Production of Reduced Graphene Oxide and Polymer based Aerogels for Oil-Water Separations

2017-09-11
In order to preserve nature as well as the future, people are prompt to seek for remediation strategies for water, especially for removal of oil from water. There are increasing number of research to find new water purification methods that cost less, spend less energy, minimize use of chemicals, and minimize the effect of chemicals on the environment. Among all the materials suggested for this purpose, aerogels are preferable in terms of commercial viability, performance criteria and cost aspects. Aerogels are very similar to hydrogels and they can be obtained by removing water from the precursor hydrogel using supercritical drying, freeze-drying etc. They have open pore structure, low density and high surface area which also make them preferable in many applications in addition to oil-water separations. In order to increase the absorbance capacity as well as to increase surface area of the aerogels, carbon based materials including activated carbon, carbon nanotube, and graphene oxide have been used for the production of aerogels. In this study, graphene oxide based aerogels were prepared by using random copolymers of glycidyl methacrylate and styrene as a crosslinker and as an oil absorption enhancer. Graphene oxide was synthesized using Tour Method and characterized with ATR-FTIR, XPS, SEM, TEM and TGA analyses. Two copolymers of glycidyl methacrylate and styrene were synthesized using free radical polymerization and characterized with ATR-FTIR, GPC, 1H NMR, and TGA analyses. Copolymers of glycidyl methacrylate and styrene were prepared and 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 ranged 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, organic solvents (chloroform and toluene) and vegetable 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 vegetable 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. Higher styrene containing copolymer containing aerogels in general showed higher oil absorption capacities. The highest oil absorption values were obtained with aerogels having initial concentrations of 1.5 to 2.0 mg/mL of copolymer.
Citation Formats
Ö. Doğan and E. Bat, “Production of Reduced Graphene Oxide and Polymer based Aerogels for Oil-Water Separations,” presented at the 14th International Conference on Polymers for Advanced Technologies 2017, 11 Eylül - 13 Kasım 2017, Manchester, İngiltere, 2017, Accessed: 00, 2021. [Online]. Available: http://documents.manchester.ac.uk/display.aspx?DocID=34112.