Utilizing the biomass waste for the production of cellulose aerogel beads and tailoring their properties

Abstract

Biomass waste can be utilized for the cellulose aerogel production. Hemp and flax from Canadian suppliers were used as starting material. Within the presentation an overview on the production of cellulose aerogels from various raw materials working under different conditions will be presented. The good quality cellulose was extracted by hydrolyzing the raw material using alkali hydroxide and hydrogen peroxide. The cellulose solution was prepared by using commercial cellulose in a mixture of NaOH, urea, and water as solvent.1 Aerogel beads were produced by conventional dropping technique, washing, solvent exchange and supercritical drying. The aerogel properties were compared with the classical cellulose aerogel beads which were prepared from commercial grade cellulose. We have been investigating the use of weak organic acids as coagulants to tailor the properties of cellulose aerogel beads.2 Three weak acids, acetic acid, lactic acid, and citric acid, and a strong acid, hydrochloric acid, were chosen as regeneration baths. and optimized for each acid. The produced cellulose aerogels were characterized by nitrogen adsorption-desorption isotherm, BJH pore data analyses, density analyses, IR spectroscopy, scanning electron microscopy, and X-ray powder diffractometry, and their properties were compared. In common, all the aerogel beads showed interconnected nanofibrillar network. The pore size distribution was highly influenced by the acids employed for regeneration. High concentration of weak acids contributed to low shrinkage, high specific surface area and high pore volume. In conclusion, this study showed an alternate path way to tailor the properties of cellulose aerogel beads. Reference 1. Budtova T., and Navard P., Cellulose, 23(1), 5-55, 2015. 2. Costa D., Milow B., and Ganesan K., Chem. Eur. J., 30(51), e202401794, 2024.