Block Copolymer Hollow Fiber Membranes with Catalytic Activity and pH-Response

Abstract

We fabricated block copolymer hollow fiber membranes with self-assembled, shell-side, uniform pore structures. The fibers in these membranes combined pores able to respond to pH and acting as chemical gates that opened above pH 4, and catalytic activity, achieved by the incorporation of gold nanoparticles. We used a dry/wet spinning process to produce the asymmetric hollow fibers and determined the conditions under which the hollow fibers were optimized to create the desired pore morphology and the necessary mechanical stability. To induce ordered micelle assembly in the doped solution, we identified an ideal solvent mixture as confirmed by small-angle X-ray scattering. We then reduced p-nitrophenol with a gold-loaded fiber to confirm the catalytic performance of the membranes.

Block Copolymer Membranes for Aqueous Solution Applications

“…Additionally to the flat-sheet configuration, hollow fibers are frequently used in large membrane applications such as artificial kidney. The manufacture of block copolymer membranes in hollow fiber geometry has been demonstrated by our group 138,139 and by Radjabian et al 146 . In summary as long as the desired block copolymers is available with narrow molecular weight distribution in large amount and at reasonable cost scaling up is not a problem.…”

“…We used controlled electroless deposition of gold in different extents to reduce pore size 142 of PS-b-P4VP membranes. When incorporated in small amounts in PS-b-P4VP hollow fibers, gold could be used as catalyst for reduction reactions of pnitrophenol 139 . Analogous incorporation of silver 143 improved the biofouling resistance.…”

Nanostructured double hydrophobic poly(styrene-b-methyl methacrylate) block copolymer membrane manufactured via a phase inversion technique

“…[1][2][3] Such membranes have applications in catalysis, selective separation of proteins, and drug delivery. [4][5][6] A commonly used method to create pores in self-assembled block copolymer films is the etching of sacrificial domains or the extraction of an added homopolymer. [7][8][9] However, these methods require multiple and complicated steps to develop highly ordered nanoporous membranes.…”

Fit-for-purpose block polymer membranes molecularly engineered for water treatment

“…[106][107][108] Subsequently, the salts that were localized within the membranes were reduced to form metallic nanoparticles that introduced catalytic functionality into the membrane. 107 This study implemented a model reaction to demonstrate the catalytic activity, but the concept could be extended to the degradation of organic contaminants such that purification can be achieved through chemical conversion. Another iteration of this approach, which was discussed above, used the blending of chemically distinct block polymers (i.e., A-B and A-C types) to provide the desired functionality.…”