Development of graphene oxide based aerogels

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2017
Doğan, Öznur
Owing to their large surface area, high hydrophobicity and porous structure, graphene oxide based aerogels have been proposed as feasible and economic solutions for the increasing water pollution caused by crude oils, petroleum products and toxic organic solvents. In this study, graphene oxide based aerogels were prepared via two different routes. In the first route, random copolymers of glycidyl methacrylate and styrene were used as crosslinkers in the aerogel. In the second route, 1,3-diaminopropane was used to obtain crosslinked hydrogel precursors. Graphene oxide was synthesized using Tour Method and characterized. Morphology of graphene oxide was assessed using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) analyses. Copolymers of glycidyl methacrylate and styrene were synthesized using free radical polymerization and chemical characterizations were performed. Copolymers were used along with graphene oxide in order to synthesize the precursor hydrogels. Graphene oxide concentration in the hydrogels was kept at 5.0 mg/mL while copolymer concentrations were varied from 0 to 5.0 mg/mL. After freeze-drying and thermal reduction, morphologies of the aerogels were assessed using SEM analysis. To determine the oil absorption capacity of the prepared aerogels, chloroform, toluene and sunflower oil were used. The prepared aerogels were found to have absorption capacities in the range of 90 to 175 g/g for toluene and 90 to 200 g/g for sunflower oil. In the case of chloroform, aerogels with higher styrene content had absorption capacities ranging from 170 to 315 g/g, whereas this range was between 145-260 g/g for aerogels with lower styrene content. 1,3-diaminopropane and reduced graphene oxide based aerogels were found to have absorption capacities in the range of 230 to 534 g/g for chloroform, 109 to 202 g/g for toluene and lastly 173 to 270 g/g for sunflower oil. Aerogels with initial graphene oxide concentration of 3 mg/mL showed better absorption capacities compared to that of 4 mg/mL and 5 mg/mL. Aerogels produced by either route offer efficient absorption for oil and are promising candidates to be used in oil-water separation. 
Citation Formats
Ö. Doğan, “Development of graphene oxide based aerogels,” M.S. - Master of Science, Middle East Technical University, 2017.