A facile ionic liquid approach to prepare cellulose-rich aerogels directly from corn stalks

Abstract

Aerogels derived from corn stalks are promising materials for wide use, due to their biodegradability and biocompatibility. However, preparation of cellulose-rich aerogels directly from corn stalks is a tedious and complicated process. In this study, generation of cellulose-rich aerogels was achieved by a facile approach relying on an ionic liquid and amido-sulfonic acid used as solvents. By this method, cellulose-rich aerogels were directly obtained from corn stalks through a process whereby lignin was separated from the other components of the corn stalks in one step, an approach simplifying the traditional fabrication processes. The composition, morphology and thermal stability of the obtained aerogels were investigated as they were related to the ionic liquid solvent systems used. Furthermore, the dye adsorption mechanism of cellulose-rich aerogels was simulated. In the most favourable case, the obtained aerogel was free of lignin and had the cellulose content as high as 88.1%. In addition, the aerogel possessed a porous three-dimensional structure with a high specific area (201 m² g⁻¹) and good thermal stability. Owing to its excellent properties, this cellulose-rich porous aerogel is expected to have a potential use in dye adsorption and other fields. This aerogel displayed an absorption capacity of 549 mg g⁻¹ for Congo red and 302 mg g⁻¹ for Coomassie brilliant blue.