Patents Assigned to NL Chemical Technology, Inc
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Patent number: 11684895Abstract: A composite reverse osmosis membrane having a semipermeable bilayer polyamide composition comprising a base layer containing a rigid crosslinked aromatic polyamide and a top layer containing a flexible aliphatic polyamide is disclosed, the two layers in combination providing reduced salt passage in reverse osmosis desalination of brackish waters and of seawater.Type: GrantFiled: September 3, 2020Date of Patent: June 27, 2023Assignee: NL Chemical Technology, Inc.Inventors: John F. Thompson, Lars Kohler, Qun Song, Jane C. Li
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Publication number: 20230126220Abstract: Spiral wound reverse osmosis devices with reduced lateral leakage and thereby increased salt rejection are made by compacting a microporous layer within a composite reverse osmosis membrane longitudinally along its lengthwise periphery. Means and method for causing longitudinal indentations in composite membranes during manufacturing operations are disclosed and described.Type: ApplicationFiled: September 15, 2022Publication date: April 27, 2023Applicant: NL Chemical Technology, IncInventor: Robert Joseph Petersen
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Patent number: 11535531Abstract: Spiral wound reverse osmosis devices with reduced lateral leakage and thereby increased salt rejection are made by compacting a microporous layer within a composite reverse osmosis membrane longitudinally along its lengthwise periphery. Means and method for causing longitudinal indentations in composite membranes during manufacturing operations are disclosed and described.Type: GrantFiled: August 5, 2020Date of Patent: December 27, 2022Assignee: NL Chemical Technology, Inc.Inventor: Robert J. Petersen
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Publication number: 20220062830Abstract: A composite reverse osmosis membrane having a semipermeable bilayer polyamide composition comprising a base layer containing a rigid crosslinked aromatic polyamide and a top layer containing a flexible aliphatic polyamide is disclosed, the two layers in combination providing reduced salt passage in reverse osmosis desalination of brackish waters and of seawater.Type: ApplicationFiled: September 3, 2020Publication date: March 3, 2022Applicant: NL Chemical Technology, Inc.Inventors: John F. Thompson, Lars Kohler, Qun Song, Jane C. Li
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Publication number: 20220040643Abstract: Poly(amino acids) having hydrophilic side groups may be grafted onto active surfaces of polyamide composite membranes so as to confer fouling resistance. Polylysine, polyhistidine, polyarginine and their blends with polyglutamic acid may be grafted to membrane surfaces via amide linkages or via peroxide-induces bonding, modifying membrane surfaces behavior towards foulants.Type: ApplicationFiled: August 4, 2020Publication date: February 10, 2022Applicant: NL Chemical Technology, Inc.Inventors: Qun Song, Jane C. Li, Norman N. Li
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Publication number: 20220041474Abstract: Spiral wound reverse osmosis devices with reduced lateral leakage and thereby increased salt rejection are made by compacting a microporous layer within a composite reverse osmosis membrane longitudinally along its lengthwise periphery. Means and method for causing longitudinal indentations in composite membranes during manufacturing operations are disclosed and described.Type: ApplicationFiled: August 5, 2020Publication date: February 10, 2022Applicant: NL Chemical Technology, Inc.Inventor: Robert J. Petersen
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Publication number: 20210031149Abstract: A reverse osmosis membrane is disclosed that has a hydrogel disposed on its surface, wherein the hydrogel is formed from a crosslinked polyvinylpyrrolidone or a copolymer of vinyl pyrrolidone. The hydrogel-coated membrane resists fouling by feed water contaminants. The permeate flux rate and salt rejection of the underlying membrane are not negatively affected by the hydrogel coating.Type: ApplicationFiled: July 30, 2019Publication date: February 4, 2021Applicant: NL Chemical Technology, IncInventors: Qun Song, Jane C. Li, Norman N. Li
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Publication number: 20210031147Abstract: A water treatment membrane and method of making water treatment membranes includes an interfacially formed polyamide layer residing upon a microporous support film and having a plurality of graphene oxide quantum dots attached to an outer surface of the polyamide layer. The polyamide layer has a permeate flux and a salt rejection performance. The permeate flux is increased by the presence of the graphene oxide quantum dots attached to the outer surface of the polyamide.Type: ApplicationFiled: July 27, 2020Publication date: February 4, 2021Applicant: NL Chemical Technology, IncInventors: Patricia B. Sun, Jane C. Li, Lars Kohler
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Patent number: 6162358Abstract: Reverse osmosis membranes with improved water flux and excellent solute rejection characteristics are formed by interfacial reaction of an essentially monomeric polyamine reactant having an average of at least two amine functional groups with an essentially monomeric amine-reactive reactant having an average of at least 2.05 acyl halide functional groups, the polymerization reaction being conducted in the presence of a monohydric phenol on the surface of a porous substrate. A specific example is a high flux composite membrane prepared by coating a porous substrate with an aqueous solution containing about 0.1-20 wt % m-phenylenediamine and 0.1-9.9 wt % phenol, and interfacially contacting the coated substrate with a nonaqueous solution of about 0.01-10 wt % trimesoyl chloride for a time sufficient to form a polyamide coating, followed optionally by one or more washing and drying steps to remove the nonaqueous solvent and most or all of residual unreacted chemicals.Type: GrantFiled: June 5, 1998Date of Patent: December 19, 2000Assignee: NL Chemicals Technologies, Inc.Inventors: Norman N. Li, Mark A. Kuehne, Robert J. Petersen