Particulation, Nanostructure Control, and Functionalization of Cellulose Nanofibers by Spray-drying

Abstract

Functionalizing biomass-based materials is of utmost importance considering to its profound effects on economy, environment, and society. Therefore, in this study, we focus on exploring the potential of a bio-based wood pulp material called 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidized cellulose nanofibers (CNF). To address the challenges associated with separating and recovering CNF from liquid media, as well as handling, our research team has developed a functionalized particulate CNF with superior performance and exceptional properties using the spray drying method. This includes assessing the feasibility of CNF-loaded particles on porous silica particles with different pore diameters, to enhance the CNFs’ capacity to adsorb proteins, increasing it from 1170 mg/g to 1540 mg/g. The incorporation of magnetic nanoparticles into the CNF also enables efficient external magnetic recovery from liquid mediums. Furthermore, employing various organic solvents enables the generation of CNF particles with a range of specific surface areas, spanning from 1.5 m²/g to 222 m²/g. The impact of ethanol concentration on the surface characteristics of the CNF particles was also assessed. This paper also provides a comprehensive discussion on CNF particles formation mechanism, specifically focusing on its behavior when exposed to various solvents. These results offer useful and instructive insights into the development of CNF-based microparticles to address the challenges associated with their application in several fields, including biomedicine and environmental sustainability.