Toru Nonami

National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan

Are you Toru Nonami?

Claim your profile

Publications (32)23.57 Total impact

  • MRS Online Proceeding Library 01/2011; 599. DOI:10.1557/PROC-599-165
  • Key Engineering Materials 01/2005; DOI:10.4028/www.scientific.net/KEM.284-286.843 · 0.19 Impact Factor
  • T. Nonami, H. Hase, K. Funakoshi
    [Show abstract] [Hide abstract]
    ABSTRACT: A multifunctional composite material, titanium dioxide covered with apatite, has been developed for application in air purification and as an antimicrobial, antifungal, and antifouling coating. This composite can absorb and decompose bacteria and various other materials. TiO2 powder was soaked in a simulated physiological solution containing phosphate ions for periods of about 1h at 37°C. The composite material has the following characteristics: (1) the apatite adsorbs contaminants even without exposure to light; (2) material adsorbed by the apatite is decomposed by the titanium dioxide photocatalyst on exposure to light; (3) the apatite is used as an inert spacer, allowing blending of the material with resins, organic coatings, and other organic materials; (4) though the photocatalyst requires some time to fully decompose organic materials, capture of contaminants by the apatite ensures complete decomposition.
    Catalysis Today 10/2004; 96(3):113-118. DOI:10.1016/j.cattod.2004.06.112 · 3.31 Impact Factor
  • Source
    H. Okudera, T. Nonami
    [Show abstract] [Hide abstract]
    ABSTRACT: A transparent, rigid amorphous silica (SiO2)-anatase phase titania (TiO2) multilayer coating was fabricated on KCaZnSi glass substrate (i.e. slide glass for optical microscope use). The silica and titania layers were successively fabricated in that order by the hydrolysis of Si-tetraethoxide in ethanol and Ti-tetraethoxide in iso-propanol, respectively, at 20 °C and annealing in air at 350 °C after each cycle. X-ray diffraction profiles showed that the titania upperlayer was successfully transformed to polycrystalline anatase in samples where the thickness of the silica underlayer ds was 230 nm and/or that of the titania upperlayer dt was 99 nm and that no crystallization occurred in samples where ds and dt were 115 nm and 55 nm, respectively. No amorphous-anatase transformation occurred when the silica underlayer was not prepared nor when it was used as-deposited. This indicated that amorphous-anatase transformation in the upperlayer was hindered by the migration of elements diffused from the substrate. The silica underlayer of ds=115 nm was less effective as a barrier to these elements but was still sufficient when a thicker upperlayer, i.e. dt=99 nm, was fabricated. Ultraviolet–visible (UV–Vis) spectroscopy indicated efficient filtering of UV light by the multilayer coating where ds=115 nm and dt=99 nm. The absorption edge was determined to be at λ=318 nm, while the loss of visible light was less than 12% per coating over the range of 480–850 nm.
    Thin Solid Films 09/2003; 441(1-2). DOI:10.1016/S0040-6090(03)00885-X · 1.87 Impact Factor
  • Toru Nonami, H. Hase, Kazushi Funakoshi
    Materials Science Forum 01/2003; 439:337-343. DOI:10.4028/www.scientific.net/MSF.439.337
  • Key Engineering Materials 01/2003; 240-242:931-934. DOI:10.4028/www.scientific.net/KEM.240-242.931 · 0.19 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: For uniformly implanting hydroxyapatite (HA) granules into curved surfaces of titanium alloy implants such as dental roots, a new superplastic forming system was developed. By fixing PVA films with HA granules on a die's curved inner surface, HA granules are uniformly scattered and hold on the surface. The pressing system has a couple of wedges that enable press load to act on the both sides of a cylindrical titanium alloy sample arranged with its long axis perpendicular to the direction of the load in the die, and thereby the sample to expand in its radius direction. This technique could uniformly press HA granules into all the curved surface of titanium alloy. As a result, HA-granule-implanted titanium alloy composites with a cylindrical shape were formed under the conditions of 1023 K, 1 h, 1960 N in vacuo.
    Journal of Materials Science Materials in Medicine 03/2002; 13(2):233-6. DOI:10.1023/A:1013898500763 · 2.38 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In order to improve the biocompatibility of superplastic Ti-alloys such as Ti–6Al–4V or Ti–4.5Al–3V–2Fe–2Mo, coating of the alloy with pure titanium and TiO films by magnetron DC sputtering was examined. The sputter-deposition of the pure titanium film and the TiO films were carried out in Ar gas and in ArO2 gas mixtures, respectively. Both the pure titanium film deposited in Ar and the TiO films deposited in ArO2 appeared to be uniform and adhesive. Under AES, the Ti/O ratio in depth direction was nearly constant in each of the films and oxygen concentration increased with increasing oxygen content of the sputter gas. Based on XRD, it was concluded that oxygen atoms dissolved into α-titanium crystals at lower oxygen contents, while suboxides such as Ti4O7 and Ti6O11 and oxides such as TiO2(anatase) were formed at higher oxygen contents. It was found that the orientation of the α-titanium phase formed in the TiO films changed from (002) dominant to (011) dominant with increasing oxygen content. The Vickers hardness of the films increased linearly with increasing oxygen content, and the maximum hardness reached over Hv=1600. Furthermore, it was found that the ductility of the deposited pure titanium film was improved under such high temperatures as 800°C and that its elongation reached over 160%, while the TiO films were still brittle under such a high temperature.
