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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Úprava povrchu textilií pomocí plazmového výboje / Plasma treatment of fabrics

STEHLÍK, Radim January 2019 (has links)
The thesis deals with the surface modification of cotton fabric by low-pressure micro-wave plasma discharge. The main materials used for this experiment are cotton fabrics and hexamethyldisiloxane. The experiment itself is focused on the modification of cotton fabric to improve hydrophobic atributes. An argon process gas was used in the surface modification. The individual treated samples were operated with changes in process gas flow and the time during which the above-mentioned modifications was performed. Two methods were used to analyze the results of the experiment. The first one was aimed at determining changes in hydrophobic atributes in the form of wetta-bility in an unmodified sample compared to other modificated samples using the drop-let method. An electron microscope was used for the subsequent study of possible changes in surface topography. From the point of view of the examined results, the difference in hydrophobic properties was observed when using the droplet method to-gether with the change in the topography of the surface obtained on the electron mi-croscope in the cotton samples examined. The actual evaluation of individual methods points to the desirable changes in modified cotton compared to unmodified cotton. Further information regarding the results of the experiment, depending on the changes in individual parameters in the cotton treatment process using low pressure microwave plasma discharge, are presented in thesis.
2

Funkcionalizace biodegradabilních polymerů anhydridem kyseliny itakonové / Functionalization of biodegradable polymers by itaconic anhydride

Michlovská, Lenka January 2009 (has links)
Předložená diplomová práce se zabývá přípravou biodegradabilního termosenzitivního triblokového kopolymeru na bázi polyethylenglykolu, kyseliny polymléčné a polyglykolové (PLGA-PEG-PLGA) a dále pak především jeho modifikací anhydridem kyseliny itakonové (ITA), který dodá kopolymeru jak reaktivní dvojné vazby tak i funkční karboxylové skupiny důležité pro reakci s biologicky aktivními látkami. Hlavním cílem bylo optimalizovat reakční podmínky pro dosažení nejvyššího stupně navázání ITA na polymer za vzniku ITA/PLGA-PEG-PLGA/ITA. Uvedený kopolymer je po vytvoření heterogenního kompozitu např. s hydroxyapatitem vhodný pro biomedicíncké aplikace především v oblasti tkáňového inženýrství jako dočasná náhrada či fixace tvrdých tkání (kostí). V teoretické části uvedené práce jsou na základě literární rešerše obecně popsány hydrogely, jejich rozdělení, síťování a degradace. Stručně jsou rozepsány fyzikální a chemické vlastnosti a syntéza jednotlivých biomateriálů použitých při syntéze, anhydridu kyseliny itakonové a jejich kopolymerů. Experimentální část popisuje detailně syntézu PLGA-PEG-PLGA kopolymeru polymerací za otevření kruhu pomocí vakuové linky a Schlenkových technik. Byla sledována i kinetika polymerace s navržením nejvhodnějších podmínek syntézy. Uvedený kopolymer byl následně modifikován anhydridem kyseliny itakonové opět katalytickou reakcí za otevření kruhu. V důsledku optimalizace reakčních podmínek byl sledován vliv teploty, rozpouštědla, času a čistoty vstupních látek. Výsledný ITA/PLGA-PEG-PLGA/ITA kopolymer byl charakterizován pomocí 1H NMR, FT-IR a GPC metody. Byly sledovány kinetiky polymerace PLGA-PEG-PLGA kopolymeru a to z přesublimované a nepřesublimované kyseliny polymléčné a polyglykolové. V obou případech probíhala kinetika reakcí bez přítomnosti rozpouštědla při 130 °C po dobu 3 hodin s konverzí asi 90 %. Delší čas neměl vliv na růst konverze. U kinetiky z nepřesublimovaných monomerů byl sledován během několika prvních minut prudký nárůst konverze a pak již byl průběh konstantní, na čase nezávislý. Výsledná polydisperzita kopolymeru byla 1,26 a molekulová hmotnost 7155 g/mol. Optimálních podmínek bylo dosaženo u polymerace z přesublimovaných monomerů, kdy byl nárůst konverze do hodnoty 88 % získané během 2,5 hodin téměř lineární (polymerace byla živá) a poté byl progres konstantní. Byl získán přesně definovaný PLGA-PEG-PLGA kopolymer o molekulové hmotnosti 7198 g/mol a polydisperzitě 1,20. Nejlepších podmínek při syntéze ITA/PLGA-PEG-PLGA/ITA kopolymeru bylo dosaženo reakcí bez přítomnosti rozpouštědla při 110 °C po dobu 1,5 hodiny s přesublimovaným anhydridem kyseliny itakonové, kdy bylo na původní kopolymer navázáno 76.6 mol. %. Výsledná molekulová hmotnost kopolymeru (5881 g/mol) s polydisperzitou 1,37 stanovená pomocí GPC se shodovala s vypočítanou molekulovou hmotností z 1H NMR i s teoretickou molární hmotností (Mn(teor)/Mn(GPC)/Mn(NMR) = 1/0,89/0,96).
3

