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MAMORU AIZAWA, ATSUSHI ONO, TOSHIKI OHNO, PAK-KON CHOI
2005 Volume 19 Pages
1-6
Published: 2005
Released on J-STAGE: October 29, 2012
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We performed to synthesize the calcium-phosphate microsphere with well-controlled particle size by changing the frequency of the ultrasonic transducer. The crystalline phases of the resulting powders were composed of β-tricalcium phosphate (β-TCP) and hydroxyapatite (HAp); the Ca/P molar ratios were about 1.50. The SEM observation indicated that the resulting powders were composed of microspheres with a diameter of ~1 to ~2.5 μm. The particle sizes increased with decreasing ultrasonic frequency, and the distributions were quite narrow. The above results show that the particle size can be easily controlled by changing the frequency of ultrasonic transducer during spray-pyrolysis.
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HIROSHI ARAI, TAKAYUKI KOBAYASHI, MIHO NAKAMURA, YASUTAKA SEKIJIMA, SA ...
2005 Volume 19 Pages
7-10
Published: 2005
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The polarized Hydroxyapatite (HA) and non polarized HA pellets were intraperitoneally implanted into rats and reacted with the body fluid. The samples were extracted at 5 min, 30 min, 1 and 3 day after the implantation. Clear differences can be seen between on the polarized and non polarized surfaces of HA.
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ELENA ASABINA, VLADIMIR PET'KOV, IGOR SHELOKOV, VLADIMIR LOSHKAREV
2005 Volume 19 Pages
11-18
Published: 2005
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Crystalline phosphates A
1+xTi
2-xFe
x(PO
4)
3 and B
0.5(1+x)D
2-xFe
x(PO
4)
3 (0 ≤ x ≤ 2; A=Li, Na; B=Ca, Sr, Ba; D=Ti, Zr,Hf) were synthesized by solid-state reactions, sol-gel and combined methods. Concentration and temperature regions of phase formation of phosphates of NZP structure were examined. Heat capacity of NaD
2(PO
4)
3 (D=Ti,Zr) in the =range 7-650 K and heat conductivity of NaZr
2(PO
4)
3 and CaTiFe(PO
4)
3 in the range 298-673 K were studied. Obtained results were summarized with literature data on thermophysical and other properties of NZP phosphates.
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ETIENNE GAUDIN, HAMDI BEN YAHIA, JACQUES DARRIET
2005 Volume 19 Pages
19-24
Published: 2005
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In the AMXO
4 series (A=Li
+, Na
+, Cu
+, Ag
+, M=Cd
2+,Mn
2+, X=V
5+,P
5+) all the compounds, except AgMnPO
4, crystallize with olivine, Na
2CrO
4 or maricite-type structure. When the size of the counter-cation A
+ increases structural changes from olivine or Na
2CrO
4-type to maricite-type structure are observed. The destabilization of these two structures is also correlated to the size of the M
2+ cations.
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R. GLAUM, T. DROSS, M. BLUM, C. LITTERSCHEID, H. THAUERN
2005 Volume 19 Pages
25-29
Published: 2005
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Phase equilibria in ternary systems M/P/O, oxygen co-existence pressures in such systems, stabilisation of metals in rather low oxidation states and eventually electrical and optical charge transfer properties of phosphates are discussed for representative examples from our recent research. The observations are summarized with respect to the redox behaviour of anhydrous phosphates.
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HIROTO HASEGAWA, MIOKO MAEDA, MAKOTO SAKURAI, JOSEF NOVOSAD, MAKOTO WA ...
2005 Volume 19 Pages
30-35
Published: 2005
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The reaction of melamine with ammonium dihydrogenphosphate has been investigated by solid-state NMR spectroscopy under different conditions. Synthesized melamine diphosphate (MDP) was characterized by X-ray powder diffraction, solid-state NMR spectroscopy and was also tested for flame retardant ability. The flammability of polypropylene (PP) containing melamine diphosphate, pentaerythritol (PER) or dipentaerythritol (DPER) was characterized by limiting oxygen index (LOI).
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WOLFRAM HÖLAND, VOLKER RHEINBERGER, CHRISTIAN VAN'T HOEN, ELKE AP ...
2005 Volume 19 Pages
36-41
Published: 2005
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The objective of the study was to control the nucleation and main crystal formation of lithium disilicate, Li
2Si
2O
5, by an effective nucleating agent to develop high-strength, translucent glass-ceramics.The authors used P
2O
5 as nucleating agent to precipitate lithium disilicate in glasses derived from the SiO
2-Li
2O-Al
2O
3-K
2O-ZrO
2 system. The concentration of P
2O
5 was up to approx. 3 wt.%. Additives of P
2O
5 allowed the control of bulk crystallization. Nucleation was catalyzed by Li
3PO
4 phases. Li
3PO
4 is the heterogeneous catalyst. The final glass-ceramic is characterized by a dense microstructure with a high crystalline content of more than 70 vol.%.The mechanical strength was determined as biaxial flexural strength of approx. 740 MPa and Weibull factor of 11.3. The glass-ceramic shows the potential to be applied as a biomaterial for dental restorations. The authors conclude the effectiveness of P
2O
5 as nucleating agent on the basis of a heterogeneous nucleation of nanophases and precipitating main crystal phases by epitaxial growth.
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NAOKO IGETA, TSUYOSHI KATAKAMI, MAMORU AIZAWA
2005 Volume 19 Pages
42-47
Published: 2005
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We have successfully fabricated the apatite-fiber scaffolds (AFS) that enable three-dimensionally cell culture. The AFS with large pores of ~250μm and micro pores of about 5μm were fabricated by firing the compacts consisting of the single-crystal apatite fibers and the carbon beads with the sizes of 150μm. In order to enhance the mechanical properties of the scaffolds, we tried to modify the process of AFS fabrication.The apatite gels were
in situ precipitated on the apatite fiber via traditional wet process of hydroxyapatite. We fabricated the AFS with enhanced mechanical property using the apatite fibers coated with apatite gels. Actually, the results of compressive strength test showed that the energy for deformation of AFS with apatite gels was higher than that of AFS without apatite gels. We concluded that the apatite gel is effective to the enhancement of mechanical properties of the AFS.
