Micron Separations, Inc.

Osmonics, Incorporated

James S Johnson

Michael J Witham

Edward T Carter

John M Greenwood

A non-cracking hydrophilic polyether sulfone membrane is prepared by (a) directly coating the entire surface of a hydrophobic polyethersulfone membrane with an aqueous solution of a polyalkylene oxide polymer and at least one polyfunctional monomer, and (b) polymerizing the monomer over the entire surface of the membrane under conditions which cause the resulting polymer to attach to the polyethersulfone membrane and the polyethylene oxide to form a non-extractable surface which does not crack when the membrane is folded to form a pleated cartridge.

Non-cracking hydrophilic polyethersulfone membranes

A method for making a skinless essentially symmetrical hydrophobic polysulfone microporous membrane by the steps of (a) forming a casting solution containing (i) a dissolved polyethersulfone polymer, (ii) a solvent for the polyethersulfone polymer, and (iii) a lower aliphatic glycol; (b) coating a substrate with the casting composition; (c) exposing the coated substrate to atmospheric conditions; (d) passing the exposed coated substrate into a precipitation bath to precipitate the membrane, the precipitation bath containing a lower aliphatic glycol and water; (e) rinsing the membrane; and (f) drying the membrane.

Preparation of polyethersulfone membranes

A greatly simplified improved vacuum filter funnel consists of two pieces, namely an upper reservoir member and a lower spout member. The upper reservoir member has an annular ring downwardly extending from the bottom thereof which fits inside an annular rim upwardly extending from the top of the lower spout member. A filter disk rests on an integral grid at the top of the lower spout member and is held in place between the upper and lower members by solely the weight of the upper member. The filter disk is readily removed after simply lifting up the upper reservoir member. Both the reservoir and spout members are preferably constructed of a chemical and heat resistant organic plastic, for example polysulfone, so that the parts may be sterilized in an autoclave.

Vacuum filter funnel

Polyamide (nylon) microporous membranes are prepared from a polyamide (nylon) polymer which contains aromatic rings, aliphatic carbon chains, and amide groups. The membranes exhibit improved long term performance characteristics. The membranes are preferably prepared from a polyamide polymer having the structure: ##STR1##

Aromatic/aliphatic nylon polymer microporous membranes

Alcohol-insoluble polyamide (nylon) microporous separation membranes are prepared from alcohol-soluble polyamide (nylon) polymers. The membranes are hydrophilic and contain crosslinked amide groups of the structure: ##STR1## wherein d is an integer of about 1 to 3.

Alcohol-insoluble nylon microporous membranes

Microporous nylon materials which retain near constant time to hydrosaturation during and after heating to temperatures necessary for sealing together a plurality of surfaces, and the synthesis thereof. Nylon 46 dissolved into a mixture of liquid nylon 46 solvents and nonsolvents is dispersed on a fabric substrate, then precipitated to form a laminate, from which a wash removes the nonsolvents and forms the microporous material.

Heat resistant microporous material production and products

A continuous process for producing a microporous cellulosic membranes supported with an integral non-woven polymer web by preparing a casting lacquer comprising at least one cellulosic polymer, at least one solvent and at least one non-solvent wherein the casting lacquer is at the point of incipient gelation.

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Acton, MA, United States of America

James S Johnson