Fabrication Processes and Properties of Carbon Nanomaterials Filled Nanocomposites

Carbon nanomaterials including graphene and carbon nanotube (CNT) are promising fillers for composite materials to overcome the limitation of traditional reinforcements in composites due to their excellent mechanical and functional properties. In previous researches on carbon nanomaterial filled nanocomposites, limited improvement of properties have been shown because of strong agglomeration of the carbon nanomaterials and poor interfacial bonding between carbon nanomaterials and matrices. To solve these important issues, a new fabrication process, named molecular level mixing process, has been developed to fabricate carbon nanomaterials filled nanocomposites in order to maximize the effect of filler addition in various matrices. The molecular level mixing process to fabricate carbon nanomaterials filled nanocomposite powders is composed of several steps described in Fig. 1. As a first step, the carbon nanomaterials are functionalized by attaching functional molecular groups on surfaces. Second step is to fabricate a precursor carbon nanomaterial bonded with matrix ions induced by chemical interaction. Third step is to mix the carbon nanomaterial with matrix by nucleation and growth of matrix phase. Fourth step is the synthesis of nanocomposite powders, in which the carbon nanomaterial and matrix phase are homogeneously mixed together. Homogeneous dispersion of carbon nanomaterials with strong interfacial bonding with matrices have been achieved by molecular level mixing process. Inorganic matrices nanocomposites filled with carbon nanomaterials, such as CNT/Cu, CNT/Al, Graphene/Al2O3, exhibit outstanding mechanical properties including strength, modulus and fracture toughness. Also, wide scope of possible applications as stretchable conductors, electrode for supercapacitor and organic photovoltaic materials are expected for polymer matrix nanocomposites filled with carbon nanomaterials, such as AgNW/Graphene/PDMS, CNT/carbon fibers and Graphene/P3HT:PCBM. It is suggested that the carbon nanomaterials filled nanocomposites are new emerging materials for multi-functional applications.