The Influence of Cellulose Nanocrystal Characteristics on Regenerative Silk Composite Fiber Properties

Cellulose nanocrystals (CNCs), obtained from natural resources, possess great potential as a bioderived reinforcement for natural-fiber-reinforced composites (NFRPs) due to their superior crystallinity and high aspect ratio. To elucidate the specific parameters of CNCs that significantly affect their mechanical performance, various CNCs were investigated to fabricate high-performance nanocomposite fibers together with regenerated silk fibroin (RSF). We confirmed that the high aspect ratio (similar to 9) of the CNCs was the critical factor to increase the tensile strength and stiffness rather than the crystallinity. At a 1 vol% of CNCs, the strength and stiffness reached similar to 300 MPa and 10.5 GPa, respectively, which was attributed not only to a stable dispersion but also to alignment. This approach has the potential to evaluate the parameters of natural reinforcement and may also be useful in constructing high-performance NFRPs.

Automated summary

Cellulose nanocrystals (CNCs), derived from natural resources, show promise as a bio-based reinforcement for natural-fiber-reinforced composites (NFRPs) due to their high crystallinity and aspect ratio. The mechanical performance of CNCs was investigated in relation to their specific parameters using regenerated silk fibroin (RSF) to fabricate high-performance nanocomposite fibers. It was found that the high aspect ratio of CNCs (about 9) significantly increased the tensile strength and stiffness. At a 1 vol% of CNCs, the strength and stiffness reached approximately 300 MPa and 10.5 GPa, respectively, due to both stable dispersion and alignment. This approach has the potential to evaluate natural reinforcement parameters and aid in the construction of high-performance NFRPs.