Kinetics and Thermodynamics of Adsorption of VB12 onto Mesoporous Carbon Coated with PMMA

作     者：GUO Zhuo ZHANG Wei-wei DING Xiang-ping LI Sha MA Lei 

作者机构：School of Materials Science and Engineering Shenyang Institute of Chemical Technology Shenyang 110142 P R. China State Key Laboratory of lnorgnic Synthesis and Preparative Chemistry Jilin University Changchun 130012 P. R. China 

出 版 物：《Chemical Research in Chinese Universities》 (高等学校化学研究（英文版）)

年 卷 期：2010年第26卷第3期

页      面：431-435页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 070305[理学-高分子化学与物理] 09[农学] 080501[工学-材料物理与化学] 0903[农学-农业资源与环境] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 090301[农学-土壤学] 

基　　金：Supported by the National Natural Science Foundation of China(No.20771049) 

主　　题：Mesoporous carbon VB12 adsorption Equilibrium Kinetics Thermodynamics 

摘      要：Ordered mesoporous carbons CMK-3, CMK-I coated with poly（methyl methacrylate）（PMMA）（CMK-3- PMMA and CMK-1-PMMA） and pristine mesoporous carbons CMK-3, CMK-1 were employed to adsorb vitamin B12（VB12） from water solution. Adsorption isotherm and kinetics of adsorption were investigated via batch experiments. It was found that the adsorption capacity of VB 12 at 30, 40 and 50 ℃ can reach 688.2, 572.4 and 428.7 mg/g, respectively. The adsorption isotherm can be described by Langmuir model. The pseudo first- and second-order kinetic models were employed to fit the dynamic adsorption. It was found that the dynamic adsorption follows the pseudo second-order model. The thermodynamic equilibrium coefficients obtained at different temperatures were used to evaluate the thermodynamic constants △G^0, △H^0 and △S^0. The negative value of Gibbs free energy, △G^0 indicates that the adsorption occurred via a spontaneous process. The increase in the value of-△G^0 with increasing temperature indicates that higher temperatures were favourable to the sorption process. The enthalpy values of △H^0〉40 kJ/mol（66.36 kJ/mol and 56.43 kJ/mol） for CMK-3-PMMA and CMK-1-PMMA confirm that chemisorption were involved in the adsorption process. This is consistent with the IR spectra and is another evidence for the formation of hydrogen bond between PMMA in the pore of CMK-3 and VB 12.