Plasmonic Antennas / Plasmonic Antennas

Kvapil, Michal January 2015 (has links)
Tato disertační práce pojednává o plazmonických anténách. Rezonanční vlastnosti plazmonických antén jsou studovány teoreticky i experimentálně. Teoretické výpočty jsou prováděny v programu Lumerical FDTD Solutions užitím numerické metody konečných diferencí v časové doméně. Pro experimentální studium byly antény vyrobeny pomocí elektronové litografie. Rezonanční vlastnosti vyrobených antén jsou studovány fourierovskou infračervenou spektroskopií. Práce se zaměřuje na studium rezonančních vlastností antén vyrobených na vrstvě nanokrystalického diamantu. Dále zkoumá možnost využití antén jako plazmonického senzoru funkcionalizovaného k detekci streptavidinu. Nakonec je představena anténa tvaru písmene V, u které dochází v důsledku porušení symetrie antény ke směrovému rozptylu dopadajícího světla. Tato směrovost se ovšem projevuje jen na vlnových délkách blízkých kvadrupólovému módu antény.
4

Funkční nanočástice pro plasmonické biosenzory / Functional nanoparticles for plasmonic biosensors

Přítulová, Marie January 2016 (has links)
This thesis aims to prepare functional gold nanoparticles (AuNPs) and use them in conjunction with a surface plasmon resonance (SPR) biosensor for highly sensitive detection of carcinoembryonic antigen (CEA). In this work, preparation of colloidal AuNPs was investigated and a three-step synthesis was optimized to yield spherical nanoparticles with a diameter of about 100 nm and smooth surface. The synthesized AuNPs were functionalized by a self-assembled monolayer of carboxy-PEG alkanethiols and streptavidin and characterized by UV/VIS spectroscopy and -potential method. Finally, the functionalized AuNPs were employed in sandwich assay for the sensitive detection of CEA and it was demonstrated that they can enhance sensor response to CEA by a factor of 100 compared to the direct detection of CEA.
5

Studium interakcí funkčních povrchů s biologickými systémy / The study on interactions of functional surfaces with biological systems

Víšová, Ivana January 2021 (has links)
Title: The study on interactions of functional surfaces with biological systems Author: Ivana Víšová Department: Institute of Physics of the Czech Academy of Sciences, Department of optical and biophysical systems. Supervisor: RNDr. Hana Vaisocherová-Lísalová, Ph.D., Institute of Physics of the Czech Academy of Sciences, Department of optical and biophysical systems. Abstract: This work is devoted to the study of processes influencing the performance of functional antifouling polymer brush coatings and their interactions with complex biological media. Specifically, both results of the fundamental and applied research on the i) functionalization processes influencing coating resistance, ii) tailoring of the physico-chemical properties of the antifouling coatings to minimize the nonspecific interactions with complex biological samples, and iii) behavior and performance of the polymer brush coatings in varying environments are presented. Acrylamide and methacrylamide-based polymer brushes with side hydroxyl, carboxybetaine, and sulfobetaine groups were studied, showing the great potential of their optimized copolymer structures as tunable antifouling functionalizable platforms for cell research or biosensor applications. Moreover, newly developed procedures for antifouling properties recovery after EDC/NHC...
6

Zpevnění polymerních kompozitů uhlíkovými nanotrubkami / Hardenning of polymeric composites by nanotubes

