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Fluorescent nanoparticles based on organic chromophores
Čekal, Josef ; Kratochvíl, Matouš (referee) ; Vala, Martin (advisor)
This study aims to create Host-Guest nanoparticle systems exhibiting white light emission (WLE) using organic molecules, achieved through Förster resonance energy transfer (FRET) mechanisms. Substituted stilbene-based compounds were utilized for the preparation of nanoparticle systems, with CA-DPS-V (H2) and CA-DPS-CHO (H1) used as donor/matrix materials, and CA-DPS-DCV (G1) and DPA-DXS-IOO (G2) as acceptor/dopant materials. Three nanoparticle systems were synthesized via nanoprecipitation from common solutions of the compounds in THF: system 1 (H1+G1), which did not achieve WLE, system 2 (H2+G1), and system 3 (H2+G2). Systems 2 and 3 were characterized using fluorescence spectroscopy and FRET parameter calculations. It was found that the Förster distance in system 2 is shorter than in system 3. This variation in Förster distance affects the composition ratios capable of WLE. The closest proximity to the white point (0.33, 0.33) was observed in system 2 at molar ratios of 110:1 (0.32, 0.38) and 164:1 (0.29, 0.32), and in system 3 at ratios of 340:1 (0.34, 0.30) and 476:1 (0.31, 0.28). Thus, the goal of the study was achieved, demonstrating that nanoparticles capable of WLE can be prepared in this manner. However, a drawback of the prepared nanoparticles was their low photostability. Future work could focus on synthesizing more stable nanoparticles from structurally similar compounds. These particles could then be further characterized in terms of structure and other properties for potential applications.
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Internal Communication in a Selected Company
Vala, Michal ; Konečná, Zdeňka (referee) ; Konečný, Štěpán (advisor)
The diploma thesis deals with internal communication in a selected company. The thesis is divided into three parts. The first part is theoretical, in which the issues of communication, internal communication and manager communication are presented. The second part is the analytical part where the selected company is introduced and then the evaluation and results of the qualitative research are presented. The last part contains recommendations about internal communication based on the results of the semi-structured interviews. After the implementation of these recommendations, the internal communication in the company should improve.
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Virtual commisioning of one purpose production cell
Vala, Martin ; Bražina, Jakub (referee) ; Štěpánek, Vojtěch (advisor)
Master thesis deals with the issue of virtual commissioning and PLC programming. In the first part of the thesis a research in the field of control systems and softwares for virtual commisioning is conducted. The second part of the thesis deals mostly with NX Mechatronics concept designer software, where the initial modification of the model and its configuration for virtual commissioning takes place. The actual preparation of the model is followed by the virtual connection of the TwinCAT 3 control system and previously mentioned NX MCD using a virtual OPC server. The control program code is then created using the TwinCAT 3 development environment to control the assembly operations. This is followed by the actual virtual commissioning of single purpose station for assembly of the steel strapping machine.
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Logging of vehicle's position by a differential GPS with base station
Vala, Matěj ; Repka, Martin (referee) ; Straka, Tomáš (advisor)
The present work deals with the study of GPS, differential GPS and GPS with base station. The research focuses on the functioning, present status and future development of these systems. Further the thesis presents the actual measurement of the vehicle route using different GPS system. Base station, experimental vehicle, ADMA-G-PRO+, RT3000 and conventional GPS devices were used for the route measurement. The measurements were performed with and without correction. The analysis of the measured data was carried out in Matlab software in TeleMatrix, focusing on different parameters for each GPS system. The first analysis evaluates the route measurements using three GPS systems (RT3000, ADMA-G-PRO+ and a conventional GPS device). The results obtained show the effect of signal quality, horizontal speed, number of satellites, vehicle orientation, heading standard deviation and accuracy status during normal driving and during specific runs for the different GPS systems. The second analysis evaluates the RT3000 with and without correction for different manoeuvres. The evaluated results show that the RT3000 with correction provides higher accuracy than the RT3000 without correction. The RT3000 with correction shows a lower standard deviation of heading in the range of 0.210° - 2.228°, confirming its higher accuracy compared to the RT3000 without correction, where the standard deviation of heading ranges from 0.384° - 4.418°.
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Chromophores based on push-pull substituted stilbenes
Ševčíková, Veronika ; Kratochvíl, Matouš (referee) ; Vala, Martin (advisor)
This bachelor thesis deals with the examination of the relationship between the structure and optical properties of organic luminophores based on push-pull substituted stilbene and the determination of their emission in the solid state and in solution - dual state emission (DSE). Four newly synthesized luminophores based on push-pull substituted diphenylaminodibromostilbene and diphenylaminodi(2,6-xylil)stilbene containing different electron acceptor groups were selected for measurements. Due to the limited amount of samples, only solutions of the luminophores in dichloromethane were prepared. Emission spectra, quantum yields and fluorescence lifetime were measured for these luminophores in solid state. For solutions of these luminophores in DCM, all described optical properties were measured along with the absorption spectra. Determined optical properties were related to the structure of the luminophores. For the diphenylamine-dibromostilbene-based luminophores, fluorescence of the NIR radiation was detected, while the fluorescence of these luminophores was found to be weakened due to the presence of Br substituents. The investigated diphenylaminodi(2,6-xylil)stilbene-based luminophores show relatively weak push-pull effect. The fluorescence of these luminophores was found to be intense in solution, but weakened in the solid phase, which was attributed to the weak push-pull effect. According to the measured results, it was concluded that the investigated luminophores based on diphenylaminodi(2,6-xylil)stilbene are suitable candidates for further research and potential applications considering their properties.
