# US 10,766,004 B2 · Composite membranes and methods of use

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- Number: US 10,766,004 B2
- Document ID: US10766004B2
- Status: Granted
- Kind: B2
- Application number: 15/108,892
- Filed: 2014-12-24
- Published: 2016-11-10
- Granted: 2020-09-08
- Earliest claimed: 2013-12-30
- Assignees: 3M Innovative Properties Company
- Applicants: 3M Innovative Properties Company
- Inventors: Jinsheng Zhou; Ryan C. Shirk; David Scott Seitz
- Web page: https://patentgrep.com/patent/US10766004B2

## CPC

- B01D 61/362: {Pervaporation}
- B01D 61/366: {Apparatus therefor}
- B01D 67/0006: {by chemical reactions (in-situ polymerisation, polycondensation, cross-linking or reaction for manufacturing composite membranes B01D69/125)}
- B01D 67/0095: {Drying}
- B01D 69/107: {Organic support material}
- B01D 69/12: Composite membranes; Ultra-thin membranes
- B01D 69/125: {In situ manufacturing by polymerisation, polycondensation, cross-linking or chemical reaction}
- B01D 71/401: {Polymers based on the polymerisation of acrylic acid, e.g. polyacrylate}
- B01D 71/421: {Polyacrylonitrile}
- B01D 71/44: Polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds, not provided for in a single one of groups B01D71/26-B01D71/42
- B01D 71/48: Polyesters
- B01D 71/5222: {Polyetherketone, polyetheretherketone, or polyaryletherketone}
- B01D 2323/30: Cross-linking
- B01D 2323/345: UV-treatment
- B01D 2323/46: Impregnation
- B01D 2325/022: Asymmetric membranes
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)

## Abstract

A composite membrane for selectively pervaporating a first liquid from a mixture comprising the first liquid and a second liquid. The composite membrane includes a porous substrate comprising opposite first and second major surfaces, and a plurality of pores. A pore-filling polymer is disposed in at least some of the pores so as to form a layer having a thickness within the porous substrate. The polymer is more permeable to the first liquid than the second liquid but not soluble in the first liquid or the second liquid. The composite membrane may be asymmetric or symmetric with respect to the amount of pore-filling polymer throughout the thickness of the porous substrate.

## Claims

### Claim 1

A method of separating alcohol from a mixture of alcohol and gasoline, the method comprising contacting the mixture with an asymmetric composite membrane comprising:
a porous substrate comprising opposite first and second major surfaces, and a plurality of pores; and
a pore-filling polymer disposed in at least some of the pores so as to form a layer coating all of the first major surface of the porous substrate and having a thickness within the porous substrate, with the amount of the pore-filling polymer at or adjacent to the first major surface being greater than the amount of the pore-filling polymer at or adjacent to the second major surface;
wherein the starting materials for the pore-filling polymer include a (meth)acrylate-containing monomer and/or oligomer, and the starting materials for the pore-filling polymer also comprise one or more polymeric additives that (a) have a strong affinity with the pore-filling polymer so that the pore-filling polymer is reinforced by the one or more polymeric additives and (b) enter pores of the porous substrate with the starting materials and thereby form an interpenetrating polymer network, the polymeric additive is selected from polyacrylic acid, polymethacrylic acid, polyacrylamide or its copolymers, polyethylene oxide, polyvinyl alcohol, poly(ethylene-co-vinyl alcohol) (EVAL), poly(N-vinylpyrrolidone), and mixtures or copolymers thereof, the amount of polymeric additive is in the range of from at least 0.20 wt-% up to 75%, based on the total amount of pore-filling polymer plus polymeric additive, the molecular weight (weight average) of the polymeric additive is in the range of from 1,000 to 500,000; and
wherein the pore-filling polymer is more permeable to alcohol than gasoline but not soluble in alcohol or gasoline.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the layer is a continuous layer.

### Claim 3 (depends on 1)

The method according to claim 1, wherein the porous substrate is a polymeric porous substrate.

### Claim 4 (depends on 1)

The method according to claim 1, wherein the porous substrate comprises a nanoporous layer.

### Claim 5 (depends on 1)

The method according to claim 1, wherein the porous substrate comprises a microporous layer.

### Claim 6 (depends on 1)

The method according to claim 1, wherein the porous substrate comprises a macroporous layer.

### Claim 7 (depends on 1)

The method according to claim 1, wherein the porous substrate has a thickness measured from one to the other of the opposite major surfaces in the range of from 5 μm up to and including 500 μm.

