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Plasma Chemical Surface Treatment of Polymeric Materials for Biomedical Applications
Mikušková, Radka ; Kozáková, Zdenka (referee) ; Krčma, František (advisor)
The theoretical part of bacalor thesis summarizes a plasma application for surface modification of materials used for biomedical applications. The main focus is on polymeric materials. Practical part focuses on specific surface modifications. An aim is to obtain from the initially hydrophobic surface hydrophilic by plasma chemical surface treatment and to optimize the method. Hydrophilicity is achieved by treating the sample in low temperature low pressure plasma generated in air based gaseous mixtures. The surface treatment efficiency is characterizad by water leak through the material. Structural changes of material surface are confirmed by X-ray photoelectron spectroscopy.
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Fibre reinforcement with plasma in cement composites
Žižková, Lucie ; Hela,, Rudofl (referee) ; Bodnárová, Lenka (advisor)
The usage of polymer fibres can be increased by the new progressive method of the plasma treatment. This thesis is focused on verification of the influence of the low-temperature treatment on polymer fibres´ surface used in concrete. The treatment of polypropylene fibres in low-temperature plasma is described in the theoretical part. The impact of the treatment on the volume differences of cement composites is also evaluated. The influence of the addition of commercially available fibres and plasma treated fibres on the volume differences of cement composites is also experimentally verified.
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Characterization and application of microwave plasma on wound healing
Smejkalová, Kateřina ; Skoumalová, Petra (referee) ; Krčma, František (advisor)
The aim of the Master thesis is the investigation of the influence of microwave discharge for skin wound healing. Microwave discharge used for this work was argon microwave plasma generated by the surface wave and direct vortex torch. The theoretical part is focused on basic information about plasma and processes that occur in plasma discharge under specific conditions. Plasma generates various active particles such as hydroxyl radicals, nitric oxide radicals, excited nitrogen molecules, atomic nitrogen, argon and oxygen. All of these particles together with plasma generated photons are usable in biomedical applications and summary of them is shown in the theoretical part. The experimental part is focused on the comparison of torch discharge and microwave plasma generated surface wave in skin wound healing. The model wounds on laboratory mousses were treated by plasma and wound healing was examined during 3 weeks after the plasma treatment. Both plasma systems showed healing acceleration. Application of torch discharge was proved to be the most effective method in the healing of skin defects. Additionally, determination of active particles was taken by optical emission spectroscopy. Based on these measurements, plasma parameters were determined: electron temparutare, rotational and vibrational temperatures. To determine role of different plasma active species, the treatment of indigo coloured artificial skin model was treated under various conditions by both plasma systems. Results show that the direct interaction between plasma particles is the main effect, role of radiation, only, is more or less negligible. Finally, the plasma vortex system was visualized using fast camera at selected powers and gas flows.
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Study of plasma interaction with bacteria for cosmetic applications
Kocianová, Magdaléna ; Krčma, František (referee) ; Kozáková, Zdenka (advisor)
This bachelor thesis is focused on sterilization effects of low temperature plasma on grampositive, anaerobic non-sporulating bacteria Propionibacterium acnes. The plasma sterilization process is fast, effective, non-toxic, environmentally friendly, cost- effective and safe not only for servicing staff, but mainly for the patient. Another advantage of using low temperature plasma is the promotion of cell proliferation and wound healing. The experimental part is conducted to provide an inhibition effect of low-temperature plasma on the Propionibacterium acnes bacterium that causes a purulent inflammation. This bacteria was inoculated in various concentrations on culture soil and treated by plasma at a distance of 1 mm from the agar surface. Two plasma devices were used for plasma generation. One of them was a traditional torch discharge, the second one was based on the surface wave discharge. The microwave discharge was generated in argon at a power of 9 W, gas flow rate of 5 l/min and with water cooling to avoid thermal effects on the treated surface. From the achieved results it can be stated that the low temperature plasma has sterilization effects on a grampositive, anaerobic non-sporulating bacteriu Propionibacterium acnes.
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Study of the properties of cement composites with polypropylene fiber modified low-temperature plasma
Žižková, Lucie ; Herka, Petr (referee) ; Bodnárová, Lenka (advisor)
Plasma treatment of polypropylene fibers presents a new progressive method, how to increase the utility properties of these fibers. The thesis is focused on verifying the effect of surface treatment of polypropylene fibers in concrete with low-temperature plasma discharge in the normal atmosphere. The paper describes the procedure for treatment of polypropylene fibers with low-temperature plasma and evaluate the impact of this adjustment on the volume changes of cement composites. It should also be emphasized that the thesis is focused on the initial volume changes, ie volume changes in the early stages of solidification and only for your own mixture, which is not considered an external load. Subsequently, the experimental verification of the effect of the addition made commercially available fibers and fibers treated plasma volume changes to a selected physico-mechanical properties of the test compounds.
