Novel Synthesis and Characterization of Inorganic Fullerene Type WS2 and Graphene Hybrids

With the aim to develop personal protection systems with improved mechanical properties and reduced weight, this research combined graphene with tungsten disulfide, and studied this hybrid system included in epoxy resin. A novel plasma production process generated nanometric size tungsten oxide (WO3) spherical particles. The nanospheres were sulfurized to produce inorganic-fullerene type tungsten disulfide (IF-WS2). The plasma IF-WS2 particles exhibited smaller particle size, characteristic hollow cores and larger angle facets than IF-WS2 from commercial WO3, and morphological characteristics that are correlated with improved mechanical properties. Exfoliated graphene sheets were prepared from graphite nanopowder through oxidization and subsequent exfoliation at 800 C in inert atmosphere. Sample microstructures were characterized by XRD, SEM, TEM and FIB. Protocols to fabricate hybrid graphene/IF-WS2 with nanoscale dispersions were developed. Hybrids from in-situ routes and physical mixtures of individual components were included in epoxy matrices for nanoindentation tests. Results showed the Young s modulus (normalized for bare epoxy) increased 12.23%, while hardness increased 27.87% through inclusion of 1% wt loadings of graphene/IF-WS2. These results were compared to carbon nanofibers/IF-WS2 hybrid composites recently produced by the functional materials research group at NPS. This research represents a step toward development of lightweight nano-architectures for advanced personal protection systems.