Acta Phys. -Chim. Sin. ›› 2001, Vol. 17 ›› Issue (05): 416-421.doi: 10.3866/PKU.WHXB20010508

• ARTICLE • Previous Articles     Next Articles

New Perturbation Theory Model for Chainlike Molecule Fluid and the Predicted Heat Capacity

Liang Shi-Qiang;Zhang Bing-Jian;Lu Ying-Hong;Hu Wen-Xuan;Jin Zhi-Jun   

  1. Department of Chemistry,Zhejiang University,Hangzhou 310027;Department of Earth Sciences,Nanjing University,Nanjing 210093;Basin and Reservoir Research Center,China Petroleum University,Beijing 102200
  • Received:2000-09-21 Revised:2000-12-19 Published:2001-05-15
  • Contact: Zhang Bing-Jian

Abstract: A model for the freely jointed square well chain fluid is developed based on the thermodynamic perturbation theory of BarkerHenderson,Zhang and Wertheim.The analytic representations of squarewell monomer by Zhang are extended to obtain a series of representations for thermodynamic properties of squarewell chain fluids using the incorporating structural information for squarewell monomer of Wertheim's TPT1 model.The same work has been done using incorporating structural information for the diatomic squarewell fluid of TPTD model.The calculated results of compressibility factor,residual internal energy and constantvolume heat capacity of 4mer,8mer and 16mer chain fluids are tested against the MC results and a careful comparison between the model from TPT1 and that from TPTD has been made.The former agree with MC results much better than the later,especially for internal energy.To obtain the constantvolume heat capacity,NVT MC simulations have been performed.

Key words: Chain-like molecule, Square-well potential, Perturbation theory,  Thermodynamic property, Monte Carlo simulation