Partition usage of cellulose by coupling approach of supercritical carbon dioxide and cellulase to reducing sugar and nanocellulose

Abstract Cellulose is the most abundant renewable resource on earth, and its economic utilization has long been a hot research topic. To address these challenges, based on the coexistence of crystalline and amorphous structures within cellulose, we coupled supercritical carbon dioxide (SC-CO2) and cellulase to utilize cellulose subregions. This approach is taken into consideration from the structure of cellulose. Cellulose amorphous regions were enzymatically hydrolysed into reducing sugar, and crystalline regions were converted to nanocellulose, representing efficient use of available raw material. This nanocellulose exhibited different properties with these derived from the traditional method. The smallest effective diameter almost was approximately 5nm, suggesting good uniformity and stability of the nanocellulose. Cellulose characterization results showed that the coupled method exposed more free hydroxyl groups which enhanced the accessibility between the cellulose and substrate, and the stability of nanocellulose. The established process was tested on cotton linters and similar results were obtained.