CALCULATION OF CONFORMATIONAL ENTROPY AND FREE ENERGY OF POLYSILANE CHAIN

The conformational entropy S and free energy F were calculated by exact enumeration of polysilane chain up to 23segments with excluded volume (EV) and long-range van der Waals (VW) interaction. A nonlinear relation between S_(EV+VW)and chain length n was found though S_(EV) was found to vary linearly with n. We found that the second-order transitiontemperature of polysilane chain with VW interaction increases with the increase of chain length, while that of polysilanechain without VW interaction is chain length independent Moreover, the free energies F_(EV+VW) and FEv are both linearlyrelated with n, and F_(EV+VW)