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A flow-micro-reactor system was employed to fabricate hydroxyapatite (HAp) in order to mimic the interface between calcium and phosphate solutions on a wet chemical procedure. The mixing ratio of calcium nitrate tetrahydrate and diammonium hydrogenphosphate solution was set to the stoichiometric atomic ratio HAp, 1.67, while pH value of the product suspension was varied from 6.4 to 10.0. The product morphology was changed from nano-sheet type to nano-particle type via nano-rod one, while their size was decreased from 100–500 nm to 50 nm. All as-prepared samples, irrespective of pH value of the resultant suspension, consisted of HAp, predominant phase, octacalcium phosphate (OCP), and dicalcium phosphate dihydrate (DCPD) or dicalcium phosphate anhydrate (DCPA). A batch system using the same solutions yielded very similar results, which confirmed that the reactions in this micro-reactor well reproduced a large-scale mixing system. Calcining sample obtained from pH 6.4 suspension for 2 h at lower temperatures (

Chitosan–γ-glycidoxypropyltrimethoxysilane (GPTMS)–tetraethoxysilane (TEOS) hybrid membranes were prepared by the sol–gel method. The effects of Si(IV) released from them on cell proliferation and differentiation were examined in terms of cell metabolic activity and the alkaline phosphatase (ALP) activity of MG63 osteoblastic cells. The amount of Si(IV) released from the hybrid membranes increased with the TEOS content. The released Si(IV) inhibited cell proliferation but promoted cell differentiation. Thus, the osteocompatibility of the chitosan hybrid membranes in the chitosan–GPTMS–TEOS system can be controlled by the amount of Si(IV) released from them when they are applied to cell culture.

Amino-modified TiO2 particles were derived from precursor mixtures of tetraethylorthotitanate and aminopropyltriethoxysilane (APTES) that both were dissolved in ethanol/water solution. Size, morphology, crystalline structures, and formation mechanism of the particles were discussed in terms of the APTES amount and the pH value in the solution. The addition of APTES resulted in amorphous amino-modified TiO2 particles. The low crystallinity in the final particles was attributed to the polar amino groups.

We report on the effect of using a spatial gap on heterogeneous nucleation on the surface of thermally oxidized titanium substrates. Induction of heterogeneous nucleation of bone-like hydroxyapatite (BHAp) was evaluated in the spatial gaps between substrates that were thermally oxidized at temperatures of 100-800°C on exposure to a simulated body fluid (SBF). After soaking in a SBF for 7 d, BHAp spontaneously deposited inside the gap on the surface of samples that were thermally oxidized at temperatures above 400°C, but not on samples that were thermally oxidized at temperatures of 300°C or less. Among the substrates studied, BHAp particles were most readily deposited inside the gap on the surface of the samples that were thermally oxidized at 400°C after soaking in an SBF. A smaller gap led to a higher number of BHAp particles being deposited on the surface of the samples that were thermally oxidized at 400 or 500°C. Our results suggest that the formation of BHAp in a SBF is dependent on the temperature during thermal oxidization, and also on the spatial gap between the samples. The ease of formation of BHAp on thermally oxidized titanium increases with increasing thickness of the rutile phase and the number of Ti-OH groups, which are produced during the thermal oxidization process. In addition to the surface structure of the substrates, the spatial gap is regarded as an important parameter for enhancing the deposition of BHAp. Since the formation of BHAp allows osteoconduction to occur after implantation in a bony defect, it is possible to design titanium-based implants with a high biological affinity to bone by processing using an appropriate spatial design of the substrate.

Ultraviolet (UV) light was irradiated in air for 1 h on titania (rutile) films prepared by thermal oxidation of titanium substrates from 300°C up to 800°C, coded as HT300UV, HT400UV, HT500UV, HT600UV, HT700UV, and HT800UV, respectively. All samples were then soaked in a simulated body fluid (SBF, Kokubo solution) and their in vitro apatite-forming ability was evaluated. It was found that bone-like apatite particles were deposited on HT500UV, HT600UV, and HT700UV within 7 d whereas that was not the case with others during the same period. Moreover, the apatite particles were deposited more on HT500UV than on the others. Therefore, the ultraviolet light irradiation enhanced the in vitro apatite-forming ability of the thermally oxidized titanium.

