Bundling of Cellulose Nanofibers in PEO Matrix by Aqueous Electrospinning

Cellulose nanofiber (CNF), which is processed by refining wood fiber, is a promising biomass-derived material with excellent properties, including high strength and light weight. CNFs can be applied to fillers, films, and thickeners. Highly oriented and integrated CNFs can be used to produce ultra-high-strength and ultra-lightweight materials that surpass wood; however, precise alignment of CNF is still difficult. In this study, mechanically-defibrated CNF suspensions supplemented with polyethylene oxide (PEO), a good spinnable polymer, were electrospun to obtain CNF fiber bundles, and their properties were characterized. When CNFs dispersed in a PEO aqueous solution were subject to electrospinning, a nanofiber sheet was obtained. As shown in a tensile test experiment, the elastic modulus and tensile strength improved as the CNF content increased, while TEM observations showed that CNF was bundled along the axial direction. These results demonstrated that by using electrospinning, CNFs can be oriented and integrated inside the PEO fine fibers, leading to the realization of a high-strength material in which the CNF bundle is highly oriented.