A robust anti-fouling multifunctional aerogel inspired by seaweed for efficient water purification

Developing effective and green methods to treat large volumes of oily sewage is a significant challenge for aquatic pollution. In this study, an environmentally friendly, economical, self-cleaning, and multifunctional sodium alginate (SA)-tannic acid (TA) aerogel for emulsion separation was prepared via simple freeze-drying and in-situ gelation methods. The microstructure and chemical composition of the SA-TA aerogel are characterized by SEM, EDS, FT-IR, and XPS. As a result, the SA-TA aerogel has an interconnected 3D network structure, high porosity and rough microstructure. Furthermore, the SA-TA aerogel behaves a robust super hydrophilicity, underwater superoleophobicity, anti-crude oil-fouling performance and self-cleaning effect. Thus, it has excellent performance to separate oil-in-water emulsion with high water flux only under gravity and shows terrific cyclic stability. It is worth to note that SA-TA aerogels show improved mechanical properties, stable wettability in various chemical environments, and excellent adsorption properties for soluble dyes, which enable them to be used in complex actual water treatment.

Automated summary

This study developed an environmentally friendly and multifunctional SA-TA aerogel for emulsion separation, which showed excellent performance in treating oily sewage. The aerogel exhibited robust super hydrophilicity, underwater superoleophobicity, anti-crude oil-fouling performance, self-cleaning effect, and high cyclic stability. Furthermore, it also demonstrated improved mechanical properties, stable wettability in various chemical environments, and excellent adsorption properties for soluble dyes, making it suitable for complex water treatment applications.