Hydrophobic Superoleophilic Fluorinated Graphene Nanosheet Composites with Metal Organic Frameworks for Oil Water Separation

Abstract

Oil spills and industrial oily wastewater discharge into water bodies pose a considerable threat to marine networks and human health, along with massive loss to the economy. The crucial factors remain in oil-water separation research, includes designing robust hydrophobic-oleophilic sorbents with excellent performance, selectivity, including simple synthesis and high separation efficiency, lightweight, and environmental compatibility. Selective oil and organic solvent collection devices with effective recovery of oils from the water surface using advanced sorbents with special wetting properties. Keeping this in mind, in the first working chapter, we employ a simple in-situ synthesis to prepare cobalt-based zeolite imidazole framework (ZIF-67) supported over fluorinated graphene nanosheets showing hydrophobic-oleophilic functions. The key features of the work include in-situ growth and assembly of ZIF-67 over oxygen functionalized fluorinated graphene f-FG, solution processing, and spray coating over polyurethane sponge. The hydrophobic f-FG-ZIF-67 show a WCA of 140±1°, and the f-FG-ZIF-67-PU sponge displayed oil/organic sorption ability in the range of 46 to 62 g/g, besides gingelly oil recovery from oil spill clean-up was demonstrated. Moreover, the durability of the f-FG-ZIF67-PU sponge with respect to extreme pH, weight, and exposure to sunshine were tested followed by castor oil sorption. newlineIn the second working chapter, we explore, room-temperature synthesis of hydrophobic and superoleophilic copper-based metal organic framework (HKUST-1) supported on multi-layered FG nanosheets. The intrinsically hydrophilic HKUST-1 (WCA - 0°) changed into a hydrophobic with a WCA of 147±3° and a surface free energy of 7.1 mJ m-2 when grown over the multi-layered FG newline