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Modification of Organic High Performance Pigments for Applications in Organic Electronics
Cigánek, Martin ; Imramovský, Aleš (oponent) ; Vyňuchal, Jan (oponent) ; Krajčovič, Jozef (vedoucí práce)
The doctoral thesis deals with the study, synthesis and chemical derivatization of molecules belonging to the group of organic high-performance pigments and their potential application in the fields of organic electronics. The theoretical part of the work is focused on the latest trends in the area mentioned above, both from the application potential of specific derivatives and in terms of synthetic possibilities and their structural derivatization. The experimental part describes in detail the preparation of a wide range of intermediates and final products, including derivatives of diketopyrrolopyrroles (DPP), benzodifuranone (BDF), epindolidione (EP), naphthyridinedione (NTD) and thiophene-based polymer (PT). A total of 103 molecules were synthesized, of which 49 were final products, and 27 of them were completely novel, as yet unpublished. Herein, the main motive for the derivatization of pigment molecules is the incorporation of bulky adamantyl substituents into the resulting derivative structures. In the next part of the work, individual chemical modifications leading to the final products are discussed in more detail. In the series of N,N'-; N,O'- and O,O'-substituted DPP derivatives, the influence of both the alkyl chains’ character and binding position in the DPP molecule on the selectivity of the reaction, the thermal and optical properties of the resulting derivatives is comprehensively described.
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Synthesis and Study of Nano-Structured Perovskites for Applications in Organic Electronics
Jančík Procházková, Anna ; Kuřitka, Ivo (oponent) ; Částková, Klára (oponent) ; Krajčovič, Jozef (vedoucí práce)
Diversity and unique properties, such as exceptionally high photoluminescence quantum yields (PLQYs), predetermine metal halide perovskite nanoparticles (PNP) to be applied in optoelectronic and photonic devices. In this work, nature-inspired capping agents were employed not only for the PNP stabilization but also for modifying their surface to broaden the functionality of the resulting material. In the very beginning, a ligand-assisted precipitation technique was optimized for the preparation of the PNP. Here, adamantane-1-amine (AdNH2) alongside hexanoic acid (HeA) were chosen as capping agents for nanoparticles stabilization and passivation. It was demonstrated that the choice of the solvent system and the precipitation temperature have a crucial effect on the resulting optical properties of the colloidal solutions. Simultaneously, the influence of concentration of precursor chemicals on the resulting morphology and optical properties was investigated. Also, different carboxylic acids were tested as capping agents among AdNH2 and the colloidal stability of the resulting colloidal solutions was evaluated. To demonstrate the diversity of the ligand-assisted precipitation technique of PNP preparation, L-lysine and L-arginine were employed initially for the surface passivation. As a result, colloidal solutions with emission within a narrow bandwidth of the visible spectrum and remarkable photoluminescence quantum yield (PLQY) close to 100% were obtained. Blocking -amino group of L-lysine by tert-butoxycarbonyl group suggested preferential binding of the side chain of L-lysine to the perovskite core. Furthermore, defined amounts of water were added into the precursor solutions which caused shifts of emission spectra due to quantum confinement effects. Water molecules were assumed to form highly mobile species leading to the enhancement of controlling the perovskite lattice growth. Merging perovskite nanomaterials with peptides are expected to pave a way to the new class of materials possessing exceptional optoelectronic properties alongside self-assembly and sensing abilities. As a proof-of-concept, a cyclic(RGDFK) pentapeptide was used for PNP stabilization. However, peptides are known for their sensitivity to their environment. Therefore, peptide nucleic acid (PNA) was used for PNP stabilization as a robust artificial analogue for deoxyribonucleic acid (DNA). Here, optical properties of thymine-based PNA monomer and trimer stabilized PNP were studied. Additionally, the sensing ability of the PNA ligand for adenine moiety was demonstrated by photoluminescence quenching via charge transfer. We envision that combining the unique tailored structure of PNA and the prospective optical features of PNP could expand the applications especially in the field of optical sensing devices.
