Ultralight, Mechanically Enhanced, and Thermally Improved Graphene-Cellulose-Polyethyleneimine Aerogels for the Adsorption of Anionic and Cationic Dyes

Graphene-cellulose-polyethyleneimine aerogels (GA-MCC-PEI) were prepared using a simple, environmentally friendly method to remove anionic and cationic dyes in water. Graphene-cellulose hydrogels were prepared using a hydrothermal method and then immersed in a polyethyleneimine aqueous solution for 48 h to obtain graphene-cellulose-polyethyleneimine hydrogels, which were then freeze-dried. The light and porous composite aerogels had a good compression resistance, and the maximum allowable pressure of the graphene-cellulose-polyethyleneimine aerogel with a cellulose content of 43% was 21.76 kPa, which was 827 times its weight. Adsorption of the anionic dye amaranth and the cationic dye methylene blue by the graphene-cellulose-polyethyleneimine aerogel was satisfactorily modeled using the Langmuir isothermal equation, indicating monolayer adsorption. When the cellulose content was 39%, the equilibrium adsorption capacities of the composite aerogel for amaranth and methylene blue were 369.37 mg/g and 237.33 mg/g, respectively. This graphene-cellulose-polyethyleneimine aerogel can be used to remove dye pollutants in water to maintain ecological balance, thus broadening the application space of aerogel materials, that is, as adsorbents in different environments.

Automated summary

Graphene-cellulose-polyethyleneimine aerogels were prepared to remove anionic and cationic dyes in water. These aerogels had good compression resistance and satisfactory adsorption capacity for amaranth and methylene blue, making them suitable for use as adsorbents in different environments to remove dye pollutants and maintain ecological balance.