Phosphorus Research Bulletin

X-RAY PHOTOELECTRON SPECTROSCOPIC (XPS) STUDY OF DENTIN APATITE TREATED WITH FLUORIDE ION

TAKASHI SUZUKI, YOSHIAKI TANIZAWA

1992 Volume 2 Pages 1-11
Published: 1992
Released on J-STAGE: October 29, 2012

DOIhttps://doi.org/10.3363/prb1992.2.0_1

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The reaction of NaF with hydroxyapatite is of interest owing to the dental application. A main constituent of dental hard tissue is not the stoichiometric hydroxyapatite (HAP) but a carbonate-hydroxyapatite (CHAP). In present study, the reaction of bovine dentin as a CHAP with NaF has been investigated. XPS studies have shown that the dentin behaved similarly to the noncarbonated HAP as far as formation of fluoridated hydroxyapatite (FHAP) was concerned. However, it has also been found that CaF₂ was formed even in neutral conditions in contrast to the case of stoichiometric HAP.

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CRYSTAL GROWTH OF APATITES ON CALCIUM SALTS UNDER SUPERSATURATED CONDITIONS

Takao UMEGAKI, Takashi NAGASAKI, Jun HIRABAYASHI, Motohide MATSUSDA, K ...

1992 Volume 2 Pages 13-16
Published: 1992
Released on J-STAGE: October 29, 2012

DOIhttps://doi.org/10.3363/prb1992.2.0_13

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The crystal growth of hydroxyapatite on various calcium salts under supersaturation was studied on the basis of measurement of growth rate by the constant composition method and SEM observation

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Preparation of Calcium Phosphate Fibers

Toshihiro KASUGA, Yoshihiro ABE

1992 Volume 2 Pages 17-20
Published: 1992
Released on J-STAGE: October 29, 2012

DOIhttps://doi.org/10.3363/prb1992.2.0_17

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β-calcium metaphosphate fibers were successfully extracted from crystallized glasses by leaching with distilled water or a dilute NaOH aqueous solution. The fibers of high aspect ratios (30~120) were obtained from the crystallized glasses of which molar ratio of CaO/P₂O₅ is slightly less than unity. It is expected that the fibers are available for new applications to biomedical fields.

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CHARACTERIZATION OF ELECTROLYTICALLY DEPOSITED CALCIUM PHOSPHATES

Hideki MONMA

1992 Volume 2 Pages 21-26
Published: 1992
Released on J-STAGE: October 29, 2012

DOIhttps://doi.org/10.3363/prb1992.2.0_21

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Electrolytic calcium phosphate depositions on stainless steel were carried out by electrolyzing 0.21 mol/dm³ Ca (H₂PO₄)₂. H₂O solutions added with and without NaNO₃ at a cathode current of mainly 6mA/cm² at 20-90°C. CaHPO₄ 2H₂ O formed below 30±5°C and CaHPO₄ above the temperature. Both plate-like crystals were deposited nearly parallel to the stainless steel cathode face, and changed to fine grains with increasing current. By further increasing current or decreasing calcium phosphate concentration the formation of apatite became possible.

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HYDROTHERMAL SYNTHESIS OF STRONTIUM HYDROXYAPATITE FINE SINGLE CRYSTALS

Koji IOKU, Mitsushi FUJIKI, Kazumichi YANAGISAWA, Nakamichi YAMASAKI

1992 Volume 2 Pages 27-32
Published: 1992
Released on J-STAGE: October 29, 2012

DOIhttps://doi.org/10.3363/prb1992.2.0_27

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Strontium hydroxyapatite fine single crystals were synthesized hydrothermally at 200°C under the saturated vaper pressure of solution for 10 h. The crystals were nonaggregated particles with hexagonal prismatic shape of about 110 nm in length with aspect ratio of about 6.5. Their lattice parameters (a=0.9767 nm, c=0.7278 nm) were in good agreement with those of the stoichiometric Sr apatite. An X-ray profile analysis indicated that the crystals had no compositional fluctuation. The Sr/P atomic ratio of these crystals was 1.67 of correct apatite stoichiometry by ICP analysis.

