Highly sustainable water mist-responsive superwetting sponge (DTMO/FS-50/Hollow-CuCo-ZIF@Sponge) for speedy pollutants removal and solvent-free regeneration

Abstract

Smart solvent-responsive superwetting materials are particularly favored due to their ability to handle different types of pollutants. However, most of them rely on organic solvent vapors, and neglect the desorption efficiency of pollutants, especially using the solvent-free desorption method. A responsive sponge was fabricated by coating hollow MOFs particles with different sizes, greatly enhancing roughness and porosity, and followed by modification with short-chain fluorinated surfactants, long-chain siloxanes, tannic acid, and polydopamine. There are several advantages in this paper: (I) a hollow MOFs structure was achieved, greatly enhancing specific surface area, porosity, and active sites, which acted as a superior container for responsive modifiers network. (II) the reactions among biomass dopamine hydrochloride (PDA), tannic acid (TA), long-chain siloxanes, short-chain fluorinated surfactants and PU substrate, formed smart responsive biomass macromolecular networks, not only greatly improved adhesion between hollow MOFs and sponge substrate, but also showed enhanced synergistic effects for smart wettability transition. (III) the coated sponge showed smart responsive superwetting behaviors under environmentally friendly water mist rather than organic vapors or unfriendly vapors. (IV) the coated sponge could handle various kinds of pollutants based on polarity selection, and also quickly desorb the pollutants after change the polarity under water mist activation. The intelligent sponge can quickly and selectively adsorbed various microplastics and efficiently deal with oil-in-water and oil-in-water emulsions. It has good mechanical durability, maintaining a separation capacity of more than 88% after repeated adsorption and desorption of MPs180 times.