Preparation of titanium dioxide/ZIF-8 composite superhydrophobic sponge and its oil-water separation performance

Treatment of oily wastewater problem of oil spills at sea and the discharge of oily wastewater have brought huge damage to the economy and the environment. This paper used polydopamine to adhere the self-made dual-scale ZIF-8/TiO₂ nanoparticles to the polyurethane sponge, and prepared the superhydrophobic oil-water separation sponge by modification with octadecylamine. The structure was characterized and analyzed by FTIR, XRD, etc.. ZIF-8 and TiO₂ two kinds of nano-particles constructed a two-scale rough structure, and the influence of the amount of the two kinds of particles on the surface performance of the composite coating was deeply explored. The results show that when the molar ratio of ZIF-8 and TiO₂ nanoparticles is 2∶1, the contact angle reaches the maximum value of 153°.The composite sponge has good oil-water separation performance, the absorption capacity is 40 to 118 times its own weight, and the separation efficiency is on average more than 96%. The temperature can rise by 55℃ within 10 s under 808 nm laser irradiation, and it has good light-to-heat conversion performance.