DYNAMIC MONTE CARLO SIMULATION OF KINETIC PROCESS FOR POLYMER COLLAPSE TRANSITION

Based on the bond-fluctuation lattice model and dynamic Monte Carlo simulation, with explicitly including the hydrophobic interaction between water molecular and polymer,the kinetic process for the coil-globule transition of a homopolymer chain was studied. The distribution of collapse time observed the Gaussian profile, and the variation of averaged collapse time on the quench depth was similar with that for protein folding, but exhibited no local minima. What's more, the averaged collapse time was exponentially dependent on the chainlength. In the kinetic process, the polymer chain's conformation was found to evolve from an ellipsoid-like random coil to necklace-like conformation, then to sausage-like conformation, and eventually to a spherical globule. The four-stage kinetic process previously proposed by other peoples has been distinctly defined in this paper via some characteristic parameters, i.e., the number of cluster, cluster size and aspherity, thus providing a convenient criterion for stage partition and comparison for specific collapse process.