化学势的普遍化表达式及其应用  

The generalized expression of chemical potential and its applications

作　　者：王慧娟[1] 韩光泽[1] 

机构地区：[1]华南理工大学物理系,广东广州510640

出　　处：《华北电力大学学报（自然科学版）》2012年第1期109-112,共4页Journal of North China Electric Power University：Natural Science Edition

基　　金：广东省自然科学基金资助项目(S2011010000739);广东省科技计划项目(2010B050300007)

摘　　要：化学势是判断热力学系统相平衡的依据,是物质相变、扩散和化学反应的推动力。以能量公理为基础,从热力学基本原理出发推广了化学势的定义,导出了外场作用下化学势的普遍化表达式。外场作用下的化学势不仅是温度、压强和组分摩尔分数的函数,还与外场的特征参数有关。利用该普遍化表达式导出了重力场、离心力场和电磁场作用下的化学势,尤其是电场作用下电介质的化学势。利用该化学势研究了电场作用下纯物质的气液相变过程,结果表明,电场作用可以使极性物质的蒸汽压略有上升,对非极性物质没有影响,该结论与实验相符。对外场强化萃取和蒸馏等传质过程提供了一种新的研究方法。Chemical potential is not only the criterion to estimate chemical equilibrium but also the cause of diffusions,phase transitions and chemical reactions.In this paper,based on the energy postulate and thermodynamic principles,a generalized expression of chemical potential with the effect of external fields was derived,which shows that chemical potential not only depends on temperature,pressure and molar fraction of the components,but also is strongly affected by the characteristic parameters of the external fields.The gravitational,centrifugal,electric and magnetic chemical potentials were deduced from this generalized expression,especially the chemical potential of dielectric in electric field was also obtained.The vapor-liquid equilibrium of pure substance acted by electrostatic field was investigated with this new chemical potential.The results show that the electric field can slightly raise the saturated vapor pressure of polar substances,but no change of nonpolar substance,which coincide with the experimental results.This work provides a new method for the study of mass transfer,such as extraction and distillation,enhanced by external field.

关 键 词：能量公理 化学势 相平衡 气液相变 

分 类 号：O642.4[理学—物理化学] O414.1[理学—化学]