Composite ion exchange membrane and method of making same
An anion exchange membrane is made by mixing 2 trifluoroMethyl Ketone [nominal] (1.12 g, 4.53 mmol), 1 BiPhenyl (0.70 g, 4.53 mmol), methylene chloride (3.0 mL), trifluoromethanesulfonic acid (TFSA) (3.0 mL) to produce a pre-polymer. The pre-polymer is then functionalized to produce an anion exchange polymer. The pre-polymer may be functionalized with trimethylamine in solution with water. The pre-polymer may be imbibed into a porous scaffold material, such as expanded polytetrafluoroethylene to produce a composite anion exchange membrane.
1. A composite ion exchange membrane comprising:
a) a porous scaffold material having pores and selected from the group of porous polyolefin and porous fluoropolymer;
b) a pre-polymer comprising:
i) 2 trifluoromethyl ketone;
ii) 1 biphenyl;
iii) methylene chloride; and
iv) trifluoromethanesulfonic acid,
wherein the prepolymer is configured in the pores of said porous scaffold material;
c) a functional polymer bonded with the prepolymer, said functional polymer selected from the group consisting of hydroxide halide and oxyanions; and
d) trimethylamine; and
wherein said functional polymer is functionalized with said trimethylamine to produce said composite ion exchange membrane having quaternized ammonium hydroxide functional groups.
2. The composite ion exchange membrane of claim 1 , wherein the porous scaffold is a hydrophilic porous scaffold.
3. The composite ion exchange membrane of claim 1 , wherein the porous scaffold material consists of porous polyolefin.
4. The composite ion exchange membrane of claim 3 , wherein the porous polyolefin comprises polyethylene.
5. The composite ion exchange membrane of claim 1 , wherein the porous scaffold material comprises porous polyethylene film.
6. The composite ion exchange membrane of claim 1 , wherein the porous scaffold material comprises expanded ultra-high molecular weight polyethylene.
7. The composite ion exchange membrane of claim 1 , wherein the porous scaffold material-comprises expanded polytetrafluoroethylene.
8. The method of making an ion exchange membrane of claim 7 , wherein the porous scaffold material further comprises a surface modifier to produce a hydrophilic expanded polytetrafluoroethylene membrane.
9. The composite ion exchange membrane of claim 8 , wherein the surface modifier comprises a surfactant.
10. The composite ion exchange membrane of claim 8 , wherein the surface modifier comprises an ion exchange medium.
11. The composite ion exchange membrane of claim 1 , wherein the ion exchange polymer is cationic.
12. The composite ion exchange membrane of claim 1 , wherein the ion exchange polymer is anionic.
13. The composite ion exchange membrane of claim 1 , where in the ion exchange membrane is less than 50 microns.
14. The composite ion exchange membrane of claim 1 , where in the ion exchange membrane is less than 25 microns.
15. The composite ion exchange membrane of claim 1 , where in the ion exchange membrane is less than 15 microns.