We analyzed thermal phase changes of substrates (20^o-1000^oC) of binary mixtures Li₂CO₃ - MgHPO₄•3H₂O prepared with a percentage molar ratio of 90%-10%. The research was done using differential thermal analysis (TG, DTG, DTA), IR-spectrophotometry and WAXS. The above-mentioned substances changed the structure when heated for 1 h up to 500^oC and 1000^oC. MgHPO₄•3H₂O (Newberyite) changes its structure at 500^oC into not completely formed Mg₂P₂O₇ and at 1000^oC) into Mg₂P₂O₇. Lithium carbonate (20^o - 1000^oC) does not change its structure. Binary mixtures change the structure depending on the molar ratio and at 1000^oC they form Li₃PO₄, LiMgPO₄, MgO and Mg₂P₂O₇. At the molar ratio of 90% Li₂CO₃ - 10% MgHPO₄•3H₂O they form a sinter with the porcelain of the melting pot.

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The objective of this work is to study the feasibility of two raw materials, calcite and dolomite, as adsorbent for phosphate removal from wastewater. The natural ores were characterized by using both chemical analysis and x-ray diffraction. The results indicate that the calcite sample having the chemical formula CaCO₃(99 %Ca) and the dolomite is CaAlFeCO₃ (30 %Ca). The effects of pH, contact time and phosphate concentrations on the efficiency of removing were studied. The results indicate that the optimum conditions are : pH = 12, time of contact = 15 min, and the adsorption capacity increased as the phosphate content in the initial solution increased due to the increase of diffusion of the phosphate species. The calcite samples have a higher efficiency than that for dolomite, this may attributed to the higher content of Ca²⁺ which acts the more active sites. The mechanism of removing was suggested according to the presence of cations derived from the adsorbent surface and anions loaded on the aqueous medium.

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The oxidative dehydrogenation of propane was investigated on vanadate catalysts supported on barium hydroxyapatite (VOx/BaHAp). The catalytic activities on VOx/BaHAp were compared to those on vanadate catalysts supported on calcium and strontium hydroxyapatites (VOx/CaHAp and VOx/SrHAp, respectively). The order of the activity was followed as VOx/SrHAp>VOx/CaHAp>VOx/BaHAp under the same reaction conditions. The results obtained from the reduction with H2 followed by the re-oxidation of those two supported catalysts reveal that a stronger interaction of vanadate with SrHAp than that with BaHAp affected the redox nature of vanadates on those two supports, resulted in the greater activity on VOx/SrHAp

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Plate-like hydrated cerium phosphate, Ce₂(PO₄)₂HPO₄•H₂O, has attracted attention because of its unique UV-shielding ability with excellent comfort when applied on the skin. Optimization of preparation conditions of hydrated cerium phosphate is required to obtain medium size plate-like particles of 5-50 μm in diameter which provide good comfort for human skin. Plate-like hydrated cerium phosphate, ca 20 μm in diameter, was obtained by the hydrothermal reaction of Ce(SO₄)₂ in H₃PO₄ aqueous solution at 200^oC for 3 h. The sample showed excellent comfort, absorption ability of light less than 450 nm of wavelength and lower oxidation catalytic activity than undoped ceria.

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15BaO-10PbO-5SrO-70P₂O₅ phosphate glass has been prepared by 2.45 GHz microwave heating by changing temperature of glass formation and their physical properties have been investigated by ³¹P MAS NMR, ¹H MAS NMR and AC conductivity. The four bands named as band-A, band-B, band-C and band-D were observed in ¹H MAS NMR spectra. The band-A and band-B originate in protons in the glass, whereas band-C and band-D originate in protons in adsorbed water on the surface of glass. From the result that AC conductivity increases with increase of the intensity of band-B and decreases with increase of the intensity of band-A, proton for band-B can be assigned to be mobile proton.

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Urea was added to the preparation of nickel - magnesium phosphate from nickel, magnesium nitrate and phosphoric acid solutions. The precipitations and their thermal products were estimated about the chemical composition, powder and acidic properties. The magnesium ratio in precipitations changed a little smaller by the addition of urea. Samples prepared with urea had larger weight loss than those prepared without urea. By the addition of urea, particle size became larger and narrow distribution. The adsorption of trimethylamine was affected from specific surface area and amount of acidic sites.