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Kinetic study of excited state proton transfer in polymer-surfactant system
Bačová, Jana ; Vala, Martin (referee) ; Mravec, Filip (advisor)
In this bachelor thesis were studied interactions between hyaluronic acid and cationic septonex by steady-state and time-resolved fluorescence with fluorescence probes pyrene and 1-naphthol. At first was determined critical micelle concentration of septonex. In the case of both fluorescence probes was studied area below and above critical micelle concentration. It was found, that 1-naphthol undergo very fast deprotonation in aqueous solution, while in the present of micelles the rate of deprotonation is c significantly retarded. In the system of hyaluronic acid – septonex it was observed, that formation of aggregates occurs at lower concentrations than in the system without hyaluronic acid. Molecules of probe are probably distributed between hyaluronic acid – septonex aggregates and free micelles above critical micelle concentration.
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Development of Light Emitting Electroluminescent Device by Means of Material Printing
Hrabal, Michal ; Syrový,, Tomáš (referee) ; Boušek, Jaroslav (referee) ; Vala, Martin (advisor)
Cílem této práce je vývoj světelného zdroje založeného na technologii tlustostěnného elektroluminiscenčního panelu napájeného střídavým napětím (ACPEL). V současné době se jedná se o jedinou technologii založenou na metodách materiálového tisku vhodnou pro přípravu velkoplošných, flexibilních a vzorovaných zdrojů světla. Důraz je v této práci kladen na představení, prozkoumání a odstranění typických problémů, které jsou spojovány s touto technologií. Tyto problémy jsou omezený odstín barvy emitovaného světla a dlouhodobá stabilita elektroluminiscenčního prvku, který je vystaven vlivům prostředí. Rešeršní část dizertační práce je zaměřena na představení a identifikaci depozičních technik, vhodných pro reprodukovatelnou přípravu ACPEL panelů. Dalším cílem je identifikace fyzikálních parametrů, vhodných pro charakterizaci velkoplošných zdrojů světla. Praktickým cílem práce je nalezení vhodné metodologie pro popis a charakterizaci panelů, jakožto plošných světelných zdrojů. Fotometrická veličina jas L a spotřeba elektrické energie P byly vyhodnoceny jako vhodné parametry, určující aplikaci ACPEL panelů. Na modrém panelu bylo dosaženo maximální hodnoty jasu L = 133 cd•m2 při napětí Upp = 500 V a frekvenci f = 1000 Hz. Hodnoty spotřeby elektrické energie, vztažené na jednotkovou plochu panelů zkoumaných v této práci, jsou (7±3) mW. Tyto dosažené hodnoty dělají ze světelných zdrojů založených na ACPEL technologii zajímavé kandidáty pro různé aplikace. Vlivu rostoucí amplitudy a frekvence budícího napětí na dlouhodobou stabilitu panelů je důležitým cílem této práce. Pro popis stability byly zavedeny parametry L50 and L75. Bylo zjištěno, že rostoucí frekvence budícího napětí zkracuje životnost panelů. Laminovaný panel napájený napětím s přibližně trojnásobně vyšší frekvencí vykazoval přibližně třetinové hodnoty parametrů L50 a L75. Nejvyšších hodnot stabilitních parametrů dosahoval panel enkapsulován mezi skleněné pláty – přibližně sedminásobnou hodnotu oproti laminovanému panelu s trojnásobnou frekvencí. Optimální stability panelů lze dosáhnout při nastavení frekvence v rozmezí 400–800 Hz a zapouzdřením mezi sklo. Úzká paleta odstínů barev emitovaného světla je jeden z typických problémů, který dále zkoumán v dizertační práci. Tato práce zkoumá nadějnou metodu, přídavek vhodného materiálu pro konverzi barvy (CCM). Nový derivát diketopyrrolopyrrolu (DPP), absorbující v modré oblasti, byl přidán k modrému fosforu a byl pozorován sedminásobný narůst hodnot absolutního spektrálního ozáření v oblasti vlnových délek odpovídajících maximální emisi CCM materiálu. Jednoduchost přípravy vyvinutých zdrojů světla spolu s velmi nízkou spotřebou a vysokou dobou života dělají z ACPEL panelů zajímavé kandidáty pro podsvícení prvků například v automobilovém průmyslu, pro dekorativní osvětlení, pro „branding“ – zvýraznění reklamních značek.
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Preparation of organic electrochemical tranzistors for biosensorics
Ehlich, Jiří ; Vala, Martin (referee) ; Salyk, Ota (advisor)
The goal of this thesis is to describe the process used in preparation of organic electrochemical transistors thus biosensors for testing potential drugs aimed for cardiomyocytes. Then explore some physical properties of developed sensors such as adhesion of materials used, conductivity of developed structures and stability of developed structures in various water environments. As primary technology used for creating our OECTs was used inkjet printing of special inks with electrical properties on PET and PEN substrate cured with special treatment before and after printing. This thesis results in complete view on technology and development of biosensors we had created.
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Study of humic and fullvic acids by excitation emission matrix method
Enev, Vojtěch ; Vala, Martin (referee) ; Fasurová, Naděžda (advisor)
A bachelor thesis was focused on fluorescence measurement by emission-excitation matrix method (EEM) and finding of the main fluorophores of soil humic and fulvic acids samples. The results of the position of the main peak of fulvic acid isolated from soil type Cambisol were compared and were similar to the position of Elliot soil FA standard II. For determining of secondary peaks of fulvic acids the synchronous method (3D SFS) at lower wavelengths was used.
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