Preparation of nanocomposite hydrogels based on zwitterionic polymer functionalized MXene nanosheets for antifouling application

Conventional hydrogels typically exhibit poor mechanical properties, high water loss, and susceptibility to swelling and structural degradation. Nanocomposite hydrogels offer a promising solution, demonstrating considerable potential for marine antifouling applications. Herein, polyethyleneimine (PEI) was successfully grafted onto MXene surfaces via tannic acid-mediated self-assembly polymerization through Schiff-base or Michael addition reactions. The resulting MX-PEIS exhibited effective antibacterial and anti-algal properties. Nanocomposite hydrogels were then synthesized via heat-initiated free radical polymerization. The MX-PEIS/Gel hydrogel demonstrated outstanding antifouling performance, achieving an antimicrobial rate of 95 % and a 99 % enhancement in anti-algal activity compared to the blank hydrogel. This improvement was attributed to the synergistic effects of MX-PEIS nanosheets and the hydrogel's surface hydration, which inhibited biofilm formation by killing, suppressing, and preventing the adhesion of bacterial and microalgal cells. Furthermore, the incorporation of MX-PEIS nanosheets significantly enhanced mechanical properties, increasing tensile stress from 0.07 MPa to 0.16 MPa and tensile strain from 581.2 % to 1022.4 %. Additionally, the modified hydrogel exhibited improved water retention, anti-swelling, and lubrication properties, contributing to greater structural stability and an extended service life.