerical analysis of the equations derived in the Gaussian self-consistent method for kinetics at the collapse tran sition of a homopolymer in dilute solution. The kinetic laws are obtai ned with and without hydrodynamics for different quench depths and vis cosities of the solvent. Some of our earlier analytical estimates are confirmed, and new ones generated. Thus the first kinetic stage for sm all quenches is described by a power law decrease in time of the squar ed radius of gyration with the universal exponent alpha(i)=9/11 (7/11) with (without) hydrodynamics. We find the scaling laws of the charact eristic time of the coarsening stage, tau(m) similar to-N-gamma m, and the final relaxation time, tau(f) similar to N-gamma f, as a function of the degree of polymerization N. These exponents are equal to gamma (m)=3/2, gamma(f)=1 in the regime of strong hydrodynamic interaction, and gamma(m)=2, gamma(f)=5/3 without hydrodynamics. We regard this pap er as the completion of our work on the collapse kinetics of a bead an d spring model of a homopolymer, but discuss the possibility of studyi ng more complex systems. (C) 1996 American Institute of Physics.