Superhydrophobic polyvinylidene fluoride/graphene porous materials

We demonstrated a simple method to produce superhydrophobic polyvinylidene fluoride (PVDF)/graphene porous materials. The hybrid PVDF/graphene gel was formed by the diffusion of non-solvent (methanol or water) into PVDF/graphene suspension in N,N-dimethylformamide (DMF). By carefully replacing DMF in aged gels by water, gel samples were freeze-dried to produce skinless porous materials. This drying method effectively avoids pore-shrinkage because of the capillary force in the drying process of gels, giving porous materials with high specific surface area and surface roughness. Furthermore, compared with pure PVDF porous materials, the addition of small amount of graphene in hybrid gels not only influences the crystallization of PVDF, but also leads to a dramatically morphology change which significantly increases their surface roughness in nanoscale, thus generating superhydrophobic porous PVDF/graphene materials.