Abstract: A porous membrane product is provided which is formed from a porous membrane substrate having its surface completely modified with a perfluorocarbon copolymer composition. The porous membrane product has substantially the same permeability as the porous membrane substrate.

Abstract: A porous membrane product is provided which is formed from a porous membrane substrate having its surface completely modified with a perfluorocarbon copolymer composition. The porous membrane product has substantially the same permeability as the porous membrane substrate.

Abstract: A porous membrane is provided which is formed from a porous polyperfluorocarbon membrane substrate having its surface modified with a perfluorocarbon polymer composition. The modified surface is directly wet with an aqueous liquid.

Abstract: A heat exchange apparatus is provided which is formed from at least one multilayer presealed element and at least one monolayer element that are insert molded together. The heat exchange apparatus is provided with an inlet and an outlet for a process fluid and at least one inlet and at least one outlet for a heat exchange fluid. The sealing configuration of the presealed elements and the seal provided by the insert molding effect a seal configuration that causes heat to be transferred between the process fluid and the heat exchange fluid while preventing mass transfer between the two fluids.

Abstract: Water to be purified is passed through a reverse osmosis step to produce a pure water stream and a waste water stream. The waste water is directed to a deionization step to produce purified deionized water which is recycled to the reverse osmosis step. The process directs far less water to waste as compared to conventional reverse osmosis processes. The process also produces water of higher organic and inorganic purity than can be obtained by either reverse osmosis or deionization alone.