# US 12,109,540 B1 · Multifunctional diselenide-based polyimide membrane for gas separation and purification

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- Number: US 12,109,540 B1
- Document ID: US12109540B1
- Status: Granted
- Kind: B1
- Application number: 18/657,831
- Filed: 2024-05-08
- Granted: 2024-10-08
- Earliest claimed: 2024-05-08
- Assignees: Imam Mohammad Ibn Saud Islamic University
- Applicants: Imam Mohammad Ibn Saud Islamic University
- Inventors: Tarek Ahmed Yousef; Saad Shaaban
- Web page: https://patentgrep.com/patent/US12109540B1

## CPC

- B01D 71/64: Polyimides; Polyamide-imides; Polyester-imides; Polyamide acids or similar polyimide precursors
- B01D 53/228: {characterised by specific membranes}
- B01D 67/0011: {Casting solutions therefor}
- B01D 67/0013: {Casting processes}
- C08G 73/1057: {Polyimides containing other atoms than carbon, hydrogen, nitrogen or oxygen in the main chain}
- C08G 73/1078: {wholly aromatic in the diamino moiety}
- C08G 73/1085: {Polyimides with diamino moieties or tetracarboxylic segments containing heterocyclic moieties}
- C08J 5/18: Manufacture of films or sheets
- B01D 2053/221: {Devices}
- B01D 2323/081: Heating
- C08J 2379/08: Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- 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)
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)

## Abstract

A polyimide membrane based on a polymer comprising polymerized units of a diselenide compound and having Formula I. A method of fabrication of the membrane using the polyimide-containing polymer and a method for separating one or more gases from a gaseous mixture using the membrane.

## Claims

### Claim 1

A polyimide, comprising:
reacted units of a 4,4′-diselanediyldianiline; and
reacted units of an ethylenediaminetetraacetic dianhydride,
wherein the reacted units of the 4,4′-diselanediyldianiline are bonded to the reacted units of the ethylenediaminetetraacetic dianhydride through one or more imides in an alternating pattern.

### Claim 2 (depends on 1)

The polyimide of claim 1, wherein a molar ratio of the 4,4′-diselanediyldianiline to the total amount of the ethylenediaminetetraacetic dianhydride is 1:1.

### Claim 3 (depends on 1)

The polyimide of claim 1, wherein the polyimide is made by a process comprising:
dissolving the 4,4′-diselanediyldianiline in a polar organic solvent to form a solution;
adding the ethylenediaminetetraacetic dianhydride to the solution;
stirring the solution for a time sufficient to form a poly(amic acid); and
heating the poly(amic acid) to a temperature of 170 to 200° C. for 8 to 10 hours to form the polyimide.

### Claim 4 (depends on 3)

The polyimide of claim 3, wherein the process of making the polyimide comprises stirring the solution for from 10 to 14 hours.

### Claim 5 (depends on 1)

The polyimide of claim 1, having repeating units of Formula I:
wherein n=2−1000.

### Claim 6 (depends on 1)

A membrane, comprising: the polyimide of claim 1.

### Claim 7 (depends on 6)

The membrane of claim 6, wherein the membrane is made by a process comprising:
dissolving the polyimide in a polar organic solvent to form a casting solution,
casting the casting solution on a substrate; and
heating the substrate with the casting solution progressively to form the membrane.

### Claim 8 (depends on 7)

The membrane of claim 7, wherein the polyimide is 10 to 30 weight percent of the casting solution.

### Claim 9 (depends on 7)

The membrane of claim 7, wherein the substrate is a silica substrate.

### Claim 10 (depends on 7)

The membrane of claim 7, wherein the progressive heating is held at a first temperature of 50 to 70° C. for 10 to 30 hours.

### Claim 11 (depends on 7)

The membrane of claim 7, wherein the progressive heating is held at a second temperature of 90 to 110° C. for 4 to 8 hours.

### Claim 12 (depends on 7)

The membrane of claim 7, wherein the progressive heating is held at a third temperature of 140 to 160° C. for 10 to 30 hours.

### Claim 13 (depends on 6)

A method of gas separation, comprising:
contacting the membrane of claim 6 with a gaseous mixture,
wherein the gaseous mixture comprises at least two gases,
permeating at least a portion of a first gas of the gaseous mixture through the membrane to form a permeate gas having a greater concentration of the first gas than the concentration of the first gas in the gaseous mixture.

### Claim 14 (depends on 13)

The method of claim 13, wherein the separating includes adsorbing one of the at least two gases on the membrane.

### Claim 15 (depends on 13)

The method of claim 13, wherein the gases mixture comprises hydrogen, nitrogen, methane, carbon monoxide, carbon dioxide, and hydrogen sulfide.