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  • Author or Editor: L. Szirtes x
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Abstract  

The ion exchange equilibrium was determined for Fe, Mn, Ni, Co, Sr, Rb, Ba, and Cs ions using tracer technique. Based on these data column operations were carried out. The barium—caesium and strontium—rubidium ions can be separated with good effiency.

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Abstract  

The changes in the ion exchange properties of crystalline zirconium phosphate, cerium phosphate and cerium arsenate after irradiation have been investigated. The absorbed gamma dose was 109 rad in all cases, the experiments were carried out before and immediately after irradiation with the same samples. Besides the investigations of structural change, the ion exchange behaviour of the above mentioned materials was studied in detail. The ion exchange capacities were determined using a tracer technique for the alkali metal ions, and some relations between ion exchange and structure were revealed.

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Abstract  

Zirconium phosphate-phosphite have various structure belonging to the drying heat of the sample. While sample dried above sat. NaCl solution had interlayer distance of 1.30 nm (result fromd 1=0.74 nm andd 2=0.56 nm for phosphite layer), the sample dried under IR lamp on air having interlayer spacingd=0.74 nm charactderistic for -Zr(HPO4)2·H2O containing little amount of phosphite groups. The composition of the first sample can be characterized by chemical formula, as Zr(HPO4)0.7(HPO3)1.3· ·0.5H2O. The X-ray powder diffraction data ofn-butylamine intercalate suggest that in the process take place only the phosphate region of zirconium phosphate-phosphite (ZrPP).

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Abstract  

The -crystalline form zirconium phosphate was investigated. For its lattice parameters was found:a=0.538 nm,b=0.664 nm,c=2.459 nm, =94.2° and basal spacing (d)=1.22 nm. It was determined by IR spectrophotometric method that the phosphate is present in groups of H2PO 4 and PO 4 3– of equal quantity. Two moles of crystalline water per formula unit were found where the moles are bound differently. The compound can be characterized by the following chemical formula: Zr(HPO4)(PO4)·2H2O.

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Abstract  

FT-IR studies were carried out for various α- and γ-crystalline intercalates of zirconium phosphate (ZrP) and also for zirconium phosphatephosphite (ZrPP). The characteristic peaks of n-alkanols, n-alkylamines, benzylalcohol and benzylamine, diethyleneglycol and also some amino acid intercalates/derivatives were determined. Based on the data assumptions are made about the type of bonding between the layers and also the variety of intercalates of various crystalline form zirconium phosphates was determined.

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Abstract  

Silica-containing -zirconium phosphate (-ZrSiP) was prepared by the precipitation method. X-ray diffractometry was used to characterize -ZrSiP and to compare it with other -zirconium phosphates (ZrP). A monoclinic cell with parameters of a=0.9038 nm, b=0.529 nm, c=1.4183 nm and =91.76° was identified for -ZrSiP, i.e. silica modifies the original -ZrP structure. The specific surface area of -ZrSiP was found to be two orders of magnitude higher then that of -ZrP.

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Abstract  

Layered organic derivatives of crystalline zirconium phosphate were synthesized and investigated for their intercalation behaviours. Derivatized zirconium phosphates having hydroxy groups take up different polar molecules such as alcohols, amines etc. by increasing the interlayer distance determined by X-ray diffraction method. The intercalation processes on these materials can be considered as heterogenous phase acid-base reactions.

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Abstract  

A precipitation method was used to prepare amorphous mixed zirconium-titanium phosphates with various titanium contents. In this way the acidic solutions of ZrOCl2.8H2O and TiCl4 in various ratios were rapidly mixed with a phosphoric acid solution under continuous stirring. The resulting precipitate, characterized as [ZrxTi/1–x//HPO4/2.n H2O] was contacted with water of ethanol, then washed to pH 3.0 and dried at room temperature. The samples were irradiated with -rays of a60Co source giving a 6.6×107 Gy total dose. The thermal, chemical and ion-exchange properties of irradiated samples were investigated.

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Abstract  

The intercalation process ofn-butylamine was investigated. The adsorption ofn-butylamine in interlamellar space had stepwise character in case of both crystalline forms of zirconium phosphate. The intercalatedn-butylamine existed at low concentration as bilayered complex. The reaction heat was determined by a microcalorimetric method. It was found that about 90% of it refers to the neutralization ofn-butylamine and only about 10% is related with surface adsorption (ion exchange). The steps of adsorption are 6.0 J/g and 1.0 J/g reaction heat values, respectively. The enthalpy balance of total process in dilute solution system (c 0=3.0 vol%) is 14.67 kJ/mol. The calculated value for ion adsorption (exchange) was 1.37 kJ/mol.

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