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HIDEKO INOUE, HIROKAZU NAKAYAMA, MITSUTOMO TSUHAKO
2002 Volume 14 Pages
1-8
Published: 2002
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On-line analysis of organic phosphorus compounds with P-O-C and P-C bonds have been developed based on HPLC and two-step postcolumn reactions. The calibration curve for the organic phosphorus compounds showed good linearity (correlation coefficient>0.9918). The standard deviations (n=9) of the method were smaller than 0.91%. The detection limits (S/N=2) of the organic phosphorus compounds were ca. 0.5 nmol as the injected amount. This method could be applied to the determination of the organic phosphorus compounds in the 5-100 μM range (injection volume, 100 μl).
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BRAHIM EL BALI, ALI BOUKHARI, HASSAN ALLOUCHI
2002 Volume 14 Pages
9-13
Published: 2002
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SrNiZn(PO
4)
2 is isostructural to SrNi
2(PO
4)
2 [P-1, Z=2, a=5.4560 (10), b=6.7110 (10), c=9.1820 (10), α=110.600 (10), β=101.100 (10), γ=98.080 (10), 1009 independent reflexions (I>2σ(I)), 119 parameters, R1=6.98, wR=7.03], with sheets made of edge-sharing [NiO
6] and [ZnO
5]. However in the new compound, Ni form dimers [Ni
2O
10] with short d
Ni-Ni of 3.006 Å.
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DÖRTE STACHEL, ANNETT OLBERTZ
2002 Volume 14 Pages
15-22
Published: 2002
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Ultraphosphate structures are polymeric and consist of the anion framework and the cations between. But, the anion framework strongly depends on the cations, their charge, size, and value. Some selection rules exist, which point out the number of possible structure bonds related to the number and charge of the cations. Concerning anion framework, there exist discrete cyclic units as well as ribbons and layer structures with different ring sizes, number of connecting {PO
4} tetrahedra and connection possibilities. The cations are isolated from the others within the frameworks because of their low content. But, when the cations were connected each other with thinkable bonds, we get a detailed insight into the structure interactions between anion configurations and the cations between. In all evaluated crystalline ultraphosphate structures, the cations have 6 cations “around” to form octahedra with different distances and symmetries from one cation to the next neighboured one. The so-called repeatable units seem to depend on the complexity of the anionic framework: the more complex the anionic structure, the less complicate the cationic relations, and reversed. This means, that ultraphosphate structures possess strong relations between the {
PO4} groups and the cations. The result are complex interconnecting structures.
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E. T. ATAKUZIEV, S. S. KASIMOVA, T. A. ATAKUZIEV, D. A. HAITOVA
2002 Volume 14 Pages
23-32
Published: 2002
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Processing of phosphogypsum on sulfoaluminate-silicate cement allows to receive decorative and usual rapid-setting cements of mark 400-600. In comparison with white Portland cement it allows to save a significant amount of technological fuel. Productivity of the furnace raises on 15-25% for the account of lower contents of limestone in a raw mix of sulfoaluminate-silicate cement in comparison with Portland cement a raw mixture. We have investigated the behaviour of phosphorus in this process.
