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Organic materials for photonic applications
Kubíček, Václav ; Heinrichová, Patricie (referee) ; Weiter, Martin (advisor)
The bachelor's thesis focuses on characterisation of optical properties of substituated diphenyl-distyrylbenzenes for their potancial aplication in organic photonics. Dependance of molecular structure, used solvent and form on optical properties was studied. The theoretical part consists of research about current situation in organic photonics, it focuses mainly on organic photovoltaics. Results show that optical properties fundamentally depend on electronacceptor power of substituated group. Optical properties are also influenced by used solvent.
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Business Plan
Letochová, Kamila ; Ing.Vít Kubíček (referee) ; Sládková, Jitka (advisor)
This bachelor works describes a business plan designed for launching an e-shop with clothes and accessories. The work contains information about the launching and also the analyses of a current situation in the branch and analyses of customers and competitors.
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Characterization of blowing films from softened polylactide
Kubíček, Václav ; Tocháček, Jiří (referee) ; Bálková, Radka (advisor)
The master's thesis focuses on preparation of blown films from polylactid acid (PLA) which was blended with selected polyesteres – poly(butylene adipate-co-terephtalate) (PBAT), polycaprolactone (PCL) and polybutylene succinate (PBS) – and thermoplastic starch (TPS) in amount of 30% in order to soften PLA films. The influence of the aditives on static and mechanical tensile properties, on structure, morphology and thermal properties of the films was determined and the obtained parameters were compared to properties of films prepared from neat PLA and high density polyethylene (HDPE). The results showed that the additives increased crystalinity of PLA and thus significantly influenced the properties of the films. In contrast to the film from neat PLA, softening in terms of lowering glass transition temperature occured only by adding PBS and TPS, in terms of increasing ductility only by adding PBAT. All PLA films showed nearly constant elastic modulus up to the beginning of glass transition enabling their potential application till 50 °C. Preparation of the film with TPS was problematic and the film showed the worst mechanical properties. Preparation of other films was without any problems. The most promising additive from the tested ones was PBAT which showed comparable mechanical properties as the film from HDPE.
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Ditopic ligand based on 1,4,7-triazacyclononane
Kačmarčík, Jaroslav ; Kubíček, Vojtěch (advisor) ; Kotek, Jan (referee)
The radioisotopes 64 Cu and 68 Ga are used in radiomedicine and imaging (PET) due to their properties. The metal ion must be complexed with a suitable ligand forming a stable and kinetically inert complex. The aim of this bachelor thesis was to synthesize polydentate ligand based on the TACN macrocycle, followed by the preparation of its gallium (III) and copper (II) complexes. Based on the dependence of absorbance A on the wavelength λ, d-d transitions in the VIS (λ = 440 - 800 nm) region and CT transitions with transitions on the aromatic cycle in the UV region (λ = 220 - 380 nm) for the [Cu(L)] were also observed. The [Cu(L)] complex was studied by UV-VIS titration. The complex [Ga(L)] was also synthesized, but its further characterization and study of coordination properties were not carried out. Key words: macrocyclic ligands, complexes, stability, radiomedicine, PET
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Nanofiber membranes generating singlet oxygen with magnetic separation
Liška, Vojtěch ; Mosinger, Jiří (advisor) ; Kubíček, Vojtěch (referee)
This thesis focuses on the preparation and study of a new type of photoactive polyurethane nanofiber membrane with encapsulated 5,10,15,20-meso-tetraphenylporphyrin (TPP) photosensitizer and maghemite nanoparticles. The membrane was prepared by electrospinning and shows effective photogeneration of O2 (1 Δg) and photoantibacterial effect on the surface. The membrane can be easily separated by a magnetic field. The magnetic behaviour of the maghemite nanoparticles was studied using Mössbauer spectroscopy. Their size was estimated by DLS. The final nanofiber membrane was characterized by UV-VIS, emission spectroscopy, and by electronic microscopy (SEM). The kinetics of O2 (1 Δg) generation was studied by time-resolved spectroscopy and the relative efficiency of photooxidation was studied using external acceptor of O2 (1 Δg). Significant photoantibacterial properties against bacteria strain Escherichia coli were detected on the surface of the membrane functionalized with TPP photosensitizer.
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Zirconium ternary complexes with fluoride anions
Zach, Kamil - Lukáš ; Kubíček, Vojtěch (advisor) ; Schulz, Jiří (referee)
Modern medicine uses non-invasive imaging methods for diagnostic purposes. Positron emission tomography is one of them. During the examination, the patient is injected with a radiopharmaceutical that is accumulated in tissue abnormalities and emits detectable radiation during its nuclear decay. The world's most commonly used radionuclide for these purposes is the radioisotope 18 F. The biodistribution of the fluoride ion itself is not very specific, so the radioisotope is usually bound to the structure of bioactive molecules. The actual preparation of these molecules is very challenging, so new labeling methods are currently being sought. One of the new possibilities is the preparation of labeled ternary complexes. In this work, the preparation of two polyazamacrocyclic ligands, H3NOTA and H3PCTA, which have acetate arms attached to their skeleton via aliphatic nitrogen atoms, is described. Zirconium complexes were prepared with these ligands. Subsequently, coordination and dissociation studies of fluoride ions to the prepared complexes were carried out. The measurements were monitored with a fluoride ion selective electrode. Both kinetic and thermodynamic aspects of coordination and decoordination were investigated in the measurements. Furthermore, characterization of the prepared ternary...