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YUSUKE KODERA, MIOKO MAEDA, MAKOTO SAKURAI, JOSEF NOVOSAD, MAKOTO WATA ...
2005 Volume 19 Pages
48-53
Published: 2005
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Calcium phosphate cements (CPCs) are usually modified by organic/inorganic additives to improve their mechanical performance and to adjust their mechanical and setting properties. In this work we used several organic compounds (polyvinyl alcohol, polyacrylic and citric acids) and sodium silicate for the modification of CPCs.
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C. LITTERSCHEID, R. GLAUM
2005 Volume 19 Pages
54-59
Published: 2005
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The new quaternary phosphates Cr
3Ti
4(PO
4)
6 (dark brown, transparent crystals, Fe
7(PO
4)
6 structure type), CrTi
2(P
2O
7)
2-black (lavender coloured powder), and CrTi
2(P
2O
7)
2-
purple (pink powder) have been synthesized and crystallized by means of chemical vapour transport in a temperature gradient. The crystal structure of Cr
3Ti
4(PO
4)
6 has been refined from single crystal data (
P1 (No.2), Z=1;
a=9.4139(13)Å,
b=8.1056(9)Å,
c=6.3517(8)Å, α=101.25(1)°, β= 107.54(1)°, γ=106.23(1)° (from Guinier-photographs); conventional residual R
1=0.0312 for 2810 F
0 > 4σ(F
0), 170 parameters; 19 atoms in the asymmetric unit). A preliminary refinement shows
CrTi2(P2O7)2-black (P6
3/m (No.176), Z=3, a=8.9855Å, c=12.3183Å, R
1=0.0884 for 1013 F
0 > 4σ(F
0), 51 parameters; 11 atoms in the asymmetric unit) to be structurally related to Fe
IIFe
2III(P
2O
7)
2. The Guinier diffraction pattern of CrTi
2(P
2O
7)
2-purple shows strong similarity to that of CuFe
2(P
2O
7)
2.
Absorption bands in the electronic spectra of Cr
3Ti
4(PO
4)
6, CrTi
2(P
2O
7)
2-black, and CrTi
2(P
2O
7)
2-purple are in agreement with electrons located on Cr
2+ and Ti
3+ ions.
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YUTAKA MINAMI, KENICHI IMAEDA, MAKOTO SAKURAI, MAKOTO WATANABE
2005 Volume 19 Pages
60-64
Published: 2005
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15BaO-10PbO-5SrO-70P
2O
5 glasses were prepared with temperature-controlled microwave heating by changing holding temperature (700°C,800°C and 850°C) and holding time (0 min and 10 min). The glass prepared at 700°C for 0 min showed the highest AC contdiuctity of 1.7×10
-4Scm
-1 at 200°C.
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IBUKI MURASE, KENICHI IMAEDA, MAKOTO SAKURAI, MAKOTO WATANABE
2005 Volume 19 Pages
65-70
Published: 2005
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We prepared 15BaO-10PbO-5SrO-70P
2O
5 glasses by temperature -controlled microwave heating and measured
31P MAS NMR spectra to investigate the manner of appearance of Q
3 band which indicates the presence of branching structure. It is found that the Q
3 band appears in the glasses prepared over 700°C.
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KAZUYOSHI OHKUBO, YASUTAKA SEKIJIMA, SATOSHI NAKAMURA, MIHO NAKAMURA, ...
2005 Volume 19 Pages
71-76
Published: 2005
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Adsorption properties of hydroxyapatite (HA) for acidic and basic proteins has been recognized to be improved by electrically polarization. In this study, adsorptions of bovine serum albumin and lysozyme to powders of the polarized HA using column chromatography were examined. Based on SEM observation, the morphologies of the polarized HA powders immersed in 0.01M phosphate buffer solution at pH 7.40 and 6.60 revealed that the dissolution of the powders was negligible for adsorption evaluation. The adsorption abilities of the polarized HA powder were significantly higher than those of non-polarized HA, in the pH ranging from 6.60 to 7.40, regardless of the adsorbate
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K. PANAGIOTIDIS, R. GLAUM, J. SCHMEDT AUF DER GÜNNE, W. HOFFBAUER
2005 Volume 19 Pages
77-82
Published: 2005
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Syntheses, crystal structures and spectroscopic properties of Pd
2P
2O
7 and AuPO
4 are reported.Furthermore,lattice parameters are given for the first iridium phosphates Ir(PO
3)
3 and Ir
3Si
2O(PO
4)
6.
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HIROYUKI SHIMOMICHI, MIOKO MAEDA, MAKOTO SAKURAI, JOSEF NOVOSAD, MAKOT ...
2005 Volume 19 Pages
83-89
Published: 2005
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The flame retardancy of polypropylene-wood-fibre composites(CM)have been investigated. CM - new generation of materials - were prepared on a two-roll machine. Ammonium polyphosphate (APP I & II), melamine phosphate (MP), melamine diphosphate (MDP) and pentaerythritol (PER) were used as flame retardants. The experimental results show that the LOI values of the CMs increase in line MPP - MDP -APP I - APP II and the char former/blowing agent ratio has a great effect on the flame retardancy of the propylene-wood fibre composites.
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SUKHANOV MAXIM, PET'KOV VLADIMIR, ERMILOVA MARGARITA, OREKHOVA NATALIA ...
