Sodium deoxycholate functionalized graphene and its composites with polyvinyl alcohol

Sodium deoxycholate (SDC), a kind of bile derivative, is used to noncovalently functionalize graphene. Stable and high concentration (up to 20 mg ml(-1)) of graphene colloid is obtained. The stabilization mechanism is revealed to be hydrophobic interaction, electrostatic repulsion and hydrogen bonding. Single-layer and few-layer graphene are obtained in the colloid. Subsequently, the obtained graphene sheets are incorporated into a polyvinyl alcohol (PVA) matrix by solution casting to fabricate PVA/graphene composites. Morphological observations substantiate the homogeneous dispersion of graphene in the PVA matrix and strong interfacial adhesion between them. Significant improvements in tensile strength and modulus of the composite films are observed.