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Oxygen detection using gas sensor
Jelínek, Tomáš ; Pytlíček, Zdeněk (referee) ; Prášek, Jan (advisor)
In this master´s thesis various types of gas sensors, their characteristics, principle, active layer and structure are described. This work is focused on semiconductor gas sensors. In the experimental part gas test station is used to measure the main characteristic of commercial sensor Figaro TGS 822 and own SnO2 gas sensors and reaction to oxygen. Both sensors and measurement results are compared with each other.
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Characterization of sensitive nanomaterials for MOX gas sensors
Priščák, Juraj ; Gablech, Imrich (referee) ; Chmela, Ondřej (advisor)
This thesis deals with one-dimensional (1D) and two-dimensional nanomaterials (2D) in terms of their utilization for new types of gas sensors. Thesis focuses on study of sensing elements for gas sensors based on semiconductor metal oxide materials (MOX) and their manufacturing technology. The objective of the thesis is the design and implementation of a sensing elements formed by selected nanomaterials based on the structure of interdigital electrodes. The result of the practical part of the thesis is the characterization and comparison of materials in terms of their detection parameters in the presence of selected test gases. The first part of thesis hierarchically defines chemoresistive gas sensor, characterizes and explains its operation principle. Second part studies 1D and 2D nanomaterials of sensing elements for MOX chemoresistive gas sensors, contains a research of their properties and describes their methods of manufacturing and implementation. The last part deals with the implementation of the sensitive layer of the sensor with selected nanomaterials, characterizes and compares their detection properties.
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Gas sensor based on carbon nanoparticles
Morávek, Petr ; Pytlíček, Zdeněk (referee) ; Prášek, Jan (advisor)
This thesis deals with characterization of gas sensors based on carbon nanomaterials. In the theoretical chapter, the basic terms connected with the gas detection field, properties of different carbon nanoparticles and methods of their preparation are described. Practical experiments include the evaluation of samples` responses to ammonia, influence of annealing on their response and comparison of pure samples and their modifications.
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Electrical, Optical and Sensoric Properties of Organic Semiconductors
Pochekailov, Sergii ; Zmeškal, Oldřich (referee) ; Nešpůrek, Stanislav (advisor)
There is big interest in cheap, sensitive and selective gas sensors. In this work, substituted soluble phthalocyanines are proposed as a sensing materials for several gases. Optical, electrical and gas sensing properties of several phthalocyanines were studied and the mechanisms of their interaction with several analyte gases are described. It was found, that sulfo-substituted Pcs has good sensitivity to humidity. Sulfonamide-substituted phthalocyanines are promising for nitrogen dioxide and volatile organic compounds detection. tert-Butyl-substituted phthalocyanines are sensitive to NO2 under higher temperature and seems to be used for environmental monitoring. Commercial gas sensors for NO2, ethanol and humidity were successfully created.
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The gas level measuring device with a capillary made by 3-D printing
Halva, Ondřej ; Búran, Martin (referee) ; Adámek, Martin (advisor)
This thesis is concerned with the experimental design, manufacture, and testing of a 3D printed prototype of a capillary. The aim is to introduce the reader to the issue of 3D printing related to the manufacture of capillaries and focus on chemiresist sensors. Furthermore, the features of microcontroller Atmel Atmega2560 and its applications in sensory technology will be described. In the second part of the thesis, the capillary for sample pre-processing with an output to a gas measuring device with an electrochemical sensor is designed and produced. For the control of the device, the Atmel Atmega 2560 microcontroller is to be used and the device must enable data transfer to PC. The possible applications of the capillary are to be evaluated.
