聚氧乙烯尾形链构象统计的Monte Carlo模拟

Monte carlo study on conformational statistics for polyoxyethylene tail chains

本文采用聚氧乙烯链的实际键长、键角和Θ条件下每一链段处于不同旋转异构态的条件概率生成样本链分子,讨论了聚氧乙烯尾形链的构象性质,计算了尾形链的均方末端矩及其分量、用完全计算法及理论推导作了检验。讨论了样本库内均方末端矩的构象分布。结果表明,该方法能较精确地重现尾形链在平衡态时的真实构象分布,适用于尾形链的构象统计研究。

In this paper, the real bond length and real bond angle and the conditional probabilities under θ condition of polyoxyethylene （PEO） chain is adopted to simulate the sample stock of PEO tail chains,. The mean square end-to-end distance and its components and the distribution of 〈 R^2 〉 are calculated both for free and tail PEO chains using monte-carlo method. The results are compared with those from exact enumeration and theoretical deduction and shows that： 1 ） the sample stock of chain molecular simulated using this method can reappear the real conformational distribution at equilibrium state both for free and tail chains. 2） The calculated results are in accordance with those from exact enumeration and theoretical deduction. So the suggested method is available in the study of conformational statistics of PEO tail chain.