Nanofibrillated cellulose (NFC) has garnered significant attention as a sustainable biomaterial, but its chemical reactivity with respect to its generation, i.e., fibrillation, has heretofore been unexplored. We prepared NFC samples with varying levels of fibrillation by controlling mechanical energy followed by acetylation as a probe to explore chemical reactivity. The degree of substitution (DS) reached a global maximum after which, surprisingly, it dropped to lower values at higher fibrillation or higher input (generation) energies. This behavior was attributed to two factors: the presence of higher bound water molecules at fibrillated surfaces, which hinder accessibility to cellulose chains, and enhanced self-aggregation of surface hydroxyl groups of NFC due to formation of hydrogen bonds at higher fibrillation. The discovery of these two mitigating factors provides a promising physicochemical strategy for efficient and sustainable production and modification of NFC to optimize performance for different applications.

Based on publications related to the use of micro- and nanofibrillated cellulose (MNFC) in papermaking applications, three sets of parameters (intrinsic and extrinsic variables, furnish composition, and degree of dispersion) were proposed. This holistic approach intends to facilitate understanding and manipulation of the main factors describing the colloidal behavior in systems comprising of MNFC, pulp fibers, and additives, which directly impact paper product performance. A preliminary techno-economic assessment showed that cost reductions driven by the addition of MNFC in paper furnishes could be as high as USD 149 per ton of fiber (up to 20% fiber reduction without adverse effects on paper’s strength) depending on the cost of papermaking fibers. It was also determined that better performance in terms of strength development associated with a higher degree of MNFC fibrillation offset its high manufacturing cost. However, there is a limit from which additional fibrillation does not seem to contribute to further strength gains that can justify the increasing production cost. Further research is needed regarding raw materials, degree of fibrillation, and combination with polyelectrolytes to further explore the potential of MNFC for the reduction of weight of paper products.

Based on publications related to the use of micro-and nanofibrillated cellulose (MNFC) in papermaking applications, three sets of parameters (intrinsic and extrinsic variables, furnish composition, and degree of dispersion) were proposed. This holistic approach intends to facilitate understanding and manipulation of the main factors describing the colloidal behavior in systems comprising of MNFC, pulp fibers, and additives, which directly impact paper product performance. A preliminary techno-economic assessment showed that cost reductions driven by the addition of MNFC in paper furnishes could be as high as USD 149 per ton of fiber (up to 20% fiber reduction without adverse effects on paper's strength) depending on the cost of papermaking fibers. It was also determined that better performance in terms of strength development associated with a higher degree of MNFC fibrillation offset its high manufacturing cost. However, there is a limit from which additional fibrillation does not seem to contribute to further strength gains that can justify the increasing production cost. Further research is needed regarding raw materials, degree of fibrillation, and combination with polyelectrolytes to further explore the potential of MNFC for the reduction of weight of paper products.

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