Titania layers were deposited on titanium substrates in titanylsulfate solutions under varied concentration (0.01 and 0.03M), pH (0.67-1.27) and temperature (60 and 80°C). They were rinsed and subsequently aged in water at 80°C for 3d. The layers consisted of only rutile or rutile with trace anatase, depending on the conditions. The X-ray diffraction intensity indicates that the rutile particles grew preferably in (101) plane, regardless of being aged or not. When aged, the anatase diffraction intensity increased, and anatase newly grew in the layer consisting only of rutile. When soaked in a simulated body fluid (SBF) of the Kokubo recipe, the rinsed layer with only rutile was weakly active to deposit apatite within 5 d, while the other two exhibited no deposition. The aging improved activity. Although anatase is reported in the literature to be more active than rutile, the present study indicates that the rutile layer is more active. Thus, it is concluded that topotaxy or epitaxy would not work well but other issues like the presence of Ti-OH affect apatite deposition.

y-Methacryloxypropyltrimethoxysilane (y-MPS) was grafted on a silicone elastomer by emulsion polymerization in order to improve cytocompatibiiity. The wettability of the grafted surface was evaluated with a contact angle toward distilled water. By grafting within 30 min at 60°C, the contact angle was reduced from 110° to about 70° while it remained almost constant for longer grafting. A larger number of osteoblastic cells (MC3T3-E1) and fibroblast cells (L929) proliferated on the surface modified with γ-MPS compared with the original silicone surface. After culturing for 7 d, the cells completely covered the grafted surface and even formed a cell layer.

A novel approach to fabricate sub-μm scale arrays is demonstrated with the growth of rutile TiO2 on titanium substrates. The fabrication process is template-free, simply involving coating of the titanium substrate with sodium tetraborate glass, Na2O•2B2O3: when the glass coating was removed by dissolution in distilled water at 80°C for about 5 h, random or well-ordered submicron-scale rod arrays of rutile were left on the substrate. A glass phase topotaxial (GPT) nucleation and growth mechanism is thought to operate in the crystal growth process.

A new approach is presented to prepare a rutile layer on titanium substrates. According to this approach, pulverized glass, composed of 3CaO•4B2O3•3TiO2, is first developed on the substrate, heated up to 700 to 850°C, and then removed by soaking in hot water. During the heating process, rutile grew at the glass coating-substrate interface to form nano-sized crystallites. The rutile layer induced apatite formation within 3 d when soaked in simulated body fluid of the Kokubo recipe. Such in vitro bioactivity was attributed to many Ti-OH groups on the crystallite surface derived from hydrolysis of bonds at the crystallite-flux (matrix) interface like (rutile)-Ti-O-B or Ti-O-Ca-(the borate matrix).

This study concerns with the adsorption of pathogenic substances on highly blood-compatible titania and the adsorption mechanism. Titania was prepared through a sol-gel procedure by hydrolyzing tetraethylorthotitanate and calcining up to 705°C for 3 h. Pore size distribution and surface charge density were measured as a function of calcining temperature. Adsorption of bilirubin, as a typical pathogenic substance, as well as albumin on the titania powder was studied. Bilirubin was adsorbed either in 4 to 8-nm pores or on the surface with a higher positive charge. Thus, either entrapping bilirubin in the pores or electrostatic interaction between bilirubin and titania surface was effective for the adsorption of bilirubin. The titania powder adsorbed a greater amount of bilirubin than the anion-exchange resin used in clinics, hence they have potential for blood purification therapy.

Synthesized were organically modified silicate (ORMOSILs) hybrids containing colloidal silica as an ingredient, starting from poly (dimethylsiloxane) (PDMS), tetrathoxysilane (TEOS) and calcium nitrate through sol-gel processing. The effects of pre-hydrolysis of TEOS on mechanical strength and viscoelasticity were examined. A sample of composition PDMS/TEOS = 0.60 (molar ratio) with pre-hydrolysis of TEOS showed about 65% maximum failure strain. Thus obtained hybrid exhibited a peak at around −75°C in the storage modulus-temperature curve of the hybrid, due to transverse movements of the PDMS chains. This hybrid, heated at 200°C deposited apatite within 1 d in the simulated body fluid of the Kokubo recipe.