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HIDEKAZU TANAKA, KANJI MASUDA, RYOZI HINO
2002 Volume 14 Pages
33-38
Published: 2002
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Titanium ethyl phosphates (TiEP) synthesized by the reaction of Ti(SO
4)
2 with a mixture of mono- C
2H
5OPO
3H
2 and diethyl phosphates (C
2H
5O)
2PO
2H (EP) in aqueous media were characterized by various means. XRD pattern of TiEP featured a strong diffraction peak at 2θ=6.8°. When TiEP was treated at 900°C in air, the material crystallized as TiP
2O
7, implying the molar ratio P/Ti of TiEP to be 2.0. This indicates that only monoethyl phosphate ions reacted with Ti
4+ ions. The chemical formula of TiEP could be shown as (C
2HSOPO
3)
2Ti·1.7H
2O. These facts suggested that TiEP is composed of a multilayer alternating bimolecular layer of ethyl phosphates and hydrated titanium phosphate phase. Ethyl groups and H
2O molecules in the layers were removed by outgassing at 200°C to give the materials having mesopores with a diameter of ca. 2.6nm
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SABURO SHIMABAYASHI, MASASHI HOSHINO, TOMOAKI HINO
2002 Volume 14 Pages
39-46
Published: 2002
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Adsorption of polyethyleneglycol mono-p-isooctylphenylether (TX-100) on hydroxyapatite (HAP) was accelerated in the presence of sodium dodecylsulfate (SDS). This is because TX-100 was captured into hemimicelle/ admicelle of SDS formed on the surface of HAP. The adsorption amount on and affinity to HAP of TX-100 increased with the adsorption amount of SDS, forming the mixed micelle on the surface. Sodium dodecylbenzenesulfonate (SDBS) was also adsorbed on HAP in the same manner as that of SDS. However, polyoxyethylene (23) laurylether (C12n23) was little adsorbed by itself and scarcely accelerated the adsorption of SDBS. Anionic surfactants such as SDS and SDBS were adsorbed directly on the surface, while nonionic surfactants such as TX-100 and C12n23 required hydrophobic area to be adsorbed on the surface. The hydrophobic patch on the surface should be formed after the adsorption of the anionic surfactant on HAP. The roles of hydrophobic interaction and cooperative adsorption in the adsorption of nonionic surfactants were discussed.
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TAKESHI MORIGUCHI, KAZUYUKI YANO
2002 Volume 14 Pages
47-56
Published: 2002
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Hydroxyapatites (HAPs) containing carbonate were sintered between 400 and 1200°C, and the sintered HAPs were analyzed by FT-Raman spectroscopy to give the spectra indicating typical four phosphate bands ν
1(PO
4)-ν
4(PO
4), OH translation ν
5, notable bands ν
6-ν
8 in lattice modes, and several combination bands. The band intensities of ν
2(PO
4)+ν
5 and ν
1(PO
4), and these intensity ratio R
cp values were changed according to the carbonated types in the HAPs. From these results, we conclude that the changes in Raman intensities possibly reflect the particle growth and volume shrinkage in the HAPs. The present Raman study may be applied to structural elucidation study of other substituted apatites such as fluorinated and magnesium apatites as well as forensic study.
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MICHAL HENRYK UMBREIT, AGNIESZKA JEDRASIEWICZ, JOLANTA KLOS, AGNIESZKA ...
2002 Volume 14 Pages
57-68
Published: 2002
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The influence of temperature (20°-1000°C) on substrates Zn
3(PO
4)
2 2H
2O (1), MgHPO
4·3H
2O (11) and their binary mixtures in percentage ratio from 10%-90% (2-10) was investigated. The researches were done in mean of differential thermal analysis (TG, DTG, DTA), IR-spectroscopy, electron microscopy, and WARS-Ray. On the grounds of mentioned above analytical methods, there was stated that Zn
3(PO
4)
2·2H
2O-Hopeite and MgHPO
4·3H
2O-Newberyite both occur in crystalline form. Heating these substrates to 500°C cause transformation to Zn
3(PO
4)
2 and Mg
2P
2O
7. On the thermal curves (DTA) this transformation is pointed until at 670°C. This is caused by the transformation this substrate to amorphous forms. Further heating of substances even to 1000°C don't cause other transformation. Additionally, Zn
2Mg(PO
4)
2 was made from binary mixtures, during heating in oven at 1000°C in any percentage ratio. This was brought about the phenomenon of fluidisation of Mg
2P
2O
7.
