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Deposition of Nanocomposite Thin Films
Kratochvíl, Jiří ; Kylián, Ondřej (advisor) ; Straňák, Vítězslav (referee)
Nanocomposite thin films can find application in photovoltaics, optics, fabrication of sensors, or in biomedicine. This work investigates fabrication and characterization of thin metal-plasma polymer nanocomposite films which have direct application because of their unique optical properties (e.g. SERS - Surface-Enhanced Raman Spectroscopy) or antibacterial effects (biomedicine). We fabricated metal nanoparticles either by magnetron sputtering (island growth) or by means of gas aggregation source of nanoparticles, thereby we got nanoparticles with very different morphologies. We used silver as a material for nanoparticles because of its antibacterial effects. We incorporated these nanoparticles into sputtered Nylon and sputtered PTFE (polytetrafluoroethylene) plasma polymer matrix. These two polymers have very different chemical structure and related different surface energy. First, we compared growth of nanoparticles on substrates of sputtered Nylon and PTFE. Then we compared properties of sandwich nanocomposites polymer-Ag-polymer for both types of nanoparticles and for both matrix materials. We characterized produced thin films especially with respect to their stability in water (antibacterial films), thermal stability (sterilization by heating) and stability on the open air (storage). Finally, the tests...
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Nanoclusters coatings for biomedical applications
Divín, Radek ; Kylián, Ondřej (advisor) ; Hanuš, Jan (referee)
Title: Nanoclusters coatings for biomedical applications Author: Radek Divín Department: Department of Macromolecular Physics (110. 32-KMF) Supervisor: RNDr. Ondřej Kylián, Ph.D. Abstract: The copper nanocluster films were prepared with the aid of the gas cluster aggregation source based on the principle of material sputtering from the magnetron target to the relatively high pressure of the working gas (Ar). The nanocluster films prepared in this way were subsequently overlapped with the layer of plasma polymer deposited by RF magnetron sputtering from the nylon polymer target in the atmosphere of the working gas (Ar, 2 Pa). A repetition of this procedure enabled to prepare nanocomposite layers having a multilayer character. These layers were subsequently investigated with regard to their morphology, chemical composition, surface wettability and optical properties. The chemical composition of the surface layer formed by nanocomposite films was determined by the X-ray photoelectron spectroscopy (XPS). It turned out that the chemical surface composition of prepared nanocomposites was not markedly influenced by the presence of the Cu nanoclusters. The morphology of prepared films was studied by the scanning electron microscopy (SEM) and the atomic force microscopy (AFM), which showed that the resulting...
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Ultrathin films deposited by means of magnetron sputtering and their characterization
Petr, Martin ; Kylián, Ondřej (advisor) ; Straňák, Vítězslav (referee) ; Tichý, Milan (referee)
Presented work is focused on the deposition and characterization of thin and ultrathin plasma polymer films, then also on the preparation of nanocomposites metal/plasma polymer. The characterization of plasma polymer films was partly done in-situ without exposing the samples to the atmosphere. The thickness of prepared films was measured by spectral ellipsometry, the chemical composition was measured by XPS. The morphology and optical properties of deposited films were measured ex-situ. It is shown that during the initial stages of growth the properties of plasma polymer films depend on their thickness and also on the material of the substrate. Many interesting applications were explored for prepared nanocomposites metal/plasma polymer. They can be used as superhydrophobic coatings, gradient coatings, substrates for Raman spectroscopy or as antibacterial coatings. Moreover, special optical properties of prepared nanocomposites were studied in detail. Presented work has an experimental character.
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Depozition of hydrophobic fluorocarbon coatings by plasma polymerization methods
Petr, Martin ; Kylián, Ondřej (advisor) ; Kudrna, Pavel (referee)
In this work we study the deposition of hydrophobic fluorocarbon coatings by magnetron sputtering of polymeric PTFE target. We show what is the influence of the conditions of the deposition process - the pressure in the chamber, the RF power - on the properties of the resulting CFx thin films (their chemical composition, morphology, wettability, barrier and optical properties, stability and possible bio-aplications). In this work we use a novel way to control the morphology and the chemical composition of the surface of thin films independently by using nano-particles, both metal (Pt, Cu, Al) and polymeric (C:H, Nylon). With nano-particles we can control the hydrophobicity of thin films and we can prepare super-hydrophobic films. Work has an experimental character.
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Fabrication of metal nanoclusters and their characterization
Kratochvíl, Jiří ; Kylián, Ondřej (advisor) ; Kousal, Jaroslav (referee)
Copper nanoclusters have potencial for fabrication of nanostructured surfaces, which can be used in electronics, electrotechnics, optics and in biomedical applications. To create such surfaces, it is necessary to create and characterize the nanoclusters deeply first and this is the main topic of this work. First, we found repeatable procedure to create copper nanoclusters by the gas aggregation nanocluster source. We studied homogenity of prepared surfaces by quartz crystal microbalance and optical ellipsometry, we determined conditions for deposition of homogeneous coatings. Next, we studied deposition rate in dependence on the magnetron current, pressure in the aggregation and deposition chambers. Deposition rate linearly increased with current, but in low currents it was nearly zero. Furthermore, we found maximum deposition rate for a given pressure in the aggregation chamber and determined the range of pressure in deposition chamber where it is possible to deposit thin films of copper nanoclusters. This is important for fabrication of nanocomposite surfaces. We studied also the size, shape of nanoclusters and growth of surface by scanning electron microscope. The surfaces were very porous. We measured roughness and optical absorbance where anomalous optical absorption was found. Finally, we found that...
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Diagnostics of plazma in the deposition sources using the Langmuir probes
Šedivý, Petr ; Kousal, Jaroslav (advisor) ; Kylián, Ondřej (referee)
This experimental work is concerned with measurement of elementary characteristics of plasma - potential of plasma, electron temperature and density of particles. As research methods were selected the Langmuir probes - especially the single probe. At the beginning of the thesis there are explained shortly the elementary characteristics of plasma and the procedure of determination particular parameters of the plasma from the volt-ampere characteristics of the probe. The third chapter is focused on description of the experiment, the probe, the apparatus and its control. Plasma measured within this work originated from the new hollow magnetron which will serve as future source of nanoparticles. Results of the work are focused on the description of individual parameters of the plasma in dependence on other variables such as the magnetron power, pressure of gas, spatial dependence or presence of additional auxiliary magnetic field.
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