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Standardní adsorpční isotermy argonu a dusíku pro Al2O3, TiO2, MgO a CPG
Matějová, Lenka ; Schneider, Petr ; Šnajdaufová, Hana ; Šolcová, Olga
The standard (master) isotherms describe relation between thickness, t, of adsorbed film and relative pressure, x (x = p/po is the adsorptive pressure, p, relative to adsorptive vapor pressure po, at measurement temperature,).They appear during the assessment of the core size, rk(x) (as determined by the Kelvin equation) in a pore just filled/emptied by/from capillary condensate, r(x) (r(x) = rk(x) +t(x)) and during the evaluation of adsorbed amount in pores free of capillary condensate. Such isotherms were experimentally determined for Ar and N2 on Al2O3, TiO2, MgO and Controlled Porous Glass.
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Nízkoteplotní příprava příprava tenkých vrstev TiO2
Bartková, H. ; Klusoň, P. ; Šolcová, Olga ; Cajthaml, Tomáš
This work was based on a rational design of a titania particle form and its function through the use of template-assisted sol-gel generation at temperatures compatible with plastic supporting substrates. Specifically reverse micelles of nonionic surfactants were used as templates to impose the nanometer scale order. The process yielded relatively high surface area particles that were uniform in size and shape.
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Distribuce porů z permporometrických měření
Šolcová, Olga ; Schneider, Petr
Two measurement modes for obtaining wet-curves were suggested and verified. In the figure the obtained wet and dry curves for two catalysts are shown. It was verified that LEPP gives consistent pore size distribution of flow-through pores and, thus, should be tried as the standard texture characteristic suitable for prediction and/or simulation of gas flow in porous media
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Propustnost podél hranic zrn v dobře definovaných polykrystalických vrstvách silikalitu-1 a v samostatných krystalech
Brabec, Libor ; Zikánová, Arlette ; Kočiřík, Milan
Self-supporting silicalite-1 layers were grown on mercury surface from clear solutions at temperatures 140-180 oC. Large silicalite-1 crystals were synthesized using TPABr as template. Layer morphology and thickness were characterized by SEM. Phase purity of silicalite-1 and orientation of crystals were determined by XRD. Layers with the thickness > 40 .mu.m were found to be highly compact. Wet HF etching of as-synthesized polycrystalline silicalite-1 layers caused formation of deep sharp slits at grain boundaries and thus it visualized them. Contrary to this result etching of calcined layers led to a kind of a negative image represented by preserved thin shells at crystal boundaries which were found to be impregnated by carbon residues formed during template removal. Results of etching experiments give a strong indication of the existence of a thin amorphous silica interface between neighbouring crystals. The etching patterns were somewhat different for large silicalite-1 crystals.
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