    Thin Solid Films 05/2001; 386(2):227–232. DOI:10.1016/S0040-6090(00)01655-2 · 1.87 Impact Factor
  • Key Engineering Materials 01/2001; DOI:10.4028/www.scientific.net/KEM.192-195.745 · 0.19 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Apatite coating on orthopedic and dental implants contributes to fixation of implants to bone. To bond apatite on the implants with good bonding strength, plastic carbonateapatite (CHAP) ceramics were prepared and implanted in cavities on the surface of pure titanium implant. The CHAP ceramics were held firmly in the cavities by the implantation. The CHAP-implanted titanium was implanted in mandibles of female mongrel dogs. After 4 weeks, fibrous tissue become thinner and remarkable new bone formation was observed in the implantation cavities facing toward the CHAP implanted surface, while fibrous tissue around titanium surface still remains thick. The CHAP implantation was considered to provide favorable condition for the long-term stable fixation of the implants.
    Phosphorus Research Bulletin 01/2001; 12:25-30. DOI:10.3363/prb1992.12.0_25
  • Key Engineering Materials 01/2001; 192-195:437-440. DOI:10.4028/www.scientific.net/KEM.192-195.437 · 0.19 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Titanium and some of its alloys are commonly accepted materials for orthopedic implants such as artificial tooth roots mainly due to their superior durability. Enhancement of bone formation around the implants can make a considerable contribution to long-term stable fixation of the implants. However, the surface of titanium is less osteoconductive than bioactive ceramics such as hydroxyapatite (HAP). In this study, spherical HAP ceramics were implanted on the surface of pure titanium by a loading rate of 0.1 kN/min up to 1 kN at 1123 K to provide the surface of pure titanium with osteoconductive spots. By this method, the spherical HAP ceramics were mechanically held by deformed pure titanium.
    Materials Science and Engineering C 09/2000; 13:105-107. DOI:10.1016/S0928-4931(00)00183-1 · 2.74 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: TiO2-coated hydroxyapatite single crystals were prepared by hydrolysis of Ti-bearing dicalcium phosphate powder. On the surface of the TiO2-coated hydroxyapatite single crystals, TiO2 regions and hydroxyapatite regions can function as photocatalysts and adsorbents for organic contaminants, respectively, allowing simultaneous decomposition of organic contaminants by the photocatalysis of TiO2 under irradiation. Therefore, the TiO2-coated hydroxyapatite single crystals can favorably be applied for antibacterial applications and environmental purification.
    05/2000; 15(06):1243 - 1244. DOI:10.1557/JMR.2000.0178
  • T Nonami, S Tsutsumi
    [Show abstract] [Hide abstract]
    ABSTRACT: Glass-ceramics were investigated to obtain a glass with a composition of CaO. MgO. 2SiO(2). 0.375TiO(2). 0.007Ag(2)O. The glass melted at 1500 degrees C and could be cast. Crystallization of diopside of this glass is controlled by volume nucleation and growth processes. In a crystallization treatment at 850 degrees -870 degrees C, this glass presented a milky white, semitransparent color. The crystals formed were diopside, their crystal grain diameter was 1-2 micrometer, and crystallization was 15-25%. The bending strength of the glass produced by a crystallization treatment of 25 min at 850 degrees C was 400 MPa, which is suitable for artificial bones. This crystallized glass also was extremely stable, with no weight loss after stability testing in artificial saliva. The softening point, as determined from the viscosity curve, was 830 degrees C, and the crystallization temperature was 895 degrees C. Thus this glass can be press-formed at a temperature of 830 degrees -880 degrees C. Actual press-forming at a pressure of 0.64 MPa was carried out for 40 min at 850 degrees C and resulted in the formation of desired shapes. Given its ready formation into desired shapes and its great strength after crystallization, such glass is applicable for use as artificial bones and as dental roots and crowns.
    Journal of Biomedical Materials Research 05/2000; 50(1):8-15.
  • Toru Nonami, Sadami Tsutsumi
    [Show abstract] [Hide abstract]
