Forward Osmosis, Reverse Osmosis, and Nano/Micro Filtration Membrane Structures

Patent metadata

Field	Value
Publication number	US-2015165389-A1
Application number	US-201314108402-A
Country	US
Kind code	A1
Filing date	Dec 17, 2013
Priority date	Jun 17, 2011
Publication date	Jun 18, 2015
Grant date	—

Abstract

Disclosed is a composition for forming or treating reverse osmosis (RO), forward osmosis (FO), microfiltration (MF), or nanofiltration (NF) membranes, which includes a stable liquid blend of two of the following polymers: an oxygen polymer, a nitrogen polymer, and a sulfur polymer, where each polymer in a blend have matched solubility parameters; provided, that a nitrogen polymer can be in the form of a powder; where the weight ratio of polymers in each blend can range from 1:99 to 99:1; where each polymer optionally can be halogenated; where any polymer can be dispersed in a solvent for forming the blend.

First claim

We claim:

1 . A composition for forming or treating reverse osmosis (RO), forward osmosis (FO), microfiltration (MF), or nanofiltration (NF) membranes, which comprises:
a stable liquid blend of two of the following polymers: an oxygen polymer, a nitrogen polymer, and a sulfur polymer, where each polymer in a blend have matched solubility parameters; provided, that a nitrogen polymer can be in the form of a powder; where the weight ratio of polymers in each blend can range from 1:99 to 99:1; where each polymer optionally can be halogenated; where any polymer can be dispersed in a solvent for forming the blend.

2 . The composition of claim 1 , wherein said oxygen polymer is one or more of a cellulose acetate, a cellulose triacetate, an acrylic, acrylic modified alkyd, an epoxy, polyvinyl alcohol, polyvinyl chloride, polyvinyl acetate, or a polyester; said nitrogen polymer is one or more of a special nylon, an amine, a melamine, or a polyurethane; and said sulfur polymer is one or more of a polysulfide, a polysulfone, or a polyethersulfone.

3 . The composition of claim 1 , which additionally comprises one or more of amino acids, chelating agents, or nano or micro size particles or fibers.

4 . The composition of claim 1 , which is in the form of particles.

5 . The composition of claim 1 , which additionally comprises one or more of anionic polymers or oligomers; nonionic polymers or oligomers; cationic polymers oligomers; zwitterionic polymers; polymers that contain amino acids and chelating functionality; amino acids; chelating agents; micron or nanosize organic or inorganic materials; polymeric powders, zeolites; carbon fibers; polymeric fibers; inorganic fibers; graphene; epoxy/amine cross-linking agents; diisocyates; polyols; amines; or melamines; melamine/acids.

6 . The composition of claim 1 , which comprise one or more of 75%-90% cellulose acetate and 2%-25%% polyamide copolymer soluble in at least one solvent in which cellulose acetate is soluble; and 95% polyvinyl acetate and 5% polyamide copolymer soluble in at least one solvent in which polyvinyl acetate is soluble.

10% Nylon/90% CA

25% Nylon/75% CA

50% Nylon/50% CA

2% Nylon/98% CTA

4% Nylon/96% CTA

15% Nylon/85% CTA

5% Nylon/95% PVOAC

10% Nylon/90% CA/Mesh

7 . A process for forming reverse osmosis (RO), forward osmosis (FO), or nanofiltration (NF) membranes, which comprises the steps of:
(a) casting a wet film or extruding a hollow fiber of a membrane composition comprising a stable liquid blend of two of the following polymers: oxygen polymer, a nitrogen polymer, and a sulfur polymer, where each polymer in a blend have matched solubility parameters; provided, that a nitrogen polymer can be in the form of a powder; where the weight ratio of polymers in each blend can range from 1:99 to 99:1; where each polymer optionally can be halogenated; where any polymer can be dispersed in a solvent for forming a blend; (b) evaporating solvent from said cast film or extruded hollow fiber, where low solvent evaporation times produce an ultrafiltration or nanofiltration morphologies, medium solvent evaporation times produce FO morphology, and long evaporation times produce reverse osmosis morphology; (c) water quench said evaporated cast film or extruded hollow fiber to solidify its structure, where the quench water optionally can contain one or more of inorganic or organic microparticles or nanoparticles; nonionic, anionic, cationic, zwitterionic polymers; or amino acids; and (d) annealing at a temperature ranging between 50° C.-80° C. for 5 to 10 minutes said water quenched cast film or extruded hollow fiber, optionally wet with water and cosolvents.