Kuběna, Martin January 2013 (has links)
This diploma thesis focuses on the influence of carbon nanotubes (CNTs) on the mechanical properties of a composite material with polyurethane (PU) matrix. The material was supplied in the form of thin films with thickness from 0.2 mm to 1.2 mm. The theoretical part of this thesis describes the production technology, properties and applications of composite materials PU/CNTs, and also deals with preparation technology and properties of both components of this composite material separately. The theoretical part also describes the principle of tensile testing of polymer materials. The experimental part of the thesis was primarily focused on comparing the tensile properties of a composite material PU/CNTs with tensile properties of pure PU. At first, tensile properties of pure PU were investigated, while the influence of various factors like strain rate, specimen thickness, heat treatment and aging was examined. In adition, stress relaxation tests and tests with strain rate jumps were performed on pure PU specimens. Then composite PU/CNTs was tested in tension and the results were compared with the results of tensile tests of pure PU. Composite material PU/CNTs was prepared with various concentrations, so it was possible to determine the effect of CNTs content on the tensile properties of the composite. The last part of this thesis deals with tensile tests of PU composite material with functionalized carbon nanotubes (PU/FCNTs), where the influence of surface modification (functionalization) of CNTs on the tensile properties composites was investigated. It was shown that the effect of both CNT and FCNT on mechanical properties of the composite is not significant. This conclusion was discussed on basis of the works of other authors, which do not unambiguously proved the positive effect of CNT or FCNT on mechanical properties of composites with polymer matrix.
7

Příprava a vlastnosti stavebních bloků speciálních polymerů / Preparation and properties of building blocks of specialty polymers

Šichová, Kristýna January 2014 (has links)
This Diploma Thesis presents results obtained by solution of two partial projects: a) Preparation of monomers from renewable sources using metathesis and tandem hydrogenation catalyzed with ruthenium compounds - project solved during my Erasmus stay at the Université de Rennes 1 in France; b) Preparation and properties of ,-bis(tpy)quarterthiophene oligomers carrying ionic side groups as oligomonomers for polyelectrolyte conjugated dynamers - project solved at the Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University in Prague. Project a): Self-metathesis of 1,2-epoxyhex-5-ene (but-3-enyloxirane) and its cross-metathesis with methyl acrylate and acrylonitrile catalyzed with ruthenium compounds as well as tandem design of these metatheses and consecutive hydrogenation of their products by gaseous hydrogen have been optimized. The following influences have been studied and tuned: (i) type of the catalyst (Grubbs, Hoveyda, Zhan) and its concentration and method of dosing, (ii) concentration of reactants and additives, (iii) type of solvent, and (iv) reaction temperature. Reactions were monitored by the GC, GC and MS methods and the products were characterized by the NMR method. Methyl 6,7-epoxyheptanoate (methyl 5-oxiranylpentanoate) obtained by the tandem...
8

Povrchová funkcionalizace materiálů s využitím plazmových technologií / Surface functionalization of the materials by plasma technologies

TROUP, František January 2014 (has links)
This thesis deals with the plasma functionalization of nanofiber materials for biomedical applications. Nanofibers of SiO2 and PCL was functionalized using a microwave plasma in order to establish amine functional groups. The work includes theoretical assumptions selection of these materials, their properties and current use with emphasis on biomedical applications. The paper also presents the theoretical foundations of plasma technology, their principles and practical applications. The experimental part of the work includes the optimization of process parameters for each nanofiber materials, review hydrophilisation surface and material degradation through SEM and private functionalization. In conclusion outlines proposals for further action beyond the experiments of this work.
9

Multikomponentní plazmové polymery s prostorově řízenými vlastnostmi / Multicomponent plasma polymers with spatially controlled properties

Pleskunov, Pavel January 2020 (has links)
Title: Multicomponent plasma polymers with spatially controlled properties Author: MSc. Pavel Pleskunov Department / Institute: Department of Macromolecular Physics/Charles University Supervisor of the doctoral thesis: Prof. Ing. Andrey Shukurov, PhD, Department of Macromolecular Physics / Charles University Abstract: Mixing of two (or more) polymers often leads to phase separation and to the formation of nanoscale architecture, which can be highly attractive in various applications including controllable drug delivery, fabrication of separation and solid electrolyte membranes, gas storage, etc. Different wet-chemistry techniques already exist to produce nanophase-separated polymers; however, capturing the resultant polymeric structure in a predictable manner remains a challenging task. In this thesis, a low-temperature plasma-based strategy is investigated for the production of multicomponent thin films of plasma polymers with spatially discriminated nanoscale domains. Gas aggregation cluster source is used for the fabrication of nanoparticles of plasma polymerized acrylic acid, whereas Plasma-Assisted Vapor Phase Deposition is used for the deposition of thin films of poly(ethylene oxide) plasma polymer. Embedding of nanoparticles into matrices of thermodynamically incompatible plasma polymer as well as...

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