2005 Volume 19 Pages
90-98
Published: 2005
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New phosphates Ca
0.5+xNi
xZr
2-x(PO
4)
3 (x=0.5, 1.0) and the phosphates B
0.5Zr
2(PO
4)
3(B=Ca,Ni) were prepared by the precipitating method. Phosphates were characterized using XRD, IR-spectroscopy and microprobe analysis. The specific surface areas of the samples were determined by the adsorption of nitrogen. It is shown that phosphates Ca
0.5+x?Ni
xZr
2-x(PO
4)
3 (x=0, 0.5, 1.0) were crystallized in the NaZr
2(PO
4)
3-type structure and the phosphate Ni
0.5Zr
2(PO
4)
3 was obtained as a single-phase with Sc
2(WO
4)
3-type structure. The conversion of methanol was studied in a convenient Ar-flow system, in the temperature range from 450 to 750 K. It is shown that the properties of the described phosphates as well as catalytic activity, selectivity, yields of products and alcohol conversion depend on the temperature, structure type, Ni-position in the framework of the phosphate or its cavities and the Ni content in the materials.
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KAZUMICHI YANAGISAWA, KONGJUN ZHU, RIE SHIMANOUCHI, AYUMU ONDA, KOJI K ...
2005 Volume 19 Pages
99-105
Published: 2005
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The continuous solid solutions in the systems of Ca-Cd HAp, Ca-Sr HAp and Ca-Pb HAp were successfully synthesized at 200°C for 12 hours under hydrothermal conditions. The Rietveld analysis indicates that the Cd ions have a slight tendency to occupy the M (2) sites in the apatite structure, Sr ions preferentially occupy the M (2) sites with high Sr content, and Pb ions showed the high preferential occupancy in the M (2) sites. The preferential occupancy of metal ions can be explained mainly by ionic radius and electronegativity of the metal ions.
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YOSHIYUKI YOKOGAWA, SATOSHI TAKAGI, TAKASHI HIROSE, YUTAKA DOI, NOBUTA ...
2005 Volume 19 Pages
106-111
Published: 2005
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Hydroxyapatite ceramics has been paid attention as bone filler, and bone graft substitutes, due to its biocompatibility and osteo-conduction. Recent studies have found a new surface functionalisation method for creating favorable local conditions that lead to nucleation and growth of calcium phosphate over substrates. Phosphorylation is a surface functionalization method for that purpose. Authors have conducted calcium phosphate coating over chitosan films that were produced by a process based on phosphorylation, Ca(OH)
2 treatment and SBF immersion. The obtained samples were commercial chitin, phosphorylated chitin, Ca(OH)
2 treated phosphorylated chitin and Ca(OH)
2 treated phosphorylated chitin after immersion in SBF solution. These materials were implanted at cranial bone of rats, and the biocompatibility was estimated. 4 weeks after implantation, fibrous tissues were observed between bone and commercial chitin or phosphorylated chitin material. Little fibrous tissue, although was found in the interface between bone and Ca(OH)
2 treated phosphorylated chitin after immersion in SBF solution. The Ca(OH)
2 treatment and SBF immersion facilitates the formation of a calcium phosphate over the phosphorylated samples in vivo as well as in vitro.
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TAKAFUMI AKAMATSU, TOSHIHIRO KASUGA, MASAYUKI NOGAMI
2005 Volume 19 Pages
112-117
Published: 2005
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Fine-sized magnesium metaphosphate, calcium metaphosphate, or zinc metaphosphate glass powders were reacted with distilled water and hydration immediately occurred,resulting in the formation of hydrogels with high viscosity.
31P MAS-NMR spectra showed that the hydrogels contain orthophosphates and long-chain phosphates coordinated to H
+ or M
2+(M=Mg, Ca, Zn) ion; no significant differences in their structures among the hydrogels were shown. The hydrogels showed high proton conductivities of ~5 mS/cm at 30 °C. The conductivities were suggested to originate from proton conduction due to coexistence with large amounts of acidic P-OH groups and water molecules. Electric double-layer capacitors (EDCs) were prepared by using electrolytes consisting of the hydrogels. They showed no oxidation-reduction processes in the range of 0~1 V. The EDCs showed specific capacity of ~2 F/g. The possibility as an EDC electrolyte may be related to proton conductivities of the hydrogels.
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TOSHIYUKI AKAZAWA, MASARU MURATA, JUNICHI TAZAKI, KATSUTOSHI ITO, KATS ...
2005 Volume 19 Pages
118-123
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Biomimetic and functionally graded apatite (fg-HAp)ceramics were Prepard using bovine bone by the calcination and partial dissolution-precipitation methods.The fg-HAp ceramics had gradual distributions of the degree of crystallinity and the grain size of hydroxyapatite from the surface layer of the pore wall to the bulk structure region. The pore structure of the ceramics with specific surface areas of 30-40 m
2·g
-1 and porosities of 60-80 % was divided into a macro-pore originating from spongy bone and a micro-pore related to body fluid permeation and blood permeability.For implantation of the fg-HAp ceramics in subcutaneous tissue of rat, body fluid permeated the bulk region of the ceramics through the micro-pores. At 4 weeks after the implantation, a total size of the ceramics blocks remarkably decreased because of surface- and bulk-degradations of the fg-HAp. The body fluid was found to be immunopositive for an albumin, although in protein detection for the ceramics blocks by silver staining,several proteins with molecular weights of 20 to 70 kDa were recognized under non-reducing conditions.
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A. DINDUNE, Z. KANEPE, J. RONIS, T. SALKUS, A. KEZIONIS, E. KAZAKEVICI ...
