Synthesis and Fluorescence Properties of Europium-Lanthanum-Calcium Orthophosphates and Condensed Phosphates

Hiroaki Onoda, Takehiro Funamoto

Department of Informatics and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan.

DOI: 10.4236/ampc.2012.24031                

Abstract

Mixtures of lanthanum oxide, europium oxide, calcium carbonate, and phosphoric acid were heated with various ratios of P/(Eu + La + Ca) and La/Ca. Europium ratio was settled at Eu/(Eu + La + Ca) = 0.03. The obtained phosphates were estimated using X-ray diffraction (XRD) patterns, Fourier transform infrared spectroscopy (FT-IR) spectra, and scanning electron micrograph (SEM) images. The fluorescence spectra and resistance against hydrofluoric acid were estimated as functional properties of these phosphate materials. The mixture of lanthanum and calcium phosphates were formed from XRD patterns and IR spectra. Samples prepared in P/(Eu + La + Ca) = 2 and 3 had large particles in SEM images. The condensed phosphates showed a strong peak at 615 nm and high resistance against hydrofluoric acid.

Keywords

Condensed Phosphate; Europium; Fluorescence; Resistance against Hydrofluoric Acid

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	M. T. Averbuch-Pouchat and A. Durif, “Topics in Phos- phate Chemistry,” World Scientific Publishing Co. Pte. Ltd., Singapore City, 1996.
[2]	I. Hammas, K. Horchani-Naifer and M. Ferid, “Conduc- tion Properties of Condensed Lanthanum Phosphates: La(PO3)3 and LaP5O14,” Journal of Rare Earths, Vol. 28, No. 3, 2010, pp. 321-328. doi:10.1016/S1002-0721(09)60106-X
[3]	S. Raynaud, E. Champion, D. Bernache-Assollant and P. Tho-mas, “Calcium Phosphate Apatites with Variable Ca/P Atomic Ratio I. Synthesis, Characterization and Thermal Stability of Powders,” Biomaterials, Vol. 23, No. 4, 2002, pp. 1065-1072. doi:10.1016/S0142-9612(01)00218-6
[4]	B. Boonchom, C. Danvirutai and S. Maensiri, “Soft Solu- tion Synthesis, Non-Isothermal Decomposition Kinetics and Cha-racterization of Manganese Dihydrogen Phos- phate Dihydrate Mn(H2PO4)2?2H2O and Its Thermal Trans- formation Products,” Materials Chemistry and Physics, Vol. 109, No. 2-3, 2008, pp. 404-410. doi:10.1016/j.matchemphys.2007.12.018
[5]	S. V. Rathan and G. Govindaraj, “Thermal and Electrical Re-laxation Studies in Li(4+x)TixNb1?xP3O12 (0.0 ≤ x ≤ 1.0) Phos-phate Glasses,” Solid State Sciences, Vol. 12, No. 5, 2010, pp. 730-735. doi:10.1016/j.solidstatesciences.2010.02.030
[6]	P. Shuetz and F. Caruso, “Electrostatically Assembled Fluo-rescent Thin Films of Rare-Earth-Doped Lanthanum Phosphate Nanoparticles,” Chemistry of Materials, Vol. 14, No. 11, 2002, pp. 4509-4516. doi:10.1021/cm0212257
[7]	F. Meiser, C. Cortez and F. Caruso, “Biofunctionalization of Fluorescent Rare-Earth-Doped Lanthanum Phosphate Colloidal Nanoparticles,” Angewandte Chemie, Vol. 43, No. 44, 2004, pp. 5954-5957. doi:10.1002/anie.200460856
[8]	H. Onoda, H. Nariai, A. Moriwaki, H. Maki and I. Mo- tooka, “Formation and Catalytic Characterization of Various Rare Earth Phosphates,” Journal of Materials Chemistry, Vol. 12, No. 6, 2002, pp. 1754-1760. doi:10.1039/b110121h
[9]	H. Onoda and T. Funamoto, “Synthesis and Fluorescence Properties of Europium-Substituted Lanthanum Ortho- phos-phate and Condensed Phosphates,” Advances in Ma- terials Physics and Chemistry, Vol. 2, No. 1, 2012, pp. 50-54. doi:10.4236/ampc.2012.21008
[10]	K. Rajesh, P. Shajesh, O. Seidei, P. Mukundan and K. G. K. Warrier, “A Facile Sol-Gel Strategy for the Synthesis of Rod-Shaped Nanocrystalline High-Surface-Area Lan- thanum Phosphate Powders and Nanocoatings,” Advan- ced Functional Materials, Vol. 17, No. 10, 2007, pp. 1682-1690. doi:10.1002/adfm.200600794
[11]	H. Onoda, K. Taniguchi and I. Tanaka, “Additional Ef- fects of Urea on Preparation and Acidic Properties of Lanthanum Or-thophosphate,” Microporous and Mesopor- ous Materials, Vol. 109, No. 1-3, 2008, pp. 193-198. doi:10.1016/j.micromeso.2007.04.043
[12]	H. Onoda, H. Matsui and I. Tanaka, “Improvement of Acid and Base Resistance of Nickel Phosphate Pigment by the Addition of Lanthanum Cation,” Materials Science and Engineering B, Vol. 141, No. 1-2, 2007, pp. 28-33. doi:10.1016/j.mseb.2007.05.009
[13]	M. Bettinelli, F. Piccinelli, A. Speghini, J. Ueda and S. Tanabe, “Excited State Dynamics and Energy Transfer Rates in Sr3Tb0.90Eu0.10(PO4)3,” Journal of Luminescence, Vol. 132, No. 1, 2012, pp. 27-29. doi:10.1016/j.jlumin.2011.07.018
[14]	A. Tor, “Removal of Fluoride from Water Using Anion- Ex-change Membrane under Donnan Dialysis Condition,” Journal of Hazardrous Materials, Vol. 141, No. 3, 2007, pp. 814-818. doi:10.1016/j.jhazmat.2006.07.043
[15]	C. M. Lew, Y. Liu, B. Day, G. M. Kloster, H. Tiznado, M. Sun, F. Zaera, J. Wang and Y. Yan, “Hydrofluoric-Acid- Resistant and Hydrophobic Pure-Silica-Zeolite MEL Low-Dielectric-Constant Films,” Langmuir, Vol. 25, No. 9, 2009, pp. 5039-5044. doi:10.1021/la803956w
[16]	D. E. C. Corbridge and E. J. Lowe, “The Infra-Red Spec- tra of Inorganic Phosphorus Compounds. Part II. Some Salts of Phosphorus Oxy-Acids,” Journal of the Chemical Society, Vol. 493, 1954, pp. 4555-4564. doi:10.1039/jr9540004555