Multifunctional aluminum 12-hydroxystearate/lignin polyurethane foam for selective gelation and efficient separation of oil and organic solvents

During frequent transportation, the marine environment is continuously exposed to significant threats from crude oil and organic solvent leakage. Non-covalent self-assembly of organogelator on the adsorbent matrix to fix non-polar solvents is an efficient and sustainable remediation method. This contribution proposes an organogelator-adsorbent composite by blending aluminum 12-hydroxystearate (Al HSA) and expanded graphite (EG) during lignin-based polyurethane foaming. Al HSA molecule synergizes with EG to modulate the shape (hexagonal), oil retention, mechanical property, and hydrophobicity (water contact angle = 151.3°) of the lignin-based polyurethane foam (LPUF) skeleton. Al HSA-LPUF (OTS-LPUF/EAH) superhydrophobic foam exhibits sorption capacity up to 13.2–53.0 g  g −1 in various oils and organic solvents. From the microscopic morphology, the Al HSA on the skeleton self-assembles into spherical nanoclusters driven by hydrogen bonding, realizing the capturing of oils and organic solvents. Even after 20 cycles, the foam still has a high oil/water separation capacity and mechanical performance. OTS-LPUF/EAH also shows improved flame retardancy and a 61 % reduction in total smoke release (TSR) compared to pristine LPUF.