We are conducting research on producing CFRP using the braiding technique, which is one of the textile technologies. In this report, we propose a calculation method for the cover factor to integrally mold CFRP braided structures onto common curved hollow pipes, which are prone to stress concentration in mechanical structures. The cover factor is an important indicator to prevent voids (hollow spaces) during press molding. For calculating the expanded cell area on the torus surface of the curved pipe, a three-dimensional torus model, we employed a 2D approximation by considering the torus as a continuous thin surface. Using this 2D approximation, we conducted numerical calculations necessary for creating braided structures in curved hollow shapes and carried out actual fabrication based on these calculations. As a result, we compared the expanded cell area calculated using the three-dimensional torus model and the 2D approximation, demonstrating the usefulness of calculating the cover factor using the 2D approximation. We also compared the calculated cover factor from numerical calculations with the measured values obtained from image analysis of the prototype preform, considering the validity of the calculated values.

In order to apply carbon nanofiber (CNF) to various electrode materials and adsorbents, surface properties such as specific surface area and pore size and pore volume are important. We prepared CNF with pre-perforated pores using a template, and examined the pore properties of CNF by subjecting this CNF to alkali activation treatment. As a result, it was found that the BET specific surface area of CNF with pores was greatly improved by alkali activation treatment compared with CNF without pores. In addition, it was found that the specific surface area and pore volume of CNF after alkali activation treatment changed depending on the size of pores provided in advance. Furthermore, it was found that the BET specific surface area was the highest when sodium hydroxide was used as the alkali activation treatment rather than potassium and lithium counterparts.