Topological Constraint in Ring Polymers Studied by Monte Carlo Simulation

点击翻译按钮获取中文摘要

I studied equilibrium conformations of ring polymers at their theta-conditions using a Monte-Carlo simulation. The Flory's critical exponents, nu, were obtained from the dependence of the radius of gyration, Rg, on the segment number of the polymers, N. At the theta-temperature the excluded volumes of linear polymers are screened completely by the attractive force between segments, where the nu value is 1/2 and the trajectories of the chains can be described as a random walk. If the nu value for ring polymers is not 1/2 at the theta-temperature for linear polymers, the chain conformations of ring polymers are not described as a closed random walk. I reported that the theta-temperature for trivial-, 3_1 and 5_1 ring polymers are lower than that for linear polymers. I also suggested a new simulation algorithm, where polymer chains were placed on a face-centered cubic lattice and can move not only with the local motion but also with the trans-location in the algorithm.