A defect free semipermeable composite membrane having excellent integrity and high water permeability is provided. Said composite membrane comprises an inside support layer to provide sufficient mechanical strength; an outside barrier layer to provide selective separation; and a middle layer to provide both physical adhesion and chemical binding between said support and said barrier layer to bond them together. Three different methods for making said defect free composite membrane are discovered. These methods have been successfully utilized to produce high quality coatings and defect free composite membranes, which are independent of chemical composition and physical structure of said support. In the present invention, ultrasonic sonication is discovered to be effective to speed up the phase inversion process of a membrane casting solution, thus allows produce a composite membrane at a speed much higher than those disclosed in the prior art. Said defect free composite membranes have broad applications, ranging from filtration of fruit juice, wine and milk to biotech down stream processing and purification of drinking water, municipal and industrial wastewater.
本发明提供了一种无缺陷半透膜复合材料,具有极佳的完整性和高透
水性。所述复合膜包括一个内支撑层,用于提供足够的机械强度;一个外阻隔层,用于提供选择性分离;以及一个中间层,用于在所述支撑层和所述阻隔层之间提供物理粘合力和
化学结合力,将它们粘合在一起。我们发现了三种不同的制作上述无缺陷复合膜的方法。这些方法已成功用于生产高质量涂层和无缺陷复合膜,它们与所述支撑物的
化学成分和物理结构无关。在本发明中,发现超声波能有效加快膜铸造溶液的相反转过程,从而能以远高于现有技术的速度生产出复合膜。这种无缺陷的复合膜应用广泛,从果汁、葡萄酒和牛奶的过滤到
生物技术的下游处理以及饮用
水、城市和工业废
水的净化。