    ABSTRACT: Glass–ceramics were investigated to obtain a glass with a composition of CaO · MgO · 2SiO2 · 0.375TiO2 · 0.007Ag2O. The glass melted at 1500°C and could be cast. Crystallization of diopside of this glass is controlled by volume nucleation and growth processes. In a crystallization treatment at 850°–870°C, this glass presented a milky white, semitransparent color. The crystals formed were diopside, their crystal grain diameter was 1–2 μm, and crystallization was 15–25%. The bending strength of the glass produced by a crystallization treatment of 25 min at 850°C was 400 MPa, which is suitable for artificial bones. This crystallized glass also was extremely stable, with no weight loss after stability testing in artificial saliva. The softening point, as determined from the viscosity curve, was 830°C, and the crystallization temperature was 895°C. Thus this glass can be press-formed at a temperature of 830°–880°C. Actual press-forming at a pressure of 0.64 MPa was carried out for 40 min at 850°C and resulted in the formation of desired shapes. Given its ready formation into desired shapes and its great strength after crystallization, such glass is applicable for use as artificial bones and as dental roots and crowns. © 2000 John Wiley & Sons, Inc. J Biomed Mater Res, 50, 8–15, 2000.
    Journal of Biomedical Materials Research 04/2000; 50(1):8-15. DOI:10.1002/(SICI)1097-4636(200004)50:13.0.CO;2-8
  • Toru Nonami, Sadami Tsutsumi
    [Show abstract] [Hide abstract]
    ABSTRACT: Glass–ceramics were investigated to obtain a glass with a composition of CaO · MgO · 2SiO2 · 0.375TiO2 · 0.007Ag2O. The glass melted at 1500°C and could be cast. Crystallization of diopside of this glass is controlled by volume nucleation and growth processes. In a crystallization treatment at 850°–870°C, this glass presented a milky white, semitransparent color. The crystals formed were diopside, their crystal grain diameter was 1–2 μm, and crystallization was 15–25%. The bending strength of the glass produced by a crystallization treatment of 25 min at 850°C was 400 MPa, which is suitable for artificial bones. This crystallized glass also was extremely stable, with no weight loss after stability testing in artificial saliva. The softening point, as determined from the viscosity curve, was 830°C, and the crystallization temperature was 895°C. Thus this glass can be press-formed at a temperature of 830°–880°C. Actual press-forming at a pressure of 0.64 MPa was carried out for 40 min at 850°C and resulted in the formation of desired shapes. Given its ready formation into desired shapes and its great strength after crystallization, such glass is applicable for use as artificial bones and as dental roots and crowns. © 2000 John Wiley & Sons, Inc. J Biomed Mater Res, 50, 8–15, 2000.
    Journal of Biomedical Materials Research 01/2000; 50(1):8 - 15. DOI:10.1002/(SICI)1097-4636(200004)50:1<8::AID-JBM2>3.0.CO;2-8
  • 01/2000; 108(1264):1122-1125. DOI:10.2109/jcersj.108.1264_1122
  • [Show abstract] [Hide abstract]
    ABSTRACT: Titanium and some of its alloys are commonly accepted as materials for orthopedic implants such as artificial tooth roots mainly due to its superior mechanical strength. Bone formation around titanium implants can make a contribution to long-term stable fixation of the implants. Therefore, enhancement of osteoconductivity of the surface of the implants has been a key to improve the implant. We are attempting to improve the fixation of the titanium implants to bone by implanting hydroxyapatite (HAP) spots on the implant’s surface. The spherical HAP ceramics were pressed against the surface of pure titanium substrate by a loading rate of 0.1 kN/min up to 1 kN at 850°C. By this method, most part, except near surface, of the spherical HAP ceramics was surrounded by deformed titanium, resulting in mechanical holding of the spherical HAP ceramics. The HAP spots on the titanium surface are expected to bond to bone much faster than titanium. Furthermore, cavities made by the implantation have sufficient volume to induce bone ingrowth that contributes long-time stability of the implants by microanchoring.
    Proceedings of the 12th International Symposium on Ceramics in Medicine; 10/1999
  • Toru Nonami, Sadami Tsutsumi
    [Show abstract] [Hide abstract]
    ABSTRACT: Diopside was prepared by sintering a powder compact of composition CaO-MgO-2SiO2 at 1300 C for 2 h. The bending strength of diopside was 300 MPa and the fracture toughness was 3.5 MPa m1/2. It was proved that diopside has no general toxicity in cell culture. Diopside implanted in rabbits came in close contact with the newly grown bone. X-ray microanalysis spectral diagrams show a change of composition across the junction from the diopside to the newly grown bone. High-resolution transmission electron microscopy revealed crystal growth at the interface between diopside and the newly grown bone, and continuity between diopside lattices and those of the new crystals.
    Journal of Materials Science Materials in Medicine 01/1999; 10(8):475-479. DOI:10.1023/A:1008996908797 · 2.38 Impact Factor
  • Materials Science Forum 01/1999; DOI:10.4028/www.scientific.net/MSF.304-306.747