Superhydrophobic starch-based cryogels modified with silylated magnetic nanoparticles for oil spill cleanup

Abstract

Superhydrophobic smart adsorbents have attracted wide attention for the cleanup of oil spill that endangers the aquatic ecosystem. Herein, a super-water-repellent coating (HOS/Fe3O4) was achieved through hydrolytic condensation of hexadecyltrimethoxysilane and tetraethyl orthosilicate in the presence of Fe3O4 nanoparticles. The coating was then introduced onto the surface of starch cryogel (SC) by spray-coating technique to fabricate the superhydrophobic and magnetic starch-based adsorbent (HOS/Fe3O4@SC). The surface chemical composition and hierarchical micro/nanostructures that contribute to the high water contact angle (>151°) and low sliding angle (<5°) of the as-obtained material were characterized in detail. The HOS/Fe3O4@SC exhibited excellent water repellent, self-cleaning, and anti-fouling properties. The structural support and stable chemical bonding endow the material with good mechanical and chemical durability. The HOS/Fe3O4@SC also possessed reasonable adsorption capacities to various organic solvents, and its oil absorption kinetics was also comprehensively studied. The HOS/Fe3O4@SC can be applied for heavy oil absorption underwater and magnetically guided oil slick cleaning. This novel starch-based absorbent exhibits promising application in tackling oil contamination in complex environments.