Synthesized through sol-gel processing were Ormosil type hybrid gels containing varied mass fractions of colloidal silica, poly (dimethylsiloxane) (PDMS), tetraethoxysilane (TEOS) and calcium nitrate. Viscoelasticity, mechanical strength and 29 Si MAS NMR spectra were measured, and in vitro apatite deposition in a simulated body fluid (SBF) of the Kokubo recipe was examined. The relative height of a Tg peak at about -100°C in tan δ versus temperature curves grew with the colloidal silica content. This peak growth was accounted for the relative increase in PDMS-colloidal silica interactions. As the increase in the compressive strength followed the increase in colloidal silica content, the number of PDMS-silica bonds and hydrogen bond of colloidal silica increased due to the NMR spectra and tan δ curve. Thus, mechanical strength was dependent on PDMS-silica bonds and the hydrogen bond of colloidal silica. On the other hand, as the relative PDMS content increased, the number of PDMS-silica bonds was little influenced while PDMS chain structure increased. The gel (with a molar ratio TEDS:PDMS:H 2 O:HCl:Ca (NO 3 ) 2 .4H 2 O=1:0.48:5.0:0.9:0.10) containing 14 mass% colloidal silica (CS 14 P 0.48 Ca 0.10 ) exhibited the highest maximum failure strain (about 70%) among all samples. Thus, the relative content of PDMS chain structure depending on PDMS content influenced the maximum failure strain. CS 14 P 0.48 Ca 0.25 could not deposit apatite within 7 d after soaking in SBF, while PDMS/TEOS=0.24 (molar ratio) could deposit apatite within 3 d. The increase in PDMS content restrained the dissolution of Ca ions.

Bone cement consisting of polymethylmethacrylate (PMMA) powder and methylmethacrylate (MMA) liquid is clinically used for fixation of implants such as artificial hip joints. However, it does not show bone-bonding ability, i.e. bioactivity. The essential prerequisite for an artificial material to bond to bone is the formation of an apatite layer on its surface when implanted in a bony defect. This apatite layer can be, for example, formed in a simulated body fluid (Kokubo solution) with ion concentrations similar to those of human extracellular fluid. The present authors recently showed the potential of bioactive PMMA-based bone cement through modification with y-methacryloxypropyltrimethoxysilane (MPS) and calcium chlorides. In this study, the effects of the kinds of calcium salts on apatite-forming ability were examined by exposure to Kokubo solution. PMMA powder (molecular weight of 100000 and 14 μm in average particle size) was mixed with 20 mass% of calcium salts consisting of calcium chloride (CaCl 2 ), calcium acetate (Ca(CH 3 COO) 2 ), calcium hydroxide (Ca (OH) 2 ), calcium lactate (Ca(CH 3 CHOHCOO) 2 ), calcium benzonate (Ca(C 6 H 5 COO) 2 ) and calcium methacrylate (Ca(CH 2 = C (CH 3 )COO) 2 ), while 20 mass% of MPS was added in the MMA liquid. The appropriate setting time was obtained by the usage of calcium acetate or calcium lactate, although the modification with MPS and calcium salts leads to an elongation of the setting time of the cement. Apatite formation could be detected after soaking in Kokubo solution for 1 d when the cements were modified with calcium chloride, calcium acetate, or calcium methacrylate. Apatite formation could be observed on the modified cement with calcium hydroxide after 7 d of soaking in Kokubo solution. The higher solubility of calcium salts allows for a higher rate of apatite formation in Kokubo solution. Furthermore, changes in pH after exposure of the cement are related to the apatite-forming ability, because the addition of calcium hydroxide also gives the cement the ability of apatite formation, even if the cement releases a small amount of calcium ions into the surrounding fluid. Smaller dissolution of calcium salts results in less decrease in compressive strength after exposure to a body environment. The release of calcium ions, followed by changes in pH, must be controlled to achieve a successful design of bioactive PMMA bone cement by modification with MPS and calcium salts.

