A porous monolith polysaccharide-based adsorbent aerogel with enhanced mechanical performance and efficient adsorption capacity

Recently, the preparation of environmentally friendly adsorbent aerogels with reinforced mechanical performance has attracted much attention. As one of the promising environmentally friendly bio-materials, polysaccharide-based aerogels have a high potential for use in environmental engineering, especially for the absorption of water pollutants. However, the poor mechanical properties have seriously restricted their practical applications hence the development of a polysaccharide-based adsorbent with high mechanical properties is a critical challenge. Herein, we successfully fabricated a new kind of kappa-carrageenan/polyacrylamide double network aerogel containing graphene oxide (GO) nanosheets. The aerogel demonstrated excellent compressive strength (25.902 MPa), good toughness, resilience, and shape recovery, simultaneously. This could be mainly explained in terms of synergistic effects of newly formed reversible interactions induced by the formation of interpenetrating network structure, as well as the bridging effect of the GO nanosheets between the networks. Moreover, the adsorption experiments showed that the nanocomposite double network aerogel could effectively remove cationic and anionic dyes (maximum adsorption capacity: methylene blue = 105.18 mg/g, Congo red = 42.95 mg/g). It is hoped that this knowledge can contribute to the development of environmentally friendly adsorbent aerogels with high service life by enhancing their mechanical performances and can expand their applications, especially for the purification of contaminated aqueous media under high hydrostatic and hydrodynamic stresses.