Abstract: Theoretical and expermental researches have been made on the hydrodynamic in-stabililty of casting film solution and the formation of an ultrathin membrane. The results show that the hydrodynamic instability of the solution leads to forming holes in the skin layer of the membrane. The solution thickness on the solid support during the ultrathin film casting operation is significantly responsible for hydrodynamic instability. With an optimum thickness of ultrathin membrane, the instability can be suppressed and the holes in the skin layer can be reduced or eliminated, so that the ultrathin composite membrane will have high rejection as well as high water flux.

摘要： 通过理论分析和实验研究证明了成膜过程中铸膜液的流体力学不稳定性是导致膜表层缺陷孔洞的重要原因,而膜厚是影响流体力学不稳定性的重要参数。适当的厚度可以抑制失稳的发生,从而减少甚至消除膜表层的缺陷孔洞,在使膜获得高透水率的同时使膜获得高分离性能。