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Electrochemically Investigated pH-dependent Redox Properties of Copper Complexes of Azamacrocyclic Ligands
Koláčná, Lucie ; Maďar, M. ; Kubíček, V. ; Ludvík, Jiří
Investigated Cu(II) complexes are based on plain or cross-bridged cyclam. The\nelectrochemically inactive cyclam was modified by carboxylate, phosphonate, or phenolate\npendant arms. Cu(II) represents the main redox center of the complexes. Modification of the\nligand causes a changed pattern of complex redox response in buffered aqueous solution.\nIrreversible Cu(II) reduction results in complex decomposition to amalgamated copper and\nligand in excess. After Cu(0) electrochemical in situ re-oxidation, copper and ligand are recomplexed.\nComplexes undergo isomerization, accelerated by increasing the temperature. The\ninfluence of pH on complex isomerization and the reversibility of its reduction was described.
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HPLC of Bioactive Compounds
Lukšanová, Aneta ; Kubíček, Vladimír (advisor) ; Lázníčková, Alice (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Biophysics and Physical Chemistry Consultant: Ing. Vladimír Kubíček, CSc. Student: Aneta Lukšanová Title of thesis: HPLC of bioactive compounds This diploma thesis is focused on finding conditions of HPLC analysis of midazolam and it's two metabolites - 1-hydroxymidazolam and 4-hydroxymidazolam, on method validation and on finding an appropriate internal standard. The analysis was carried out under reversed-phase conditions, the chosen column was POROSHELL 120 EC-C18, 3.0 X 100 NM, 2.7 µm, and a mixture of acetonitrile and ammonium acetate buffer with pH 4.5 in a ratio of 35/65 has been proven to be effective mobile phase. Detection was carried out using the diode array detector with wavelength values 223 nm and 272 nm. The column was thermostated at 25 řC, the analysis time was 10 minutes. Flow rate of mobile phase was 0.700 ml/min. Diazepam was found as a suitable internal standard. The method was validated only for 1-hydroxymidazolam and 4-hydroxymidazolam determination in rat plasma due to a submitter's request. Within the analytic method validation the following parameters were tested: precision, accuracy, lower limit of quantitation, linearity and selectivity.
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Synthesis of chelators for use in diagnostic imaging
Kretschmer, Jan ; Polášek, Miloslav (advisor) ; Kubíček, Vojtěch (referee) ; Hrubý, Martin (referee)
Metals play a crucial role in medicine as a part of therapeutic or diagnostic preparations. However, in the majority of cases, their properties cannot be utilized entirely in free ionic form. Organic molecules capable of chelation are used to open the full potential of the metal. The molecules are called chelators and are the core theme of this thesis. The most important function of these molecules is the chelation and coordination of the metal, but chelators can provide other important functionalities. This work, therefore, focuses on the design, synthesis, and application of such polyfunctional chelators and is divided into two parts: DO3A-Hyp This part of the thesis deals with chelators that can be used as amino acids to incorporate lanthanides into peptides. The developed chelators provide a short and rigid connection of the metal to the peptide chain. Tripeptides containing two units of such chelators with a central amino acid bearing a CF3 group were synthesized to demonstrate the capability of DO3A-Hyp building blocks. Two paramagnetic metals were combined within this tripeptide, and it was shown that such a rigid and locked system could be used for combining their magnetic susceptibility tensors. These magnetic susceptibility tensors were used for manipulation of the 19 F NMR shift of the CF3...
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Trivalent and tetravalent metal complexes for radiodiagnostics
Hacaperková, Eliška ; Kubíček, Vojtěch (advisor) ; Drahoš, Bohuslav (referee) ; Polášek, Miloslav (referee)
Fluorine-18 is the most utilized nucleus for positron emission tomography (PET). In 2009, incorporation of fluorine-18 to the coordination sphere of Al(III) was introduced as a new alternative for commonly employed compounds with F-C bond. Such a radiotracer consists of two parts: a metal complex with a fluoride and a peptide or a small/part of biomolecule. Shortly after that, first clinical studies showed a promising potential of such com- pounds for clinical use. Despite a great number of papers dealing with this issue, the research is mostly application-driven and focused on the peptide part of the molecule responsible for specific accumulation within the organism. Studies oriented on a sta- bility of metal-ligand-fluorine ternary system are rather rare and only very little is known about such a three-component system from a chemical point of view in gen- eral. However, stability of F-Al bond strongly dependents on the chemical structure of other ligands in the coordination sphere. Pendant arms of a hexadentate ligand (usually used for Al(III) complexation, e.g., H3NOTA) can compete with fluoride and cause its release which leads to unspecific radioactivity accumulation. Lower ligand denticity should increase the F-Al bond stability, but can decrease the stability of the whole complex at the...
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