Aligena Ag

Research Products Rehovot Ltd.

Gershon Aviv

Charles Linder

Mordechai Perry

Reuven Kotraro

Dynamic membranes are obtained by coating on a porous polymeric substrate containing functional groups a chemically reactive hydrophilic polymer from a dilute aqueous solution under pressure and crosslinking said polymer present on the porous substrate as thin layer with low molecular polyfunctional compounds. The new membranes show good solvent and compaction resistance and resistance to separation of the individual layers. They can be used in ultrafiltration and reverse osmosis processes.

High flux RO/UF membranes

Semipermeable membranes of a porous polymeric substrate whose external and all internal surfaces (pores) are encapsulated by a semipermeable thin film of a hydrophilic polymer are provided. The encapsulating film consists of at least one layer of said polymer which is cross-linked/stabilized by polyfunctional compounds containing at least two functional (reactive) groups. The membrane substrate is optionally pretreated--before the encapsulation step--with polyfunctional compounds. The new membranes can be used in ultrafiltration and reverse osmosis processes. They are solvent-, pressure- and temperature-resistant and show good separation capacities, e.g. for separating organic compounds from salt solutions.

Semipermeable encapsulated membranes, process for their manufacture and

Semipermeable membranes of modified styrene polymers are obtained by modifying styrene polymers containing reactive groups

Semipermeable membranes of modified styrene-based polymers, process for

Semipermeable membranes of modified polysulfones are provided which comprises repeating units of the formula

Chemically modified semipermeable membranes and their use in reverse

Chemically modified semipermeable polysulfone membranes and their use in

Dynamically formed membranes

Semipermeable membranes of polyacrylonitrile or copolymers of acrylonitrile and other ethylenically unsaturated monomers are chemically modified through reaction with (a) hydroxylamine and (b) a poly functional ionic colorless cyclic carbonic acid imide-halide capable of reaction with amidoxime groups, and optionally containing ionic groups. The new membranes show good compaction and solvent resistance and are stable over a broad temperature and pH range. They are suitable for reverse osmosis and especially ultrafiltration processes.

Modified acrylonitrile polymer containing semipermeable membranes

The invention provides amidoxime derivatives of the general formula ##STR1## wherein R.sub.1 is an alkyl group of 1 to 8 carbon atoms, phenyl, a heterocyclic ring structure of 5 to 8 atoms containing one or more nitrogen or oxygen atoms or combinations thereof or a bicyclic condensed ring system optionally containing at least one heterocyclic ring which groups may each be optionally substituted. R.sub.2 is a mono or bicyclic heterocyclic radical containing at least two nitrogen atoms which radical is also optionally substituted. R.sub.3 and R.sub.4 are independently H, or an alkyl of 1 to 4 carbon atoms or one, but not both, is ##STR2## and the other, H, wherein R.sub.5 or R.sub.6 are alkyls of 2 to 5 carbon atoms optionally substituted by R.sub.1, or a phenyl optionally substituted by R.sub.1 or R.sub.5 or R.sub.6 is combined with R.sub.1 to jointly form cyclic imidoximes or imidedioximes. The invention also provides processes for the preparation of these compounds and many uses therefor including application in affinity chromatography, enzyme reactors and for preparing dense and porous fibers, fabrics and particles.

Growing community of inventors

Tel Aviv, Israel

Gershon Aviv