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S.M.A. MOUSA
2002 Volume 14 Pages
69-76
Published: 2002
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Three powder samples of lanthanum phosphate were prepared via the precipitation method. La
2O
3, LaCL
3, (NH
4)
3PO
4 and H
3PO
4 were used as precursor materials. Chemical and thermal analyses, infrared spectra, X-ray diffraction and particle size techniques were used for characterization. The results of chemical analysis indicated that the three samples are in non-stoichiometric state which attributed to the solubility of the products in the aqueous medium and/or to the partial precipitate of HPO
42- and H
2PO
4- species. The results of infrared spectra exhibited the specific bands of phosphate salts such OH, O=P-O, P-O and O-P-O. A band at 1380 cm
-1 corresponding to PO
22- is observed in sample I and II which may due to make complexation species between the phosphates and the metal ions.
The X-ray diffraction indicated the formation of lanthanum phosphates of hexagonal structure of rhabdophane LaPO
4.0.5H
2O. DTA/TGA curves show that the prepared samples remain thermally stable at high temperatures.
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MOHAMED Sh. KHALIL, ADLY A. HANNA, MARWA A. EL-SAYED
2002 Volume 14 Pages
77-87
Published: 2002
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Substituted AlPO
4 and FePO
4 with Na
+ and Cd
+2 were synthesized by sol-gel method from H
3PO
4 and the chloride salts using ethylene oxide as a gelating agent. Chemical analysis, Infra red spectra and x-ray diffraction were measured for characterizing the products. Electrical conductivity of the samples, dried and sintered at 550°C, was performed.
The results of characterization indicate that the substitution process depends on the mole%of the substituant cations where they improved the crystallinity of the formed phases. The electrical conductivity measurements indicated that the prepared phosphates behave as semiconductor materials and its value depends on the nature of cations, and the thermal treatment.
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KAIA TÕNSUAADU, MERIKE PELD, VILLEM BENDER, MARINA PUZ
2002 Volume 14 Pages
89-92
Published: 2002
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Thermal changes in synthetic apatites (Aps) at calcination up to 1000°C were studied by TG/DTA, FTIR and XRD. The Aps containing CO
3 2-, SO
4 2-, F
-, and Na
+ substitutions were precipitated from aqueous solutions. Reorganization of CO
3 2- and SO
4 2-substituted Ap structure takes place in a temperature range of 600-930°C and the substitutes are displaced. The temperature of the changes decreases with an increase in F content in Ap. In F containing Ap SO
4 2- displaces in one-step and CaSO
4 is formed. From hydroxyapatite structure SO
4 2- disengages continuously up to 1000°C. CO
2 evolves in 1-3 steps. If C/P≈0.3, most of CO
2 (70%) evolves at 700-800°C and CaO [Ca(OH)
2] is formed. If C/P≈0.1, most of CO
2 evolves at 830°C.
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ANASTASSIA MANUILOVA, KAIA TÕNSUAADU, MIHKEL VEIDERMA
2002 Volume 14 Pages
93-98
Published: 2002
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Thermal reactions of SO
2 with natural and synthetic apatites (Aps) have been studied by thermogravimetric analysis. Experiments under dynamic and isothermal conditions were performed in the air-SO
2 flow with different SO
2 content (0.07%, 1%, 10%). The reactions proceeded at temperatures from 400°C to 800-850°C according to two- or three-dimensional diffusion models, the reaction rate depending on temperature, SO
2 concentration and substitutions in the Aps structure (PO4↔CO
3). Thermal interaction of Aps with SO
2 led to decomposition of apatite. At heating during one hour at 800°C in an air-SO
2 (10%) flow, 40% of fluorine from fluorapatite (FAp) and 72% from carbonateapatite (FCO
3Ap) was removed.
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ATSUSHI TAKENAKA, RANKO MATSUDA
2002 Volume 14 Pages
99-103
Published: 2002
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Zinc oxide-ammonium dihydrogenphosphate-urea mixtures were heated in a stream of nitrogen gas to obtain a large amount of cyclo-tetraphosphate. A trace of cyclo-tetraphosphate was formed only at 500°C and with the molar ratios of urea/ZnO/NH
4H
2PO
4 of 1/1/2 and 2/1/2. Instead of the cyclo-tetraphosphate, zinc polyphosphate (β-Zn(PO
3)
2) with long-chain anion was a main product above 400°C.
