UV treated membranes
Non-coherent UV-treated porous halopolymer membranes are disclosed.
1. A method of filtering a corrosive fluid comprising passing the corrosive fluid through a microporous PTFE membrane comprising a first surface and a second surface and a thickness and bulk defined by the first and second surfaces, the microporous PTFE membrane modified by subjecting the microporous PTFE membrane to non-coherent broadband UV irradiation while pores of the membrane are impregnated with a liquid, the membrane having a critical wetting surface tension (CWST) of at least 26 dynes/cm (0.26 erg/mm 2 ) through the thickness and bulk of the microporous PTFE membrane, a wetting/dewetting ratio of at least about 0.7 for 2 or more cycles, and wherein the first and second surfaces each have a fluorine/carbon (F/C) ratio of about 1.5 or more and an oxygen/carbon (O/C) ratio in the range of from about 0.01 to about 0.15, and obtaining filtered corrosive fluid passing through the membrane.
2. The method of claim 1 , wherein the corrosive fluid comprises concentrated acid.
3. The method of claim 1 , wherein the corrosive fluid comprises concentrated base.
4. The method of claim 1 , wherein the corrosive fluid comprises an oxidizer.
5. The method of claim 1 , wherein the corrosive fluid comprises a hot concentrated acid.
6. The method of claim 5 , wherein the hot concentrated acid comprises sulfuric acid.
7. The method of claim 6 , wherein the corrosive fluid further comprises an oxidizer.
8. The method of claim 2 , wherein the concentrated acid comprises sulfuric acid.
9. The method of claim 1 , wherein the corrosive fluid comprises a cold concentrated acid.
10. The method of claim 9 , wherein the cold concentrated acid comprises sulfuric acid.
11. The method of claim 1 , wherein the microporous PTFE membrane has a CWST of at least about 40 dynes/cm (0.40 erg/mm 3 ).
12. The method of claim 1 , wherein the microporous PTFE membrane is free of a coating.