One-pot catalytic isolation of cellulose nanocrystals from agricultural biomass – Oat hull, wheat straw, and flax straw: Physicochemical characterization

The depletion of fossil fuel resources and their environmental impact have driven interest in renewable materials. Cellulose, derived from lignocellulosic biomass, has emerged as a promising candidate for sustainable applications due to its abundance, biodegradability, and versatile properties. This study explores isolating cellulose nanocrystals (CNCs) from oat hulls, wheat straw, and flax straw using a one-pot Cu²⁺-catalyzed method. Compared to traditional acid hydrolysis methods, the Cu²⁺-catalyzed approach reduces chemical consumption, eliminates the need for multistep neutralization, and achieves CNC yields of up to 61.9 %, with high crystallinity and improved thermal stability. CNCs were characterized to evaluate their surface chemistry, structural morphology, and thermal properties, with XPS confirming minimal Cu²⁺ residues in dried samples. These results highlight the potential of agricultural byproducts as sustainable sources for high-value nanomaterials, advancing circular bioeconomy solutions.