|
|
Catalytic synthesis of polyanilines
Bláha, Michal ; Vohlídal, Jiří (advisor) ; Omastová, Mária (referee) ; Trchová, Miroslava (referee)
This Ph.D. thesis is dealing with catalytic polymerization of aniline (ANI) and partially also of substituted anilines with FeCl3/H2O2 catalyst system, in which according to obtained results both active species, Fe3+ and HO , participate in the overall polymerization mechanism, creating a synergic system. The Fe3+ /H2O2 catalyst system, also called Fenton's system can considerably lower contamination of forming neat polyanilines (PANIs) by side-products characteristic of stoichiometric polymerization. However, catalytically prepared PANIs exhibit reduced conductivity related most probably to side reactions involving radicals generated as integral components of the FeCl3/H2O2 system. Catalytic polymerization of ANI with FeCl3/H2O2 system was found to be the reaction of approx. 2nd order with respect to ANI and gives PANIs of a good quality only when [H2O2] in the reaction mixture was kept low, i.e., at under- stoichiometric ratios [H2O2]/[ANI]. At over-stoichiometric ratio [H2O2]/[ANI], PANIs of lowered conductivity, worse spectroscopic characteristics and increased size of PANI nanostructures were obtained; nevertheless, these PANIs were not over-oxidized to pernigraniline state. The reaction-time profiles of the open-circuit potential of reaction mixtures exhibited an inflection related to the...
|
|
|
Structure Analysis of Plant Bifunctional Nuclease TBN1
Kovaľ, Tomáš ; Dohnálek, Jan (advisor) ; Brynda, Jiří (referee) ; Schneider, Bohdan (referee)
This work is dedicated to thorough structural analysis of plant bifunctional nuclease TBN1, the representative of plant nuclease I group. TBN1 along with homologous nucleases from this family plays an important role in plant cell life cycle and also shows considerable anticancerogenic effects. Two variants of TBN1 (wild type and N211D mutant) were studied. Properties of both variants in different solutions were analyzed. Both were successfully crystallized. Structures of both types of TBN1 were solved using X-ray diffraction. The phase problem was solved by Multi-wavelength anomalous dispersion using Zn2+ ions natively present in TBN1. Structural properties of TBN1 such as fold, active site composition, effect of glycosylation and surface electrostatic potential distribution were analyzed. Reaction mechanism of TBN1 was proposed on the basis of structural properties and comparisons with similar structures.
|
|
|
Theoretical Investigation of Friedlander Reaction catalyzed by CuBTC
Položij, Miroslav ; Nachtigall, Petr (advisor) ; Čejka, Jiří (referee)
The mechanism of Friedlander reaction was investigated theoretically. The main objective was to find a reaction path of Friedlander reaction catalyzed by Cu3(BTC)2 (BTC = benzene-1,3,5-tricarboxylic acid), a microporous metal organic framework. In addition, possible mechanisms of non-catalyzed and acid-catalyzed reaction were investigated in the gas phase and in the solution. The suitability of Cu3(BTC)2 as catalyst for Friedlander reaction is discussed based on the computational results obtained.
|
|
|
Computational modelling of a laboratory burner using FLUENT code
Broukal, Jakub ; Vondál, Jiří (referee) ; Hájek, Jiří (advisor)
Tato diplomová práce je zaměřena na porovnání různých turbulentních a chemických modelů na příkladu volné metanové trysky ústící do vzduchu. Nejprve je uveden teoretický úvod k modelům, následován CFD (Ansys Fluent) simulacemi plamene pomocí vybraných modelů. Jako součást práce je provedeno a vyhodnoceno experimentální měření. V závěru jsou experimentální výsledky porovnány s nasimulovanými daty.
|
|
| |
|
| |
guest ::
