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  • Author or Editor: A. Sopková x
  • Chemistry and Chemical Engineering x
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Abstract  

The synthetic pyrethroide insecticide (R, S)-α-cyano-3-phenoxybenzyl-IR, S-cis,trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanocarboxylate in solid form could be enclosed in and therefore stabilized by natural clinoptilolitic zeolite. The resulting host-guest complex exhibited characteristics different from those of the starting compounds and also their physical mixtures. The product was more stabile against the tested solvents (distilled water and acetone) and also against thermal decomposition, which suggests its possible use as a slowly-releasing insecticide.

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Abstract  

Tetracyanocomplex clathrates and their changes caused by heating were studied. The intermediates formed were characterized by IR and UV-VIS spectroscopy. Elemental analysis and XRD patterns were also used. For the visualisation of changes occurring on the surface and the distribution of metallic elements therein were studied by electron microscopy and EDX. The extent of the non-stoichiometric changes introduced by the topochemical course of the degradation reactions was correlated with the measured electrical values.

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Abstract  

TG, DTG and DTA measurements were used to study the thermal properties of the synthetic zeolite ZSM5, its silver form (Ag-ZSM5) and a zeolitic product containing silver iodide (K-ZSM5/AgI). Thermoanalytical measurements were supplemented by morphology studies.

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Abstract  

An iodine containing natural zeolitic material of the clinoptilolite type heated to different temperatures was investigated by means of X-ray photoelectron spectroscopy and thermal analysis methods. At room temperature the iodine was found to be present, depending on the preparation conditions, in the form of iodide or iodide combined with elementary iodine. After heating to 200°C, only iodide was observed which persists in the product in a small amount also after heating to 900°C.

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