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Stability of plasma polymers under various conditions
Matoušek, Jindřich ; Biederman, Hynek (advisor) ; Čech, Vladimír (referee) ; Novák, Rudolf (referee)
Title: Stability of plasma polymers under various conditions. Author: Jindřich Matoušek Department/Institute: Department of Macromolecular Physics/Charles University in Prague Supervisor of the doctoral thesis: prof. RNDr. Hynek Biederman, DrSc., Department of Macromolecular Physics Abstract: The depositions of plasma polymer thin films were carried out using plasma polymerization depostition. The working gas mixture consisted of argon and monomer vapours. The source monomers used were n-hexane and terthiophene. The depositions of nanocomposite thin films Sn/pp n-hexane by means of magnetron sputtering in a working gas mixture of argon and n-hexane were done. The resulting thin films were characterized by XPS, FTIR, AFM, SEM, TEM, optical microscope and elipsometry. The influence of deposition parameters on the resulting thin film propertires was studied. The ageing of the thin films in humidity and distilled water was studied. The current-voltage characteristics of selected thin films were measured. Keywords: plasma polymer, nanocomposite, ageing.
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Study of the interaction of nanocomposite films with plasma
Steinhartová, Tereza ; Hanuš, Jan (advisor) ; Kousal, Jaroslav (referee)
The theoretical part deals with basic characteristics of low-temperature, low-pressure plasma. It describes the principles of preparation of nanocomposite films using this type of plasma and also the etching process in chemically active plasma. It further explains the basic principles of methods used to characterize our samples. The experimental part describes the process of optimalization of chemically active plasma ($O_2/Ar$) employed for etching of plasma polymer films. After finding suitable etching parameters several types of films were prepared. First, films of plasma polymer and then nanocomposite films composed of metal and plasma polymer. Afterwards the samples were treated in defined conditions of oxygen plasma. The aim was to study the physico-chemical properties of these films, especially their chemical composition using X-ray photoelectron spectroscopy, and wettability. Attention was given to the change of the water contact angle as a function of etching time and morphology of the pample. In case of oxygen etching ageing of the film was studied. By increasing of roughness superhydrophobic (SHF) film was prepared.
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XPS analysis of plasma polymers and nanocomposite films without breaking vacuum
Artemenko, Anna ; Biederman, Hynek (advisor) ; Čech, Vladimír (referee) ; Novák, Stanislav (referee)
Title: XPS analysis of plasma polymers and nanocomposite films without breaking vacuum Author: Anna Artemenko Institute: Charles University in Prague, Department of Macromolecular Physics Supervisor of the doctoral thesis: Prof. RNDr. Hynek Biederman, DrSc., Charles University in Prague, Department of Macromolecular Physics. Abstract: Plasma polymers and metal/ plasma polymer nanocomposites have been widely used for various biomedical proposes. Naturally, surface properties of the coatings such as high wettability, stability on the open air and in aqueous media, resistance towards different sterilization processes and cells adhesion are required for bioapplications. This thesis is mainly dedicated to the investigation of chemical composition of deposited coatings using XPS analysis. Nylon-like plasma polymer, PEO-like coatings, fluorocarbon plasma polymer (PTFE) films and Au/PEO-like, Ag/C:H, Al/C:H nanocomposites were chosen as the subject material. In addition, results of XPS measurements were used for the computer simulation for calculation of filling factor of metal/ plasma polymer nanocomposites. These results were in a good agreement with experimental data. Keywords: plasma polymer, nanocomposite, XPS analysis, bioapplication, simulation.