2005 Volume 19 Pages
124-129
Published: 2005
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The compounds of the Li
3Sc
2-xB
x(PO
4)
3 system (where x=0÷2) were synthesized by a solid state reaction and studied by X-ray diffraction. For the investigation of electric properties the ceramic samples were sintered and the ceramic (x=0; 0.5; 1) and glass (x=2) samples were investigated in frequency range 10
6-1.2·10
9 Hz at temperatures 300-600K. Two regions of the relaxation dispersion were found in conductivity spectra of the ceramics. They are related to the fast Li
+ ion transport in the bulk and grain boundaries of the ceramics. The isomorphic substitution Sc→B leads to the change of the temperature of phase transition to γ- phase (T
γ). The increase of the stoichiometric factor x caused the increase of the values of bulk (σ
b) and total (σ
tot) conductivities, and also decrease of their activation energies in the temperature range below T
γ.
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KAORU DOKKO, KEIGO HOSHINA, KIYOSHI KANAMURA
2005 Volume 19 Pages
130-135
Published: 2005
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Anatase TiO
2 thin-film electrode was prepared on Li
1+xAl
xTi
2-x(PO
4)
3-based (LTP) solid electrolyte bya sol-gel coating method. The prepared thin film was characterized with X-ray diffraction, Raman spectroscopy, and it was confirmed that the thin film consisted of the single phase of anatase TiO
2. The prepared thin film was very flat and crack-free. An electrochemical cell Li/Polymer-gel electrolyte/LTP/TiO
2/Au was fabricated and the electrochemical properties of the TiO
2/LTP were investigated. The Li
+ ion insertion/extraction into/from the TiO
2 took place reversibly through the solid-solid interface.
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Hiroshi ENDO, Kiyoshi ITATANI, Tomohiro UMEDA, Seiichiro KODA
2005 Volume 19 Pages
136-141
Published: 2005
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Various flexible forms of β-calcium orthophosphate (β-Ca
3(PO
4)
2; β-TCP) composites containing alginate,
e.g., thread, membrane and honeycomb, were fabricated in order to utilize them as bone substitute materials. The commercially available β-TCP powder was mixed with sodium alginate; the mass ratios of β-TCP to sodium alginate were 2/1, 1/1 and 1/2. After the ball mill grinding of mixed powders for 5 h, the de-ionized water heated at 60°C was put into them to form the paste of homogeneous composition; the concentration of alginate for unit mass of de-ionized water was kept at 7.5 mass%. The thread was prepared by pushing the paste into 0.03 mol·dm
-3 of CaCl
2 solution through an injector, where thread-shaped composites were instantaneously prepared; the membrane and honeycomb could be fabricated by putting the paste in the mould, followed by pouring of 0.03 mol·dm
-3 of CaCl
2 solution onto them. The phases present in the resulting materials were β-TCP and alginate. Microstructures of these composites showed that the grains with sizes of approximately 0.5-5μm were coated with alginate.
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KATSUMA ITEYA, YOH SASAKI, SEISHIRO ITOH, JUNKO ICHIHARA
2005 Volume 19 Pages
142-146
Published: 2005
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In CetylPy
10[H
2W
12O
42]-catalyzed epoxidation solid-phase-system, high crystallinity of apatite and a uniform size of apatite particle were found to be important factors as a solid disperse phase.
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FUMIHIRO KAJI, SOUHEI NAKAGAWA, NOBUYUKI MATSUDA, TAKATSUGU YOSHIOKA, ...
2005 Volume 19 Pages
147-151
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The adsorption amount of artificial sebum on various forms and chemical compositions of hydroxyapatite was measured by gas chromatography analysis (GC). From these results, it has been shown that the adsorption amount of oleic acid was in order of Spherical-HAP>SiO
2>FL-HAP (SC)>FL-HAP. The adsorption of artificial sebum is not influenced by shape or particle diameter of hydroxyapatite, and preferential adsorption of oleic acid, which is unsaturated fatty acids in artificial sebum, was clarified. The selectivity of silica as a comparison material was not confirmed. The adsorption amount of oleic acid for each I g of Spherical-HAP was 38mg. It seemed also that the adsorption amount of oleic acid showed tendency to increase with increase in calcium content. As for the adsorption mechanism, the possibility of relation to c-plane (Ca sites) was suggested. Moreover, when the effect of cosmetics that mixed with hydroxyapatite was examined, the adsorption amount of oleic acid was about 1.5 times compared with the control. The prevention of shiny skin and makeup deterioration due to removal of the unsaturated fatty acid by hydroxyapatite is presented in the cosmetics field.
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KIYOSHI KANAMURA, KEISUKE SHIRAISHI, KAORU DOKKO
2005 Volume 19 Pages
152-157
Published: 2005
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LiFePO
4 as a cathode material for rechargeable lithium batteries was prepared by hydrothermal process at 170°C under inert atmosphere. The starting materials were LiOH·H
2O, FeSO
4·xH
2O and (NH
4)
3PO
4·3H
2O. The electrochemical properties of LiFePO
4 were characterized in a mixed solvent of ethylene carbonate and diethyl carbonate (1:1 in volume) containing 1.0 mol dm
-3LiClO
4. The LiFePO
4 synthesized by hydrothermal process exhibited a discharge capacity of 90 mA h g
-1, which was considerably smaller than theoretical capacity (170 mA h g
-1). The annealing of LiFePO
4 at 400°C in argon atmosphere was effective in increasing the discharge capacity. The discharge capacity of the annealed LiFePO
4 was 150 mA h g
-1.
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Toshiyuki MIYAUCHI, Takeki HATAI, Yoshitaka YAMAMOTO, Kosuke OUE, Hide ...
2005 Volume 19 Pages
158-165
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The iron(II) phosphonate complex [DEP-Fe(II)] was prepared by the reaction of diethylphosphonate with iron(III) nitrate in acetonitrile. The compound has a sheet-like lamellar structure of (P-O-Fe-O-P-O-Fe-O-P)
n,. The use of the DEP-Fe(II) complex could be as a solid acid catalyst in esterifications and as a color reagent for a spectrophotometric determination of 1-naphthol.
