聚乙烯链塌缩相变的研究

通过对高分子链构象的完全计数，研究了聚乙烯链的塌缩相变现象．聚乙烯链在金钢石格点上生成，计算中考虑了聚乙烯链的近程相互作用和远程相互作用．结果表明，聚乙烯链在温度下降时，会发生从高温下的伸展状态到低温下的紧缩状态的塌缩现象．对有限长的聚乙烯链，塌缩与链长和吸引势的强度有关，链越长，吸引势越大，塌缩发生的温度就越高，而且我们还发现，聚乙烯链的塌缩相变是一级相变

Study of Collapse Transition of Polyethylene Chain

The collapse transition of polyethylene chain is studied by exact enumeration of all possible conformations of short chains. The polyethylene chains which submitted to short range and long range interactions are generated on a diamond lattice.The results show that a collapse will occur with decreasing temperature for polyethylene chains. The collapse is largely dependent on the chain length and the density of attractive potential for definite long polyethylene chains. The temperature where the collapse occurs increases with the chain length and the density of attractive potential. The collapse transition is found to be a first order phase transition in the limit of an infinite long polyethylene chain.