The in vitro bioactivity, in terms of apatite-forming ability, of calcium silicate glasses containing 10 mol% fluoride ions in the NaF-CaO-SiO 2 system was examined by soaking in Kokubo's simulated body fluid (SBF) at 36.5°C for 7 d. The surface structure of the glasses was examined by thin-film X-ray diffraction (TF-XRD) and Fourier transform infrared reflection spectroscopy (FT-IR) in order to confirm the apatite deposition. The structure of the calcium silicate glasses was examined by 29 Si magic angle spinning-nuclear magnetic resonance spectroscopy (MAS-NMR) and X-ray photoelectron spectroscopy (XPS). Three calcium silicate glasses containing 10 mol% fluoride ions had different apatite-forming abilities. In the case of CaO/SiO 2 = 1, the apatite-forming ability of 10NaF.45CaO.45SiO 2 was lower than that of 50CaO.50SiO 2 . This indicated that the addition of fluoride ions suppressed the apatite-forming ability, irrespective of the structural similarity of the silicate network based on the ratio of CaO/SiO 2 between the glasses.

Titanium containing organic compounds were synthesized through reactions of titanium isopropoxide with o-, m- and p-hydroxybenzonic acid (hence-forth, abbreviated as o, m and p, respectively). The effects of isomers (o, m and p) on the properties of titanium containing organic compounds were investigated. Titanium containing organic compounds were self-assembled and, in o, the particles were of a uniform size and spherical, approximately 2-4μm in diameter. m and p consisted of massive particles of diameter approximately 1-3mm. A porous material was prepared by thermal decomposition of titanium containing organic compounds. For o, it was prepared at 400°C, while for m and p, it was prepared at higher temperatures (500-600°C). A material with a large pore volume was prepared from o, the average pore size being approximately 2nm in radius. Rutile easily formed from both o and m.

Al chelate compounds with different carbon chain lengths were synthesized through reactions of aluminum sec-butoxide with acetoacetic acid ethyl ester (n=2), acetoacetic acid pentyl ester (n=5), acetoacetic acid octyl ester (n=8) and acetoacetic acid oleyl ester (n=18). Silica powder was modified with aluminum sec-butoxide (ALK) and its Al chelate compounds abbreviated as C2, C5, C8 and C18 according to chain length. The effects of carbon chain length on the tap density, specific surface area, compaction and sintering behavior of modified silica were investigated. The tap density of modified silica decreased with an increase in the length of the carbon chain. In ALK, porous Al2O3 was formed by hydrolysis of aluminum sec-butoxide upon drying at 100°C. In contrast, in C2, C5, C8 and C18, porous Al2O3 was formed by thermal decomposition of Al chelate compounds above 200°C. The green density of the pressed bodies increased with an increase in the length of the carbon chain, resulting in the decrease in the porosity of sintered bodies fired at 1400-1500°C.

Nucleation and crystal growth mechanism of apatite formation on porous silica gel derived by a sol-gel procedure was investigated by the use of several simulated body fluids (SBF's) that had different concentrations of Ca(II), P(V), and OH- but had the same degree of supersaturation for hydroxyapatite. Induction time of apatite crystallization in SBF's was evaluated by thin film X-ray diffractometry. The effect of each ion on the induction time increased in the order: Ca(II)-rich SBF

Al2O3-coated graphite powder was prepared by a sol-gel method using ethyl acetoacetate aluminium diisopropoxide. An Al2O3-C castable refractory was prepared from the Al2O3-coated graphite powder. The flowability of this castable refractory was higher than that prepared from a graphite powder. The apparent porosity of the present Al2O3-C castable refractory was lower than that prepared from a graphite powder.

Calcium containing organic phosphorous compounds were synthesized through reactions of calcium acetate monohydrate with phenylphosphonic acid or phosphoric acid mono-n-butyl ester in 50vol% ethanol/water solution, and they were abbreviated as Phenyl Ca-P and Butoxy Ca-P, respectively. The effects of the phenyl and butoxy groups on the specific surface area, particle shape and thermal properties of calcium containing organic phosphorous compounds were investigated. As the amounts of added calcium acetate monohydrate (Ca/P) increased from 0.5 to 2 in the reaction solutions, the Ca/P ratios in calcium containing organic phosphorous compounds changed from 0.5 to 1. Calcium containing organic phosphorous compounds are self-assembled and have a layered structure. The interlayer distance of Phenyl Ca-P was shorter than that of Butoxy Ca-P. The Butoxy Ca-P particle was flake shaped, and the Phenyl Ca-P particle was an aggregate of tubular particles. The specific surface area of Phenyl Ca-P (30m2/g) was larger than that of Butoxy Ca-P (5-6m2/g). The thermal decomposition temperature of Phenyl Ca-P (300°C) was higher than that of Butoxy Ca-P (250°C). The crystal structure of calcium phosphate transformed from amorphous calcium phosphate to u-Ca2P2O7 by the thermal decomposition of calcium containing organic phosphorous compounds. It was possible to prepare a porous material with a hydrophobic group by using phenylphosphonic acid as a starting material.

