Bottlebrush Polymer-Functionalized Graphene Oxide-Based Multifunctional Poly(vinyl alcohol) Nanocomposite Films with Exceptional Performance

Nanocomposites consisting of two-dimensional (2D) functional reinforcements embedded in a polymeric matrix provide great opportunities for the design of multifunctional artificial materials. However, the efficient formation of materials with high-performance structures and multifunctional properties is still challenging. Herein, we demonstrate a generic approach to fabricate multifunctional poly(vinyl alcohol) (PVA)-based nanocomposite films through a solvent evaporation method with modified graphene oxide (GO) nanosheets as the functional fillers. Inspired by the lubricating protein lubricin (LUB), anchored bottlebrush polymers (BBPs) were designed as a molecular glue to maintain the bottlebrush conformation immobilized on the GO nanosheets, thereby dominating the directed assembly of GO nanosheets in a PVA matrix. The BBPs have polyzwitterionic brushes which provide a strongly bound hydrated layer and antifouling property and mussel-mimetic anchors which strongly anchor the copolymer to the GO surface. Furthermore, polyzwitterion-containing BBPs tightly combined with PVA chains act as a bridge for linking the GO nanosheets and the PVA matrix. The highly hydrated bottlebrush architecture mediates repulsion between the adjacent GO surfaces, yielding the well-dispersed and aligned GO nanosheets in the nanocomposites. The fabulous coupling of a layered arrangement of GO nanosheets and highly hydrated polyzwitterionic bottlebrushes of BBPs enables the resultant BBPs@GO/PVA nanocomposite film to exhibit a high photothermal efficiency (55.1%), UV resistance, and an exceptional gas barrier (84.8% decrease) at low modified-GO loadings as well as a superior antimicrobial property. This study provides a new approach for designing multifunctional nanocomposites with ordered structures and giving great promise to various applications.