We have proposed the filament cover method for fabricating carbon fiber-reinforced plastic (CFRP) with high axial compression characteristics to address one of the shortcomings of unidirectional CFRP, whose compressive strength is inferior to its tensile strength. In this paper, we attempt to fabricate CFRP with high compressive strength while retaining the high tensile strength of unidirectional CFRP. We propose a method for surface modification of sheath filament PBO fiber (corona discharge treatment followed by silane coupling treatment) and a method for increasing the reinforcing fiber volume fraction of CFRP (flattening reinforcing fiber bundles and shrinking the gaps between them). CFRP prototypes fabricated using them exhibit tensile strength on par with regular CFRP, the effectiveness of the method was confirmed.

The development of functional fibers has been making remarkable progress. Simultaneously, more novel fiberprocessing methods have become necessary. We developed a fabrication method that gives functionality inside of existing porous fibers. Functional particles can be fabricated in-situ in the central part of the fiber by absorbing the raw material solution and be applying microwave heating in a state where the raw material solution is pressed with immiscible liquids. We demonstrated the synthesis of silver nanoparticles inside the cotton cloth. In addition, considering the contact of the synthesized fibers with the human skin, it was confirmed that not only organic solvents but also vegetable oils can be applied as immiscible liquids used during synthesis. The present method is widely applicable to various natural porous fibers. It is applicable irrespective of the fiber or fabric form. Moreover, the applicable functional particles are of a wide range from inorganic materials to various metal nanoparticles, which are expected to be used in various situations in our lives.

The effect of introducing a cationic group to the substate on the crystallization process of electrostatic interactional silica colloidal crystals formed via heterogeneous nucleation was investigated by measuring the reflection spectrum and Kikuchi-Kossel diffraction patterns of the colloidal crystals on two types of substrate: one charged negatively by silanol groups and one with introduced amino groups. On the negatively charged substrate, the colloidal crystals formed a body centered cubic (bcc) structure and a face centered cubic (fcc) structure. On the other hand, on the substrate introduced amino groups, the colloidal crystals formed only bcc structure. The decrease in the close packing trend of the colloidal crystallin lattice was derived from the decrease in the particle mobility on the substrate with introduced cationic groups through the interaction between the negatively charged silica particles and the substrates, which resulted in the prevention of the crystalline lattice disproportionation.