Wetting-induced climbing for transferring interfacially assembled large-area ultrathin pristine graphene film

Owing to inherent 2D structure, marvelous mechanical, electrical, and thermal properties, graphene has great potential as a macroscopic thin film for surface coating, composite, flexible electrode, and sensor. Nevertheless, the production of large-area graphene-based thin film from pristine graphene dispersion is severely impeded by its poor solution processability. In this study, a robust wetting-induced climbing strategy is reported for transferring the interfacially assembled large-area ultrathin pristine graphene film. This strategy can quickly convert solvent-exfoliated pristine graphene dispersion into ultrathin graphene film on various substrates with different materials (glass, metal, plastics, and cloth), shapes (film, fiber, and bulk), and hydrophobic/hydrophilic patterns. It is also applicable to nanoparticles, nanofibers, and other exfoliated 2D nanomaterials for fabricating large-area ultrathin films. Alternate climbing of different ultrathin nanomaterial films allows a layer-by-layer transfer, forming a well-ordered layered composite film with the integration of multiple pristine nanomaterials at nanometer scale. This powerful strategy would greatly promote the development of solvent-exfoliated pristine nanomaterials from dispersions to macroscopic thin film materials.