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HIDEKI MONMA, YUSKE MORIYOSHI, TERUO URANO, TOSHINORI OKURA
2005 Volume 19 Pages
166-171
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The conversion of hardened gypsum (G
2H) into hydroxyapatite (HAp) was investigated as an effective materials recycling of waste G
2H. Calcium-deficient HAp hardened porous bodies were obtained by soaking a porous hardened G
2H in 1.0 mol dm
-3 (NH
4)
2HPO
4 solution at 45°C over 6 days. Nearly stoichiometric HAp hardened bodies were obtained at 100-140°C by using a dense hardened G
2H. HAp hardened bodies were composed of aggregates of fine crystals, and contained partly tubular HAp aggregates. Tubular HAp aggregates formed advantageously from comparatively porous hardened G
2H. Sintered porous ceramics consisting of tubular HAp and tubular β-Ca
3(PO
4)
2 were obtained by heating hardened calcium-deficient tubular HAp at 600°C and 800°C, respectively.
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TAKESHI MORIGUCHI, SOUHEI NAKAGAWA, FUMIHIRO KAJI
2005 Volume 19 Pages
172-177
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We investigated adsorption of phenolic dyes, alizarin and alizarin red S, which are often used as bone-staining agents in histological studies,onto hydroxyapatite(HAP) in water and elucidated their adsorption structures by FT-IR microspectroscopy. The structures were interpreted as a salt form constructed by interaction of vicinal phenolate groups of alizarins with Ca sites on HAP. We further applied the elucidated adsorption theory to adsorption of humic substances onto HAP in water. As a result,effective removal of humic substances was observed. This is possibly due to a lot phenolic groups in humic substances. We hope that HAP is possibly applied as a removal agent in water purification systems.
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PETR MOŠNER, LADISLAV KOUDELKA, JAROSLAV POSPÍŠIL
2005 Volume 19 Pages
178-183
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Preparation of the CaTi
4(PO
4)
6-type glass-ceramic materials by controlled crystallization of calcium-titanium borophosphate glasses was studied in the compositional series of 50CaO-10B
2O
3-40P
2O
5+xTiO
2 (x=0-56 mol% TiO
2) and 30CaO-30B
2O
3-40P
2O
5+xTiO
2 (x=0-24mol% TiO
2). The glasses crystallize under heating within the temperature region of 700-800°C and the surface nucleation mechanism prevails in all the TiO
2-doped glasses over the internal one. The major compounds formed by crystallization were CaTi
4(PO
4)
6. Ca
2P
2O
7 and BPO
4. Changes in the XRD patterns after leaching with 1M HCl or 1M HNO
3 snowed that the acids dissolve most of all the other crystalline phases than CaTi
4(PO
4)
6. In this way a porous skeleton with CaTi
4(PO
4)
6 phase is formed the specific surface area of which decreases with increasing TiO
2 content in the starting glasses.
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SABURO SHIMABAYASHI, EMIKO MOTOKI
2005 Volume 19 Pages
184-189
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Sodium benzoate(SB) and sodium salicylate(SS) were bound to sodium chondroitin-6-sulfate(NaChs) through dipole-ion interaction and hydrogen bonding, but they were not adsorbed directly to hydroxyapatite(HAP). NaChs was adsorbed on HAP through 2 mechanisms; one is due to electrostatic attractive force between surface Ca
2+ and negatively charged group of NaChs, and the other owing to isomorphous substitution of sulfate group of NaChs for surface phosphate group of HAP. SB and SS non-adsorbable to HAP were adsorbed indirectly to HAP by virtue of dipole-ion interaction and hydrogen bonding with the adsorbed NaChs. NaChs captured more SB and SS on HAP than in an aqueous phase.
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SOUHEI NAKAGAWA, FUMIHIRO KAJI, NOBUYUKI MATSUDA, MAKOTO SAKURAI, MAKO ...
2005 Volume 19 Pages
190-193
Published: 2005
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Photocatalytic apatite(PCAP) particles doped with Ti(IV) ions were synthesized by a coprecipitation method. Adsorption and decomposition of methylene blue were examined by spectrophotometry. Under dark conditions, PCAP showed higher adsorption of methylene blue than TiO
2 did. The particles were irradiated with black light after reaching adsorption equilibrium, and absorbance was decreased by the photocatalyst reaction of the PCAP as well as by the TiO
2. Decrease in absorbance of PCAP was larger than in TiO
2, and consequently the decomposition of methylene blue was seen to be much more effective by PCAP. Further, the photocatalysts were kneaded separately into resin, effects of photocatalysis by both PCAP and TiO
2 were observed in the resin, and influence on the resin was examined. Chalking occurred on the surface of the resin with TiO
2. but was not observed on the resin with PCAP, and it was determined that PCAP had little overall influence on the resin.
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HIROYUKI NARIAI, SHOUHEI MARUISHI, HIDESHI MAKI
2005 Volume 19 Pages
194-197
Published: 2005
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Cyclo-decaphosphate, Ba
2Zn
3P
10O
30, was prepared by mixing BaCO
3, ZnCO
3, and H
3PO
4 ( Ba:Zn:P=2:3:10 ) and heating the mixture at 500°C for 2h. The phosphate obtained was treated with K
2SO
4 and Na
2S aqueous solution to prepare K
4Na
6P
10O
30 nH
2O. Treated with AgNO
3 aqueous solution, Ag
10P
10O
30 nH
2O was. prepared. This silver salt was used for Boullé's process. The phosphates obtained in this study were characterized with XRD, HPLC-FIA, TG-DTA, and FT-IR. Alkali and alkaline-earth metals, Mn, Ni, and Co
cyclo-decaphosphates were obtained in a high state of purity. However, Fe and Cu salts were somewhat decomposed, and decaphosphates were selectively formed. Their thermal stability were relatively low.
