Effect of zero shear viscosity of the casting solution on the morphology and permeability of polysulfone membrane prepared via the phase-inversion process
Effect of zero shear viscosity of the casting solution on the morphology and permeability of polysulfone membrane prepared via the phase-inversion process
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DOI：
10.1016/j.desal.2010.05.002
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发表时间：
2010-09
期刊：
影响因子：
9.9
通讯作者：
Zhenghua Zhang;Quan‐Fu An;Yan-li Ji;J. Qian;Cong-jie Gao
中科院分区：
文献类型：
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作者：
Zhenghua Zhang;Quan‐Fu An;Yan-li Ji;J. Qian;Cong-jie Gao
研究了用相转化法制备的两种聚砜(PSF)铸膜液的零剪切粘度及其膜的形态和渗透性。用落球式粘度计测定了PSF/N，N-二甲基乙酰胺(DMAC)二元体系和PSF/DMAC/PVP三元体系的零剪切粘度。在浊点实验中研究了溶液的浊点，并用透光仪监测了相变过程。用扫描电子显微镜对膜的表面和横截面进行了表征，并在渗透实验中测定了膜的水通量。随着铸膜液粘度的增加，膜的表面孔洞变少，膜的表层变厚。这些实验结果归因于体系热力学性质的变化和相转化过程中组分之间的扩散较差，最终导致PSF膜的水通量较低。结果表明，铸膜液的零剪切粘度是影响同一凝固浴相转化法制备膜的形态和透气性的重要参数之一。
The zero shear viscosity of two kinds of polysulfone (PSF) casting solutions and the morphology and permeability of their membranes prepared via the phase-inversion process were investigated. The zero shear viscosities, dominated by changing the concentration of PSF and the molecular weight of poly(vinyl pyrrolidone) (PVP) additive for the PSF/N, N-Dimethylacetamide (DMAC) binary system and PSF/DMAC/PVP ternary system respectively, were measured by a falling sphere viscometer. The cloud point of solutions was investigated in the cloud point experiment, and the phase-inversion process was monitored by the light transmittance apparatus. The surface and cross-section morphology of the corresponding membranes were characterized by SEM, and the water flux of the membranes was performed in the permeation experiment. Increasing the viscosity of the casting solution leads to the less porous surface and thick-skinned top-layer of the membrane. These experimental results are attributed to the mutable thermodynamic property of the system and the poor diffusion between components during the phase-inversion process, and finally results in the low water flux of PSF membranes. It suggests that the zero shear viscosity of the casting solution is one of the most important parameters for the morphology and permeability of membranes prepared via the phase-inversion process with the same coagulation bath.