Al2O3-coated graphite powder was prepared using ethyl acetoacetate aluminium diisopropoxide through the sol-gel method. The fluidity of the Al2O3-coated graphite powder slurry was studied. The apparent viscosity of a 2mass% Al2O3-coated graphite powder slurry was lower than that of a graphite powder slurry in the range of 25-40mass% solid loading. It is concluded that the fluidity of the Al2O3-coated graphite powder slurry depends on the fraction of free water of the slurry, the degree of dispersion and the wettability by water of the Al2O3-coated graphite powder.

Al chelate compounds with different carbon chain length were synthesized by reactions of aluminum sec-butoxide with β-ketoesters having different carbon chain length, such as acetoacetic acid ethyl ester (n=2), acetoacetic acid pentyl ester (n=5), acetoacetic acid octyl ester (n=8) and acetoacetic acid oleyl ester (n=18). Silica was modified by aluminum sec-butoxide and these Al chelate compounds (ALK, C2, C5, C8 and C18 respectively). Then the modified silica was dried at 100°C and heated up to 400°C. We studied the influence of carbon chain length on the hydrophilic-hydrophobic property of dried silica by measurement of adsorption amount of water vapor. In addition the surface property of heated silica was studied by measurement of specific surface area and pore size distribution. It was found that the adsorption amount of water vapor on dried silica decreased with increasing the length of carbon chain such as ALK, C2 and C5. Adsorption amount of water vapor was the same on C5, C8 and C18. Porous Al2O3 was prepared from ALK and C2 by drying at 100°C by hydrolysis of aluminum sec-butoxide and Al chelate compounds. Porous Al2O3 was also prepared by thermal decomposition of Al chelate compounds from C5, C8 and C18 by heating at 200°C. The mechanism of pore formation changed according to the carbon chain length of Al chelate compounds. The porous Al2O3 prepared from Al chelate compounds had smaller and more uniform pore size than that prepared from aluminum sec-butoxie.

An alumina-zirconia (AZ) composite powder was prepared by thermal decomposition of organic precursors synthesized from ethyl acetoacetate aluminium di-isopropylate and zirconium n-butoxide. The specific surface area of AZ was higher than that of alumina-zirconia (ALK) prepared from aluminium sec-butoxide and zirconium n-butoxide. The true density of AZ was lower than that of ALK. Selective reduction of nitrogen oxide with propylene in oxygen-rich atmosphere on AZ was superior to that on ALK.

31P MAS-NMR spectra were measured for pulverized binary and ternary glasses containing Ca2+ ions after soaking in a simulated body fluid (Kokubo solution; pH=7.25) for 1d, and the chemical state of adsorbed phosphate ions were examined. The 31P chemical shift indicated that orthophosphate ions, HxPO4-(3-x) (0

Amorphous tungsten trioxide films were prepared from iso-polytungstic acid as a precursor and by RF magnetron sputtering method. Framework structure was investigated based on X-ray diffraction analyses, in which amplitude function as well as radial distribution function was used. And the previously reported films prepared by vacuum evaporation and an ion exchange method using Na2WO4⋅2H2O as a precursor were also re-examined. It was found that, in the films derived from iso-polytungstic acid, the framework had a similar manner to that in hexagonal-WO3 crystal, whose framework was constructed by 3-, 4- and 6-membered rings formed by WO6 octahedra. It was supposed that edge-sharing polyhedra and tungsten and/or WO6 defects were present in the as-prepared film and changed to corner-sharing connection and continuous framework by post-annealing. It was also suggested that structural water was present in a hexagonal tunnel in the framework. These structural characteristics were also observed in the films prepared by vacuum evaporation and ion exchange methods. As for the sputtered films, formation of two framework-types without structural water was confirmed. The hexagonal-WO3 like framework was formed in the films prepared under a low O2 partial pressure, and tetragonal-WO3 like one with an ordinary ReO3-type structure made up with 4-membered rings was produced at a high O2 pressure.