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Room temperature ethanol detection using carbon materials
Kočí, Michal
Allotropic forms of carbon, in particular graphene oxide (GO) or nanocrystalline diamond (NCD), attracted the attention of many research groups due to their unique electronic structures and extraordinary physical and chemical properties, preferable for many different applications, including sensor devices. This work focuses on responses of various sensing layers (NCD with hydrogen termination (H-NCD), graphene oxide (GO), reduced graphene oxide (rGO), thiol-functionalized graphene oxide (GO-SH) and their hybrid structures to ethanol vapor with concentrations up to 100 ppm in synthetic air at room temperature. The measured parameters of the tested sensors, especially stability, reproducibility and regeneration, are compared and critically evaluated. The high sensitivity of tested sensors achieved at room temperature makes them very promising for monitoring ethanol vapor as well as other volatile substances (e.g., isopropyl-alcohol or acetone).
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Development and measurement of gas sensors for room temperature applications
Kočí, Michal
Gas sensing properties of a nanocrystalline diamond with a hydrogen-terminated surface (H-terminated NCD) and a molybdenum disulphide (MoS2) are investigated as conductivity sensors with built-in interdigital metal electrode structures. The H-terminated NCD was prepared by plasma-enhanced chemical vapour deposition (PECVD), and the MoS2 by a carbide-free one-zone sulfurization method. The sensor's responses were measured for oxidizing (NO2) and reducing (NH3) gases by the same equipment and setup. The parameters of the tested sensors are compared and critically evaluated. Advantageously, the MoS2/H-terminated NCD heterostructure enhances the gas sensing response at room temperature compared to the H-terminated NCD and MoS2 layers.
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IoT air monitoring
Kousal, Martin ; Povalač, Aleš (referee) ; Frýza, Tomáš (advisor)
The purpose of this bachelor work is to make a device that can measure air quality parameters and send them wirelessly to the server, where that measured data are processed and then shown to the user. The aim is to create a device with the lowest possible power consumption for the possibility of battery operation.
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Characterization of sensitive nanomaterials for MOX gas sensors
Priščák, Juraj ; Gablech, Imrich (referee) ; Chmela, Ondřej (advisor)
This thesis deals with one-dimensional (1D) and two-dimensional nanomaterials (2D) in terms of their utilization for new types of gas sensors. Thesis focuses on study of sensing elements for gas sensors based on semiconductor metal oxide materials (MOX) and their manufacturing technology. The objective of the thesis is the design and implementation of a sensing elements formed by selected nanomaterials based on the structure of interdigital electrodes. The result of the practical part of the thesis is the characterization and comparison of materials in terms of their detection parameters in the presence of selected test gases. The first part of thesis hierarchically defines chemoresistive gas sensor, characterizes and explains its operation principle. Second part studies 1D and 2D nanomaterials of sensing elements for MOX chemoresistive gas sensors, contains a research of their properties and describes their methods of manufacturing and implementation. The last part deals with the implementation of the sensitive layer of the sensor with selected nanomaterials, characterizes and compares their detection properties.
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Novel fluorosensors based on naphthalimide derivatives
Garbárová, Veronika ; Dian, Juraj (advisor) ; Hraníček, Jakub (referee)
The aim of the diploma thesis was to prepare and characterize fluorescence sensor systems based on fluorophores and supramolecular components - cyclodextrins - attached to solid supports. In this work, functionalized 75 µm glass beads and two types of Nafion membranes were used as negatively charged solid surfaces. Derivatives of naphthalimide with a positively charged part allowing the attachment to surfaces were synthesized. The positively charged naphthalimide derivative was then attached on negatively charged surfaces via electrostatic interactions and the binding to the solid supports was examined using UV-VIS spectroscopy. Alternatively, the positively charged β-cyclodextrin derivative was also attached to the surface in an equimolar ratio with PNI-HEMPDA. The focus of the work were measurements of fluorescence sensor responses in the gas and liquid phase to linear alcohols - methanol to n-hexanol - for all sensor systems. For the studied sensor systems, the selected sensor parameters were determined - sensitivity, the limit of detection, linear dynamic range and a sensor response time constant. A practical application of the novel sensor system for the detection of ethanol in gasoline was examined. Fluorescence sensor response measurements of the prepared systems based on naphthalimide and...
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