THE MONTE CARLO SIMULATION OF THE COLLAPSE TRANSITION OF A SEMI-STIFF POLYMER CHAIN
半刚性高分子链塌缩相变的蒙特卡洛模拟

The configurations and the collapsed polymer state of a semi-stiff chain under various temperatures, especially below the theta point ,are presented in this paper. The Monte Carlo method is used to simulation the behavior of a semi-stiff polymer chain in simple cubic lattice. In our model the inter-segmental interactions included the hard core volume effect, longer ranged attractive part and the local stiffness potential. The stiffness of a chain is determined by the ratio of stiffness potential and attractive effect. Our results have been obtained showing a shrinkage of the coil dimension of a polymer chain with decrease temperature. But there has some differences between a flexible chain and a semi-stiff polymer chain. At first the soil demintion of a semi-stiff chain is expanded due stiffness potential, then it shrinkage with decrease temperature. From the behaviou of the specific heat we concluded that the collapsed transitions of a polymer chain is a second-order phase transitions.