ZrO2-dispersed MgO-Al2O3 ceramics with various MgO to Al2O3 compositional ratios were prepared from Mg(OH)2 powder, α-Al2O3 powder and Zr-n-butoxide by calcining at 1000°C for 2h and sintering at 1600°C for 1h. The influence of the MgO-Al2O3 compositional ratio on the sinterability and mechanical properties was studied. Addition of 10vol% ZrO2 improved the relative density of the sintered specimens containing 50 and 62.5mol% Al2O3. However, the addition was not effective at other compositional ratios. The bending strength was improved at composition containing more than 50mol% Al2O3, where the dispersed ZrO2 particles were in the form of tetragonal phase. The bending strength increased with increase in Al2O3 content in the ZrO2 dispersed specimens. The fracture toughness was improved for all specimens by ZrO2 dispersion, especially, for the specimen in which MgO-Al2O3 component was in a single crystalline phase.

Carbon dioxide gas in a 10% CO2-90% N2 mixture was fixed with Ca(OH)2 granules under a dry condition between 100 and 800°C. The fraction of fixed CO2 was highest between 500 and 600°C. More than 90% CO2 was fixed under the controlled gas flow rate, weight of Ca(OH)2, temperature and time. The porous CaO particles, which were prepared by dehydration of Ca(OH)2, reacted with CO2 gas and CaCO3 was formed on the surface of CaO particles. The CO2 recovery system using Ca(OH)2 makes possible to CO2 fixation by the use of simple equipment and method, and this system is effective for the minor factory.

MgO-C bricks containing 0 to 30 vol% flake graphite and expanded graphite were prepared and heat-treated at 800 and 1400°C. The dependence of mechanical properties of the MgO-C bricks on the graphite content was studied. The maximum values of bending strength, elastic modulus and fracture toughness were obtained at 2 to 3 vol% expanded graphite and at around 5 vol% flake graphite. The effective fracture energy increased with an increase in graphite content up to 30 vol% for expanded graphite. However, no slight increase in effective fracture energy was observed above 20 vol% flake graphite. Thermal shock resistance parameters R″″ and Rst were calculated based on the data obtained. R″″ was not correlated with graphite content. On the other hand, Rst remarkably increased above 7 vol% graphite and larger Rst was obtained with expanded graphite. Consequently, improvement of the spalling resistance of MgO-C brick was expected with expanded graphite.

Anatase of good crystallinity has been developed on titanium substrates by soaking in a 30 mass% hydrogen peroxide solution at 80°C for 8h, soaking in distilled water at ambient temperature for 12h, and subsequently aging in distilled water at 80°C for 3d. The anatase layers exhibit good bioactivity as inducing apatite deposition in Kokubo's simulated body fluid within 2d.

We examined the effect of raw materials on the properties of alumina-magnesia powders. In particular, we investigated about the amorphous structure of alumina-magnesia powders (AMA20 and AMH20, MgO content=20mol%) prepared by sol-gel method. The specific surface area of an AMA20 powder prepared from ethyl acetoacetate aluminum diisopropoxide and magnesium acetate tetrahydrate was larger than that of an AMH20 powder prepared from ethyl acetoacetate aluminum diisopropoxide and magnesium hydroxide. Crystallization behavior and true density depended on the raw materials used for magnesia. It is considered that the alumina and magnesia components in alumina-magnesia amorphous powder AMA20 were homogeneously mixed at the atomic level.

MgO particles were coated with a chelate compound of aluminum and heated in air to prepare Al2O3-coated MgO particles for modifying surface properties. The dissolution of MgO in water was suppressed by the Al2O3 coating. The amount of dissolved Mg ion was minimum after heating at 500°C. The Al2O3-MgO layer 10-30nm thick was observed on the surface of the MgO particles heated at 500°C. Fine particles 10nm in diameter were seen in the coating layer and they aggregated into clusters 300-500nm in diameter after heating at 1000°C. It was also found that the adherence of coating layer to MgO particles decreased after heating at 1000°C compared with those heated at 500°C.

