Effect of Mild Thermal Annealing on Structure and Properties of Graphene Oxide-Polymer Nanocomposites

Two-dimensional materials can be employed as interesting nanofillers due to their unique structure and properties based on large surface area. Graphene oxide (GO), a representative two-dimensional material, is an oxidized form of graphene. GO can easily interact with hydrophilic polymers through hydrogen bonding owing to the high specific surface area and abundant oxygen functional groups, Thus, chain structure and dynamics of polymers at the interface is known to be sensitively dependent on the nature of GO surface.

While the thermal- or chemical- reduction of GO significantly weakens the dispersibility of GO in a solvent and reduces the interaction with the hydrophilic polymers, undergoing of mild thermal annealing to the extent that reduction does not occur does not remove the functional groups but redistributes them to the edge. This weak opening will alter the interaction between GO and polymer and ultimately affect the final structure and properties of polymer-based products such as GO-polymer nanocomposites. In this regard, we investigate the change of the crystallization and melting behaviors of polymers with mild thermal annealing of GO and show the migration of the functional groups vary the GO-polymer interaction ultimately changing the nature of polymer crystallization.