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NAOKO ODA, SABURO SHIMABAYASHI
2005 Volume 19 Pages
198-203
Published: 2005
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Water-insoluble dodecylphosphate (DP) was solubilized by a micelle of a nonionic surfactant such as Triton X-100(TX) and Triton N (TN), forming a mixed micelle. The mixed micelle was adsorbed by HAP after isomorphous substitution of phosphate group of DP for orthophosphate ion on HAP and electrostatic attractive force between a negative charge of DP and Ca
2+ on HAP. As a result, nonadsorbable nonionic surfactant was adsorbed indirectly to HAP together with DP forming hemi- and/or admicelle. In an aqueous solution of CaCl
2, the solution of nonionic surfactant-DP became turbid. DP was selectively captured by Ca
2+, resulting in formation of the Ca-DP precipitate, which was separated from the mixed micelle. However, nonionic surfactant remained in an aqueous phase. Thus, the mixed micelle showed different behavior on the surface of HAP and in an aqueous phase.
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KAZUSHI OHTA, MASANORI KIKUCHI, TOSHIYUKI IKOMA, SHUNJI YUNOKI, AKIRA ...
2005 Volume 19 Pages
204-208
Published: 2005
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Adsorption properties of proteins on c-axis oriented mesoporous HAp aggregates were investigated by liquid chromatography using the mesoporous HAp aggregates as an adsorbent. Elution molarity ratios of acidic proteins on the mesoporous HAp aggregates between before and after heat-treatment at 600°C increased with increasing the molecular weight in the order of ferritin > fibrinogen > catalase > BSA, whereas the elution molarity ratios of basic proteins were considerably lower than those of acidic proteins. These results suggested that the acidic proteins could be penetrated into the pore of the mesoporous HAp aggregates after heat treatment and were selectively adsorbed on the mesoporous wall consisting of the a-surface of the HAp aggregate. On the other hand, the basic proteins could be adsorbed on the wide outer surface of the plate-like HAp aggregates. Therefore, the elution molarity ratios of basic proteins decreased with decreasing the specific surface area by the heat treatment, independent of the mesoporous structure.
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HIROAKI ONODA, SAYAKO UKITA, AKI HAYASHI, ATSUSHI TAKENAKA, KAZUO KOJI ...
2005 Volume 19 Pages
209-214
Published: 2005
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Aluminum orthophosphate was prepared from aluminum nitrate solution and phosphoric acid solution in the molar ratio of Al/P=1/1. Urea and hexamethylenetetramine were added in this preparation process. The thermal behavior of the obtained phosphates was analyzed by differential thermal analyses, X-ray diffraction, and Fourier transform infrared spectroscopy. Furthermore, these materials and their thermal products were estimated by scanning electron micrograph and particle size distribution. Specific surface areas and pore size distribution of phosphates were calculated from the amount of nitrogen gas adsorbed at the temperature of liquid nitrogen by BET and DH methods. The acidic property was estimated from the adsorption of trimethylamine gas.
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DAVID A. PACHECO TANAKA, MARGOT A. LLOSA TANCO, HIROMICHI HAYASHI, YUK ...
2005 Volume 19 Pages
215-221
Published: 2005
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Zr (IV) and Ce (IV) phosphates were incorporated into organic supports and applied to the selective adsorption of Pb (II). α-Zirconium phosphate (ZrP) was loaded into porous Amberlite XAD-7 and used for the column enrichment of Pb (II) (10ppb) from aqueous solution. The recovery efficiency was dependent on the pH and the feeding rate of the sample solution. A Pb (II) selective membrane filter was fabricated by blending Ce (IV) phosphate (CeP) with cellulose fiber. Enrichment of Pb (II) was achieved by filtration of the aqueous sample through the membrane and was visually detected by immersing the membrane in a 3% solution of Na
2S. A dark spot was observed at Pb (II) concentrations as low as 5 ppb.
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KIYOKO SAKAMOTO, SHUNRO YAMAGUCHI
2005 Volume 19 Pages
222-227
Published: 2005
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β-tricalcium bis (orthophosphate) [Ca
3(PO
4)
2] (β-TCP) was mechanochemically treated with mortar grinder. The ground β-TCP was hydrolyzed in organic-aqueous binary systems (octane-H
2O, and octanol-H
2O) to give Ca-deficient hydroxyapatite (HAp) involving small amount of CO
32- ions. The rate of the hydrolysis in octane-H
2O binary system was faster than that in ammonium aqueous solution, however, shape of the products in the binary system did not so much differ from that in the aqueous system. Fluorination of the ground β-TCP proceeded much faster than that of β-TCP to form fluoridated hydroxyapatite (FHAp).
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ANATOLY SELEVICH, ELENA GRUSHEVICH, LUDMILA IVASHKEVICH, GALINA KRUL, ...
2005 Volume 19 Pages
228-233
Published: 2005
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Thermal behavior of the MO-NH
4PO
3 systems where M=Mg, Ca, Sr, Ba, Mn, Co, Ni, Cu, Zn, Cd, and Pb was studied at 300 and 400°C. General regularities of formation of double divalent metal-ammonium phosphates were established. Conditions of preparation of some known and novel binary divalent metal-ammonium phosphates, M(NH
4)2(PO
3)
4 (M=Mg, Ca, Mn, Co, Zn, and Cd), M(NH
4)
2P
4O
12 (M=Sr and Pb), MNH
4(PO
3)
3 (M=Mg, Co, Ni, Cu, Zn, and Pb),MNH
4P
3O
9 (M=Mg, Ca, Mn, and Cd), Ba
2NH
4(PO
3)
5, Cu
3(NH
4)
2P
8O
24, and Ba(MH
4)
4(PO
3)
6 were determined. Preliminary XRD studies have been performed for powder samples of Ba
2NH
4(PO
3)
5 (space group
Pc,_unit cell dimensions
a=8.649(1),
b=7.312(1),
c=13.873(2)Å; β=128.14(1)°) and Ba(NH
4)
4(PO
3)6 (space group_
P31
c, unit cell dimensions
a=11.1911(2),
c=8.9375(2)Å).
