Solvent Regulation Approach for Preparing Cellulose-Nanocrystal-Reinforced Regenerated Cellulose Fibers and Their Properties

[Image: see text] An electrolyte and aprotic solvent mixture were used to prepare cellulose solutions containing cellulose nanocrystals (CNCs). All-cellulose composite fibers were then produced by dry–wet spinning these solutions. The presence of CNC in the all-cellulose fibers was demonstrated, and the effects of the CNC on the fiber properties were investigated. The all-cellulose fibers were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and electronic tensile measurements. These results showed that CNCs were present in the mixture and that their structure was maintained in the all-cellulose fibers. No compatibility problems between the CNC and cellulose II matrix were observed. Introducing CNC enhanced the crystallinity, thermal stability, and mechanical properties of the composite fibers.