Prediction of EVAL membrane morphologies using the phase diagram of water-DMSO-EVAL at different temperatures

POLYMER

卷:40

Article

Young, TH ; Cheng, LP ; You, WM ; Chen, LY

关键词: EVAL membranes;    temperature;    crystallization;   

DOI  :  10.1016/S0032-3861(98)00455-8

来源: Elsevier

【 摘 要 】

The effects of precipitation temperature on the structures of the EVAL membranes formed in a wet phase inversion process were studied. As the temperature was changed, the phase behavior (liquid-liquid demixing and crystallization boundaries) of the membrane formation system changed accordingly. Therefore, a wide variety of morphologies of the EVAL membranes could be synthesized at different temperatures. At low temperatures (e.g., 25 degrees C), the membrane solution precipitated into a particulate morphology that was governed by the polymer crystallization mechanism, whereas at elevated temperatures (e.g., 65 degrees C) liquid-liquid demixing process dominated the precipitation process and the membrane became cellular in its morphology. In the intermediate cases, the membrane exhibited a structure containing features from both types of phase separations. For the current system, it was found that there existed a good correlation between the phase behavior and the morphology of the membranes. (C) 1999 Elsevier Science Ltd. All rights reserved.

【 授权许可】

Free