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ANATOLY SELEVICH, KONSTANTIN KHURS, ALEXANDER LYAKHOV, ANATOLY LESNIKO ...
2005 Volume 19 Pages
234-239
Published: 2005
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Using the thin-layer technique, phase equilibria in the Yb
2O
3-P
2O
5-H
2O system have been studied within the temperature range of 20-300°C at the molar ratios P
2O
5: Yb
2O
3=(3÷10):1. The diagram of the crystallization fields for stable phases, YbH
3(PO
4)
2·0.5H
2O, YbH
3(PO
4)
2, Yb
3H
5(PO
4)
2(P
2O
7)
2, YbHP
2O
7, and Yb(PO
3)
3 (form II), has been constructed. Preliminary XRD studies have been performed for powder samples of YbH
3(PO
4)
2 (monoclinic unit cell with
a=10.989(2),
b=6.858(2),
c=9.123(2)Å; β=101.72(2)°), Yb
3H
5(PO
4)
2(P
2O
7)
2 (tetragonal unit cell with
a=6.884(1),
c=17.554(2)Å), and YbHP
2O
7 (orthorhombic unit cell with
a=11.994(1),
b=6.870(1),
c=6.846(1)Å). it was found that increasing temperature and/or decreasing water content cause a consecutive crystallization of ytterbium phosphates in the followlng order: YbH
3(PO
4)
2·2H
2O, YbH
3(PO
4)
2·0.5H
2O, YbH
3(PO
4)
2, Yb
3H
5(PO
4)
2(P
2O
7)
2, YbHP
2O
7, Yb(PO
3)
3-C or Yb
4(P
4O
12)
3-
A, and Yb(PO
3)
3-II.
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AKIO TADA, NORIYASU OKAZAKI
2005 Volume 19 Pages
240-249
Published: 2005
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The activity of AlPO
4 and modified AlPO
4 for HC-SCR-NO (HC: C
2H
4, C
3H
6 and C
3H
8) was examined and compared with those of Al
2O
3 and SiO
2. The activity of AlPO
4-based catalysts was evidently higher than that of SiO
2-based catalysts. Although the conversion of NO to N
2 in HC-SCR-NO over AlPO
4 alone was lower than that of Al
2O
3, because of its low NO oxidation ability to form NO
2, Pt-loaded AlPO
4 showed much higher activity than Pt-loaded Al
2O
3.
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Keiichiro TAGO, Kiyoshi ITATANI, Seiichiro KODA
2005 Volume 19 Pages
250-255
Published: 2005
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Effect of tiring conditions,
i.e., pressureless sintering, controlled-atmosphere sintering (water (H
2O) vapor) and hot-isostatic pressing, on the fabrication of high-density and fine-grained hydroxyapatite (Ca
10(PO
4)
6(OH)
2: HAp) ceramic was examined; the tensile elongation of HAp ceramic during the heating was measured in order to evaluate the superplasticity. Relative densities of three types of HAp ceramics exceeded 99%; grain sizes were varied, according to the firing conditions: controlled-atmosphere sintering (1.09 μm) > hot-isostatic pressing (0.59 μm) > pressureless sintering (0.56 μm). Reflecting the magnitudes of grain sizes, the tensile elongations at 1100°C were arranged as follows: hot-isostatic sintering (176%) > pressureless sintering(156%)> controlled-atmosphere sintering (102%). The highest elongation of HAp ceramic fabricated by hot isostatic pressing was attributed not only to the small grain size but also to the elimination of defects.
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KAZUYA TAKAHASHI, YOSHIO SAKKA, TOHRU S. SUZUKI, SHIGERU ITO, NOBUYUKI ...
2005 Volume 19 Pages
256-261
Published: 2005
Released on J-STAGE: October 29, 2012
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A hydroxyapatite is the main component of a human's body and teeth, and a crystal orientation is required because it has different properties for each plane. In this study, a hexagonal rod-like powder was used. The aqueous suspension was prepared and was slipcast with and without a high magnetic field. The particle orientation was confirmed by the XRD patterns on the planes parallel and perpendicular to the direction of the magnetic field. It is confirmed that the particles orientate with the c-plane parallel to the magnetic field.
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HIDEKAZU TANAKA, MIE YAMAGUCHI, MASAKAZU FUTAOKA, RYOZI HINO
2005 Volume 19 Pages
262-267
Published: 2005
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Synthetic colloidal calcium hydroxyapatite (Ca
10(PO
4)
6(OH)
2: Hap) was treated with pyrophosphoric acid (H
4P
2O
7: PP) in acetone and the materials were characterized by a variety of techniques. XRD pattern and morphology of Hap particles were essentially not changed by the modification.The additional amount of PO
4 of Hap increased with an increase of PP concentration and the Ca/P molar ratio of the particles decreased from 1.62 to 0.8l. IR results indicated that the isolated surface P-OH band developed with increasing the PP concentration up to 6.0 mmol dm
-3 by the reaction of isolated surface P-OH groups of Hap and PP. Above 10.2 mmol dm
-3, hydrogen-bonding surface P-OH band appeared at 2913 cm
-1 and enlarged with increasing the PP concentration, while the isolated surface P-OH band weakened. The results of N
2 and H
2O adsorption measurement revealed that the modified particles rather aggregated compared to the unmodified ones.
