Cellulose nanofiber (CNF) has attracted significant attention as a next-generation insulating material due to its ecofriendly nature and outstanding functionalities. However, conventional kraft insulation paper suffers from limited dielectric breakdown strength and long-term reliability under high-voltage conditions, highlighting the need for alternative materials. In this study, kraft pulp was combined with five types of CNFs (A, B, C: wood-based / D, E: non-wood-based) to fabricate composite insulation papers, and their electrical and mechanical properties were systematically evaluated. The results showed that CNF incorporation generally enhanced density and tensile strength, while certain types contributed to lowering dielectric constant and improving breakdown strength. Among the wood-based CNFs, type C exhibited the most balanced performance in terms of dielectric stability and mechanical reinforcement. Among the non-wood-based CNFs, type E demonstrated notable improvements in structural compactness and tensile strength, suggesting favorable reliability. Therefore, this study identifies CNF C among wood-based types and CNF E among non-wood-based types as the most promising candidates for insulation performance enhancement, suggesting their applicability as next-generation insulating materials for power equipment and ecofriendly electronic devices.
The continuous rise of atmospheric carbon dioxide (CO₂) emissions highlights the urgent need for sustainable air purification technologies. Current Direct Air Capture (DAC) filters often rely on toxic amines, which limit long-term stability and safe application. Here, we report a non-toxic PAN-based nanofiber air filter fabricated by electrospinning and urea-assisted carbonization. Structural analyses confirmed the introduction of nitrogen functionalities that enhanced CO₂ affinity, while SEM and FT-IR revealed graphitic carbon formation. In air-chamber tests, the optimized carbonized nanofiber reduced CO₂ concentration from 25,000 ppm to 2,000 ppm, a level generally regarded as acceptable for indoor environments, while simultaneously removing over 95% of PM10, PM2.5, and PM0.1 particulates. This dual functionality, combined with facile fabrication and material safety, demonstrates strong potential for PAN-derived carbon nanofiber membranes in DAC systems and eco-friendly air purification devices. These findings suggest a viable pathway toward scalable, sustainable air-filter technologies for carbon-neutral applications.
TiO2 has excellent photocatalytic properties and several studies have reported the increase in its specific surface area. The structure of TiO2 nanofibers indicates promising improved photocatalytic properties and these nanofibers can thus potentially be applied in air pollution sensors and pollutant removal filters. In this study, a TiO2 nanofiber was fabricated by the electrospinning method. The fabrication processing factors such as the applied voltage, the distance between nozzle and collector, and the inflow rate of solution were controlled. The precursor was titanium (Ⅳ) isopropoxide and as-spun TiO2 nanofibers were heated at 450℃ for 2 h to obtain an anatase crystalline structure. The microstructure was analyzed using field emission scanning electron microscope (FE-SEM) and X-ray diffraction analysis (XRD). The anatase phase was observed in the TiO2 nanofibers after heat treatment. The diameter of TiO2 nanofibers increased with the flow rate, but decreased with decreasing applied voltage and nozzle to collector distance. The diameter of TiO2 nanofibers was controlled in the range of 364 nm to 660 nm. These nanofibers are expected to be very useful in photocatalytic applications.
In this work, one dimension In2O3 nanostructures as detecting materials for indoor toxic gases were synthesized by an electrospinning process. The morphology of electrospun In2O3 nanofibers was controlled by electrolyte composition, applied voltage and working distance between a nozzle and a substrate. The synthesized In2O3 nanofibers-based paste with/without carbon black additives was prepared for the integration on a sensor device. The integration of In2O3 sensing materials was conducted by a hand-printing of the paste into the interdigit Au electrodes patterned on Si wafer. Gas sensing properties on CO and HCHO gases were characterized at 300℃. The evaluated sensing properties such as sensitivity, response time and recovery time were improved in In2O3 nanofiber pastes with carbon black, compared to the paste without carbon black.
In this study ensuring a filming technology is attempted through dispersion technologies and mixing polymer scaffolds in order to produce films based on the nanowaires obtained from chitin. In addition this study proposes technologies in measuring and improving characteristics of films produced using nanowires and for applying electric conductivity to the films as a chemical and physical manner. Also, a possibility in applications of mass productive films or substrates to producing flexible and transparent films is proposed. In the experiment implemented in this study, it is verified that developments of high strength, high transparency, and high flexibility films can be developed through combining it with producing flexible and transparent films.
In this study, we propose a novel fabrication of an oxide-based lateral thermoelectric pn couple and investigate the characteristics of the thermoelectric couple. Electrospun ZnO and LaSrCoO3 nanofibers are used as n- and p-legs of the couple, respectively. The Seebeck coefficients of the n- and p-type nanofibers and the pn couple are -98.1 μV/K, 42.4 μV/K, and 118.8 μV/K, respectively. The thermoelectric couple generates an output voltage of 484.7 μV at a temperature difference of 4.1 K.
First
Prev
