Screen printed electrodes based on polymer/MWCNT and polymer/G nanocomposite for advanced gas sensing application (original) (raw)
Related papers
IEEE Transactions on Nanotechnology, 2000
Gas sensors have been widely used in many applications including environmental monitoring, industrial control, and detection in warfare or for averting security threats. High sensitivity, selectivity, and fast response time are required for application in real-time monitoring and detection of toxic gases. Single-walled carbon nanotubes (SWCNTs) provide large specific surface area beneficial for gas adsorption thereby increasing sensor sensitivity. In this paper, ammonia (NH 3 ) gas sensors based on SWCNTs were developed using interdigitated silver electrodes printed with nanoparticulate ink on alumina substrates. Simple and inexpensive methods including shaking and dispersion in appropriate solvents were used to debundle SWCNTs for improving sensor response. The fabricated sensors showed a maximum response of 27.3% for 500 ppm NH 3 at room temperature. Detection limit of the sensor devices at room temperature were estimated to be ∼ 3 ppm.
Robust fabrication of selective and reversible polymer coated carbon nanotube-based gas sensors
Sensors and Actuators B: Chemical, 2010
In this study, a systematic investigation was carried out to produce reliable and reproducible polymer coated nanotube sensors to enhance their selectivity against exposed analyte molecules. To do this, a series of uniformly distributed, randomly aligned SWNT films were prepared via vacuum filtration from suspended HiPCO nanotubes and transferred to photolithography patterned silicon chips with high reproducibility and yield. The SWNT film density was optimized for detection of dimethyl methylphosphonate and ammonia at the percolation threshold range of nanotube electric conductance. Cyclic voltammetry (CV) was used to polymerize seven different polymers in aqueous solutions and coat a thin layer onto optimized SWNT films. Polymer coated SWNT-based sensors were analyzed for selectivity for a variety of gases. Results indicate that the electropolymerization of different polymers onto nanotube surfaces can be a simple and promising way to obtain controlled, reliable, and modulated response for various analyte molecules.
IEEE Sensors Letters
CNTs based chemiresistive gas sensors are known to not fully recover to the baseline after gas exposure. This is why often heat is applied to thermally activate the sensor and improve the gas desorption process occurring at the surface. In this paper, we combine single-walled CNTs (SWCNTs) with conjugated polymers (CPs) i.e., Poly(3-hexylthiophene)(P3HT), to realize chemiresistive gas sensors with improved recovery. Five configurations were fabricated with diverse positions of the sensing material layers with respect to the interdigitated electrodes (IDEs), namely: SWCNTs/IDEs and P3HT/IDEs as controls for the CNTs and P3HT singular materials; SWCNTs/P3HT/IDEs, SWCNTs/IDEs/P3HT and P3HT/SWCNTs/IDEs as combined sensing materials layers configurations. The results show that in particular, the P3HT/SWCNTs/IDEs sensors exhibit better performance with respect to the other configurations when exposed to 5, 25, and 50 ppm NH 3. Improvements in terms of response time (103 seconds faster at 5 ppm), sensor response (+26.83% at 50 ppm), and improved recovery to the baseline (+25.69% and +11.34% at 5 and 50 ppm respectively) were obtained when evaluated against SWCNTs/IDEs sensors. These findings suggest that addition of CPs (i.e. P3HT) may be a promising approach to enhance the performance and stability of SWCNTs-based chemiresistive gas sensors, providing a new direction for future research in this field. Future research to investigate the effect of others CPs on the CNTs based chemiresistive gas sensors will be needed to realize more efficient and reliable ammonia gas sensors.
Micromachines, 2022
Multi-walled carbon nanotubes (MWCNTs) were grown on a stainless-steel foil by thermal chemical vapor deposition (CVD) process. The MWCNTs were functionalized with carboxylic groups (COOH) on their surfaces by using oxidation and acid (3:1 H2SO4/HNO3) treatments for improving the solubility property of them in the solvent. The functionalized MWCNTs (f-MWCNTs) were conducted to prepare the solution by continuous stir in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), dimethyl sulfoxide (DMSO), ethylene glycol (EG) and Triton X-100. The solution was deposited onto a bendable substrate such as polyethylene terephthalate (PET) with a fabricated silver interdigitated electrode for application in a room-temperature gas sensor. A homemade-doctor blade coater, an UNO R3 Arduino board and a L298N motor driver are presented as a suitable system for screen printing the solution onto the gas-sensing substrates. The different contents of f-MWCNTs embedded in PEDOT:PSS were c...
Advanced Science Letters, 2011
In this paper, the multi-walled carbon nanotube (MWCNT)-polystyrene composite modified Pt electrode that is capable of serving as an efficient electrochemical gas sensor upon direct exposure to trace quantity of toxic gases like SO 2 and H 2 S with distinct electrochemical response is reported. Unlike other CNT-composite modified electrodes this new composite device relies on the use of MWCNTs as the sole conducting component, the other component polystyrene is non-conducting.
Electrochemically Functionalized Single-Walled Carbon Nanotube Gas Sensor
Electroanalysis, 2006
We demonstrate a facile fabrication method to make chemical gas sensors using single-walled carbon nanotubes (SWNT) electrochemically functionalized with polyaniline (PANI). The potential advantage of this method is to enable targeted functionalization with different materials to allow for creation of high-density individually addressable nanosensor arrays. PANI-SWNT network based sensors were tested for on-line monitoring of ammonia gas. The results show a superior sensitivity of 2.44% DR/R per ppm v NH 3 (which is more than 60 times higher than intrinsic SWNT based sensors), a detection limit as low as 50 ppb v , and good reproducibility upon repeated exposure to 10 ppm v NH 3 . The typical response time of the sensors at room temperature is on the order of minutes and the recovery time is a few hours. Higher sensitivities were observed at lower temperatures. These results indicate that electrochemical functionalization of SWNTs provides a promising new method of creating highly advanced nanosensors with improved sensitivity, detection limit, and reproducibility.
TOPICAL REVIEW: Recent progress in carbon nanotube-based gas sensors
Nanotechnol, 2008
The development of carbon nanotube-(CNTs-)based gas sensors and sensor arrays has attracted intensive research interest in the last several years because of their potential for the selective and rapid detection of various gaseous species by novel nanostructures integrated in miniature and low-power consuming electronics. Chemiresistors and chemical field effect transistors are probably the most promising types of gas nanosensors. In these sensors, the electrical properties of nanostructures are dramatically changed when exposed to the target gas analytes. In this review, recent progress on the development of different types of CNT-based nanosensors is summarized. The focus was placed on the means used by various researchers to improve the sensing performance (sensitivity, selectivity and response time) through the rational functionalization of CNTs with different methods (covalent and non-covalent) and with different materials (polymers and metals).
Journal of Sensors, 2012
Miniaturized gas-sensing devices that use single-walled carbon nanotubes as active material have been fabricated using two different electrode materials, namely, Au/Cr and NbN. The resistive sensors have been assembled aligning by dielectrophoresis the nanotube bundles between 40 μm spaced Au/Cr or NbN multifinger electrodes. The sensing devices have been tested for detection of the H2S gas, in the concentration range 10–100 ppm, using N2as carrier gas. No resistance changes were detected using sensor fabricated with NbN electrodes, whereas the response of the sensor fabricated with Au/Cr electrodes was characterized by an increase of the resistance upon gas exposure. The main performances of this sensor are a detection limit for H2S of 10 ppm and a recovery time of few minutes. The present study suggests that the mechanism involved in H2S gas detection is not a direct charge transfer between molecules and nanotubes. The hypothesis is that detection occurs through passivation of the...