Fabrication of lignin-functionalized MXene composite hydrogels with improved mechanical strength and antifouling performance

Hydrogels exhibit great potential in marine antifouling applications due to their ability to form a surface hydration layer that resists microbial adhesion. However, their practical application is often hindered by poor mechanical properties and limited antifouling performance. To address these challenges, nanomaterials have been employed to enhance hydrogel performance. Herein, we functionalized MXene nanosheets by grafting methacryloxyethyltrimethyl ammonium chloride (METAC) microgels, followed by electrostatic adsorption of sodium lignosulfonate (SLS), resulting in functionalized MXene nanosheets with enhanced antibacterial and antifouling properties. These nanosheets were then embedded within hydrogel matrix to form nanocomposite hydrogels. The reinforced internal crosslinking network significantly improved the mechanical performance, increasing tensile stress from 55 KPa to 167 KPa and tensile strain from 636 % to 971 %. The MXene-METAC-SLS/Gel also exhibited excellent antifouling performance, achieving antibacterial rates of 91.0 % and 93.1 % against Staphylococcus aureus and Escherichia coli, along with algal removal rates of 83.5 % and 85.1 % for Dunaliella and Porphyridium, respectively. The incorporation of functionalized nanosheets not only enhanced antimicrobial capability but also strengthened the surface hydration layer, further resisting microbial adhesion. This study expands the potential applications of nanocomposite hydrogels in marine antifouling coatings.