Superhydrophobic fire-extinguishing polyurethane foam for solar-assisted high-efficiency recovery of viscous crude oil spill

Abstract

Frequent offshore crude oil spill accidents pose a significant threat to marine ecosystems and coastal communities. Due to the high viscosity and poor fluidity of crude oil, there is an urgent need for polyurethane foam with excellent photothermal properties and oil–water separation capabilities to facilitate crude oil absorption. However, the flammability of PU foam greatly restricts its application when faced with fire scenarios in offshore petrochemical spill incidents. To solve these challenges, a flame-retardant superhydrophobic-superoleophilic polyurethane foam (PDMS@PLP@MXene@PU) is designed by assembling dual photothermal layers and flame retardant onto the foam structure via electrostatic attraction and hydrogen bonding. The results show that PDMS@PLP@MXene@PU exhibits superhydrophobic properties (water contact angle = 162.4°) and crude oil absorption capacity (64.2 g/g). The compressive strength of the PDMS@PLP@MXene is enhanced by 83.9 %. PDMS@PLP@MXene@PU exhibits good photothermal effect and thermal conductivity, which can rapidly rise to 80.0 °C under 1 kW/m² solar irradiation with a maximum oil absorption rate of ∼ 98 %. PDMS@PLP@MXene@PU can self-extinguish a flame with 52.7 % and 71.4 % reductions in peak heat release rate and total smoke production, respectively. This work offers a facile strategy for creating high-performance polyurethane foam to address crude oil spills.