SYNTHESIS OF α-ZIRCONIUM PHOSPHATE FROM ACETYL ACETONATE SOLUTION; A COMPARATIVE SYNTHESIS STUDY OF α-ZrP
| Autor: | Alaa E. Gad, Ashraf F. Ali, Adly A. Hanna |
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| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Phosphorus Research Bulletin. 22:32-40 |
| ISSN: | 1882-2363 0918-4783 |
| Popis: | 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(OPriso)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(OPriso)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. |
| Databáze: | OpenAIRE |
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