Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 17 of 17 for “"chemiresistors"”.
-
Field-structured chemiresistors : tunable sensors for chemical-switch arrays
… improved composite material for applications to chemiresistors, which are resistance-based sensors for volatile organic compounds. This material is a polymer composite containing Au-coated magnetic particles organized into electrically conducting pathways by magnetic fields. This improved …
-
Wirelessly addressable chemiresistors : carbon nanotube-based chemical sensors and dosimeters
In Chapter 1, we develop a brief tutorial on chemiresistive sensors and our rationale for choosing nanowires (NWs), specifically carbon nanotubes (CNTs), as the basis for chemiresistor research. Due to their high surface area, interwire junctions, and restricted conduction pathways, NWs give …
-
Functionalization and fabrication of single-walled carbon nanotube-based chemiresistors for sensory applications
… improves the overall robustness of SWCNT-based chemiresistors (e.g., humidity and heat). In our other studies, we fabricated sensors by drawing. Abrasion is a safe, simple, solvent-free, and low cost method for deposition of carbon-based materials onto a substrate. We successfully demonstrated …
-
Modeling and Data Analysis of Conductive Polymer Composite Sensors
… change of the sensor signals. In this work, 64 chemiresistors representing eight different carbon concentrations (8–60 vol.% carbon) were constructed by depositing thin films of a carbon black–polyisobutylene composite onto concentric spiral platinum electrodes on a silicon chip. The responses …
-
The development of multisensor arrays utilising conducting polymers.
… this format the films act as chemical resistors (chemiresistors) the current flow being influenced by the polymers' molecular electronics. Devices of this nature are potentially useful as sensors for analytes which cause the reversible modulation of the films' molecular electronics, leading to a …
-
Hybrid Nanostructures for Artificial Machine Olfaction
… this task is through the use of an array of chemiresistors in an electronic nose device. For this study, chemiresistors were constructed using 3-D silica nanospring mats with a contiguous film of ZnO nanocrystals and ZnO nanocrystals decorated by metallic nanoparticles. Samples with an …
-
Harnessing inorganic coordination chemistry for novel sensing applications
… systems. In Chapter 1, we give an overview of chemiresistors in chemical detection with an emphasis on those based on carbon nanotubes. In Chapter 2, we employ metalloporphyrin complexes bearing late first-row transition metal centers in composites with single-walled carbon nanotubes (SWCNTs) …
-
Complexing Carbon Nanomaterials and Reactive Metal Species for Selective Chemical Sensing and Tunable Catalysis
… and stabilize the Pd NPs dispersion. SWCNT-based chemiresistors and graphene field-effect transistors (GFETs) using these PAE-supported small Pd NPs are sensitive, selective, and robust sensory materials for hydrogen gas under ambient conditions. In Chapter 5, we describe chemiresistors based on …
-
Growth and characterization of carbon nanostructures on zinc oxide nanostructures
… and to test their performances when used as chemiresistors to detect low doses (~ ppm) of polluting gases, like ammonia and acetone. Nanostructures of ZnO and carbon, including carbon nanotubes, exhibit on their own exceptional qualities, which can be enhanced when they are combined in …
-
IMPLEMENTATION OF NOVEL RECEPTOR-TRANSDUCTION CONCEPTS AND MATERIAL MORPHOLOGIES IN GAS SENSORICS
… dioxide were proposed to be used as self-heated chemiresistors capable of operating in the absence of an external heater, thus paving the way for ultra-low power consumption sensors. For the first time VO2 nanowires were used to create a nano-Pirani gauge and a gas sensor employing a sharp …
-
Characterizing the role of defects on the sensing performance of carbon nanotube and graphene based gas sensors
… the sensing response seen in carbon nanotube chemiresistors is associated with a change in the resistance of the individual carbon nanotubes or changes in the resistance of the junctions. A network analysis was carried out to better understand the relative contributions of the carbon nanotubes …
-
Portable and Non-Intrusive Sensors for Monitoring Air Pollution
… variations. In this thesis, I present chemiresistors based on graphene/carboxymethyl cellulose (CMC) and carbon nanotube/CMC composites capable of sensing low, down to 20 ppm and 6 ppm, NO₂ concentration respectively. The new sensors show selectivity to NO₂ because of the selective …
-
Manipulating Conjugation in electronic polymers and graphitic materials: chemosensors, precursor routes, and self-assembly
… in SWCNT-based chemiresistive gas sensors. These chemiresistors were prepared by ball milling of SWCNTs and selectors, compression into a pellet, and mechanical abrasion between gold electrodes on paper. We demonstrate that sensing responses reflect halogen bonding trends, with some exceptions. …
-
Polythiophene als sensitive Filme in chemischen Sensoren
… the polythiophene films were demonstrated with chemiresistors for the redox active gases NO2 and NH3. The reaction kinetics were investigated depending on humidity and temperature.
-
Reliability, power dissipation, sensing, and thermal transport in carbon nanomaterials and devices
… sensitivity of graphene. Therefore, simple chemiresistors made from CVD polycrystalline graphene could be used as highly sensitive pollutant detectors in “smart” climate control systems to reduce energy consumption by residential and commercial buildings. Lastly, we develop an electrical …
-
Využití chemirezistorů pro zlepšené snímání látek při analýze dechu
Diplomová práce se zabývá otázkou analýzy dechu s využitím chemirezistorů jako detekčních prvků pro analýzu vydechovaného vzduchu. Důraz je kladen na aplikaci fluktuačně zlepšeného snímání u chemirezistorů pro analýzu dechu, konstrukční řešení použitelného měřícího systému, a jeho kalibraci. Oproti …
-
Interactive Wireless Sensor for Remote Trace Detection and Recognition of Hazardous Gases
<p>The interactive wireless sensor detects many hazardous gases such as Hexane, Propane, Carbon monoxide and Hydrogen. These gases are highly toxic and used in different kinds of manufacturing industries, domestic purpose and so on. So, building a sensor that can detect this kind of gases can save …