高等学校化学学报

高等学校化学学报

• 研究论文 • 上一篇    下一篇

草酸对非对称膜成膜过程中热力学、流变学和凝胶动力学的影响

李昕1,2, 陈翠仙2, 李继定2   

    1. 北京理工大学化工与环境学院, 北京 100081;
    2. 清华大学化工系, 北京 100084
  • 收稿日期:2008-05-08 修回日期:1900-01-01 出版日期:2009-01-10 发布日期:2009-01-10
  • 通讯作者: 李昕

Effect of Oxalic Acid on Rheological Variation, Thermodynamic Variaton and Formation Kinetics in Asymmetric Membrane Formation

LI Xin1,2*, CHEN Cui-Xian2, LI Ji-Ding2   

    1. School of Chemical Engineering and Enviroment, Beijing Institute of Technology, Beijing 100081, China;
    2. Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
  • Received:2008-05-08 Revised:1900-01-01 Online:2009-01-10 Published:2009-01-10
  • Contact: LI Xin

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被引次数

11

摘要： 以酚酞基聚芳醚砜/草酸/N,N-二甲基乙酰胺为铸膜液体系, 考察了草酸对非对称膜成膜过程中的热力学、流变学和凝胶动力学的影响. 结果表明, 草酸的加入, 在热力学上加速了铸膜液的相分离. 成膜过程中凝胶动力学的研究结果表明, 凝胶前锋位移的平方与时间不是简单的线性关系. 将凝胶过程与非对称膜的结构相对应, 分为4个连续的凝胶过程, 凝胶速度曲线由4段具有不同速度常数的线段组成. 在凝胶过程中, 凝胶速度常数最大的是皮层.

关键词: 草酸, 非对称膜, 热力学, 流变学, 凝胶动力学

Abstract: The effects of oxalic acid on rheological, thermodynamic and membrane formation kinetics were investigated in polyethersulfone with cardo/oxalic acid(OA)/N,N-dimethylacetamide cast solution. The results show that the addition of OA can work in favor of the enhancement in the demixing of casting solution thermodynamically.The membrane formation kinetics result is different from a commonly accepted conclusion obtained by Strathman et al. that a single linear correlation between square of precipitation front move(L2) and gelation time(t) existed for the whole gelation process. Four different linear correlations between the value of L2 and gelation time(t), were identified, these four correlations correspond to four consecutive gelation steps. The maximal gelation rate constant occurred the top layer.

Key words: Oxalic acid, Asymmetric membrane, Thermodynamic, Rheological, Formation kinetics

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