石墨烯诱导PE单链结晶过程的形态变化-华东理工大学学报.doc

研究简版
文章编号:
单链聚乙烯在石墨烯二维表面结晶的分子模拟研究
李延頔,何雪莲*,黄宇,宋敏驹,高睿,刘柏平
(华东理工大学化工学院上海市多相结构材料化学工程重点实验室,上海 200237)
摘要:目前对于石墨或石墨烯等片层结构对共聚聚乙烯结晶行为的影响研究相对较少,尚未系统揭示其结晶机制。本文采用分子动力学模拟方法,研究单链聚乙烯在二维石墨烯表面受限状态下的结晶过程。结果发现,与聚乙烯单链结晶不同,聚乙烯沿石墨烯表面(001)面发生表面吸附-链折叠-取向有序形成层状晶体,结晶过程由表面吸附和链折叠共同控制,随等温结晶温度变化分为三个区域。另外,支链不利于结晶,但其长度大于10CH2时,即开始发生吸附或折叠进入晶区,与主链形成共晶,从而减缓了结晶度随支链长度下降的趋势,并且支链主要进入石墨层界面附近的晶区。
关键词:石墨烯,聚乙烯,分子动力学,支链,表面
中国分类号: 文献标识码:
Molecular simulation study of single chain polyethylene crystallization on two-dimensional surface of graphene
Yan-di Li, Xue-lian He*, Yu Huang, Min-ju Song, Rui Gao, Bo-ping Liu
(Shanghai Key Laboratory of Multiphase Materials Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology,Shanghai,200237)
Abstract Few studies about the influence of lamellar structure like graphite or graphene on crystallization behavior of PE copolymer were reported, and the crystallization mechanism had not yet revealed systematically. In this paper, the crystallization process of single chain PE induced by graphene was investigated with molecular dynamics simulation. It turned out that PE tended to crystalize into lamellar structure on the surface of graphene (001) through surface absorption-chain folding-orientation process. This process, controlled by surface adsorption and chain folding, could be divided into three temperature regimes in the progr