2002

 

Kalendová, A.; Tamchynová, P.; Štengl, V.; Šubrt, J., Behaviour of surface-treated mica and other pigments with lamellar particles in anticorrosive coatings. Macromolecular Symposia 2002, 187, 367-376.

 

 

 

 

 

 

 

Šubrt, J.; Boháček, J.; Štengl, V.; Grygar, T.; Bezdička, P., Uniform particles with a large surface area formed by hydrolysis of Fe-2(SO4)(3) with urea. Materials Research Bulletin 1999, 34 (6), 905-914.
Abstract: Synthesis of poorly crystalline iron(III) hydrous oxides and basic salts (ferrihydrite, schwertmannite, and jarosite) consisting of uniform spherical particles of characteristic shape with a diameter of 10 μm is described. The preparation procedure is based on homogeneous precipitation of aqueous solutions of Fe2(SO4)3 with urea in the temperature range 60–100°C. Thermal dehydration of iron(III) hydroxide leads to an amorphous ferric oxide with a high surface area (200 m2/g) that is stable up to about 500°C. Link

 

 

 

Mitsuhashi, T.; Watanabe, A.; Balek, V.; Klosova, E.; Malek, J.; Šubrt, J.; Štengl, V., In-situ monitoring of microstructure changes during the heating of amorphous ruthenia by means of Emanation Thermal Analysis. Materials Letters 1999, 39 (1), 46-50.

Abstract: Results of Emanation Thermal Analysis (ETA), Thermogravimetry (TG) and Differential Thermal Analysis (DTA) of hydrous ruthenia measured during heating in argon from 20 to 1000°C are presented. The ETA results were interpreted using comparison with the results of TG, DTA, X-ray diffraction, transmission electron microscopy and surface area measurement. An agreement of the results was found. The ETA made it possible to monitor microstructure changes under in situ conditions of heat treatment of the samples. Link

 

 

 

 

Šubrt, J.; Štengl, V., Preparation of Acicular Alpha-Fe2O3 (Hematite). Journal of Materials Science Letters 1993, 12 (11), 836-838. Link

 

 

 

 

 

 

 

Šubrt, J.; Štengl, V.; Skokánek, M., Decomposition of Ferrihydrite Prepared From Fe(NO3)3 Aqueous-Solutions Under Varying pH. Thermochimica Acta 1992, 211, 107-119.

Abstract: Aqueous solutions of Fe(NO3)3 were subjected to precipitation at 20°C and pH in the range 2.9–8.14, at constant pH and temperature. The precipitates contained CO2−3 and NO−3 anions bound in the sample structure. It was found that the TG, DTA, DTG and evolved gas analysis (EGA) curves depend significantly on the pH of preparation of the ferrihydrite.Link

 

 

 

 

 

Drátovský, M.; Novák, C.; Petříček, V.; Štengl, V., The structure of the compounds Na24As2Z22O83 and its relationship to the structure of Na2Ma2O7, Na2W2O7. Collection of Czechoslovak Chemical Communications 1989, 54 (3), 645-652.


Abstract: X-ray study of the structure of the compounds Na24As2Z22O83 (Z = Mo, W) indicated that these compounds and the compounds Na2Z2O7 are all isomorphic. They crystallize in the orthorhombic system with a space group of Cmca. The compound Na24As2Z22O83 is formed by replacing part of the Mo atoms by As in the centres of the oxygen tetrahedra in the structure of Na2Mo2O7. This substitution As ##c Mo results in loss of one oxygen atom for every two arsenic atoms in the Na2Mo2O7 structure so that two AsO4 tetrahedra are joined through an oxygen apex to form a As-O-As bond. The exact atomic ratio As:Mo = 1:11 in the studied compounds was also sufficiently confirmed by study of the phase diagrams NaAsO3-Na2Z2O7. Link

Vyhledávání

Kontakt

Mgr.Václav Štengl, Ph.D., DSc. Ústav anorganické chemie AV ČR v.v.i.
250 68 Husinec-Řež 266 172 202