Facile fabrication of thermo-mechanically reinforced polystyrene-graphene nanocomposite aerogel for produced water treatment

Herein, we report a facile method to fabricate thermo-mechanically reinforced polymer nanocomposite aerogel for oil-field-generated water treatment applications. Polystyrene-graphene (PS-G) aerogel was prepared using solvent crystallization-induced phase separation through flash-freezing route. The fabricated polymer nanocomposite aerogel was characterized using Fourier-Transform Infra-Red spectroscopy (FT-IR), X-ray diffraction (XRD), Differential scanning calorimetry (DSC), Field-Emission Scanning Electron Microscopy (FE-SEM), and Brunauer-Emmet-Teller (BET) surface area, and nano-indentation test. The PS-G nanocomposite aerogel showed 3D-interpenetrating network structures with high specific surface area (~ 300 m²/g) and high porosity. Notably, the PS-G aerogel exhibits a reinforced compression strength of 152 kPa compared to that of PS aerogel (124 kPa). The PS-Graphene aerogel showed T_g value as high as 101.4 ^oC. The PS-G nanocomposite aerogel was found to be a potential absorbent for the rapid removal of oil from produced water samples. Interestingly, the PS-G nanocomposite aerogel exhibited an oil absorption capacity of 50 g/g and reached saturation within 20 min. Furthermore, the aerogel nanocomposite absorbent can be easily regenerated by simple squeezing or washing with methanol and was found to be efficiently recycled up to 10 cycles with only a negligible reduction in oil absorption efficiency.