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Monitoring of vitamin E content in the samples of cereals
Cibulcová, Pavla ; Borkovcová,, Ivana (referee) ; Benešová, Karolína (advisor)
Thesis deals with the analysis of vitamin E in cereal samples, namely barley and wheat and malt produced from them. Selected samples were treated with low-temperature plasma, fungicide and biological treatment to elimination fungus and mycotoxins. The aim of the thesis was to find out the influence of the treatment, the combination of several types of treatment on vitamin E content in grain and malt. If the content of health-positive substances is not reduced and grain can be used for food, malt, or for feed purposes. The theoretical part focuses on the properties, occurrence, biochemistry and importance of vitamin E for living organisms. It also focuses on the properties of cereals that are a significant source of vitamin E. Malt production and sample treatment are also described. The experimental part describes the field experiment, individual types of treatment, extraction of vitamin E from the samples and determination of vitamin E content by high performance liquid chromatography with fluorescence detection. The results are compared with the current literature. It was found that the treatment did not have a significant negative effect on vitamin E content.
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Characterization of microwave plasma jet generated in argon-oxygen mixtures
Smejkalová, Kateřina ; Mazánková, Věra (referee) ; Krčma, František (advisor)
The optical diagnostics of microwave plasma torch operating at the frequency of 2,45 GHz is a subject of this bachelor thesis. Microwave plasma is generated using the surfatron resonator in argon with oxygen admixture (up to 1,7 %) at the constant argon flow of 3 Slm. The theoretical part gives the basic information about plasma and processes running under plasma conditions. Various active particles such as hydroxyl radicals, nitric oxides, excited nitrogen molecules, nitrogen, argon and oxygen atoms are generated in the discharge. All these particles together with the plasma generated photons can be used in biomedical applications that are briefly reviewed in the theoretical part, too. The visual observation of oxygen admixture on the discharge and the optical emission spectroscopy based determination of the active particles presence along the discharge and post-discharge axis is the subject of experimental part. Based on it, the selected plasma parameters like electron, rotational and vibrational temperatures were calculated.
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Nanoparticle treatment technology to improve their dispersibility for use in cemt composites
Závacký, Jakub ; Sťahel,, Pavel (referee) ; Hela, Rudolf (advisor)
The diploma thesis deals with the possibility of using the addition of nanoparticles to improve the properties of cement composites. The theoretical part summarizes the findings of research in this area with a focus on methods of dispersion of nanoparticles and their treatment for use in cement composites. The experimental part focuses on the comparison of methods of dispersion and plasma treatment of reduced graphene oxide (rGO) nanoparticle solutions from the point of view of the agglomeration process. During this work, a method of systematic optical/visual monitoring of sedimentation/agglomeration was developed to complement sophisticated methods such as spectrophotometry (UV/Vis) and electron microscopy (SEM). Furthermore, the effect of the addition of rGO on the properties of cement mortar, in the form of aqueous solutions prepared by the dispersion methods determined in the previous section, was investigated.
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Optimization of distribution of active particles generated by low temperature plasma on biopolymer surfaces
Krupičková, Lucie ; Kozáková, Zdenka (referee) ; Krčma, František (advisor)
This thesis is focused on the optimization of the distribution of active particles (RONS), generated by the low temperature plasma, on the biopolymer surfaces. The theoretical part characterizes plasma and its active particles. Furthermore, this chapter summarizes its applications in medicine and food industry, also a review of different skin models is listed here. The last section is focused on the skin anatomy and the characterization of selected microorganisms C. glabrata, E. coli and S. epidermidis. In the experimental part, selected biopolymers with specific dyes for detection of active particles were prepared. Furthermore biopolymers were spot treated under different conditions leading to color changes in all biopolymers. This test confirmed a presence of active particles in the plasma. After that, the optimal parameters for active particles distribution over the entire surface were found. Also an experiment, which allowed the UV light to pass through but prohibited the passage of active particles, was made. In this experiment, no color change was noticed, which means, that the reaction of active particles with the colored biopolymer is responsible for the color change. The optimized parameters were used for treatment of agar plates with monoculture of C. glabrata, E. coli, S. epidermidis and with mixed culture C. glabrata + E. coli. Two different plasma torches were used – unipolar microwave discharge torch and surface wave microwave discharge jet. Treated samples were photographed after incubation. Software Aurora then calculated the surface area which was covered by the microbial culture. Based on the data, the microbial reducion was evaluated in comparison with untreated samples. The unipolar microwave discharge torch achieved higher efficiency than the surface wave microwave discharge jet, for all tested microorganisms.
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