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化学学报
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化学学报 ›› 2007, Vol. 65 ›› Issue (13): 1258-1264. 上一篇    下一篇

研究论文

PSF/TiO2杂化超滤膜形成过程的热力学和动力学研究

杨亚楠*,1, 张会轩*,1, 王鹏2, 张明耀1, 杨海东1, 胡明忠1, 金晶1   

  1. (1长春工业大学 长春 130012)
    (2哈尔滨工业大学市政环境工程学院绿色化学与技术研究中心 哈尔滨 150090)
  • 投稿日期:2006-10-07 修回日期:2006-12-25 发布日期:2007-07-14
  • 通讯作者: 杨亚楠, 张会轩

Kinetic and Thermodynamic Research of Polysul-fone/TiO2 Hybrid Ultrafiltration Membrane

YANG Ya-Nan*,1; ZHANG Hui-Xuan*,1; WANG Peng2; ZHANG Ming-Yao1; YANG Hai-Dong1; HU Ming-Zhong1; JIN Jing1   

  1. (1 Changchun University of Technology, Changchun 130012)
    (2 Research Center for Green Chemistry and Technology, School of Municipal and Environmental Engineering, Harbin In-stitute of Technology, Harbin 150090)
  • Received:2006-10-07 Revised:2006-12-25 Published:2007-07-14
  • Contact: YANG Ya-Nan; ZHANG Hui-Xuan

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采用溶胶-凝胶法制备了不同纳米TiO2含量的聚砜(PSF)/TiO2杂化超滤膜, 研究了TiO2浓度对聚砜铸膜液流变学及热力学性质的影响, 构建了计算成膜过程中表观扩散系数(Da)的新方法, 求出不同TiO2浓度及温度下的Da值, 进而剖析了铸膜液流变学和热力学性质的变化对成膜动力学的影响. 并通过扫描电镜观察、杂化膜孔隙率和超滤性能的测试考察了表观扩散系数与膜结构和性能的关系. 结果表明, 加入TiO2溶胶的PSF铸膜液由牛顿流体转变为非牛顿流体, 其粘度随TiO2浓度增大而增大. TiO2的加入减小了铸膜液对非溶剂的容纳能力, 加速铸膜液的液-液相分离, 同时TiO2引起的热力学促进作用和流变学阻碍作用相互竞争, 共同影响Da的变化. 实验得出, Da随温度升高而增大, 随TiO2浓度的增大有先增大后减小的趋势. 表观扩散系数Da与膜的结构和性能具有很好的相关性并能直观地描述整个成膜过程.

关键词: 聚砜, 二氧化钛, 有机-无机杂化膜, 流变学和热力学性质, 表观扩散系数

Polysulfone (PSF)/TiO2 hybrid ultrafiltration (UF) membranes with different nano-sized TiO2 content were prepared by sol-gel method. The effects of TiO2 concentration on the rheological and thermodynamic properties of PSF casting solution were studied firstly. A new method used to calculate apparent diffusion coefficient (Da) in membrane formation process was founded subsequently. After calculating Da under different conditions, the effects of the rheological and thermodynamic properties on the kinetics of membrane formation were examined and the relationships of Da, membrane structure and UF performance were evaluated through the methods of SEM observation, porosity test and UF experiments finally. The results showed that the rheological properties of casting solution were changed from Newtonian viscous behavior to non- Newtonian viscous behavior, and the viscosities of casting solution were increased by the addition of TiO2. The addition of TiO2 also reduced the miscibility of PSF solution with non-solvent, leading to thermodynamic enhancement for phase inversion. The diffusion behavior of solvent and non-solvent in membrane formation was strongly influenced by the complex correlation between thermodynamic enhancement and rheological hindrance due to TiO2 addition. Da increased with the increase of temperature. However, it increased firstly and then decreased with the increase of TiO2 concentration. Moreover Da had an accordant pertinence with membrane structure and properties, and could describe the entire membrane for-mation intuitively.

Key words: polysulphone, TiO2, organic-inorganic hybrid membrane, rheological and thermodynamic properties, apparent diffusion coefficient