高等学校化学学报 ›› 2010, Vol. 31 ›› Issue (3): 542.

• 研究论文 • 上一篇    下一篇

离子液体[emim]Br熔点的分子动力学模拟

冯海军, 周健, 钱宇   

  1. 华南理工大学化学与化工学院, 绿色化学产品技术广东省重点实验室, 广州 510640
  • 收稿日期:2009-07-15 出版日期:2010-03-10 发布日期:2010-03-10
  • 通讯作者: 周健, 男, 教授, 博士生导师, 主要从事分子模拟研究. E-mail: jianzhou@scut.edu.cn
  • 基金资助:

    教育部新世纪优秀人才支持计划(批准号: NCET-07-0313)和国家自然科学基金(批准号: 20536020, 20706019, 20876052)资助.

Molecular Dynamics Simulation on the Melting Point of Ionic Liquid [emim]Br

FENG Hai-Jun, ZHOU Jian* , QIAN Yu   

  1. School of Chemistry and Chemical Engineering, Guangdong Provincial Key Lab for Green Chemical Product Technology, South China University of Technology, Guangzhou 510640, China
  • Received:2009-07-15 Online:2010-03-10 Published:2010-03-10
  • Contact: ZHOU Jian. E-mail: jianzhou@scut.edu.cn
  • Supported by:

    教育部新世纪优秀人才支持计划(批准号: NCET-07-0313)和国家自然科学基金(批准号: 20536020, 20706019, 20876052)资助.

摘要:

运用分子动力学模拟, 采用直接加热法和微正则(NVE)系综法计算离子液体[emim]Br的熔点, 以期获得较好的熔点预测方法. 直接加热法通过分析体系的非键合能、密度、径向分布函数、扩散系数和平动序参数随温度的变化关系判断熔点; NVE系综法则通过获得固液共存体系判断熔点. 直接加热法中, 体系易出现过热问题; NVE系综法则能有效克服过热问题, 是在模拟研究中应优先选择的离子液体熔点预测方法.

关键词: 分子动力学模拟; 离子液体; 熔点

Abstract:

The melting point of ionic liquids being around room temperature is the key of applications of ionic liquids. In this work, molecular dynamics simulation is carried out to study the melting point of ionic liquid [emim]Br by the direct heating and NVE ensemble approaches, to find a suitable method in preclicting the melting point of ionic liquids. In the direct heating method, the variations of the Nonbonding energy(E), density(ρ), radial distribution function(RDF), diffusion coefficient(D) and translational order parameter(TOP) of [emim]Br with temperature are analyzed to determine the melting point; whereas in the NVE ensemble method, a co-existing solid-liquid system is achieved to judge the melting point. For these two methods, the direct heating method can cause superheating of the system, while the NVE ensemble method can overcome this problem. In predicting melting points of ionic liquids, the NVE ensemble method should be preferred.

Key words: Molecular dynamics simulation; Ionic liquid; Melting point

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