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To expand the application field of the pulping industry, this study conducted a series of sample preparations for processing cellulose nanocrystals (CNCs) from a dry hardwood pulp to achieve optimal sulfuric acid hydrolysis. The properties of laboratory-prepared pulp CNCs (P-CNCs) were investigated with different preparation conditions including sulfuric acid concentrations, hydrolysis temperatures, and hydrolysis durations. Results showed a gradient of color changes observed with the increase of hydrolysis duration and temperature. Under certain conditions, the derived P-CNCs exhibited nanoscale dimensions, detected by transmission electron microscopy, and a crystallinity index similar to commercial products. In addition, the surface sulfate groups were assumed to be contributed by sulfuric acid hydrolysis. However, a high acid concentration and long hydrolysis processing duration introduced more sulfate groups on the derived P-CNCs, which may have acted as flame retardants and, thus, increased the amount of char residue.

The two types of cellulose nanofiber (CNF) surface characteristics were evaluated by oil contact angle under ethanol–water solution at several concentrations as well as in air. Wood pulp-based 2,2,6,6-tetramethylpiperidine-1-oxylradical (TEMPO)-oxidized cellulose nanofiber (TOCNF) sheets and bamboo-derived mechanical counter collision cellulose nanofiber (ACC-CNF) sheets were fabricated by casting followed by drying. The CNF shows underwater superoleophobic mimicking fish skin properties and slippery surface mimicking Nepenthes pitcher. The underwater superoleophobic properties of CNF was evaluated theoretically and experimentally. The theoretical calculation and experimental results of contact angle showed a large deviation. The roughness, zeta potential, and water absorption at different concentrations were key factors that determine the deviation. Antifouling investigation revealed that CNF was a good candidate for antifouling material.

Cellulose nanocrystals (CNCs) are extracted from cellulosic fibers via sulfuric acid hydrolysis and found to exhibit unique properties due to their nanoscale, ordered structure, and surface morphology.

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The influence of acid hydrolysis conditions on cellulose nanowhiskers (CNW) made from moso bamboo (Phyllostachys edulis) was investigated in this study. Procedures with or without an alcohol–toluene extraction were tested using different acid concentrations and hydrolysis durations. The alcohol–toluene extract had no significant effect on the properties of bamboo cellulose nanowhiskers (BCNW). According to the results, a sulfuric acid concentration of 46% with 2 h of hydrolysis and a concentration of 55% with 1 h of hydrolysis were ideal for preparing BCNW because the product had a relatively high crystallinity index. In addition, the surface functional groups of the products obtained from different sulfuric acid hydrolysis conditions were similar. However, groups treated with lower acid concentrations exhibited slightly stronger thermal stability than those treated with higher acid concentrations.