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Three main routes of synthesis; namely the reflux, the direct precipitation, and the sol-gel methods, are used to prepare α-zirconium phosphate α-Zr(HPO₄)₂.2H₂O or simply α-ZrP. Within each separate method of synthesis, different starting precursors and/or reaction conditions are tested for optimization to obtain the crystalline product. Different products were characterized using TGA-DTA data, SEM photos, N₂-gas absorption-desorption measurements, and FT-IR absorption spectra. The products showed different extents of crystallinitiy as roughly or qualitatively shown by their XRD patterns. The results are explained on the basis of each synthesis route and reaction conditions. In contrast to the familiar results that the initial un-refluxed product of rapid precipitation is basically amorphous ZrP, a careful washing strategy confirmed that this is a crystalline ZrP contaminated with a minority of solid H₃PO₄. This is shown by the XRD patterns of this product after intercalation with butylamine. For sol-gel experiments, reflux could not greatly improve the crystallinity of the products obtained from a mixture of Zr(OPr^iso)₄ and phosphoric acid solutions while a product obtained in presence of acetylacetone, as a complexing agent, presented some better tendency for crystallization with reflux. All products of refluxing Zr(OPr^iso)₄ with a 1:1 mixture of mono- and diethyl phosphates were amorphous. Chemical analysis shows a reasonable agreement between the experimental ratios of P/Zr and the calculated values. Compared to other methods of synthesis, the direct precipitation seems to be more efficient in obtaining a product of good yield and improved crystallinity.

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Effects of arginine (Arg) and Triton such as Triton-X (TX) and Triton-N (TN) on the solubility of monoalkyl phosphoric acid (MAP) such as dodecyl (DP), myristyl (MP), and cetyl phosphoric acid (CP) in an aqueous phase were studied. Although these MAPs are scarcely soluble in water, their solubility at 70 ^oC increased with a concentration of Triton added. The effect of TN was stronger than that of TX. DP became soluble at room temperature when Arg was added up to the mixing ratio of Arg/DP = 3 in mole. MP and CP were hardly soluble yet in the presence of Arg alone while these became soluble after adding Triton together with Arg. Their acidic head group was ionized by Arg, resulting in an increase in its affinity for water. DP was soluble just after the ionization while MP and CP were soluble after the ionization and concomitant formation of the mixed micelle with the Triton added. Methyl yellow, barely soluble in water, was solubilized after entrapment into the mixed micelle. Its solubility increased with a concentration and chain length of the MAP added as a solubilizing agent.

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The biogenic amines (dopamine, serotonin, noradrenaline, and adrenaline) were intercalated into layered zirconium phosphates (ZrP). The intercalation reaction into α-ZrP depended on pH of their aqueous solutions. On the other hand, for γ-ZrP the uptake of dopamine and serotonin increased with the increase of their concentration, where as that of noradrenaline and adrenaline depended on pH. Their intercalation compounds were microscopically investigated by solid-state NMR.

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Reaction of Ca-deficient hydroxyapatite, HAP-400, with heavy metals, Pb (II), Fe (III), Fe (II), Cu (II), Cd (II), Cr (II), Co (II), Ni (II), and Zn (II) was investigated at 25^oC for 4 h in water, compared with stoichiometric hydroxyapatite HAP-300. From heavy metal consumption and [Ca]/[Metal], which is defined by molar ratio of eluted Ca and consumed heavy metal, the reactions of HAP-400 with the heavy metals except for Pb (II) and Fe (III) proceed via metal-adsorptive substitution mechanism. In the reactions of HAP-400 with Pb (II) and Fe (III), the metals were completely consumed with equivalent elution of Ca, but these reactions proceeded by no simple substitution mechanism to afford Pb (II)- and Fe (III)-bearing HAP-400 with specific structures, namely HAP-400-Pb and HAP-400-Fe. By XRD and FT-IR microspectroscopy, it was found that HAP-400-Pb is constituted of both newly formed lead apatite crystal and the original apatite crystal, and that HAP-400-Fe is constituted of much amorphous FePO₄ phase around the original apatic phase. Therefore, it was concluded that the reactions of HAP-400 with Pb (II) and Fe (III) proceed by the following mechanism: erosion of the apatic structure and formation of a brand-new structure containing metal. This mechanism can be named apatite-erosive substitution mechanism.

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