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Samonosné pelety z (Al)-SBA-15
Topka, Pavel ; Zub, Yu.L. ; Šolcová, Olga
Self-supporting pellets were successfully formed from SBA-15 and Al-SBA-15 powder without the addition of binder or plasticizer. Prepared self-supporting pellets maintained the porous structure of original powder. In comparison with parent sample, a decrease of mesopore surface area and mesopore volume up to 40 % was noticed in the case of pellets formed with the highest 17.7 MPa pressure. The Al-SBA-15 pellets prepared using 4.7 MPa forming pressure were enough mechanically stable to retain the structural integrity during batch alkylation of toluene with benzyl alcohol at 110 °C. The conversion reached with Al-SBA-15 pellets after 60 min of the reaction was about five times lower than that accomplished with powder Al-SBA-15.
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Nanoporézní vrstvy TiO2 a jejich využití
Krejčíková, Simona ; Matějová, Lenka ; Cajthaml, Tomáš ; Matěj, Z. ; Strýhal, Z. ; Šolcová, Olga
Titania that is promising as catalytic agent for removing of organic impurities from waste water and air, photovoltaic cell and pigment, were studied. Doped Titania layers deposited on various substrates were prepared by sol-gel technique. Sol was prepared by using nonionic surfactants Triton X, organic solvent, water and metal precursors. Deposited gel layers were converted to anatase layers by calcination at 400°C for 4 hours or by subcritic H2O/ supercritic CO2 extraction/ subcritic CH3OH extraction (SWE/SFE/PFE). For deeper textural and structural characterization of prepared layers nitrogen physical adsorption, XRD, AFM and SEM analyses were performed.
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Měření vnitřní difuze pomocí kapalinové chromatografie
Soukup, Karel ; Schneider, Petr ; Šolcová, Olga
Liquid chromatography setup was used in liquid diffusion studies. The Kubin-Kucera model was employed for mathematical description of processes inside the chromatographic column. Effective diffusivities were evaluated by time-domain fitting chromatographic response peaks of columns packed with tested porous particles. Axial dispersion coefficients were determined independently by analysis of response peaks of columns packed with nonporous pellets; this improved significantly the confidence of effective diffusion coefficients. An attempt was made to exclude the end effects of chromatographic columns by analyzing response peaks of pairs of columns differing by lengths.
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Příprava TiO2 pro fotokatalytické aplikace
Matějová, Lenka ; Cajthaml, Tomáš ; Matěj, Z. ; Strýhal, Z. ; Benada, Oldřich ; Šolcová, Olga
Powder nanoporous TiO2 with narrow monodisperse pore-size distribution in the range from 2 to 30 nm were prepared by self-assemble micelle system in nonpolar and polar solvents at laboratory temperature and pressure. Nonionic surfactants Triton X-102, 100, 114, 45, 15 were used for preparation of micelle systems. Various approaches were applied for removing of residual organic matter from prepared titania gels: a) calcination, b) improved extraction by supercritical (CO2) and subcritical fluids (H2O, CH3OH) and c) the combination of both forenamed approaches.
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Podrobné materiálové charakteristiky z transportních procesů a texturní analýzy
Soukup, Karel ; Šolcová, Olga ; Schneider, Petr
The structure of porous solids is traditionally characterized by mercury porosimetry or physical adsorption of inert gases. The transport characteristics can be advantageously determined by evaluation of simple transport processes (e.g. multicomponent gas diffusion or permeation). Transport characteristics and textural properties of a set of porous catalyst pellets with wide range of mean pore radii (from 30 up to 3000 nm) were determined. by evaluated of multicomponent counter-current gas diffusion and permeation measurements. For gas diffusion the results from the Wicke-Kallenbach and Graham cell were compared.
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Transport Parameters and Textural Properties of Porous Solids
Soukup, Karel ; Šolcová, Olga ; Schneider, Petr
Based on a study of a set of porous materials with wide range of mean pore radii (from 50 to 3000 nm) and mono- or bidisperse pore structure, transport characteristics and textural properties are compared. Structure characteristics relevant to transport processes were evaluated from multicomponent gas diffusion and gas permeation measurements. For data analysis the Mean Transport Pore Model (MTPM) based on Maxwell - Stefan diffusion equation and Weber permeation law was used. Two standard methods - physical adsorption of nitrogen and mercury porosimetry (ASAP2010M and AutoPore 9200, Micromeritics, USA) were used for determination of textural properties. Results from liquid expulsion permporometry that correspond to situation in industrial processes were also taken into account.
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