Simple construction of PVA hydrogels based on dehydration drying method via polydopamine-modified graphene nanocomposites

Abstract

The traditional freeze-drying method for preparing polyvinyl alcohol (PVA) hydrogels involves a complex process. Conventional one-step drying processes for preparing high-strength PVA hydrogels often yield materials with inadequate mechanical properties and insufficient lubrication. To overcome these limitations, this study introduces polydopamine-modified graphene as a reinforcing nanofiller within PVA hydrogels. The surface modification significantly improves graphene dispersion in the hydrogel matrix, leading to substantial enhancements in mechanical performance. Incorporating just 0.5 wt% polydopamine-modified graphene results in a remarkable 200% increase in tensile strength and a 62% improvement in Young’s modulus compared to unmodified PVA hydrogels. Furthermore, subsequent treatment with a straightforward deep eutectic solvent (DES) and UV-initiated crosslinking synergistically boosts the hydrogel’s overall strength by 500% and reduces its coefficient of friction by 50%, significantly enhancing lubrication properties. This combined strategy of nanomaterial reinforcement and solvent/UV processing presents a facile and effective approach for fabricating robust, high-strength PVA hydrogels with excellent lubricity, holding promise for demanding biomedical and engineering applications.