High-nanofiller-content graphene oxide-polymer nanocomposites via vacuum-assisted self-assembly

Highly ordered, homogeneous polymer nanocomposites of layered graphene oxide are prepared using a vacuum-assisted self-assembly (VASA) technique. In VASA, all components (nanofi ller and polymer) are pre-mixed prior to assembly under a fl ow, making it compatible with either hydrophilic poly(vinyl alcohol) (PVA) or hydrophobic poly(methyl methacrylate) (PMMA) for the preparation of composites with over 50 wt% fi ller. This process is complimentary to layer-by-layer assembly, where the assembling components are required to interact strongly (e.g., via Coulombic attraction). The nanosheets within the VASA-assembled composites exhibit a high degree of order with tunable intersheet spacing, depending on the polymer content. Graphene oxide-PVA nanocomposites, prepared from water, exhibit greatly improved modulus values in comparison to fi lms of either pure PVA or pure graphene oxide. Modulus values for graphene oxide-PMMA nanocomposites, prepared from dimethylformamide, are intermediate to those of the pure components. The differences in structure, modulus, and strength can be attributed to the gallery composition, specifi cally the hydrogen bonding ability of the intercalating species.