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MAKOTO WATANABE, HIROKAZU SUZUKI, SHINJI KAWASAKI, MIOKO MAEDA, MAKOTO ...
2002 Volume 14 Pages
105-110
Published: 2002
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Ammonium polyphosphate (APP) form II was prepared by heating a mixture of ammonium orthophosphate and urea at 280 to 300°C under wet ammonia which was made by passing air through 3 to 5% ammonia water. Simple dry process of the preparation of APP form V was studied and APP form V was prepared by heating a mixture of ammonium orthophosphate and urea at 330 to 340°C under wet ammonia which was made by passing air through 15 to 29% aqueous ammonia. These APPs showed an oxygen index higher than 26 when they were added to synthetic organic polymers.
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SHIGERU SUGIYAMA, YOSHIHARU FUJII, HIROMU HAYASHI
2002 Volume 14 Pages
111-118
Published: 2002
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Oxidative coupling of methane to ethylene and ethane has been investigated on binary hydroxyapatite catalysts; calcium-lead hydroxyapatite (CaHAp-PbHAp) and barium-lead hydroxyapatite (BaHAp-PbHAp) at 973 K. Although BaHAp, CaHAp and PbHAp were inactive for the oxidative coupling of methane, those binary hydroxyapatites afforded C
2 compounds rather selectively. During the oxidation on CaHAp-PbHAp catalysts, those catalysts were mainly converted to Ca
5.5Pb
4.5(PO
4)
6(OH)
2 to afford great activities while an unfavorable conversion of CaHAp to Ca
3(PO
4)
2, which was inactive for the oxidation of alkanes, was rather suppressed. In contrast, BaHAp in the BaHAp-PbHAp catalysts was extensively converted to inactive Ba
3(PO
4)
2, resulted in the complete deactivation on BaHAp-PbHAp, particularly on PbHAp-rich catalysts.
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SOUHEI NAKAGAWA, FUMIHIRO KAJI, TOSHIHIRO YAMAGAMI, MAKOTO SAKURAI, MA ...
2002 Volume 14 Pages
119-122
Published: 2002
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The lead removal ability of two kinds of board-shape hydroxyapatites with different Ca/P molar ratio were evaluated. The samples reacted with Pb(NO
3)
2 in an aqueous solution produced a mixture of hydroxyapatite and hydroxypyromorphite. The results showed that Board-shape Ca-deficient type HAP(HAP-400) has Pb
2+ removal ability superior to Board-shape HAP with stoichiometric composition(HAP-300).
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KIMIHIKO YAGINUMA, MASASHI SEKI, JUN SHINODA, RYUTA FUJII, NORIYASU OK ...
2002 Volume 14 Pages
123-128
Published: 2002
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The activity of AlPO
4 for C
2H
4-SCR-NO was examined and discussed on the basis of its reaction pathway. The conversion of NO to N
2 in C
2H
4-SCR-NO over AlPO
4 was very low, because of its low NO oxidation ability to form NO
2. Therefore, C
2H
4-SCR-NO over several metal-loaded AlPO
4(M/AlPO
4) was also investigated to achieve higher activity.
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TOMOYA SAKAGUCHI, SHINGO MITA, EMIKO MATSUI, MOTOI TAKAHASHI, NORIYASU ...
2002 Volume 14 Pages
129-134
Published: 2002
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The oligomerization of ethene was investigated over several catalysts involving Ni/SiO
2·Al
2O
3(Ni/SA) and BPO
4. The oligomerization of ethene activity of SA or BPO
4 was very low, while that of Ni/SA was very high. Butene was predominantly observed over Ni/SA, while no product was observed over BPO
4. Combined use of Ni/SA and BPO
4 was more effective for promoting the ethene oligomerization than Ni/SA, especially for increasing C
6 fraction. 1-Butene as C
4 products in the ethene oligomerization was mainly obtained in the presence of Ni/SA alone, while an equilibrium mixture of n-butene was formed using Ni/SA and BPO
4 together, suggesting that the isomerization of n-butene formed from ethene occurs over BPO
4.
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