Graphitic oxide and graphene as enhancers for combustible mixtures

Abstract

The aim of this thesis was to study the effects of using graphene (G) and graphitic oxide (GO) as additives in energetic reactions. The thermite oxidative reaction was selected as the main reaction to test. The rationale behind the use of GO and G as additives originates from the fact that GO has the ability to release its oxygen groups when heated at low temperatures and graphene burns off generating volatile species at moderate temperatures. GO or G were added to thermite mixtures and heated to promote the aluminum oxidation in the presence and absence of iron oxide, in inert and oxygen containing atmospheres. The changes in mass were recorded using thermogravimetric analysis while the heat flows involved were determined by calorimetry. A mass spectrometer analyzed the evolved gases. The solid crystalline precursors and byproducts were identified using x-ray diffraction techniques and their microstructural characteristics and identity studied using microscopy and spectroscopy. Evidenced by the byproducts generated, the thermogravimetric/calorimetric study of the processes and the microstructures observed, the addition of GO or G to aluminum accelerates the oxidation reaction. A mechanism for the different oxidation steps when additives are used is proposed and discussed. In addition to the thermite reaction, GO and G were also used as additives in the combustion of propellant mixtures. Testing was conducted to determine changes in visible smoke and flame distance from the propellant during burn.