Frenkel与Schottky热缺陷统计理论描述液体PVT行为的比较

Comparison of Statistical Theory of Frenkel Thermal Defects and That of Schottky Thermal Defects for Description of PVT Behavior of Liquids

本文导出了基于不完全晶体中Ｆｒｅｎｋｅｌ热缺陷的液体晶格中被占座席分率的表达式及相应的ＳＨＴＦ状态方程，用１５个聚合物液体，１７个大分子烃液体和６个常用有机溶剂的ＰＶＴ数据检验了该模型对液体的描述能力，并同作者前期工作建立的基于不完全晶体中Ｓｃｈｏｔｔｋｙ热缺陷的ＳＨＴ状态方程做了比较。计算结果表明，两个状态方程均能较好地描述从分子量较小的有机溶剂到分子量极大的聚合物液体的热力学性质，但ＳＨＴ状态方程的计算精度略优于ＳＨＴＦ状态方程。

The occupied-site fraction in liquid lattice based on the Frenkel thermal defects of an imperfect crystal and the corresponding Equation of State SHTF EOS were derived in this work. The ability of the EOS for describing liquid properties was tested using the P-V-T data for 15 polymer liquids, 17 large molecular weight hydrocarbon liquids and 6 commonly usded organic solvents, and compared with the SHT EOS which was proposed by us in our previous work on the basis of the Schottky thermal defects of an imperfect crystal. The results show that both EOSs can give good accuracy for both organic solvents and polynier liquids, but the SHT EOS is more accurate than the SHTF EOS.This comes the conclution that the physical picture given by the Schottky thermal defects of an imperfect crystal is more close to the real liquid structure than that given by the Frenkel thermal defects, and the former can describe the thermodynamic properties of liquids better than the latter.