单分散椭圆粒子体系的动力学和结构性质研究
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- 英文论文题名：Study on the structural and dynamical properties of two-dimensional ellipse system
- 论文作者：王亮 ; 卢宇源 ; 安立佳
- 英文论文作者：Liang wang ; Yuyuan Lu ; Lijia An ; State Key Laboratory of Polymer Physics and Chemistry ; Changchun Institute of Applied Chemistry ; Chinese Academy of Sciences ; University of Chinese Academy of Sciences
- 年：2016
- 作者机构：中国科学院长春应用化学研究所高分子物理与化学国家重点实验室;中国科学院大学;
- 论文关键词：相变 ; 玻璃化转变 ; 不稳定向列相 ; 事件驱动分子动力学
- 会议召开时间：2016-08-25
- 会议录名称：中国化学会2016年软物质理论计算与模拟会议论文摘要集
- 语种：中文
- 分类号：TB30
- 学会代码：ZGHY
- 会议名称：中国化学会2016年软物质理论计算与模拟会议
- 会议地点：中国天津
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：2
- 文件大小：163k
- 原文格式：D
- 会议级别：全国
摘要
与圆球体系相比,椭球体系在相变、玻璃化转变以及jamming转变上具有很多独特的性质。因此,近几年有关椭球粒子体系的研究逐渐成为人们关注的焦点。在本工作中,利用事件驱动分子动力学(EDMD)[1]模拟,我们研究了二维单分散椭圆硬球体系的相变与玻璃化转变的一些性质。我们的研究结果表明:在长径比k=1.5时,体系转动玻璃化转变比平动玻璃化转变所对应的密度值略高。随着长径比的增加,体系的转动玻璃化转变密度点逐渐降低,而平动玻璃化转变密度点逐渐升高,并在长径比k=1.7时,两者的转变密度点相等;对于体系的结构性质,我们利用键取向关联函数[2]以及角度取向关联函数[3]的计算,获得了体系由各向同性相到塑性相以及由各向同性相到向列相的转变点,并且证明了体系中存在的不稳定向列相[4]只是体系向列相中的一个亚相。
We present an event-driven molecular dynamics(EDMD) study of phase transition and glass transition in two-dimensional ellipse system.Then we study the structural and dynamical properties through this simulation.For dynamical case,we find the orientational and translational glass transition occur at different area fractions with the system aspect ratio of k = 1.5,the orientational glass transition density is a bit higher than that of translational glass transition.However,with aspect ratio increasing,the orientational glass transition density will decrease while the translational glass transition density will increase.Around aspect ratio k=1.7,this two glass transitions will occur at the same density.For the structural case,we quantitatively determine the locations of isotropic-plastic transition and isotropic-nematic transition through the bond-orientation correlations and the angular correlations.At last we demonstrate that the unstable nematic phase may just be a mesomorphic phase of a nematic phase.
We present an event-driven molecular dynamics(EDMD) study of phase transition and glass transition in two-dimensional ellipse system.Then we study the structural and dynamical properties through this simulation.For dynamical case,we find the orientational and translational glass transition occur at different area fractions with the system aspect ratio of k = 1.5,the orientational glass transition density is a bit higher than that of translational glass transition.However,with aspect ratio increasing,the orientational glass transition density will decrease while the translational glass transition density will increase.Around aspect ratio k=1.7,this two glass transitions will occur at the same density.For the structural case,we quantitatively determine the locations of isotropic-plastic transition and isotropic-nematic transition through the bond-orientation correlations and the angular correlations.At last we demonstrate that the unstable nematic phase may just be a mesomorphic phase of a nematic phase.
引文
[1]Donev,A.;Torquato,S.;Stillinger,F.H.J.Comput.Phys.,2005,202:765
[2]Halperin,B.I.;Nelson,R.R.Phys.Rev.Lett.,1978,41:121
[3]Frenkel,D.;Eppenga,R.Phys.Rev.A.,1985,31:1776
[4]Cuesta,J.A.;Frenkel,D.Phys.Rev.A.,1990,42:2126
[2]Halperin,B.I.;Nelson,R.R.Phys.Rev.Lett.,1978,41:121
[3]Frenkel,D.;Eppenga,R.Phys.Rev.A.,1985,31:1776
[4]Cuesta,J.A.;Frenkel,D.Phys.Rev.A.,1990,42:2126