Key insights into TEMPO-mediated oxidation of cellulose: influence of starting material

Abstract

The present study investigates the intricate relationships between the properties of cellulose nanomaterials (CNMs) and the lignocellulosic feedstocks from which they are derived. The starting pulps, consisting of eucalyptus, pine, hemp, and sisal commercial bleached pulps where characterized, and later subjected to TEMPO-mediated oxidation at several concentrations, followed by mechanical treatment in a high-pressure homogenizer. The resulting CNMs were extensively analyzed to assess carboxyl content, nanofibrillation yield, optical transmittance, and rheological and structural properties through methods including X-ray diffraction, X-ray photoelectron spectroscopy, solid-state 13C nuclear magnetic resonance, and sugar composition analysis post-acidic methanolysis. Despite the consistent processing conditions, the study reveals significant differences in the physicochemical and rheological behaviors of CNMs, strongly linked to the inherent properties of their respective feedstocks. These disparities highlight the pivotal influence of feedstock characteristics on the final attributes of CNMs, while most of the previous works linked these differences either to chemical or structural differences. The findings suggest that optimizing CNM properties for specific applications requires precise control over feedstock selection and processing parameters, underscoring the critical role of material origin in the development and application of advanced nanomaterials