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Semiconductive gas sensors for detection of organic gases and vapours
Šedivý, Matúš ; Gablech, Evelína (referee) ; Gablech, Imrich (advisor)
This bachelor thesis is focused on gas sensors. Basic characteristics of sensors are discussed in the first part. Next part contains an overview of the most used types of gas sensors based on different physical principles. The main aim of thesis outlines last chapter where process of making gas sensors with different semiconductive metal oxides active layers is described. This thesis also describes measuring of their characteristics and characteristics of commercial gas sensor TGS 822 made by Figaro. Measured data are processed in graphs and tables and then were used for comparison with created sensors. In conclusion, there are discussed possibilities of improving selectivity of gas detection by using sensors with different active layer.
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Functionalized hyper-cross-linked porous polyacetylenes
Havelková, Lucie
An atom-economic one-step chain-growth coordination homopolymerization providing high yields of functionalized hyper-cross-linked polyacetylenes with permanent micro/mesoporous texture and specific surface area up to 1062 m2 /g was introduced and optimized. Substituted 1,3-diethynylbenzenes served as monomers simultaneously providing functionalization and hyper-cross-linking of the networks. The homopolymerization was compatible with the heteroatom groups of the monomers and allowed to prepare polyacetylene networks with the wide spectrum of univalent functional groups: -F, -Cl, -Br, -NO2, -COOCH3, -CH2OH, -COOH and -CH=O decorating the aromatic segments of the networks in a high extent (7.87 mmol/g). A novel two-step synthesis of functionalized hyper-cross-linked polyacetylenes was introduced combining chain-growth coordination polymerization of acetylenic monomers and covalent templating using acetal and Schiff base protecting groups. By postpolymerization hydrolytic removal of the protecting segments from the primary networks, the networks with a high content (up to 9.61 mmol/g) of univalent functional groups -CH2OH, -CH=O and -NH2 were prepared. These groups were placed either on the cross-linking or linear (aromatic and aliphatic) network segments, even in the vicinity of the main...
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Functionalized hyper-cross-linked porous polyacetylenes
Havelková, Lucie ; Sedláček, Jan (advisor) ; Brožek, Jiří (referee) ; Balcar, Hynek (referee)
An atom-economic one-step chain-growth coordination homopolymerization providing high yields of functionalized hyper-cross-linked polyacetylenes with permanent micro/mesoporous texture and specific surface area up to 1062 m2 /g was introduced and optimized. Substituted 1,3-diethynylbenzenes served as monomers simultaneously providing functionalization and hyper-cross-linking of the networks. The homopolymerization was compatible with the heteroatom groups of the monomers and allowed to prepare polyacetylene networks with the wide spectrum of univalent functional groups: -F, -Cl, -Br, -NO2, -COOCH3, -CH2OH, -COOH and -CH=O decorating the aromatic segments of the networks in a high extent (7.87 mmol/g). A novel two-step synthesis of functionalized hyper-cross-linked polyacetylenes was introduced combining chain-growth coordination polymerization of acetylenic monomers and covalent templating using acetal and Schiff base protecting groups. By postpolymerization hydrolytic removal of the protecting segments from the primary networks, the networks with a high content (up to 9.61 mmol/g) of univalent functional groups -CH2OH, -CH=O and -NH2 were prepared. These groups were placed either on the cross-linking or linear (aromatic and aliphatic) network segments, even in the vicinity of the main...
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Semiconductive gas sensors for detection of organic gases and vapours
Šedivý, Matúš ; Gablech, Evelína (referee) ; Gablech, Imrich (advisor)
This bachelor thesis is focused on gas sensors. Basic characteristics of sensors are discussed in the first part. Next part contains an overview of the most used types of gas sensors based on different physical principles. The main aim of thesis outlines last chapter where process of making gas sensors with different semiconductive metal oxides active layers is described. This thesis also describes measuring of their characteristics and characteristics of commercial gas sensor TGS 822 made by Figaro. Measured data are processed in graphs and tables and then were used for comparison with created sensors. In conclusion, there are discussed possibilities of improving selectivity of gas detection by using sensors with different active layer.
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