Impact of Weak Organic Acids as Coagulants on Tailoring the Properties of Cellulose Aerogel Beads

Abstract

Cellulose is the most abundant polysaccharide on Earth and is well known for its renewability, biodegradability and chemical stability.1-2 We have been investigating the use of weak organic acids to tailor the properties of cellulose aerogel beads.3 The cellulose solution was prepared by using commercial cellulose in a mixture of NaOH, urea, and water as solvent.4 Three weak acids, acetic acid, lactic acid, and citric acid, and a strong acid, hydrochloric acid, were chosen as regeneration baths. The production of aerogel beads by conventional dropping technique was studied 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. Furthermore, cellulose from biomass waste can be used for such products too. Thus, 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. Reference 1. Wang S., Lu A., and Zhang L., Prog. Polym. Sci., 53, 169-206, 2016. 2. Wong L. C., Leh C. P., and Goh C. F., Carbohydr. Polym., 264, 118036, 2021. 3. Costa D., Milow B., and Ganesan K., Chem. Eur. J., 30(51), e202401794, 2024. 4. Budtova T., and Navard P., Cellulose, 23(1), 5-55, 2015.