8 . The process of claim 7 , wherein in step (b) low solvent evaporation times range up to 3 minutes; medium solvent evaporation time range between about 3 and 5 minutes; and long evaporation times range from between about 5 and 30 minutes.

9 . The process of claim 7 , wherein said oxygen polymer is one or more of a cellulose acetate, a cellulose triacetate, an acrylic, acrylic modified alkyd, an epoxy, polyvinyl alcohol, polyvinyl chloride, polyvinyl acetate, or a polyester; said nitrogen polymer is one or more of a special nylon, an amine, a melamine, or a polyurethane; and said sulfur polymer is one or more of a polysulfide, a polysulfone, or a polyethersulfone.

10 . The process of claim 7 , wherein said membranes in step (d) are microembossed.

11 . The process of claim 7 , wherein said cosolvents in step (d) comprise one or more of alkanols, inorganic microparticles or nanoparticles; organic microparticles or nanoparticles; nonionic polymers; anionic polymers; cationic polymers; zwitterionic polymers; or amino acids.

12 . The process of claim 7 , wherein said flat sheet membranes have an active about 0.1 to about 0.2 micron size dense layer on a about 1 to about 30 mils substrate layer; and said hollow has an outside diameter ranging between about 85 and about 2000 microns and an inside diameter ranging between about 42 and about 200 microns.

13 . A method for making roll-to-roll nanoimprint embossing plates for nanoimprinting reverse osmosis (RO), forward osmosis (FO), or nanofiltration (NF) membranes, which comprises the steps of:
(a) photolithograph silicon wafers with a nano/micro pattern; (b) cast a silicone polymer over said patterned silicon wafer; (c) casting a thermoformed polyurethane over said patterned silicone polymer and curing said polyurethane; and (d) electroplating said cured patterned polyurethane with metal to form a metal embossing plate for nanoimprinting reverse osmosis (RO), forward osmosis (FO), or nanofiltration (NF) membranes.

14 . The composition of claim 13 nanoimprinted with the process of claim 13 .

15 . A method of treating reverse osmosis (RO), forward osmosis (FO), microfiltration (MF), or nanofiltration (NF) membranes, which comprises the steps of:
(a) coating one side of said membrane with the composition of claim 1 ; and (b) applying suction to the other side of said membrane to pull said composition into the membrane pores without clogging them.

16 . The method of claim 15 , wherein said composition comprises a stable liquid blend of two of the following polymers: an oxygen polymer, a nitrogen polymer, and a sulfur polymer, where each polymer in a blend have matched solubility parameters; provided, that a nitrogen polymer can be in the form of a powder; where the weight ratio of polymers in each blend can range from 1:99 to 99:1; where each polymer optionally can be halogenated; where any polymer can be dispersed in a solvent for forming the blend.

17 . The method of cla

Assignees

• Battelle Memorial Institute

Inventors

• Mcginniss Vincent D
• Sayre Jay Randall
• Koper Olga B
• White Gregory R
• Masterson David C
• Spahr Kevin B
• Ellis Jeffrey
• Clay John Dee
• Stickel John R
• Luttinger Manfred
• Lane Ann
• Mueller Jr Jerry K

Classifications

• C08L29/04

  Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids · CPC title

• C08L27/06

  Homopolymers or copolymers of vinyl chloride · CPC title

• C08L1/12

  Cellulose acetate · CPC title

• B01D67/0013

  Casting processes · CPC title

• C08L81/06

  Polysulfones; Polyethersulfones · CPC title