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AN EVIDENCE FOR THE COORDINATION OF NITROGEN ATOMS OF IMIDOCYCLOPOLYPHOSPHATE ANIONS TO METAL IONS

M. KOMIYA, T. MIYAJIMA, M. SAKURAI, S. SATO, M. WATANABE

1992 Volume 2 Pages 33-38
Published: 1992
Released on J-STAGE: October 29, 2012

DOIhttps://doi.org/10.3363/prb1992.2.0_33

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⁹Be, ²⁷Al, and ³¹P NMR spectroscopic methods were used to study the structures of the complexes of Be²⁺ and Al³⁺ ions with monoimidocyclotriphosphate, c(NH)P₃, diimidocyclotriphosphate, c(NH)₂P₃ and triimidocyclotriphosphate, c(NH)₃P₃ in aqueous solutions. The NMR results suggest that Al³⁺ ions bind to the bridging nitrogen atoms of imidocyclopolyphosphateanions.

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THE THERMAL PROPERTY OF IMIDOOLIGOPHOSPHATES

MAKOTO SAKURAI, MAKOTO WATANABE

1992 Volume 2 Pages 39-44
Published: 1992
Released on J-STAGE: October 29, 2012

DOIhttps://doi.org/10.3363/prb1992.2.0_39

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Diimidocyclotri-, monoimidocyclotri-, and tetraimidocyclotetraphosphates have been made by using phosphazene as a starting material. The thermal property of the imidooligophosphates was studied according to TG-DTA measurement.

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THERMAL BEHAVIOR OF VARIOUS COBALT CYCLO-PHOSPHATES

HIROYUKI NARIAI, ITARU MOTOOKA, MITSUTOMO TSUHAKO

1992 Volume 2 Pages 45-50
Published: 1992
Released on J-STAGE: October 29, 2012

DOIhttps://doi.org/10.3363/prb1992.2.0_45

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The thermal behavior of various cobalt cyclo-phosphates, Co₂P₄O₁₂·8H₂O(P_4m), Co₃P₆O₁₈·14H₂O(P_6m), and Co₄P₈O₂₄·18H₂O (P_8m), was investigated using TG-DTA, HPLC, X-ray diffraction analysis, and IR. P_4m decomposed perfectly to short-chain phosphates and oligo phosphates (P_oligo:chain length n=5-14) with the elimination of water of crystallization. With an increase in temperature, their phosphates condensed to insoluble highpolyphosphates (P_{high poly}). The decomposition of P_4m proceeded faster under humid air than dry air. P_6m, also decomposed to short-chain phosphates and P_oligo (n=7-14). Although the water vapor accelerated the decomposition of P_6m, it prevented the condensation of phosphates. At temperatures above 540°C, all the phosphates changed to P_{high poly}. P_8m lost the most of water of crystallization to decompose to short-chain phosphates and oligophosphates at about 150°C. An increase of oligo phosphates (n=9-17) and soluble polyphosphates (n=18-20) was observed at 400 °C. Under a higher water vapor pressure, the decomposition of P_8m proceeded rather faster than in a lower one, while the rate of condensation reactions slower than in the higher one. At 400°C, a little amount of P_6m formed. At higher temperatures, all the phosphates changed to P_{high poly}.

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INTERCALATION OF n-ALKYLDIAMINES TO H_xWO(P₂O₇)

Nobukazu Kinomura, Kiyoshi Onda, Nobuhiro Kumada

1992 Volume 2 Pages 51-56
Published: 1992
Released on J-STAGE: October 29, 2012

DOIhttps://doi.org/10.3363/prb1992.2.0_51

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n-Alkyldiamine complexes of WO(P₂O₇) were prepared by the acid-base reaction at room temperature. The basal spacing of the complex, [(NH₂)C_mH_2m(NH₂)]_yH_xWO(P₂O₇)·nH₂O, with odd carbon number of m (m≥5) is systematically longer than that of the complex with even carbon number of m+1 and linear relationships between the basal spacing and carbon number are observed for odd and even carbon numbers, respectively. The decrease of basal spacing on going from odd to even carbon number and the slopes of the linear relationships indicate that the alkylchain in the interlayer space is inclined very much≈35°.

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COMPLEX FORMATION OF BOVINE SERUM ALBUMIN WITH SODIUM DODECYL SULFATE ON THE SURFACE OF HYDROXYAPATITE

SABURO SHIMABAYASHI, MIHO MATSUMOTO

1992 Volume 2 Pages 57-62
Published: 1992
Released on J-STAGE: October 29, 2012

DOIhttps://doi.org/10.3363/prb1992.2.0_57

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Interaction among bovine serum albumin (BSA), sodium dodecyl sulfate (SDS), and hydroxyapatite (HAP) was studied in a phosphate buffer solution(pH 7.0) containing 0.02% sodium azide as an antiseptic at 25°C. Both BSA and SDS were simultaneously adsorbed on the surface of HAP. Adsorption amount of SDS in its low concentration range was higher in the presence than in the absence of BSA due to the complex formation between them on the surface of HAP. On the contrary, that of BSA decreased and levelled off after attaining a maximum with an increase in a concentration of SDS. The increase in the adsorption amount of BSA is by virtue of the formation of SDS-BSA complex on the surface. The decrease is owing mainly to the expansion/denaturation of BSA molecule through the complex formation with much amount of SDS on the surface of HAP.

