Ionics, Inc.

Warren A Waite

Russell B Hodgdon

Hans I Viklund

Apparatus and process for separating a fluid mixture into less permeable and more permeable fractions employing novel selectively permeable barriers comprised of a porous, emulsion treated substrate and a non-porous selectively permeable barrier layer thereon.

Selectively permeable barriers

Semi-permeable membrane and membrane/support assemblies and systems for microfiltration, ultrafiltration, nanofiltration, reverse osmosis, electrodialysis, electrodeionization and piezodialysis filter systems are formed of polymer membranes (14), including fine particle moieties (24) or threads (16) of substantially water insoluble, oligodynamic bioactive (biostatic and/or biocidal) dispersed material. When these membranes systems are used in aqueous liquids the dispersed material dissolves slowly and provides a continuous biostatic and/or biocidal action over a long duration to counteract membrane fouling propensities of the system environment.

Anti-fouling semi-permeable membrane system

A composite semipermeable membrane having improved chlorine tolerance, produced by employing the development of a thin film polymer layer by precipitation of the polymer at the interface of an aqueous (or organic) liquid layer; and an aqueous emulsion polymer layer at or near the surface of a semiporous support or substrate. No chemical reaction is involved.

Composite semipermeable membrane created by precipitation of emulsion

A thin film composite (TFC) semipermeable membrane on a semiporous substrate is produced by an interfacial polymerization reaction between (1) an aqueous phase comprising a blend of water soluble and water dispersable compounds, (the latter being a chlorine or other oxidant neutralizer which protects the resulting semipermeable membrane from short term damage by chlorine or other oxidants) and (2) an organic phase comprising polyfunctional crosslinking reagents capable of reacting and/or polymerizing with one or more of the ingredients of said aqueous phase.

Chlorine tolerant composite semipermeable membrane

A composite semipermeable membrane on a semiporous support or substrate is produced by employing an interfacial polymerization reaction between (1) an aqueous phase comprising a blend of water soluble and water dispersable compounds and (2) an organic phase comprising poly-functional crosslinking reagents capable of reacting and/or polymerizing with one or more of the ingredients of said aqueous phase.

Composite semipermeable membrane

This invention is directed to electrodialysis, electrochemical membrane cells and particularly to components comprising the ion-exchange membranes. These membranes are fabricated containing a reinforcing structure comprised of non-woven carbon fibers derived for example from carbonized polyacrylonitrile. The membranes so produced have a low D.C. electrical resistance (increased conductivity) which enables electrodialysis to be performed more economically.

Ion-exchange membranes reinforced with non-woven carbon fibers

The reaction of vinylbenzyl chloride and N, N, N', N', 2-pentamethyl-1,2-propanediamine (PMPDA) produces a high capacity, base stable, crosslinked, anion exchange polymer useful especially when manufactured in sheet or membrane form for use in electrodialysis apparatus.

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Burlington, MA, United States of America

Warren A Waite