Anion exchange polymers and anion exchange membranes incorporating 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 trimethylamamine 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 anion exchange pre-polymer membrane comprising:
a) a porous scaffold membrane comprising pores;
b) an anion exchange pre-polymer which is a reaction product of
i) 2 trifluoroMethyl Ketone;
ii) 1 BiPhenyl;
iii) methylene chloride; and
iv) trifluoromethanesulfonic acid;
wherein the anion exchange pre-polymer is within the pores of the porous scaffold membrane and forms surface layers on a first side and a second side, opposing said first side;
wherein the anion exchange pre-polymer extends from a first side to a second and opposing side of the composite anion exchange membrane;
wherein the porous scaffold has a thickness of no more than about 50 μm; and
wherein the porous scaffold has an open area of at least 75%.
2. The composite anion exchange membrane of claim 1 , wherein the porous scaffold has a thickness of no more than about 25 μm.
3. The composite anion exchange membrane of claim 1 , wherein the porous scaffold has a thickness of no more than about 15 μm.
4. The composite anion exchange membrane of claim 1 , wherein the porous scaffold has an open area of at least 85%.
5. The composite anion exchange membrane of claim 1 , wherein the porous scaffold is an expanded polytetrafluoroethylene membrane.
6. The composite anion exchange membrane of claim 5 , wherein the porous scaffold has a thickness of no more than about 25 μm.
7. The composite anion exchange membrane of claim 5 , wherein the porous scaffold has a thickness of no more than about 15 μm.
8. The composite anion exchange membrane of claim 5 , wherein the porous scaffold has an open area of at least 85%.
9. The composite anion exchange membrane of claim 1 , wherein the anion exchange pre-polymer is functionalized to form an anion exchange membrane having a functional group derived from trimethylamine.