2.5 Production of nanocellulose from hardwood using Fenton pretreatment with emphasis on fiber fragmentation and resulting coating performance
- Morassa Raouf
- PhD student,
- Karlstad University
- Co-author(s): Björn Sjöstrand
- Supervisor (PhD-students/postdocs): Björn Sjöstrand
- A novel cellulose-based nanomaterial was developed using a carefully controlled Fenton oxidation process involving hydrogen peroxide and ferrous ions. The selected reaction conditions facilitated iron-catalyzed oxidative reactions that, together with subsequent mechanical processing, promoted efficient fibrillation of cellulose fibers into nanoscale structures. To assess the structural changes, optical microscopy was employed to compare the morphology of untreated hardwood pulp with that of Fenton-treated fibers, clearly demonstrating the extent of fibrillation and fiber disintegration caused by the treatment. The drainage behavior of the treated samples was investigated to evaluate fiber accessibility and the degree of fibrillation achieved. Surface charge measurements indicated a significant increase in negative charge density, attributed to the formation of carboxyl groups on the cellulose surface. This chemical modification is crucial for improving the dispersion, stability, and interaction of cellulose nanofibrils and microfibrillated cellulose (CNF/MFC) in aqueous systems. The presence of newly introduced carboxyl groups was further verified using Fourier-transform infrared spectroscopy (FTIR), confirming the effectiveness of the Fenton oxidation process. The produced CNF/MFC material was directly applied as a coating on paper substrates without incorporating additional additives or binders. The coated papers were then evaluated for air permeability and surface roughness, revealing improvements in barrier performance and potential for enhanced hydrophobic characteristics. These findings demonstrate that Fenton oxidation is a viable and effective method for producing high-quality nanocellulosic materials with tailored properties. Overall, the study highlights the potential of this approach for developing sustainable, functional cellulose-based coatings suitable for advanced material and packaging applications.
- Time of presentation: 10.50