中国物理B ›› 2011, Vol. 20 ›› Issue (4): 46601-046601.doi: 10.1088/1674-1056/20/4/046601

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Phase behaviour of polyethylene knotted ring chains

章林溪1, 温晓会2, 夏阿根2, 陈宏平2   

  1. (1)Department of Physics, Wenzhou University, Wenzhou 325027, China; (2)Department of Physics, Zhejiang University, Hangzhou 310027, China
  • 收稿日期:2010-07-18 修回日期:2010-10-03 出版日期:2011-04-15 发布日期:2011-04-15
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 20574052, 20774066, 20974081, and 20934004), the Program for New Century Excellent Talents in University of the Ministry of Education of China (Grant No. NCET-05-0538), and the Ph.D. Program Foundation of the Ministry of Education of China (Grant No. 20090101110002).

Phase behaviour of polyethylene knotted ring chains

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)   

  1. a Department of Physics, Zhejiang University, Hangzhou 310027, China; b Department of Physics, Wenzhou University, Wenzhou 325027, China
  • Received:2010-07-18 Revised:2010-10-03 Online:2011-04-15 Published:2011-04-15
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 20574052, 20774066, 20974081, and 20934004), the Program for New Century Excellent Talents in University of the Ministry of Education of China (Grant No. NCET-05-0538), and the Ph.D. Program Foundation of the Ministry of Education of China (Grant No. 20090101110002).

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.

关键词: molecular dynamics method, phase transition, polyethylene knotted ring chain

Abstract: 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 <$\delta$*> 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.

Key words: molecular dynamics method, phase transition, polyethylene knotted ring chain

中图分类号:  (Polymers)

  • 66.30.hk
82.35.Lr (Physical properties of polymers) 87.15.rp (Polymerization)