Durable LBL microcapsule-based sponges with superhydrophobic/super-oleophilic and photothermal behaviors for oil–water separation

Abstract

Spills of marine oily pollutants and illegal discharges of industrial organic solvents have severely undermined the natural resources and ecological sustainability. Herein, a versatile and durable modified melamine sponge (MS) was fabricated by integrating with multilayered microcapsules (MCs) and chemical vapor deposition of 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES), namely PFDTES@MCs@MS. The combination of giant microcapsules on the sponge structure imparts the rough surface micro-construction, accompanied by the hydrophobic modification, which enabled PFDTES@MCs@MS to exhibit superhydrophobic/super-oleophilic and self-cleaning capabilities. PFDTES@MCs@MS displayed outstanding oil–water mixtures or emulsions separation capabilities with the separation efficiencies more than 99%. Impressively, PFDTES@MCs@MS preserved mechanical and chemical durability in 100 recycle tests or chronic processes under harsh conditions. In addition, PFDTES@MCs@MS exhibited the remarkable uptake capacity of organic solvents or oils, and the adsorption amount of light or heavy oil was barely impacted with squeezing after the 50 times of circulation. Furthermore, the PFDTES@MCs@MS displayed antibacterial performance. Significantly, the PFDTES@MCs@MS showed superior photothermal conversion capability, the temperature of it increased dramatically to approximately 80 °C within 180 s under simulated sunlight from room temperature (about 25 ℃), and the flux of separating high-viscosity oils was significantly increased. This study presents a novel oil sorption and separation materials with excellent durability and repeatability, which establishes the foundation for the judicious design of innovative weapons to combat the challenging oil spills.