### Claim 8 (depends on 1)

The method according to claim 1, wherein the pores of the porous substrate include pores having an average size in the range of from 0.5 nanometers (nm) up to and including 1000 μm.

### Claim 9 (depends on 1)

The method according to claim 1, wherein the pore-filling polymer is formed using starting materials comprising ethylenically unsaturated monomers and/or oligomers.

### Claim 10 (depends on 1)

The method according to claim 1, wherein the pore-filling polymer is in the form of a pore-filling polymer layer that forms at least a portion of the first major surface of the porous substrate.

### Claim 11 (depends on 1)

The method according to claim 1, wherein the pore-filling polymer is in the form of a pore-filling polymer layer having an exposed major surface, which coats the first major surface of the porous substrate, and an opposite major surface disposed between the opposite first and second major surfaces of the porous substrate.

### Claim 12 (depends on 1)

The method according to claim 1, wherein the pore-filling polymer exhibits an alcohol selectivity in the range of from at least 30% up to and including 100%.

### Claim 13 (depends on 1)

The method according to claim 1, wherein the pore-filling polymer exhibits an average alcohol permeate flux in the range of from at least 310 g/m2/hour up to and including 30 kg/m2/hour, using a feed temperature in the range of from at least 20 C up to and including 90 C, a permeate vacuum pressure in the range of from at least 20 Torr (2.67 kPa) up to and including 760 Torr (101 kPa), a feed pressure in the range of from at least 10 psi (69 kPa) up to and including 100 psi (690 kPa), and an alcohol concentration in feed mixture in the range of from at least 2% up to and including 20%.

### Claim 14 (depends on 1)

The method according to claim 1, wherein the asymmetric composite membrane is in a replaceable cartridge for separating alcohol from an alcohol and gasoline mixture.

### Claim 15 (depends on 1)

The method according to claim 1, wherein the porous substrate is a polymeric porous substrate that comprises a nanoporous layer, a microporous layer, and a macroporous layer.

### Claim 16 (depends on 1)

The method according to claim 1, further comprising disposing the asymmetric composite membrane in a fuel system of an internal combustion engine, wherein the asymmetric composite membrane selectively pervaporates alcohol from an alcohol and gasoline fuel mixture stored in a storage tank.

### Claim 17 (depends on 1)

The method according to claim 1, wherein the pore-filling polymer is formed using starting materials comprising ethylenically unsaturated (meth)acrylate-containing monomers and/or oligomers, selected from the group of a polyethylene glycol (meth)acrylate, a polyethylene glycol di(meth)acrylate, a silicone diacrylate, a silicone hexa-acrylate, a polypropylene glycol di(meth)acrylate, an ethoxylated trimethylolpropane triacrylate, a hydroxylmethacrylate, 1H,1H,6H,6H-perfluorohydroxyldiacrylate, a urethane diacrylate, a urethane hexa-acrylate, a urethane triacrylate, a polymeric tetrafunctional acrylate, a polyester penta-acrylate, an epoxy diacrylate, a polyester triacrylate, a polyester tetra-acrylate, an amine-modified polyester triacrylate, an alkoxylated aliphatic diacrylate, an ethoxylated bisphenol di(meth)acrylate, a propoxylated triacrylate, 2-acrylamido-2-methylpropanefulfonic acid (AMPS), and combinations of such monomers and/or oligomers.

### Claim 18 (depends on 17)

The method according to claim 17, wherein the (meth)acrylate-containing monomers and/or oligomers are selected from the group of a polyethylene glycol (meth)acrylate, a polyethylene glycol di(meth)acrylate, a silicone diacrylate, a silicone hexa-acrylate, a polypropylene glycol di(meth)acrylate, an ethoxylated trimethylolpropane triacrylate, a hydroxylmethacrylate, 1H,1H,6H,6H-perfluorohydroxyldiacrylate, a polyester tetra-acrylate, and combinations of such monomers and/or oligomers.

### Claim 19 (depends on 1)

The method according to claim 1, wherein the pore-filling polymer is formed using starting materials comprising ethylenically unsaturated (meth)acrylate-containing monomers and/or oligomers selected from one or more of the following:
(a) di(meth)acryl-containing compounds;
(b) tri(meth)acryl-containing compounds;
(c) higher functionality (meth)acryl-containing compounds;
(d) oligomeric (meth)acryl compounds;
(e) perfluoroalkyl meth(acryl)-containing compounds;
(f) charged meth(acryl)-containing compounds; and
(g) polar meth(acryl)-containing compounds.