物理化学学报 >> 2002, Vol. 18 >> Issue (01): 62-65.doi: 10.3866/PKU.WHXB20020114

研究简报 上一篇    下一篇

硅胶自水溶液中吸附丙酸和丁酸的计量置换吸附模型

陈禹银;刘凡   

  1. 乐山师范学院化学系,乐山　614004
  • 收稿日期:2001-06-11 修回日期:2001-08-22 发布日期:2002-01-15
  • 通讯作者: 陈禹银 E-mail:Chy514@163.net

Stoichiometric Displacement Model for the Adsorption of Propionic Acid and nButyric Acid by Silica Gel from Aqueous Solution

Chen Yu-Yin;Liu Fan   

  1. Department of Chemistry, Leshan Teacher′s College, Leshan　614004
  • Received:2001-06-11 Revised:2001-08-22 Published:2002-01-15
  • Contact: Chen Yu-Yin E-mail:Chy514@163.net

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摘要： 实验研究了硅胶在293、303和313 K下,从水溶液中对丙酸和丁酸的吸附.发现该吸附服从液固吸附中的计量置换吸附模型（SDMA）.根据吸附模型的线性参数研究了吸附热力学和吸附机理.该吸附是一个自发的、放热的熵减少过程.丁酸的标准吸附自由能比丙酸大,而标准吸附焓比丙酸小.推导出了实验条件下吸附自由能变化的计算公式.

关键词: 硅胶, 吸附, 丙酸, 丁酸, 计量置换吸附模型, 热力学

Abstract: The adsorption of propionic acid and nbutyric acid from aqueous solution by silica gel has been studied at 293,303 and 313 K respectively.It was found that the adsorption obey stoichoimetric displacement model for adsorption at liquidsolid system (SDMA). The thermodynamics and mechanism of adsorption processes were studied on the basis of linear parameter from SDMA. The adsorption is a spontaneous, exothermic process of reduced entropy. Standard free energy change for the adsorption of nbutyric acid is larger than that of propionic acid. Standard enthalpy change for the adsorption of nbutyric acid is smaller than that of propionic acid. The equation of free energy change for adsorption was derived.

Key words: Silica gel, Adsorption, Propionic acid, n-Butyric acid, 　Stoichiometric displacement model for adsorption, Adsorption thermodynamics