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Synthesis of low-crosslinked polymers by plasma polymerization
Kuchtová, Štěpánka ; Bránecký, Martin (referee) ; Čech, Vladimír (advisor)
This bachelor thesis deals with plasma enhanced chemical vapour deposition (PECVD), specifically plasma polymerisation, which has been used for the synthesis of low density crosslinked polymer thin films. Organosilicon thin films were deposited on a silicon substrate by radio frequency (RF) capacitively coupled plasma in a deposition chamber. Spectroscopic ellipsometry was used to determine the layer thickness and its optical properties. The chemical structure of the layers was investigated by Fourier transform infrared spectroscopy and the mechanical properties were investigated by nanoindentation. The effect of power and self-bias (USB) on the chemical structure, mechanical and optical properties of the as-prepared layers, which are related to the crosslinking density, was investigated in the context of achieving low crosslinking density of the material. Low crosslinked plasma polymers were synthesized at a self-bias level of 1 V, which corresponds to an approximate RF power of 0,1 W. This material can be characterized by a density of 1, 2 g·cm-3 an elastic modulus of 4 GPa, a hardness of 0,04 GPa and a refractive index of 1.53 at 633 nm (He-Ne laser wavelength). Infrared spectroscopy confirmed that this plasma polymer is composed of a carbon network with fewer embedded silicon atoms and, in particular, the highest concentration of vinyl groups compared to plasma polymers prepared at higher powers.
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Structuring of plasma polymers: new methods for fabrication of nano-architectured thin films
Nikitin, Daniil ; Shukurov, Andrey (advisor) ; Novák, Stanislav (referee) ; Straňák, Vítězslav (referee)
Title: Structuring of plasma polymers: new methods for fabrication of nano-architectured thin films Author: Daniil Nikitin Department / Institute: Department of Macromolecular Physics/Charles University Supervisor of the doctoral thesis: Doc. Ing. Andrey Shukurov, PhD, Department of Macromolecular Physics/Charles University Abstract: The PhD thesis aims at the investigation of nanostructures based on plasma polymers. The main attention is paid to the combination of a gas aggregation cluster source with plasma-assisted vapor phase deposition for the fabrication of metal-polymer nanocomposites with bactericidal potential. Copper nanoparticles were incorporated into a biocompatible matrix of plasma polymerized poly(ethylene oxide) (ppPEO). The efficiency of such nanocomposite against multi-drug resistant bacteria was demonstrated. It was found that the segmental dynamics of the plasma polymer significantly changed in the presence of nanoparticles as revealed by the measurements of the dynamic glass transition temperature. The nanoscale confinement crucially influences the non-fouling properties of poly(ethylene oxide). A separate chapter is dedicated to the examination of the nanoparticle formation, growth and transport inside the source. Copper and silver nanoparticles were detected in situ in the gas phase...
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Structuring of plasma polymers: new methods for fabrication of nano-architectured thin films
Nikitin, Daniil ; Shukurov, Andrey (advisor) ; Novák, Stanislav (referee) ; Straňák, Vítězslav (referee)
Title: Structuring of plasma polymers: new methods for fabrication of nano-architectured thin films Author: Daniil Nikitin Department / Institute: Department of Macromolecular Physics/Charles University Supervisor of the doctoral thesis: Doc. Ing. Andrey Shukurov, PhD, Department of Macromolecular Physics/Charles University Abstract: The PhD thesis aims at the investigation of nanostructures based on plasma polymers. The main attention is paid to the combination of a gas aggregation cluster source with plasma-assisted vapor phase deposition for the fabrication of metal-polymer nanocomposites with bactericidal potential. Copper nanoparticles were incorporated into a biocompatible matrix of plasma polymerized poly(ethylene oxide) (ppPEO). The efficiency of such nanocomposite against multi-drug resistant bacteria was demonstrated. It was found that the segmental dynamics of the plasma polymer significantly changed in the presence of nanoparticles as revealed by the measurements of the dynamic glass transition temperature. The nanoscale confinement crucially influences the non-fouling properties of poly(ethylene oxide). A separate chapter is dedicated to the examination of the nanoparticle formation, growth and transport inside the source. Copper and silver nanoparticles were detected in situ in the gas phase...
