Thermodynamic and rheological variation in polysulfone solution by PVP and its effect in the preparation of phase inversion membrane

被引:453
作者
Han, MJ [1 ]
Nam, ST [1 ]
机构
[1] Kyungil Univ, Dept Chem Engn, Kyunbuk 712701, South Korea
关键词
polymeric membrane; phase inversion; polysulfone; polymer additive; permeate flux;
D O I
10.1016/S0376-7388(01)00718-9
中图分类号
TQ [化学工业];
学科分类号
0817 ;
摘要
Polysulfone (PSF) membranes were prepared via the phase inversion process from casting solutions consisting of PSF. n-methylpyrrolidone (NMP), and polyvinylpyrrolidone (PVP). The PVP as a non-solvent additive reduces the miscibility of casting solutions with non-solvent water, which causes thermodynamic enhancement for phase separation. and also induces the increase in solution viscosity, which causes kinetic hindrance against phase separation. In demixing of cast solutions through the vapor exposure, the thermodynamic enhancement and the kinetic hindrance works simultaneously, showing a trade-off relationship against one another. At low concentration (5 wt.%) of PVP. the variation in thermodynamic property controls the demixing process to result in the enhanced phase separation of the solution. With further increment of PVP. however, the solution demixing is delayed and the kinetic hindrance due to viscosity buildup overwhelms the thermodynamic factor: the enhancement in thermodynamic immiscibility could not contribute to the increase in demixing rate. When prepared via immersion process, the membranes show the similar trend in the water permeability as the phase separation data in the vapor exposure. That is, at low PVP concentration of 5 wt.%, the flux increases with the enhancement in the phase separation. but it drops with further increase of PVP in the casting solution rather than improved. (C) 2002 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:55 / 61
页数:7
相关论文
共 14 条
[1]   CALCULATION OF LIQUID LIQUID-PHASE SEPARATION IN A TERNARY-SYSTEM OF A POLYMER IN A MIXTURE OF A SOLVENT AND A NONSOLVENT [J].
ALTENA, FW ;
SMOLDERS, CA .
MACROMOLECULES, 1982, 15 (06) :1491-1497
[2]   MICROSTRUCTURES IN PHASE INVERSION MEMBRANES .2. THE ROLE OF A POLYMERIC ADDITIVE [J].
BOOM, RM ;
WIENK, IM ;
VANDENBOOMGAARD, T ;
SMOLDERS, CA .
JOURNAL OF MEMBRANE SCIENCE, 1992, 73 (2-3) :277-292
[3]   POLYSULFONE HOLLOW FIBERS .1. SPINNING AND PROPERTIES [J].
CABASSO, I ;
KLEIN, E ;
SMITH, JK .
JOURNAL OF APPLIED POLYMER SCIENCE, 1976, 20 (09) :2377-2394
[4]   DIFFUSION-CONTROLLED FORMATION OF POROUS STRUCTURES IN TERNARY POLYMER SYSTEMS [J].
COHEN, C ;
TANNY, GB ;
PRAGER, S .
JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS, 1979, 17 (03) :477-489
[5]   GELATION IN AN AMORPHOUS POLYMER - A DISCUSSION OF ITS RELATION TO MEMBRANE FORMATION [J].
GAIDES, GE ;
MCHUGH, AJ .
POLYMER, 1989, 30 (11) :2118-2123
[6]   Effect of propionic acid in the casting solution on the characteristics of phase inversion polysulfone membranes [J].
Han, MJ .
DESALINATION, 1999, 121 (01) :31-39
[7]  
Kesting R.E., 1985, SYNTHETIC POLYM MEMB, V2nd
[8]   THERMODYNAMICS OF POLYMER DILUENT SYSTEMS FOR THERMALLY INDUCED PHASE-SEPARATION .1. DETERMINATION OF EQUATION OF STATE PARAMETERS [J].
KIM, SS ;
LLOYD, DR .
POLYMER, 1992, 33 (05) :1026-1035
[9]  
Loeb S., 1960, 6060 UCLA DEP ENG
[10]   FORMATION OF ASYMMETRIC POLYSULFONE MEMBRANES BY IMMERSION PRECIPITATION .1. MODELING MASS-TRANSPORT DURING GELATION [J].
RADOVANOVIC, P ;
THIEL, SW ;
HWANG, ST .
JOURNAL OF MEMBRANE SCIENCE, 1992, 65 (03) :213-229