The pressing-induced formation of a large-area supramolecular film for oil capture

Abstract

The ability to quickly and efficiently capture oil from diverse bodies of water is very important for environmental considerations. Here, we report a supramolecular film that displayed quick oil adsorption, specifically within minutes, with this film fabricated by carrying out a pressing of precipitates formed from commercially available poly(sodium 4-styrenesulfonate) (PSS) and oppositely charged dimethylditetradecylammonium bromide (DTTAB). Under mechanical pressure, the DTTAB molecules were found to form large lamellar mesophases with sizes comparable to the wavelength of visible light. These mesophases were further connected electrostatically via PSS chains into the bulk film. Oils could be captured by the hydrophobic mesophases in the film owing to the effect of the “like likes like” principle. This effect, being independent of pore size, afforded the complete adsorption of oil within minutes in water samples ranging from dilute water to saline water. Oil recovery was carried out here using a desorption process, and the desorbed film could be reused. Furthermore, the film was regenerated under mechanical pressure after being damaged. Mass-scale fabrication of the film was shown to be possible using a household noodle machine. All these features make the present film a competitive oil adsorption material that can be extended to future industrial production.