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PREPARATION AND ION-EXCHANGE PROPERTY OF CATTLE BONE-APATITE

TOSHIYUKI AKAZAWA, MASAHUMI KUDO, KOHEI KODAIRA

1992 Volume 2 Pages 63-68
Published: 1992
Released on J-STAGE: October 29, 2012

DOIhttps://doi.org/10.3363/prb1992.2.0_63

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Cattle bone-apatite (b-HAp) with low crystallinity was obtained by calcination of cattle bones at 700°C for 1 minute in a fluidized bed furnace. The b-HAp was well crystallized by heat-treatment at 800~1100°C for 24 hours in an electric furnace. The lattice parameters were a=0.942nm and c=0.688nm. Ion-exchange ratios of Ca²⁺ ion for 2.42mM-Pb²⁺ ion were decreased with increasing the heat-treatment temperature of b-HAp up to 1100°C. The value of as-prepared b-HAp by a fluidized bed furnace was 0.13 because of low crystallinity. The saturated exchange amount of Ca²⁺ ion in the b-HAp was 38.7mg·g^-1. Ion-exchange ratios for other metal ions in the b-HAp were 0.12 for for Cu²⁺ and 0.07 for Cd²⁺ and Zn²⁺.

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EVALUATION OF THE INSTABILITY OF LATTICE HYDROXIDE IONS OF HYDROXYAPATITE IN TERMS OF PROTONIC CONDUCTIVITY AT HIGH TEMPERATURES

Kimihiro YAMASHITA, Kazuhisa KITAGAKI, Takao UMEGAKI

1992 Volume 2 Pages 69-74
Published: 1992
Released on J-STAGE: October 29, 2012

DOIhttps://doi.org/10.3363/prb1992.2.0_69

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The instability of the lattice OH^- ions of hydroxyapatite was evaluated in terms of high temperature conductivity, the charge carriers of which was confirmed protons by the measurements of electromotive force. The instability of the ions was observed as the aging phenomenon of the conductivities, in which the values increased with the order of 102 in S·cm^-1 at the initial stage, then gradually decreased with time after the maximum of ca. 10^-3 S·cm^-1. The range of aging change was found dependent on the thickness as well as the annealing conditions. The H₂O vapor in the ambience of sintering was also found to have considerable influence the characteristics of the aging; the specimens sintered in air was independent of time, although their conductivities were negligible in comparison with those of specimens sintered under steam stream.

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SINTERING OF ZIRCONIA-ADDED APATITE COMPOSITE

Motohide MATSUDA, Kimihiro YAMASHITA, Takao UMEGAKI

1992 Volume 2 Pages 75-80
Published: 1992
Released on J-STAGE: October 29, 2012

DOIhttps://doi.org/10.3363/prb1992.2.0_75

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Tricalcium phosphate-free hydroxyapatite-zirconia ceramic composites were prepared by the sintering in H₂O vapor. The supply of H₂O vapor to sintering atmosphere was effective for suppressing a partially dehydration in the hydroxyapatite. The densities of prepared composites were lower comparison with those of hydroxyapatite sintered under the same condition. It was also observed that monoclinic and/or tetragonal ZrO₂ used as the starting powders transformed to cubic that after the sintering. This may be attributable to Ca-diffusion from hydroxyapatite to ZrO₂.

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FABRICATION OF Li₃PO₄-Al₂O₃ COMPOSITES BY USE OF AN ELECTROCHEMICAL DEPOSITION TECHNIQUE

MASAYUKI NAGAI, HIROMITSU TOMOYOSE, TADASHI NISHINO

1992 Volume 2 Pages 81-86
Published: 1992
Released on J-STAGE: October 29, 2012

DOIhttps://doi.org/10.3363/prb1992.2.0_81

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Li₃PO₄-Al₂O₃ composites were fabricated by an electrochemical deposition technique using porous Al₂O₃ ceramics as a matrix. Li₃PO₄ deposits were formed within the micropores in Al₂O₃ by the reaction between LiOH and NH₄H₂PO₄ solutions. The formed phase in the deposit was identified to be Li₃PO₄ of the orthorhombic system by X-ray diffraction, SEM, EPMA and IR analysis.

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