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HIDEKAZU TANAKA, KOTOMI TANIGUCHI, RYOZI HINO
2005 Volume 19 Pages
268-273
Published: 2005
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Iron organo phosphates such as iron octyl phosphate (FeOP) and iron phenyl phosphate (FePP) were synthesized by the reaction of FeCl
3 and octyl phosphate (C
8H
17OPO
3H
2) or phenyl phosphate (C
6H
5OPO
3H
2) in aqueous media and were characterized by a variety of techniques. XRD pattern of FeOP showed five diffraction peaks at 3.3, 6.7, 10.0, 13.2 and 19.5°, and a halo. The d-spacing ratio of these peaks was almost 1 : 1/2 : 1/3 : 1/4 : 1/5. While, the pattern of FePP possessed a strong peak at 20 = 5.6° The chemical formula of FeOP and FePP assayed by ICP, CHN elemental analysis was Fe(OH)(C
8H
17OPO
3H)
2and Fe(OH)(C
6H
5OPO
3H)
1.6(H
2PO
4)
0.4, respectively. From these facts,we can proposed that FeOP and FePP are composed of a multilayer alternating bimolecular layer of octyl or phenyl group and amorphous iron phosphate phases. UV-Vis spectra of these materials showed a strong absorption at ≥ 350 nm, meaning that the materials have a high absorption property in U V region.
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Takeshi TOYAMA, Masato HASHIMOTO, Tamotsu YASUE
2005 Volume 19 Pages
274-279
Published: 2005
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There have been very few reports about the Thermoluminescence (TL) phosphor whose host crystal is apatite compound. The present work was investigated about hydrothermal synthesis conditions of novel dysprosium (III) activated fluoroapatite (FAp:Dy
3+) TL phosphor and its TL property. The optimum conditions for synthesis of FAp:Dy
3+ TL phosphor were as follows: Dy/Ca atomic ratio, 0.02; hydrothermal temperature, 220°C; and time 3h. The luminance was so high that crystallinity is high.And, FAp:Dy
3+ IL phosphor had theglow peak at 145°C,190°C and 250°C,the emission color was yellowish-white.
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Emiko UENO, Toshihiro KASUGA
2005 Volume 19 Pages
280-283
Published: 2005
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A new type of glass-ceramic for novel dental fillers, which require excellent chemical durability, was investigated. Three types of glass-ceramics were prepared using compositions of 40CaO-xCaF
2-(5-x)Na
2O-25TiO
2-3OP
2O
5 (in mol%, x=0, 2.5, 5). With increasing CaF
2amount, both glass transition temperature and crystallization temperature increased. The glass-ceramics were prepared by a conventional two-step heating method. In 40CaO-5Na
2O-25TiO
2-30P
2O
5 glass-ceramic, Nasicon-type RTi
2(PO
4)
3 (R=Na, 1/2Ca) and P-tricalcium phosphate (β-TCP) crystals were precipitated in the glass-ceramic. By incorporation of fluorine to the glass, the formation of β-TCP was controlled and fluoroapatite was found to be formed preferentially. In 40CaO-5CaF
2-25TiO
2-30P
2O
5 glass-ceramic,dissolution by acid-treatment was strictly controlled. In the present work, a new type of apatite-containing phosphate glass-ceramic without silica, based on the above-mentioned glass composition, could be newly prepared.
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KOUSUKE UOE, TOSHIYUKI MIYAUCHI, HIDEHIKO MORI, MAKOTO WATANABE, YOSHI ...
2005 Volume 19 Pages
284-287
Published: 2005
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Fast proton-conducting aluminum lanthanum phosphate glasses were successfully prepared at relatively low preparation temperature. These glasses contained large number of water molecules,and their conductivity at room temperature was showed more than 10
-4Scm
-1. These high conductivities were regarded as the fast proton transfer accelerated by molecular water.
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Masafumi Uota, Hiroshi Arakawa, Nana Kitamura, Takumi Yoshimura, Junzo ...
2005 Volume 19 Pages
288-293
Published: 2005
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Acidic aqueous solution of calcium phosphate was mixed with both or either of nonaethyleneglycol monododecylether (C
12EO
9) and polyoxyethylene (20) sorbitan monostearate (Tween60) and then treated with aqueous ammonium at 25°C. In contrast to both single surfactant systems, the TEM image of the resulting solid in the mixed surfactant showed an aggregate of lath-shaped particles 4-8 nm wide and above 100 nm in length,consisting of 2-3 nm wide core particles encapsulated with calcium-stearate (Ca-St) films. On calcination at 500°C, the Ca-St encapsulated solid was converted into HAp nanoarticles with a surface area of as high as 364 m
2g
-1.
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KUNIOMI WARABINO, SABURO SHIMABAYASHI
2005 Volume 19 Pages
294-299
Published: 2005
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The objective of this study is to prepare and characterize hydroxyapatite (HAP) particles having hydrophobic surface. Alkylphosphate (AP) was incorporated to the surface of HAP by virtue of electrostatic interaction and/or isomorphous substitution, resulting in formation of hydrophobic surface on HAP. The polar head group of AP was oriented to the HAP while the nonpolar tail group oriented to an aqueous phase. Hydrophobic properties of the surface were discussed mainly by means of contact angle measurement of a water drop placed on the HAP pellet. It was confirmed that various organic and hydrophobic compounds were adsorbed to the surface of the HAP prepared here. The driving force was hydrophobic interaction. The adsorption amount of calcium cation and phosphate anion, which are the component ions of HAP, decreased with the degree of hydrophobicity of the surface, i.e., surface concentration of AP, because nonpolar groups of AP on the surface prevented these lattice ions from approaching to the surface.
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