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.

As air pollution has become increasingly serious, anti-haze filter materials have received considerable attention. In this study, a composite window screen with a sandwich structure consisting of a polyacrylonitrile (PAN) nanofiber membrane as the filter layer, a 30 mesh glass fiber mesh as the supporting layer, and a 120 mesh polyester fiber mesh as the protective layer was prepared. We analyzed the effects of different composite methods and composite parameters on the performance of the anti-haze window screen. The results showed that with an increase in the ultrasonic pressure, the peel strength increased, but the nanofiber membrane was damaged by the ultrasonic treatment and the filterability decreased. Using a hot melt adhesive compounding process, the peel strength of the composite window screen increased with an increase in adhesive amount; however, the filtration efficiency remained nearly constant at 95%, despite the increase in the filtration resistance. The optimal amount of adhesive was confirmed as 1.2 g/m². In addition, the hot melt adhesive composite technology is simple and controllable, which is beneficial for the industrial production of anti-haze window screens.

Sense spots are distributed on the surface of the skin, and skin vibration affects the touch sensation. The Kawabata evaluation system method is used for hand evaluation of fabrics to provide reproducible tactile sensation. This study aimed to investigate the effect of mechanical stimulation of the skin on the fabric hands. The measurement of physical properties of clothing materials and the touch test were conducted on 12 types of textiles. Regarding physical properties, mechanical, moisture, and heat properties, as well as air permeability, were measured. During the touch test, mechanical stimulations of the skin (skin vibration and friction) for touching the textiles with fingertips were measured and the tactile sensation of the textiles (roughness, stiffness, stickiness, dryness, thermal sensation, comfort sensation, and preference) was evaluated. The effect of physical properties of the textiles and mechanical stimulations of the skin on the tactile sensation was analyzed using multiple regression analysis. The results showed that the mechanical stimulations of the skin yielded a significant effect on the feeling of roughness, stiffness, dryness, thermal sensation, comfort sensation, and preference. Furthermore, although the evaluations of comfort and preference for the touch of textiles were similar, the friction stimulus of the skin affected the comfort, while skin vibration affected the preference. In conclusion, it is necessary to evaluate the tactile sensation of fabrics in consideration of the mechanical stimulation of the skin. We anticipate that our assay will contribute to making comfortable cloth designs.