摘要
依据液／固体系中溶质吸附计量置换模型的热力学研究，导出溶质吸附Ｇｉｂｂｓ自由能的两个分量随温度和溶质活度变化的计算公式．发现吸附质与吸附剂之间的亲合Ｇｉｂｂｓ函数变化分量ΔＧ（βα）及在相同的溶质平衡活度αＰＤｍ时溶剂自吸附剂表面的解吸Ｇｉｂｂｓ函数变化分量ΔＧ（ｑ／ｚ，ＰＤｍ）均是温度的线性函数；当温度一定时，ΔＧ（βα）为常数，ΔＧ（ｑ／ｚ，ＰＤｍ）则与ｌｏｇαＰＤｍ呈线性关系．由这两个分量分别对温度线性作图可获得溶质吸附焓变和熵变的相应分量值．对于所有这些热力学函数变化分量值的计算公式用于取自文献吸附数据的定量计算表明。
On the basis of the thermodynamics of the stoichiometric displacement model for adsorption of a solute,two equations, which are used to calculate separately two fractions of the Gibbs free energy charge for the solute adsorption which depend on temperature and the solute activity in bulk solution, were deduced.It was discovered that the amounts of Δ G (β α) (the affinity Gibbs free energy change between an adsorbate and adsorbent)in any equilibrium activity of the solute, α PD m , and the ones of another fraction Δ G (q/z,PD m) (the desorption Gibbs free energy of a solvent from an adsorbent)at an identical α PD m are both linear functions with temperature; at the same temperature, Δ G (β α) is an identical while variation of Δ G (q/z,PD m) with log α PD m shows a linear relation. The corresponding fractions of both enthalpy and entropy changes for adsorption of a solute can be derived from the plotting of the foregoing calculated Δ G (β α) and Δ G (q/z,PD m) vs. thermodynamic temperatures T , respectively. Experimental data on isotherms from the literature were used to test all of the thermodynamic function changes computed quantitatively via the equations presented in this study, and a satisfactory result was obtained.
出处
《纺织高校基础科学学报》
CAS
1997年第2期103-110,共8页
Basic Sciences Journal of Textile Universities
基金
陕西省自然科学基金
关键词
吸附
热力学
函数变分量
液固体系
吸量置换模型
liquid solid system adsorption, thermodynamic function change fraction, adsorption, stoichiometric displacement model for adsorption
