A New Kind of Membrane for Separation Processes: The Hydrophobic-Hydrophilic Membranes (Expedited Award for Novel Research)

所提出的过程将允许设计用于特定液体分离的膜。两种不混溶聚合物的单体用表面活性剂（可能是嵌段共聚物）相互分散。使用非常高的分散相摩尔分数，从而获得凝胶状的稠度。然后将凝胶压在玻璃板之间聚合。其结果是薄膜具有分离的、有序的结构域，有些是疏水的，有些是亲水的。单体的选择也使得要从液体混合物中分离的组分在分散在膜中的聚合物相中高度可溶。目标化合物不溶于其中的聚合物使液膜结构完整，而由分散相单体产生的聚合物对该化合物具有非常高的渗透性。聚合物组成了原始分散体的连续相，当膜被要从溶液中除去的溶质饱和时，膜被防止解体。潜在应用的一个例子是地下水净化，例如从受污染的含水层中去除苯。一种方法是用苯乙烯作为分散相来生产聚苯乙烯，它极易溶于苯。连续相单体的亲水性很好，如n-乙烯基吡咯烷酮。聚-n-乙烯基吡咯烷酮可以防止聚苯乙烯结构域在苯饱和时失去结构完整性，但苯通过聚苯乙烯结构域的通量应该很高。可以想象许多其他可能重要的分离，例如乙醇和水的分离。如果这一过程成功，它将构成一项重要的新兴工程技术的重大进步。

The proposed process would allow design of a membrane for a specific liquid separation. Monomers of two immiscible polymers are dispersed in one another with a surfactant (probably a block copolymer). A very high dispersed-phase mole fraction is used, so that a gel-like consistence is obtained. The gel is then pressed between glass plates and polymerized. The result is a thin membrane with separate, ordered domains, some hydrophobic and some hydrophilic. The monomers are also selected so that the component to be separated from the liquid mixture is highly soluble in the polymer phase which was dispersed in the membrane. The polymer in which the target compound is not soluble gives the liquid membrane structural integrity, while the polymer produced from the dispersed phase monomer has a very high permeability for that compound. The membrane is kept from disintegrating, as it becomes saturated with the solute to be removed from the solution, by the polymer making up the continuous phase of the original dispersion. An example of a potential application is ground water cleanup, such as the removal of benzene from a contaminated aquifer. One would use styrene as the dispersed phase to produce polystyrene, which is highly soluble in benzene. The continuous phase monomer would be very hydrophilic, such as n-vinyl pyrrolidone. The poly-n-vinyl-pyrrolidone would prevent the polystyrene domains from losing structural integrity as they became saturated with benzene, but the flux of benzene through the polystyrene domains should be very high. Many other potentially important separations can be imagined, such as the separation of ethanol from water. If this process is successful, it will constitute a major advance in an important emerging engineering technology.