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Synthesis and Characterization of New Organic Materials for Organic Electronics
Richtár, Jan ; Vícha,, Robert (oponent) ; Weidlich,, Tomáš (oponent) ; Krajčovič, Jozef (vedoucí práce)
In the modern era, organic electronics and bioelectronics go through tremendous development efforts to obtain novel organic materials with features usually unattainable by conventional silicon-based electronics. This thesis concerns the synthesis and characterization of novel organic materials for organic electronics. It deals with the synthesis of novel pentafluorosulfanylated heterocyclic building blocks, alkylated high-performance organic pigments, and bioinspired organic -conjugated materials with tunable physico-chemical properties and rational synthetic approaches towards their preparation. Pentafluorosulfanyl group (SF5) is appreciated for the high electronegativity, lipophilicity, thermal and chemical stability. It influences positively optical and electronic properties, solubility, and stability to a degree often superior to more established CF3-analogues. Two types of derivatives of 3-SF5-substituted pyrrolidines were synthesized by six and four-step synthetic approaches serving as potential versatile building blocks for the incorporation into advanced aromatic and heteroaromatic -conjugated systems via nitrogen atoms as the fluorinated terminal groups. A model derivative was introduced as a terminal group in an electron-deficient heteroaromatic system by nucleophilic substitution. Hydrogen-bonded high-performance organic pigments attract a lot of attention due to their impressive semiconducting properties, strong 2D molecular association, high thermal, chemical and photochemical stability, and non-toxicity. Nevertheless, they suffer from limited solubility and processability which is commonly solved by the introduction of solubilizing groups. Moreover, particularly bulky rigid adamantyl-bearing groups are known to improve molecular packing, thermal stability, and resulting properties due to the self-organizing ability of adamantane. The adamantylmethyl and adamantylethyl groups were incorporated into selected hydrogen-bonded dyes and pigments from groups of carbonyl azaacenes, rylene-diimides and indigoids by means of nucleophilic substitution aiming towards increasing solubility and processability while preserving the thermal stability and favorable solid-state molecular packing. Physico-chemical studies of quinacridone and epindolidione series showed thermal stability comparable or higher than for H-bonded derivatives, good solubility in organic solvents, strong fluorescence in solid state and solution in VIS region and distinct molecular packing in single crystals as was observed from X-ray analysis. Flavins are ubiquitous bio-inspired organic material with indispensable biological functions, promising physico-chemical properties, chemical and application versatility. Consequently, the focus was put on the tuning of the optical, electronic, electrochemical, thermal and other properties by the extension of the -conjugated system of said materials. Initially, two complementary synthetic approaches were envisaged in order to provide NH-free flavin series which was to undergo comprehensive physico-chemical studies. Afterwards, two different approaches were proposed to synthesize N,N’-dialkylated flavins incorporating butyl, adamantylethyl and triethyleneglycol-derived substituents. The alkylation enhanced solubility in organic solvents and aqueous media, increased fluorescence in solid state and solutions, and tuned the thermal properties depending on the alkyl substitution.
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Nature-inspired macro cyclic systems for bioorganic applications
Prekopová, Terézia ; Cigánek, Martin (oponent) ; Krajčovič, Jozef (vedoucí práce)
The bachelor thesis deals with nature-inspired macrocyclic compounds and their possible use in organic bioelectronics. The theoretical part of this bachelor thesis introduces semiconductor materials in organic bioelectronics and provides a general overview of selected classes of macrocyclic compounds currently occurring. It includes their history, properties, reactivity and use in various industries. An important point of this part are cyclodextrins, which are characterized by their high biocompatibility and affinity for a wide range of guests depending on the structure of the cyclodextrin. They are capable of molecular recognition to form inclusion complexes with guest particles. The work also deals with chemical modifications of cyclodextrins in order to improve selected physicochemical properties and practical applications of cyclodextrins. The experimental part consists of the synthesis, purification and characterization of key macrocyclic -cyclodextrin derivatives selectively modified at position 6 of one glucopyranose unit for the synthesis and study of advanced supramolecular structures for potential applications in organic bioelectronics.
