液-固吸附体系中计量置换吸附模型的热力学研究

研究了液-固吸附体系中溶质计量置换吸附过程中的自由能变,推导出了新的表示溶质种类、溶质浓度和溶剂对Gibbs自由能变贡献的数学表达式,并阐明了该表达式中各种参数的物理意义.将用通常方法测定的自由能变分为与溶质吸附和溶剂解吸附有关的两个独立的自由能变,推导出了液-固吸附体系中溶质计量置换吸附模型的两个线性参数β_a和q/Z对绝对温度倒数的线性关系,又将吸附过程中溶质的焓变和熵变分成两个独立的分量.用文献中的实验数据,对本文推导出的公式进行了检验,理论结果与实验结果一致.

Studies on Thermodynamics of Stoichiometric Displacement Model for Adsorption of Solute from Liquid-Solid System

Free energy change of stoichiometric displacement process for adsorption(SDM-A) of solute in a liquid-solid system was investigated. An expression which elucidates the contributions of each solute, solvent and adsorbent in the system to Gibbs free energy change was derived and the physical meaning of each parameter of the expression was also explained. Gibbs free energy change of adsorption for solute determined with traditional method can be divided into two independent fractions relating to the adsorption of solute and to the desorption of solvent, respectively. A linear relationship between two linear parameters BBBBBBBa and q/Z of the SDM-A and the reciprocal of absolute temperature was derived. And, each of the changes in both enthalpy and entropy of the SDM-A of solute can also be separately divided into two independent fractions. The derived equations were tested with experimental data in literatures and a conformable result between the both was obtained.