【作者】 王琳； 赵立峰； 程涛； 孙淮；

【Author】 Lin Wang,Li-feng Zhao,Tao Cheng,Huai Sun~* (School of Chemistry and Chemical Technology,Shanghai Jiao Tong University,200240,Shanghai,China)

【机构】 上海交通大学化学化工学院；

【摘要】 在半导体材料,离子液体以及离子电池电解液等领域中,体系的热传导系数是重要的参数,但是很难用实验的方法测量这些体系,分子模拟方法则提供了一种获得体系热传导系数的便捷方法。在众多计算体系热传导系数的分子动力学方法中,我们采用Muller-Plathe等开发的非平衡分子动力学方法,这种方法便于统计通量,能够得到稳定的温度梯度,同时计算效率也比较高。对于计算热传导系数中的量子效应问题,我们通过采用联合原子模型以及减少分子内自由度的方法来加以处理。采用此方法首先对小分子液体,包括水,乙醇,以及乙醇与水的混合物体系进行计算并且得到了准确的热传导系数计算结果。以此为基础,我们正在利用这种方法对碳纳米管,石墨烯等原子晶体体系进行了研究,主要考察温度,材料宽度,晶体缺陷等条件对模拟结果的影响。对于尺寸效应的影响,我们采用外推法得到依赖于模拟体系尺寸的热传导系数结果。这对于我们理解碳纳米管,石墨烯高效的热传导性能,指导合成新型导热材料提供了重要的理论指导。更多还原

【Abstract】 Thermal conductivity is an important physical property in semiconductor,ionic liquid and electrolyte.It is often difficult to measure it experimentally,so molecular simulation is an effective method to achieve the thermal conductivity.We use NEMD method produced by Muller-Plathe which can calculate the flux directly and can get steady temperature grads.And we also use the United atom model and constrain bond length in order to reduce the degree of freedom of the system which can effectively counteract the effect of quantum.First we calculate some small molecular systems,including water,ethanol and their mixture.Recently we use this method to calculate atomic crystals such as carbon nanotube and graphene and mainly focus on the effect of temperature,width and defect.We also use extrapolation to deal with the effect of finite boundary.These results can help us to understand the extreme high thermal conductivity of carbon nanotube and graphene,and synthesize new kinds of material.更多还原