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以聚乙烯醇（ＰＶＡ）和聚乙二醇（ＰＥＧ）共混，甲醛交联制备亲水性高分子膜，用于渗透蒸发过程进行海水脱盐。ＰＥＧ的引入使盐一水分离成为可能，乙酸钠的引入使膜的分离通量明显提高。通过溶胀度、ＰＥＧ水溶液的粘度和膜形态分析等方法对ＰＶＡ－ＰＥＧ体系的高分子网络结构和膜中微相分离作了研究。发现了膜结构与渗透蒸发脱盐性能的基本关系．影响膜分离的因素除了化学亲合性之外，主要是硬的溶胀性和微目分离程度。ＰＥＧ的作用是限制膜的溶胀，使水以分子状态选择性地进入膜中．乙酸钠的作用是促进ＰＥＧ在膜中的微相分离，为水分子的透过提供通道．升高温度对膜的影响是降低溶胀度，但因ＰＶＡ和ＰＥＧ的ＬＣＳＴ的不同而增大微相分离，超过最佳分离温度（７０℃）后因膜以收缩为主而使通量下降．膜的微相分离使膜在盐水浓度提高到１０％以上时仍保持高的分离性能．
Polyvinyl alcohol (PVA) and polyethylene glycol (PEG) were blended and crosslinked with formaldehyde to prepare hydrophilic polymer membrane for desalination of seawater by pervaporation. The introduction of PEG makes it possible to separate water from salt water, and the introduction of sodium acetate increases the flux of membrane separation remarkably. The polymer network structure and membrane phase separation in PVA-PEG system were studied by means of swelling degree, viscosity of PEG aqueous solution and membrane morphology analysis. The basic relationship between membrane structure and pervaporation desalination performance was found. In addition to chemical affinity, the factors that affect membrane separation are primarily the degree of hard swelling and the degree of micro-detachment. The role of PEG is to limit the swelling of the membrane, allowing water to selectively enter the membrane in a molecular state. The role of sodium acetate is to promote the microphase separation of PEG in the membrane and to provide a channel for the permeation of water molecules. The effect of increasing temperature on the membrane is to reduce the degree of swelling, but the micro-phase separation is increased due to the LCST of PVA and PEG. When the optimal separation temperature (70 ° C) is exceeded, the flux decreases due to the shrinkage of the membrane. Microphase separation of the membrane allows the membrane to maintain high separation performance when the brine concentration is increased above 10%.