Organické fluorofory pro pokročilé aplikace
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Date
Authors
Chovanec, Filip
ORCID
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Referee
Mark
C
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Vysoké učení technické v Brně. Fakulta chemická
Abstract
Predmetom skúmania tejto diplomovej práce sú organické fluorofóry s možnou, vysoko intenzívnou fluorescenciou. Ich štruktúra pri excitácii s dostatočnou energiou by potenciálne mohla viesť k zosilnenej spontánnej emisii (ASE). Všetky experimenty boli vykonávané pre charakterizáciu látok v roztoku a v pevnej fáze. Následne spin-coatingom pripravené tenké vrstvy v polystyrénovej matrici boli skúmané pre ich potenciálnu ASE. Materiály, ktoré budú predstavené v práci sú dvojakého charakteru. Jedna trojica látok je na báze diketopyrol-pyrolového jadra s modifikovanými postrannými reťazcami. Druhá skupina látok, sú organické molekuly s dlhým -konjugovaným systémom dvojných väzieb. Teoretickou rešeršou v danej problematike boli získané znalosti o stratégiách dizajnovania organických fluorofórov pre získanie požadovaných vlastností. Nadobudli sme vedomosti o tom, ako rozdielne prostredia vplývajú na vnútromolekulové pohyby a medzimolekulové interakcie fluorofórov a ako to vplýva na ich fluorescenciu. V neposlednom rade sme sa dozvedeli informácie ohľadom ASE a ich využitiu v rozdielnych odvetviach priemyslu a medicíny. UV-Vis absorpčnou spektroskopiou a fluorescenčnou spektroskopiou boli získané absorpčné, emisné a excitačné spektrá látok v troch rôznych formách. Zároveň boli študované doby života fluorescencie a kvantové výťažky týchto látok. Vo forme tenkých vrstiev bola študovaná hrúbka tenkej vrstvy a jej ASE prostredníctvom vysoko intenzívneho zdroja žiarenia. Výsledkom diplomovej práce je poznatok, že predĺženie -konjugovaného systému vedie k bathochrómnemu posunu emisie a že väčšia sila push-pull efektu taktiež vedie k červenému posunu. Fluorescenčné maximá menili svoje pozície vzhľadom na formu látky. Kvantové výťažky látok boli závislé hlavne na skupenstve látky, kde najvyššie hodnoty dosahovali látky v roztokoch. V pevnej fáze v podobe prášku efektivita fluorescencie klesla, niekedy takmer úplne zhasla. Vo forme tenkých vrstiev boli hodnoty kvantových výťažkov niekde uprostred medzi roztokom a práškom. Študované -konjugované látky neboli dostatočne dobre rozpustné pre tvorbu kvalitných tenkých vrstiev a preto boli vylúčené z merania ASE. Látky na báze DPP vykazovali určitú mieru ASE, ktorá však súvisela s kvalitou a hrúbkou tenkej vrstvy a preto sme sa aj tu stretávali s určitými problémami. Napriek tomu boli vypočítané prahové energia ASE.
The subject of this diploma thesis is the investigation of organic fluorophores with potentially high-intensity fluorescence. Upon excitation with sufficiently energetic radiation, their structure may lead to amplified spontaneous emission (ASE). All experiments were conducted to characterize the compounds both in solution and in the solid state. Thin films in a polystyrene matrix, prepared by spin-coating, were subsequently examined for their potential ASE activity. Two types of compounds were studied. The first group consists of three derivatives based on a diketopyrrolopyrrole (DPP) core with modified side chains. The second group comprises organic molecules with extended -conjugated double bond systems. A theoretical literature review was conducted to gather insights into the design strategies for organic fluorophores tailored to achieve desired optical properties. Knowledge was acquired regarding how different environments affect intramolecular motions and intermolecular interactions of fluorophores, and how these factors influence their fluorescence behaviour. In addition, information on ASE and its applications across various industrial and medical fields was obtained. UV-Vis absorption spectroscopy and fluorescence spectroscopy were employed to acquire absorption, emission, and excitation spectra of the compounds in three physical forms. Fluorescence lifetimes and quantum yields were also determined. In the form of thin films, layer thickness and ASE behaviour under high-intensity irradiation were evaluated. The results of the thesis revealed that extension of the -conjugated system leads to a bathochromic shift in emission maxima, and that an increased push-pull effect similarly results in a red shift. Fluorescence maxima were observed to shift depending on the physical form of the sample. Quantum yields were primarily dependent on the state of the material, with the highest values found in solution. In the solid state (powder form), fluorescence efficiency decreased substantially, sometimes becoming almost completely quenched. In thin-film form, quantum yields were intermediate between those in solution and powder. The studied -conjugated compounds were insufficiently soluble to form high-quality thin films and were therefore excluded from ASE measurements. DPP-based compounds exhibited a certain degree of ASE; however, the effect was strongly influenced by the thickness and quality of the spin-coated films, which posed additional challenges during evaluation. Nonetheless, lasing threshold excitation energy values were determined.
