Publications by authors named "Hisamichi Kimura"

Article Synopsis
  • Researchers created boron-mixed multi-walled carbon nanotube (B-mixed MWCNT) solids by heating and pressing purified MWCNTs combined with different amounts of boron under high temperatures (1400-1800 °C) and pressure (20 MPa).
  • They used various advanced techniques to analyze the structure and properties of the resulting materials, including SEM, TEM, and XRD, revealing significant changes in nanotube structure due to boron addition.
  • The study found that higher boron levels led to the formation of rod-like graphitic carbons, improving mechanical strength, hardness, and electrical conductivity of the B-mixed MWCNTs compared to those without boron.
View Article and Find Full Text PDF

Three types of multiwalled carbon nanotube (MWCNT) monoliths without any binders were obtained by spark plasma sintering (SPS) treatment at 2000 degrees C under 80 MPa sintering pressure. Three MWCNTs with different diameters: thin (slashed circle20-30 nm, CNT Co., Ltd.

View Article and Find Full Text PDF

We produced large binder-free multi-walled carbon nanotube (MWNT) blocks from fluorinated MWNTs using thermal heating and a compressing method in vacuo. This technique resulted in the formation of covalent MWNT networks generated by the introduction of sp(3)-hybridized carbon atoms that cross-link between nanotubes upon de-fluorination. The resulting carbon nanotube blocks are lighter than graphite, can be machined and polished, and possess average bending strengths of 102.

View Article and Find Full Text PDF

Influences of matrix elements and high viscosity in three kind of simulated body fluids (SBFs) on determination of trace metallic elements (Co, Cr, Ni, Al and V) by inductively coupled plasma atomic emission spectrometry (ICP-AES) were investigated. In addition, decreases of these effects were attempted by H(2)SO(4) fume treatment. Calibration lines of the elements were constructed by the standard solutions made of elemental solutions and HCl or the SBFs.

View Article and Find Full Text PDF

Completely glassy thin films of Zr-Al-Cu-Ni exhibiting a large supercooled liquid region (DeltaT(x) = 95 K), very smooth surface (R(a) = 0.2 nm) and high value of Vickers hardness (H(v) = 940) were deposited by sputtering. The micro/nano-patterning ability of these films is demonstrated by focused ion beam etching (smallest pattern approximately 12 nm), as well as by the imprint lithography technique (smallest feature approximately 34 nm).

View Article and Find Full Text PDF

Multiwalled carbon nanotube/polycarbosilane (MWCNT/PCS) composites were fabricated by the spark plasma sintering (SPS) method. The MWCNT/PCS composites consisted of MWCNTs and nanosized SiC particles pyrolyzed from PCS and possessing good mechanical properties for bone tissue repair or dental implantation. The MWCNT/PCS composites were implanted in the subcutaneous tissue and femur of rats at 1 and 4 weeks after implantation.

View Article and Find Full Text PDF

Multi-walled carbon nanotube (MWCNT) films were prepared by employing a condensation reaction utilizing 1,3-dicyclohexylcarbodiimide (DCC) to cross-link each MWCNT with carboxylic acid and hydroxyl groups. Morphological changes in the resultant MWCNT films were monitored using scanning electron microscopy and showed that the MWCNTs were randomly intertwined in the films. The prepared MWCNT films were 17 mm in diameter and 20 microm in thickness, and the apparent density was 0.

View Article and Find Full Text PDF

Completely glassy thin films of Zr-Al-Cu-Ni exhibiting a large super-cooled liquid region (deltaTx = 95 K), very smooth surface (Ra = 0.65 nm), and an extremely high value of Vicker's hardness (Hv = 940), as compared to bulk Zr-Al-Cu-Ni metallic glass, were deposited by radiofrequency magnetron sputtering. Nanoscale patterning ability of Zr-Al-Cu-Ni metallic glass thin films was demonstrated by a focused ion beam etching.

View Article and Find Full Text PDF