Fabrication of outstanding thermal-insulating, mechanical robust and superhydrophobic PP/CNT/sorbitol derivative nanocomposite foams for efficient oil/water separation

Water pollution caused by industrial oily wastewater, is world-widely concerned by both scientific and practical researches, owing to its catastrophic destruction to natural environment, which highlights the urgency of pro-ducing green and advanced separation materials. Herein, a novel approach was proposed to fabricate oil-absorbing and oil/water-separating microcellular polypropylene (PP)/carbon nanotubes (CNTs)/sorbitol nano-composites using a simple, green, and facile microcellular foaming technology. Owning to the effectively modified crystallization via introducing CNTs/sorbitol derivatives, the ultralight and highly-reticulated PP microcellular foam was prepared with an open-cel l content of 99.4% and an expansion ratio of 50, which facilitated the creation of nano-porous structures on cel l walls. Hence, the as-prepared PP nanocomposite foam presented pronounced absorption capacity of 40 g/g for applied oils with recove r y efficiency of 97.2%, superior thermal-insulating and mechanical performance. Furthermore, the as-achieved unique hierarchical porous structures of the PP/CNT/sorbitol foam contributed to the outstanding oil/water separation capability, separa-tion efficiency of up-to 97.6%, ascribed to its superhydrophobicity, capilla r y penetration action, high porosit y and open-ce l l content. Therefore, this work provided new insight into the feasibility of advantageous, high-efficiency, environmentally friendly, and profitable PP-based foams as oi l absorbents, which, to the best of our knowledge, outperform conventional polymer absorbents in treatment of oily wastewater.

Automated summary

Water pollution caused by industrial oily wastewater has attracted global attention due to its catastrophic destruction to the environment. This study proposes a novel approach to fabricate oil-absorbing microcellular polypropylene foam, which demonstrates superior absorption capacity and oil/water separation efficiency.