The subject of this diploma thesis is the investigation of organic fluorophores with potentially high-intensity fluorescence. Upon excitation with sufficiently energetic radiation, their structure may lead to amplified spontaneous emission (ASE). All experiments were conducted to characterize the compounds both in solution and in the solid state. Thin films in a polystyrene matrix, prepared by spin-coating, were subsequently examined for their potential ASE activity. Two types of compounds were studied. The first group consists of three derivatives based on a diketopyrrolopyrrole (DPP) core with modified side chains. The second group comprises organic molecules with extended -conjugated double bond systems. A theoretical literature review was conducted to gather insights into the design strategies for organic fluorophores tailored to achieve desired optical properties. Knowledge was acquired regarding how different environments affect intramolecular motions and intermolecular interactions of fluorophores, and how these factors influence their fluorescence behaviour. In addition, information on ASE and its applications across various industrial and medical fields was obtained. UV-Vis absorption spectroscopy and fluorescence spectroscopy were employed to acquire absorption, emission, and excitation spectra of the compounds in three physical forms. Fluorescence lifetimes and quantum yields were also determined. In the form of thin films, layer thickness and ASE behaviour under high-intensity irradiation were evaluated. The results of the thesis revealed that extension of the -conjugated system leads to a bathochromic shift in emission maxima, and that an increased push-pull effect similarly results in a red shift. Fluorescence maxima were observed to shift depending on the physical form of the sample. Quantum yields were primarily dependent on the state of the material, with the highest values found in solution. In the solid state (powder form), fluorescence efficiency decreased substantially, sometimes becoming almost completely quenched. In thin-film form, quantum yields were intermediate between those in solution and powder. The studied -conjugated compounds were insufficiently soluble to form high-quality thin films and were therefore excluded from ASE measurements. DPP-based compounds exhibited a certain degree of ASE; however, the effect was strongly influenced by the thickness and quality of the spin-coated films, which posed additional challenges during evaluation. Nonetheless, lasing threshold excitation energy values were determined.
Description
Keywords
Fluorescencia, zosilnená spontánna emisia (ASE), lasing, push-pull systém, polystyrénové tenké vrstvy, fluorescenčná spektroskopia, spektrálne vlastnosti organických molekúl, kvantový výťažok fluorescencie, doba života fluorescencie, lasing threshold, Fluorescence, amplified spontaneous emission (ASE), lasing, push-pull system, polystyrene thin films, fluorescence spectroscopy, spectral qualities of organic molecules, fluorescence quantum yield, fluorescence lifetime, lasing threshold
Citation
CHOVANEC, F. Organické fluorofory pro pokročilé aplikace [online]. Brno: Vysoké učení technické v Brně. Fakulta chemická. 2025.
Document type
Document version
Date of access to the full text
Language of document
sk
Study field
bez specializace
Comittee
doc. Ing. Zdenka Kozáková, Ph.D. (člen)
prof. Ing. Miloslav Pekař, CSc. (předseda)
doc. Ing. Viera Jančovičová, Ph.D. (člen)
prof. Ing. Michal Veselý, CSc. (místopředseda)
prof. Ing. Marián Lehocký, Ph.D. (člen)
prof. Mgr. Martin Vala, Ph.D. (člen)
doc. Ing. Petr Dzik, Ph.D. (člen)
Date of acceptance
2025-05-27
Defence
Obhajoba diplomové práce proběhla podle následujícího schématu: prezentace studenta-vyjádření vedoucí/ho-oponentský posudek-reakce na posudek-diskuse s komisí. Student přednesl dobrý výtah výsledků své diplomové práce, v odpovědích na dotazy oponentské i členů komise nebo v reakcích na připomínky k diplomové práci projevoval menší neznalosti. V diskusi tak student prokázal dobrou schopnost orientace v teoretických i praktických základech problematiky diplomové práce. Komise, s uvážením hodnocení v posudku a vyjádření vedoucí/ho, zhodnotila jeho diplomovou práci celkově jako dobrou.
Pekař: Do jakých pokročilých aplikací by se daly tyto látky použít?
Jak se měřila fluorescence vrstev a prášků?
S jakým záměrem jsou tato barviva připravována?
Kozáková: Nezkoušeli jste opakované nanášení vrstev?
Jančovičová: Jak byste zvýšil rozpustnost zelených barviv?
Result of defence
práce byla úspěšně obhájena
Document licence
Standardní licenční smlouva - přístup k plnému textu bez omezení