Hitoshi Ogihara

Simple Method for Preparing Superhydrophobic Paper: Spray-Deposited Hydrophobic Silica Nanoparticle Coatings Exhibit High Water-Repellency and Transparency

Superhydrophobic and transparent coatings are deposited onto paper by spraying alcohol suspensions of SiO(2) nanoparticles. Superhydrophobicity depends on the aggregation states of nanoparticles, which are determined by the type of alcohol used in the suspensions. The superhydrophobicity of the paper is maintained after touching the paper with a bare finger.

Facile Fabrication of Colored Superhydrophobic Coatings by Spraying a Pigment Nanoparticle Suspension

Superhydrophobic coatings were prepared by spraying a pigment nanoparticle suspension. By changing the type of pigment nanoparticles, the colors of the coating could be controlled. The particle size of the pigments, which determines the surface structure of the coatings, played an important role in exhibiting superhydrophobicity. The spray-coating process is applicable to a variety of materials (e.g., copper, glass, paper, coiled wire, and tied thread), and the superhydrophobicity was repairable.

Electrophoretic deposition of phthalocyanine in organic solutions containing trifluoroacetic acid.

The absorption spectra of copper phthalocyanine (CuPc) 1,2-dichloroethane (DCE) solutions containing trifluoroacetic acid (TFAA) shows that the number of protons coordinating to the CuPc molecule was 1 and 2 for the first and second proton adducts, respectively, which indicates the formations of CuPcH(+) and CuPcH(2)(2+). This CuPc molecule may act as a catalyst to dissociate TFAA into trifluoroacetate anion (A(-)) and H(+) and form the proton adducts. The electrical conductivity dependence of the solution on CuPc concentration also supports this mechanism. A dense film of CuPc was deposited on an indium tin oxide cathode plate by electrophoresis of the solution. Similar dense films of a wide variety of phthalocyanines (MPc; M = Cu, H(2), Fe, Ni, Zn, Pb, VO) were also deposited using this method. Similar films of CuPc were also formed using dichloromethane (DCM) and 1,1,1-trichloroethane (TCE) in place of DCE. Depositions are ascribed to the migration of positively charged monomers (i.e., protonated MPc). Scanning electron microscopy revealed that these films are composed of fibrous crystallites, size of which was found to increase with the electrophoresis time, the strength of the applied electrical field and the concentration of CuPc in the bath. The influence of the dielectric constant of the organic solvent on the film growth is discussed.

Hard and glossy-colored films composed of micropatterned organic dots and electrodeposited honeycomb-shaped nickel walls.

This paper proposes a novel approach for the preparation of colored films with a metallic luster and high hardness. The colored organic films were patterned as microdots by photolithography, and then honeycomb-shaped Ni walls were electrodeposited between the micropatterning. The organic/inorganic composite films showed the hardest grade in a pencil hardness test and high durability in wear resistance tests because the honeycomb-shaped Ni walls protected the colored organic dots.

Method for Patterning Various Nanomaterials: Electrochemical Deposition of Patterned Ni Thin Films and Their Utilization as a Strippable Mask

We report an interesting approach for preparing micropatternings of nanomaterials, such as carbon nanotubes and TiO(2) nanoparticles. In the method, exfoliation of electrodeposited Ni thin films was the key process. After patterning indium thin oxide (ITO) plates with an insulating photoresist by conventional photolithography, Ni was electrodeposited on only the exposed ITO areas. The resulting substrates were evenly covered with nanomaterials by a drop cast method. By exfoliating the electrodeposited Ni thin films from the substrates, patterned nanomaterial films were formed.

Immobilization of nanofibrous metal oxides on microfibers: a macrostructured catalyst system functionalized with nanoscale fibrous metal oxides.

Nanofibrous LaMnO(3) can be immobilized on macrostructured materials using carbon nanofibers as templates; their application as macro-nanostructured catalysts are also presented.

Nano-Scale Deposition of Hydroxyapatite on Bioactive and Bioinert Fibers Using Carbon Nanofibers as Templates

The synthesis of nano-scale hydroxyapatite (HAp) could be achieved by using carbon nanofibers (CNFs) as templates. It was shown that both silica fiber and alumina fiber are suitable substrates for the growth of CNFs templates by chemical vapor deposition (CVD) technique. It turned out that the resulting CNFs could act as promising and effective templates for nano-scale deposition of HAp on the fiber surface. However, CNFs obtained from silica fiber performed better than those grown from alumina fiber for uniform deposition of HAp on the surface.