Super-hydrophobic carrageenan cross-linked graphene sponge for recovery of oil and organic solvent from their water mixtures.

A novel ultra-light, superhydrophobic graphene based carrageenan sponge (GCS)absorbent was synthesized by one pot hydrothermal method, for the use of selective adsorption of oils and organic solvents from their water mixtures. The GO nanosheets were reacted in the presence of formaldehyde by the insertion of carrageenan, forming hydrophobic cross-linked structure in between them. The structure and properties of this GCS are well characterized by Fourier transform infrared spectroscopy, X-ray diffraction, Thermal gravimetric analysis, Scanning electron microscopy, and Water contact angle. The as-prepared GCS has good thermal stability (400 °C), low density (20 mg/cm?3), excellent hydrophobicity (water contact angle of 136.24°), and selective absorption capacity (25.2-35.95 g/g)of oils and organic solvents from their water mixtures. GCS has excellent oil sorption capacity in the range of 25.2-50 g of oil per gram of adsorbent. GCS could be easily reused by simple solvent treatment. Therefore, the adsorption capacity still retained even after 10 cycles. The present work suggests that GCS using biobased resources has high potentials for many widespread applications in industry to control environmental pollution.