中国物理B ›› 2011, Vol. 20 ›› Issue (4): 46601-046601.doi: 10.1088/1674-1056/20/4/046601
章林溪1, 温晓会2, 夏阿根2, 陈宏平2
Wen Xiao-Hui(温晓会)a), Zhang Lin-Xi(章林溪) b)†, Xia A-Gen(夏阿根)a), and Chen Hong-Ping(陈宏平)a)
摘要: The phase behaviour of polyethylene knotted ring chains is investigated by using molecular dynamics simulations. In this paper, we focus on the collapse of the polyethylene knotted ring chain, and also present the results of linear and ring chains for comparison. At high temperatures, a fully extensive knot structure is observed. The mean-square radius of gyration per bond <S>2 / (Nb2) and the shape factor <δ*> depend on not only the chain length but also the knot type. With temperature decreasing, chain collapse is observed, and the collapse temperature decreases with the chain length increasing. The actual collapse transition can be determined by the specific heat capacity Cv, and the knotted ring chain undergoes gas-liquid-solid-like transition directly. The phase transition of a knotted ring chain is only one-stage collapse, which is different from the polyethylene linear and ring chains. This investigation can provide some insights into the statistical properties of knotted polymer chains.
中图分类号: (Polymers)