/library/oar/handle/123456789/8761 2025-12-22T19:16:35Z /library/oar/handle/123456789/141611 Title: Synthesis of graphene oxide : a refined approach Authors: Magro, Maria; Vella, Daniel A.; Cassar, Glenn Abstract: The conventional method for preparing graphene oxide (GO) relies on the use of corrosive acids namely concentrated H2SO4, HNO3, and H3PO4 as well as aggressive oxidizing agents such as KMnO4 and KClO4. The application of heat further exacerbates the preparation, promoting the release of harmful acidic NOx and ClO2 fumes. The formation of the by-product Mn2O7 could also increase the risk of explosion. A safe(r) and shorter method of preparation of GO has been a challenge for many researchers. This study presents a method of preparing GO, that reduces risks by eliminating the need for heating and shortening the oxidation step. This method utilises mixtures of concentrated H2SO4 and KMnO4 with graphite thus eliminating the release of toxic fumes. Characterization studies revealed that the graphite precursor with an average lateral flake size of 15.06 ±1.87 µm was successfully oxidized to GO and subsequently exfoliated to thinner sheets. The resulting GO exhibited a reduced average lateral sheet size of 10.22 0.62 µm and comprised approximately 10 layers, indicating that the precursor material is polycrystalline. Comprehensive XPS analysis revealed that the oxygen content and chemical states of carbon in the synthesized GO was comparable to that of commercially available GO, with similar distribution of oxygen functionalities. In the in-house produced GO, the predominant functional group was found to be the C-O bond corresponding to the epoxy group, followed by the ester and acid anhydride functional groups. Furthermore, the decrease in the percentage of sp2 hybridized carbon in GO to 45.52 %—measured using X-ray induced Auger spectroscopy—confirms the successful oxidation of the precursor, which initially exhibited 80.21 % sp2 character in graphite. 2025-01-01T00:00:00Z /library/oar/handle/123456789/91850 Title: High pressure systems as sustainable extraction and pre‑treatment technologies for a holistic corn stover biorefinery Authors: Noppawan, Pakin; Gallant Lanctôt, Adrienne; Magro, Maria; Navarro, Pablo Gil; Supanchaiyamat, Nontipa; Attard, Thomas M.; Hunt, Andrew J. Abstract: This mini-review assesses supercritical carbon dioxide (scCO2) extraction and high-pressure carbon dioxide pre-treatment technologies for valorisation of corn stover agricultural residues with particular focus on showing how these can aid in the creation of a holistic biorefineries. Corn stover is currently the largest source of agriculture residues in the USA, as such there is significant potential for exploitation to yield valuable chemicals. ScCO2 extraction could lead to the recovery of a variety of different chemicals which include flavonoids, sterols, steroid ketones, hydrocarbons, saturated fatty acids, unsaturated fatty acids, fatty alcohols, phenolics and triterpenoids. Importantly, recent studies have not only demonstrated that supercritical extraction can be utilized for the recovery of plant lipids for use in consumer products, including nutraceuticals and personal care, but the processing of treated biomass can lead to enhanced yields and recovery of other products from biorefinery processes. Despite the great potential and opportunities for using scCO2 and high-pressure systems in a biorefinery context their real-world application faces significant challenges to overcome before it is widely applied. Such challenges have also been discussed in the context of this mini-review. 2021-01-01T00:00:00Z /library/oar/handle/123456789/67200 Title: How DNA can improve biodiversity knowledge and conservation Abstract: Every ecosystem is composed of a community of organisms alongside their physical environment. In order to better understand these ecosystems, conservation biologists from the Department of Biology, University of Malta (UM) have begun compiling a wildlife DNA barcode library that can help understand our local wildlife and give us the tools to protect it. 2020-01-01T00:00:00Z /library/oar/handle/123456789/66173 Title: A story of flies and ice : unravelling the mysteries of ALS Abstract: The Ice Bucket Challenge shot motor neuron diseases into the limelight in 2014. But how much did the ice cold water really represent ALS, and what legacy has it left for research into these diseases? Becky Catrin Jones speaks to Dr Ruben Cauchi and Maia Lanfranco to find out more. 2018-01-01T00:00:00Z