Synthesis of Polymer/Graphene Oxide Nanocomposite Foams: A New Dispersion-based Approach [thesis]

Ruby Mat Noor
2022
The discovery of the 2D "miracle material" graphene in 2004 by two Nobel Prize winners, Professor Andre Geim and Konstantin Novoselov has sparked the booming of research in designing and developing graphene-based nanocomposites. Early research on graphene-based nanocomposites involves the synthesis of polymer graphene-based nanocomposites using techniques such as melt mixing, solution mixing, pre-construction, and backfilling. These techniques require an extensive amount of toxic solvent, high
more » ... emperature or rigorous steps to fabricate the nanocomposites. On top of that, the state of dispersion of graphene in the polymeric medium has always been a great stumbling block to achieving the uniform distribution of the sheets in the nanocomposite. The emergence of graphene derivatives such as graphene oxide (GO), which is endowed with oxygen functional groups, has opened doors to a myriad of combinations of polymer graphene- based nanocomposites. GO can be incorporated into a water-borne polymerisation system that offers environmentally friendly and mild processing conditions. Moreover, the presence of oxygen functional groups also allows chemical functionalisation and modification of GO, granting nanocomposites tailored to specific applications. In this Thesis, 3D porous polymers and 3D porous polymer/GO nanocomposites (polymer foams and polymer/GO foams) are fabricated using a one-pot, new dispersion- based approach. The approach employs water-borne radical polymerisation (oil-in-water system – miniemulsion and emulsion) to synthesise polymer particles, followed by freeze casting to obtain the nanocomposites. The foam-forming ability, the governing mechanisms and parameters of the foam-forming system are investigated. Various acrylate and methacrylate polymers within a range of glass transition temperatures (Tg) are utilised to fabricate the polymer foams and the nanocomposite foams. The study of the foam-forming ability is also extended to crosslinked polymers. The foam-forming ability of the new dispersion-based ap [...]
doi:10.26190/unsworks/24392 fatcat:bhhqft6w4zdq5hcedmgv7zw7w4