Fabrication of Poly(ionic liquid)-Functionalized Hydrogels via Surface-Initiated Polymerization for Enhanced Antibacterial and Antifouling Applications

Herein, we prepared a poly(ionic liquid)-functionalized hydrogel by grafting a poly(ionic liquid) on the hydrogel surface via surface-initiated polymerization. First, a hydrogel matrix containing an initiator was synthesized through the chemical cross-linking of acrylic acid, acrylamide, N,N′-methylenebis(acrylamide), and the initiator MA-Br. The introduction of Fe³⁺ ions further enhanced the cross-linking density. After that, we grafted the ionic liquid IL-Cl onto the hydrogel matrix via surface-initiated polymerization. These poly(ionic liquid)-functionalized hydrogels displayed remarkable antibacterial and antifouling properties, attributed to the bactericidal activity of the ionic liquid as well as the high hydrophilicity and low adhesion of the functionalized hydrogel. Notably, the sample of PIL-MA/Gel(4h) achieved antibacterial rates exceeding 99% against two types of bacteria and a removal rate above 96% against two types of algae. Additionally, the hydrogel, after grafting poly(ionic liquid), exhibited improved mechanical strength, water retention, and water lubrication performance, making it a highly effective material for marine antifouling applications.