Photocatalyzed dimethylacrylamide polymerization in an aqueous solution using 4-nitrophenylacetylene-modified Cu2O crystals

Cu2O cubes, octahedra, and rhombic dodecahedra with and without surface 4-nitrophenylacetylene (4-NA) functionalization were used to catalyze dimethylacrylamide (DMA) photopolymerization in water. Among these samples, the 4-NA-modified Cu2O cubes presented a highest monomer conversion percentage of 69% after 1 h of 420 nm light irradiation, possibly due to the most efficient electron transfer from the particles to the Ph2ICl co-initiator. The synthesized polymers generally have high molecular weights and good dispersity values. The reaction can be easily scaled up 10 fold under room light. After simple particle removal, a transparent gel-like polymer product is obtained. The Cu2O crystals can be recycled for use in more polymerization reactions. Electron and hole scavenging experiments were conducted to support the proposed reaction mechanism. This work shows surface-controlled semiconductor nanocrystals can be simple yet highly effective photocatalysts for some polymerization reactions.