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Plazmové opracování porézních povrchů
Vaidulych, Mykhailo ; Hanuš, Jan (advisor) ; Pavlík, Jaroslav (referee) ; Tichý, Milan (referee)
Title: Plasma treatment of porous structures Author: Mykhailo Vaidulych Department / Institute: Department of Macromolecular Physics Supervisor of the doctoral thesis: Prof. Assist. Jan Hanuš, Ph.D., Department of Macromolecular Physics Abstract: The thesis is focused on the implementation of low-temperature plasma for the modification of porous materials. Two main strategies are involved: functionalization through the deposition of functional nanocomposite coatings and low-pressure plasma etching. In the first case, a gas-phase step-by-step deposition process based on the combination of deposition of nanoparticles and thin films was developed to obtain super-wettable nanocomposite coatings on filtration membranes. It was shown that the deposition parameters of thin films and particles of plasma polymer can tune the wetting characteristic of the membranes whereas embedding copper nanoparticles endows them with antibacterial properties. As a result, highly efficient superhydrophobic/superoleophilic and smart superamphiphilic membranes were successfully fabricated for oil/water separation. Plasma processing in the atmosphere of argon, oxygen or nitrogen was utilized to modify hard metal/polymer nanocomposites (Ag/a-C:H) with potential to be used as functional coatings for bone implants. An anisotropic etching...
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Plasma surface modification of glass fibers and its optimization
Širjovová, Veronika ; Knob, Antonín (referee) ; Čech, Vladimír (advisor)
Diploma thesis deals with glass fiber surface modification using plasma-enhanced chemical vapor deposition in order to prepare functional interface that enhances the properties of polymer composites. The effect of deposition conditions on shear strength was observed with respect to the chemical composition of the deposited film. Thin films were deposited on planar substrates and fibers using monomer tetravinylsilane in a mixture with oxygen at selected power of plasma discharge. Chemical composition of prepared material was analyzed by infrared spectroscopy. Planar substrate film adhesion was measured using the scratch test. The composite sample was prepared by embedding the surface modified fibers in unsaturated polyester resin, followed by the curing process. The cured composite sample underwent the short beam shear test.
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Modification of polymeric substrates by means of non-equilibrium plasma
Kuzminova, Anna ; Kylián, Ondřej (advisor) ; Čech, Vladimír (referee) ; Novák, Stanislav (referee)
Title: Modification of polymeric substrates by means of non-equilibrium plasma Author: Anna Kuzminova Department: Department of Macromolecular Physics Supervisor of the doctoral thesis: doc. RNDr. Ondřej Kylián, Ph.D. Abstract: Processing of polymeric materials by means of non-equilibrium plasma is a topic that reaches increasing attention, which is due to the wide range of possible applications. As an example can be mentioned processing of polymeric foils used for food packaging, where plasma treatment enables to improve their functional properties (e.g. increase their printability or enhance their barrier properties). In the frame of this PhD. thesis two different strategies suitable for the modification of polymeric materials were followed. The first one was based on treatment of polymers by atmospheric plasma. The main attention was devoted to the investigation of influence of atmospheric pressure plasma on surface properties of 8 commonly used polymers, namely on their chemical composition, morphology and wettability. In addition, it was observed that plasma treatment causes also alteration of their mechanical properties, may lead to their substantial etching and in some cases improves their biocompatibility. The second studied strategy was based on coating of polymers with thin functional...
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Plasma polymers in the nanostructured and nanocomposite coatings
Shelemin, Artem ; Biederman, Hynek (advisor) ; Čech, Vladimír (referee) ; Vyskočil, Jiří (referee)
Title: Plasma polymers in the nanostructured and nanocomposite coatings Author: Artem Shelemin Department / Institute: Department of the Macromolecular Physics Supervisor of the doctoral thesis: Prof. RNDr. Hynek Biederman, DrSc. Abstract: The thesis represents the main results of my research work aimed to study nanostructured and nanocomposite films of plasma polymer. A few alternative experimental approaches were developed and investigated which ranged from low pressure (gas aggregation cluster sources and glancing angle deposition) to atmospheric pressure (dielectric barrier discharge and plasma jet) plasma processing. The metal/metal oxide Ti/TiOx, AlOx and plasma polymer SiOx(CH), Nylon 6,6 nanoparticles were prepared. The analysis of morphology of deposited plasma polymer coatings was performed by AFM and SEM. The chemical composition of films was studied by XPS and FTIR. Keywords: plasma polymer, nanoparticle, thin film, nanostructures
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