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Surface and mechanical properties of a-CSi:H and a-CSiO:H films
Plichta, Tomáš ; Shukurov, Andrey (referee) ; Klapetek, Petr (referee) ; Čech, Vladimír (advisor)
The dissertation thesis deals with the preparation and characterisation of a-CSi:H and a CSiO:H thin films prepared using the process of plasma enhanced chemical vapour deposition (PECVD). Tetravinylsilane (TVS) and its mixtures with argon and oxygen were used to deposit films on both planar substrates and fibre bundles. Main characterisation techniques were employed to study the topography of films, namely atomic force microscopy (AFM). Their mechanical properties were studied through nanoindentation; the nanoscratch test was used to assess the film adhesion to the substrate. Other analysed properties were internal stress and friction coefficient. The particular attention was paid to the work of adhesion and its determination. This knowledge was further applied to the preparation of surface treatments of glass fibres and, subsequently, polymer composites. Those were tested using the push-out test and the short beam shear test. Based on the results, the effects of deposition conditions and the relationships between the studied properties and quantities were determined.
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Mechanical response of glass fiber-reinforced polymer composite
Širjovová, Veronika ; Svěrák, Tomáš (referee) ; Čech, Vladimír (advisor)
The bachelor thesis is concerned with mechanical properties of glass fiber-reinforced polymer composites depending on the surface modification of fibers and the volume fraction of fibers in the composite. The tested samples in a form of composite beams were consisted of polyester matrix reinforced with long glass fibers without surface treatment (unsized) and with commercial sizing. Shear and flexural tests were employed to evaluate adhesion at the fiber-matrix interface. The theoretical part focuses on literary search for composites, their components (matrix, reinforcement, interphase) and methods of testing their mechanical properties. The experimental part describes used materials, procedures and methods. In the result part, an assessment of the influence of the given conditions on the shear and flexural strength of the composite is summarized.
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Shear strength of the fiber-reinforced polymer composite
Jurko, Michal ; Knob, Antonín (referee) ; Čech, Vladimír (advisor)
The diploma thesis deals with the study of Inter-Laminar Shear Strength (ILSS) of polymer composites, based on unsaturated polyester resin with unidirectionally oriented basalt or glass fibers. The basis of the experimental part is the preparation of composite samples with different types of surface treatment of a fibers (a reinforcement) as well as the surface treatment itself. The untreated, the commercially treated fibers and the plasmatreated fibers used as reinforcement in the polymer composites were analysed by a short beam shear test and their ILSS was determined. The effect of various deposition conditions during Plasma-Enhanced Chemical Vapour Deposition (PECVD) on the value of ILSS of the composite with originally unsized glass or basalt fibers was studied. The impact of aging on the interlaminar shear strength of the composites was investigated for commercially treated glass fibers. The Scanning Electron Microscopy (SEM) is also used in the thesis together with the Energy Dispersive Spectroscopy (EDS). Based on all the results a proposal was made to correct and improve the deposition conditions and thus improve the interphase to achieve the required shear properties of polymer composites.
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Surface and mechanical properties of a-CSi:H and a-CSiO:H films
Plichta, Tomáš ; Shukurov, Andrey (referee) ; Klapetek, Petr (referee) ; Čech, Vladimír (advisor)
The dissertation thesis deals with the preparation and characterisation of a-CSi:H and a CSiO:H thin films prepared using the process of plasma enhanced chemical vapour deposition (PECVD). Tetravinylsilane (TVS) and its mixtures with argon and oxygen were used to deposit films on both planar substrates and fibre bundles. Main characterisation techniques were employed to study the topography of films, namely atomic force microscopy (AFM). Their mechanical properties were studied through nanoindentation; the nanoscratch test was used to assess the film adhesion to the substrate. Other analysed properties were internal stress and friction coefficient. The particular attention was paid to the work of adhesion and its determination. This knowledge was further applied to the preparation of surface treatments of glass fibres and, subsequently, polymer composites. Those were tested using the push-out test and the short beam shear test. Based on the results, the effects of deposition conditions and the relationships between the studied properties and quantities were determined.
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Shear strength of the fiber-reinforced polymer composite
Jurko, Michal ; Knob, Antonín (referee) ; Čech, Vladimír (advisor)
The diploma thesis deals with the study of Inter-Laminar Shear Strength (ILSS) of polymer composites, based on unsaturated polyester resin with unidirectionally oriented basalt or glass fibers. The basis of the experimental part is the preparation of composite samples with different types of surface treatment of a fibers (a reinforcement) as well as the surface treatment itself. The untreated, the commercially treated fibers and the plasmatreated fibers used as reinforcement in the polymer composites were analysed by a short beam shear test and their ILSS was determined. The effect of various deposition conditions during Plasma-Enhanced Chemical Vapour Deposition (PECVD) on the value of ILSS of the composite with originally unsized glass or basalt fibers was studied. The impact of aging on the interlaminar shear strength of the composites was investigated for commercially treated glass fibers. The Scanning Electron Microscopy (SEM) is also used in the thesis together with the Energy Dispersive Spectroscopy (EDS). Based on all the results a proposal was made to correct and improve the deposition conditions and thus improve the interphase to achieve the required shear properties of polymer composites.
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Mechanical response of glass fiber-reinforced polymer composite
Širjovová, Veronika ; Svěrák, Tomáš (referee) ; Čech, Vladimír (advisor)
The bachelor thesis is concerned with mechanical properties of glass fiber-reinforced polymer composites depending on the surface modification of fibers and the volume fraction of fibers in the composite. The tested samples in a form of composite beams were consisted of polyester matrix reinforced with long glass fibers without surface treatment (unsized) and with commercial sizing. Shear and flexural tests were employed to evaluate adhesion at the fiber-matrix interface. The theoretical part focuses on literary search for composites, their components (matrix, reinforcement, interphase) and methods of testing their mechanical properties. The experimental part describes used materials, procedures and methods. In the result part, an assessment of the influence of the given conditions on the shear and flexural strength of the composite is summarized.
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