Year
2018
Degree Name
Doctor of Philosophy
Department
School of Mechanical, Materials, Mechatronic and Biomedical Engineering
Abstract
Graphene has become a darling reinforcing material in the fabrication of advanced composite materials because of its excellent mechanical, electrical, thermal and chemical properties. One of the challenges is to uniformly disperse graphene fillers in the matrix materials and avoid the restacking/agglomeration of the ultrathin graphene. The nanoparticle-graphene core-shell structure compensates for the high surface energy of graphene and alleviates the agglomeration, thus improving the dispersion of graphene fillers in the composites. A combination of the hard core and the self-lubricating shell is a promising strategy to develop hybrid tribology-favoured fillers as well.
In this thesis, a wet ball milling route was firstly developed to synthesise SiC-graphene core-shell nanoparticles in situ from graphite and SiC nanoparticles. Graphite flakes were gradually exfoliated into fresh graphene nanosheets (GNSs) without significant defects, which is attributed to mechanical shearing and moderate impaction forces between graphite flakes, milling balls and SiC nanoparticles during the wet milling. The nondestructive exfoliation was characterised by Raman, Fourier transform infrared and XRay photoelectron spectroscopies. The freshly produced GNSs are energetically unstable and thin enough to be flexible and this drives the in situ attaching and scrolling of GNSs on the SiC nanoparticles. The SiC nanoparticles and GNSs were well dispersed in the wet medium and the SiC nanoparticles were individually wrapped. It was estimated that >50% of the produced GNSs were wrapped around the SiC nanoparticles and these GNSs were generally ≤6 layers.
Recommended Citation
Zhang, Jiangshan, SiC-Graphene Core-Shell Nanoparticle Reinforced Composite Materials: Synthesis and Characterisation, Doctor of Philosophy thesis, School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, 2018. https://ro.uow.edu.au/theses1/415
FoR codes (2008)
0912 MATERIALS ENGINEERING, 0913 MECHANICAL ENGINEERING
Unless otherwise indicated, the views expressed in this thesis are those of the author and do not necessarily represent the views of the University of Wollongong.