Thermal conductivity of amorphous polystyrene in supercritical carbon dioxide studied by reverse nonequilibrium molecular dynamics simulations.
Thermal conductivity of amorphous polystyrene in supercritical carbon dioxide studied by reverse nonequilibrium molecular dynamics simulations.
复制标题
反向非平衡分子动力学模拟研究非晶聚苯乙烯在超临界二氧化碳中的导热系数
DOI：
10.1021/jp9009492
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
F. Müller-Plathe
中科院分区：
文献类型：
--
作者：
E. Algaer;M. Alaghemandi;M. C. Böhm;F. Müller-Plathe
在较宽的温度、压力和浓度范围内，研究了无定形聚苯乙烯(PS)在超临界二氧化碳(sc-CO2)中溶胀的导热系数。采用全原子力场非平衡分子动力学模拟方法，计算了纯PS和超临界CO2以及不同组成的二元体系的导热系数。根据PS和CO2数据，得到了二元混合物导热系数的解析插值公式。特别注意了准简并效应和有限尺寸效应对模拟聚合物体系的影响。研究发现，除了单位体积的自由度外，骨架中的碳−碳键相对于温度梯度方向的取向对PS中的热传输也很重要。
The thermal conductivity of amorphous atactic polystyrene (PS) swollen in supercritical carbon dioxide (sc CO2) has been investigated over wide temperature, pressure, and concentration ranges. Nonequilibrium molecular dynamics simulations with a full atomistic force field have been used to calculate the thermal conductivity of neat PS and sc CO2as well as of the binary system at different compositions. An analytical interpolation formula for the thermal conductivity of the binary mixture on the basis of PS and CO2data has been obtained. Particular attention has been paid to the implications of the quasi-degeneracy and finite-size effects in the simulated polymer system. It has been found that, in addition to the degrees of freedom per volume, the orientation of the carbon−carbon bonds in the backbone relative to the direction of the temperature gradient is important for the heat transport in PS.