PbTiO3 thin films were prepared by activated reactive evaporation (ARE) through controlling evaporation rates of Pb and Ti, O2 pressure, and substrate temperature. The Pb/Ti ratio of these films depended on the evaporation rate of Ti. When the substrate temperature and O2 pressure were held at 600°C and 1.6×10-4 Torr respectively, the optimum evaporation rates of Ti and Pb for a nearly stoichiometric PbTiO3 film were 0.2 and 1.2-1.8A/s, respectively. PbTiO3 films deposited on a c-plane of sapphire showed preferred orientation of (111) plane, and those on (100) plane of MgO showed strong c-axis orientation. AES depth profile mesurements and SEM observations indicated that these films were uniform in composition and dense.

New aluminate glasses were obtained with the conventional melt-quench technique in the system SrO-ZnO-Al2O3. The glass forming region was determined. The glasses were colorless and had good chemical durability in laboratory conditions. When irradiated with UV-light, a broad absorption was induced with a peak at 470nm (2.64eV) and an ESR signal (77K and 300K) was induced with an apparent g-value of 2.006. Both the changes in optical density and the intensity of the ESR signal increased with the ZnO content. From the characteristic of ESR signal, coloring of glass was concluded to a due to the formation of hole trapped on oxygen and electron center resting on zinc ions.

As an aid for interpreting the boron oxide anomaly, the structure of several alkali borate crystals was studied. It was found that the five kinds of BO3 units, such as B3(3B3), B3(2B3, B4), B3(B3, 2B4), B3(3B4) and BR and two kinds of RBO4 units, such as B4(4B3) and B4(3B3, B4) are the basic constituents of the crystals in the range 0≤x≤1.0, where x represents the molar ratio R2O/B2O3. The variation of the fractions of those units with x shows the two tendencies. (1) The number of B4 units to which a B3 or a B4 unit is bonded increases gradually with x. (2) The fraction of each kind of B4 or B3 unit becomes maximum in one of the crystals, in which the unit is the single kind of constituent B4 or B3 unit. These tendencies suggest that four kinds of B4 units bonded with more than one B4 units appear in the range 0.5

R2O-P2O5系ガラス (R=Li, Na, 及びK) 並びにいくつかのナトリウムリン酸塩化合物 (NaPO3, Na4P2O7, 及びNa3PO4) の3N HNO3中への溶解熱を25℃にて双子型伝導微小熱量計により測定した. アルカリリン酸塩ガラスの溶解熱はモル比r=(R2O+H2O)/P2O5に対してプロットした場合, 直線的に減少しr=1で極小値をとったのち直線的に増加した. このことはP2O5にR2Oを加えるに従い, 不安定な3分岐グループが安定な2分岐グループになることによりP-O-P架橋結合が安定化されるためである. アルカリリン酸塩に関係した化学種の生成熱の文献値及び本研究における溶解熱の測定値からRPO3ガラス (R=Li, Na, 及びK) の生成熱を計算した.

The molar volume, optical basicity, X-ray fluorescence spectra of Al Kα and X-ray photoelectron spectra of O1s, B1s and Al2p core electrons were measured for alkaline earth aluminoborate (CaBAl and BaBAl) glasses as a function of molar ratio MO/(MO+B2O3)=X (M=Ca and Ba). Inflections and discontinuities in the property vs. X curves, for instance, in compositions containing 20mol% Al2O3 were discussed in terms of formation of [BO4]- and [AlO4]- units and partition of MO to B2O3 and Al2O3. Each of these anomalies was attributed to: the increase in the electron density on bridging oxygens (X=0.25), disappearance of AlO6 units (X=0.35), formation of significant amount of non-bridging oxygen (X=0.40) and decomposition of the BO4 units into O2BO- ones (X=0.44). On this basis, the triclusters were concluded to be absent in the aluminoborate glass network.

A super-absorbent polymer was fixed on alumina particles to prepare water-holding alumina powder. A mixture of alumina powder and water has various apparent viscosities between 800 and 90000Pa·s depending on the content and the condition of heat treatment of the super-absorbent polymer. This mixture was injection-molded at room temperature. The dried moldedbody has a high bending strength, about 30MPa, and densifies above 1350°C.

Etude des verres de borophosphate de baryum de composition: BaO•2(1-x)B 2 O 3 •2xP 2 O 5 ou 0≤x (mol)≤0,7. Comparaison avec les verres de borophosphate de potassium