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Synoviální hemoragie kolenních kloubů jako vitální známka prochlazení
Zátopková, Lenka ; Hejna, Petr (vedoucí práce) ; Sokol, Miloš (oponent) ; Krajčovič, Jozef (oponent)
Synoviální hemoragie kolenních kloubů jako vitální známka prochlazení Chlad představuje pro zdraví člověka podceňované riziko, protože schopnosti lidského organismu odolávat bez adekvátního oděvu nízkým teplotám zevního prostředí jsou značně limitované. Hypotermii odborná literatura definuje jako nefyziologický stav, při kterém teplota tělesného jádra klesá pod 35 řC, těžká hypotermie nastává při teplotě tělesného jádra 27 řC. Smrt prochlazením nastupuje při poklesu teploty tělesného jádra pod 25 řC. K nejrizikovějším skupinám z pohledu prochlazení patří zejména malé děti, senioři, bezdomovci, intoxikované či zraněné osoby, resp. jedinci z různých důvodů vystavení extrémnímu chladu. Postmortem diagnostika prochlazení zůstává i v éře molekulárních, genetických a virtuálních metod problematická, a to z důvodu absence specifického a konzistentního diagnostického znaku. Optimální diagnostický přístup proto musí být komplexní a zahrnovat nejen pečlivou zevní prohlídku a pitvu těla zemřelé osoby, ale i rozbor veškerých dostupných informací z místa nálezu, zhodnocení anamnézy, posouzení lokální meteorologické situace, měření tělesné teploty, provedení histologického a chemicko-toxikologického vyšetření a doplňkově i aplikaci moderních zobrazovacích metod či molekulárněbiologickou analýzu. Základní cíl předkládané...
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Study of effect of side chains of organic semiconductors for bioelectronic applications
Ivanová, Lucia ; Cigánek, Martin (oponent) ; Krajčovič, Jozef (vedoucí práce)
Organic bioelectronics is a relatively young but perspective science discipline that introduces the applicability of organic electronic materials in bioelectronic devices. The promising outlook for using these applications ranges from improving the quality of the disabled people's life to the development of artificial intelligence. The theoretical part describes the essential properties of semiconducting polymers for the utilization in bioelectronics and, moreover, it presents a way of improving these properties by the proper implementation of the side chains. It deals with the possibility of optimizing the biomimetic properties of conjugated polymers by using bio-inspired molecules as peripheral chains, specifically nucleic bases. The nucleobase groups introduced onto the polymer chain thus provide the synthetic molecules with the ability of self-assembly and recognition of each other. The second part of the thesis focuses on the modification of the adenine molecule, with the preparation of the key intermediate for Stille coupling. Subsequent cross-coupling reaction results in the extension of the adenine’s -conjugated system with the thiophene molecule.
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Novel organic semiconductors for bioelectronic applications
Veselý, Dominik ; Richtár, Jan (oponent) ; Krajčovič, Jozef (vedoucí práce)
This bachelor’s thesis deals with a highly perspective field of bioorganic electronics. It is divided into a theoretical and an experimental part. In the theoretical part of the thesis basic device functioning principles in conjunction with living organisms and production of such devices together with their practical application are elaborated on. In the next part of the thesis conductive polymers as advanced materials for organic electronics, their synthesis, chemical modification and functionalisation, but also their use for functional electronic devices are analysed. A synthetic route for preparation of new functional organic materials by the means of modification of a basic monomer on a molecular level is proposed in the final chapter. This chapter is connected with an experimental part where a basic monomer of the most important conductive polymer for bioelectronic applications is prepared.
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Back analysis of embankment dam and prediction of its behaviour during accidental design situations
Krajčovič, Ján ; Říha, Jaromír (oponent) ; Chalmovský, Juraj (vedoucí práce)
This Master's Thesis represents creation of software 2D FEM model of Slezská Harta dam in Czech Republic. Model is made with use of PLAXIS 2D software. In the opening, water work used for water supply and flood prevention is analysed. Analysis follows a geomorphology, a geology, a construction of the dam body, used materials, calculation methods and existing monitoring devices of the dam. For an understanding of 2D FEM creation, basics of the final element method -FEM, seepage analysis, material models, the sensitivity analysis and parametric analyses are presented. Afterwards creation of a model structure is defined- design of analysis order, definition of input data and boundary conditions, and creation of calibration segment. The end of the work presents the analysis of large scale of model testing, its correlation with measured values and final evaluation of the created model and its benefits for further use as testing model for limit loading cases.
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