(549i) Production and Characterization of Holocellulose Micro and Nano Fibers in Alternative Solvents

Cellulose-hemicellulose (holocellulose) fibers of micron to nano scale dimensions can be used to make a wide variety of renewable materials like holocellulose reinforced composites and substrates for flexible electronics. However, the cost of production needs to be lowered for commercialization by reducing the energy consumption in milling and drying processes. Therefore, a variety of new water-based solvents were utilized to see their impact on pulp fibrillation performance, fiber morphology and chemical structure. These aqueous solvents were made by adding low concentrations of additives like carboxymethylcellulose that acts as a viscosity modifier, or sodium hydroxide-urea which was found to be a top ranking additive from molecular dynamic simulations. Holocellulose micro/nano fibers (CNF) fibrillated in these alternative solvents were studied for energy consumption, size distribution, morphology, thin film forming qualities and composition. In particular, ¹³C solid-state NMR based techniques were investigated to understand the changes to the crystallinity of cellulose fraction in native and never-dried state and without hemicellulose removal by wet chemistry.