Polymer fiber screen surface modifications for cation exchange membranes
A sulfonated polymer fiber screen and a method for fabricating the same is disclosed. For example, a composition may include a plurality of sulfonated polymer fibers. The sulfonated polymer fibers may include polyether ether ketone (PEEK) fibers or polyaryl ether ketone (PAEK) fibers that are contacted with an acid bath that includes a sulfur containing group.
1 . A composition, comprising:
a plurality of sulfonated polymer fibers, wherein the plurality of sulfonated polymer fibers comprises sulfonated polyether ether ketone (PEEK) fibers or sulfonated polyaryl ether ketone (PAEK) fibers, wherein the plurality of sulfonated polymer fibers is created by contacting unsulfonated polyether ether ketone fibers or unsulfonated polyaryl ether ketone fibers with an acid bath comprising methane sulfonic acid, ethane sulfonic acid, sulfurous acid, or a combination thereof for between 2 to 5 seconds.
2 . The composition of claim 1 , wherein the sulfonated PEEK fibers have an average diameter of between 0.0015 inches and 0.0050 inches.
3 . The composition of claim 1 , wherein the sulfonated PEEK fibers are arranged in a screen with open spaces between the sulfonated PEEK fibers.
4 . The composition of claim 3 , wherein the screen comprises an open area of between 20 percent to 60 percent.
5 . The composition of claim 4 , wherein the screen comprises an open area of approximately 22 percent.
6 . An article, comprising:
a sulfonated polymer selective barrier material, wherein the sulfonated polymer selective barrier material comprises sulfonated polyether ether ketone (PEEK) fibers or sulfonated polyaryl ether ketone (PAEK) fibers, wherein the sulfonated polymer selective barrier material is created by contacting unsulfonated polyether ether ketone fibers or unsulfonated polyaryl ether ketone fibers with an acid bath comprising methane sulfonic acid, ethane sulfonic acid, sulfurous acid, or a combination thereof for between 2 to 5 seconds.
7 . The article of claim 6 , wherein the sulfonated polymer selective barrier material has an ion exchange capacity of between about 0.10 to about 0.20 milliequivalents per gram (meq/g).
8 . A method, comprising:
contacting an unsulfonated polymer selective barrier material with an acid bath comprising a sulfur containing group to sulfonate the unsulfonated polymer selective barrier material in a sulfonation reaction, wherein the unsulfonated polymer selective barrier material comprises polyether ether ketone (PEEK) fibers or polyaryl ether ketone (PAEK) fibers, and wherein the unsulfonated polymer selective barrier material is contacted with the acid bath comprising methane sulfonic acid, ethane sulfonic acid, sulfurous acid, or a combination thereof for between 2 to 5 seconds; and
stopping the sulfonation reaction.
9 . The method of claim 8 , wherein the unsulfonated polymer selective barrier material is arranged as a cation exchange membrane with open spaces and contacted with the acid bath in-situ.
10 . The method of claim 9 , wherein the cation exchange membrane comprises an open area of between about 20 percent to about 60 percent.
11 . The method of claim 10 , wherein the cation exchange membrane comprises an open area of approximately 22 percent.
12 . The method of claim 8 , wherein the unsulfonated polymer selective barrier material comprises the polyether ether ketone (PEEK) fibers or the polyaryl ether ketone (PAEK) fibers having an average diameter of between 0.0015 inches and 0.0050 inches.
13 . The method of claim 12 , wherein the PEEK fibers or PAEK fibers have an average diameter of 0.0028 inches.
14 . The method of claim 8 , wherein the acid bath further comprises sulfuric acid.
15 . The method of claim 14 , wherein the sulfuric acid comprises greater than 80 percent concentration of sulfuric acid.
16 . The composition of claim 1 , wherein the unsulfonated polymer selective barrier material is contacted with the acid bath to tune an ion exchange capacity for use in a cation exchange membrane.
17 . The article of claim 6 , wherein the unsulfonated polymer selective barrier material is contacted with the acid bath to tune an ion exchange capacity for use in a cation exchange membrane.
18 . The method of claim 8 , wherein the unsulfonated polymer selective barrier material is contacted with the acid bath to tune an ion exchange capacity for use in a cation exchange membrane.