Synthesis of polyaniline (printable nanoink) gas sensor for the detection of ammonia gas (original) (raw)
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Fabrication of an ammonia gas sensor using inkjet-printed polyaniline nanoparticles
Talanta, 2008
This work details the fabrication and performance of a sensor for ammonia gas analysis which has been constructed via the inkjet-printed deposition of polyaniline nanoparticle films. The conducting films were assembled on interdigitated electrode arrays and characterised with respect to their layer thickness and thermal properties. The sensor was further combined with heater foils for operation at a range of temperatures. When operated in a conductimetric mode, the sensor was shown to exhibit temperaturedependent analytical performance to ammonia detection. At room temperature, the sensor responded rapidly to ammonia (t 50 = 15 s). Sensor recovery time, response linearity and sensitivity were all significantly improved by operating the sensor at temperatures up to 80 • C. The sensor was found to have a stable logarithmic response to ammonia in the range of interest (1-100 ppm). The sensor was also insensitive to moisture in the range from 35 to 98% relative humidity. The response of the sensor to a range of common potential interferents was also studied.
Hollow Polyaniline Nanofibers for Highly Sensitive Ammonia Detection Applications
IEEE Sensors Journal, 2019
A thin film sensor based on hollow polyaniline nanofibers is fabricated for ammonia sensing applications at room temperature (25 C). Polyaniline nanotubular structures (H.PANI) are synthesized via in situ chemical polymerization method with the inner diameter of 200-300 nm and the outer diameter of 350-450 nm. FE-SEM, FTIR, and XRD tests are performed to analyze the H.PANI structure. To investigate the effect of structure on gas sensing performances, H.PANI sensor is compared with the polyaniline powder (P.PANI) sensor. The measured LOD of H.PANI sensor is 81 ppb, which is an indication that it can be used in various applications. There is a great proton exchange between H.PANI and ammonia gas due to its high surface to volume ratio, leading to high sensitivity. The response of the H.PANI and P.PANI sensors at 1 ppm ammonia are about 3.36% and 1.26%, respectively.
Chemiresistive ammonia gas sensor based on branched nanofibrous polyaniline thin films
Journal of Materials Science: Materials in Electronics, 2019
In the present study, we report a facile synthesis of polyaniline (PANI) thin films and its application for the sensitive and selective detection of ammonia (NH 3) gas. The branched nanofibers of PANI have been synthesized by in situ oxidative polymerization of aniline monomer with varying oxidant concentration followed by deposition of thin films on a glass substrate by a dip coating method. The deposited thin films were characterized for their structural, morphological, and compositional studies using X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM) and Fourier transform Raman spectroscopic (FT-Raman) techniques. The XRD patterns revealed that the synthesized films are semicrystalline in nature. FE-SEM images exhibit interconnected branched nanofibrous network of PANI. The average fiber diameter observed from FE-SEM images is ~ 45 nm. The gas sensing performance of PANI thin films was studied in terms of sensitivity, responserecovery time and selectivity for different concentration of NH 3 gas. It is observed that PANI thin film gas sensor shown selective response towards NH 3 gas even at a lowest concentration up to 10 ppm at room temperature. Thus, the developed PANI thin film sensor exhibited an admirable gas sensing performances at room temperature towards NH 3 with high sensitivity of 63.50% for 100 ppm of NH 3 gas.
Room Temperature Ammonia Gas Sensing Using Polyaniline Nanoparticles Based Sensor
2017
In the present research effort, we account for the acquisition of room temperature ammonia gas sensor based on polyaniline (PANI) nanoparticles. The polyaniline thin film was deposited on porous silicon substrate using the spin coating method. PANI nanofilms were characterized for their structural as well as surface morphologies. The XRD analysis showed partially crystalline nature polyaniline thin film. The Ammonia gas sensing response of PANI was obtained for different concentration of ammonia (50, 100, 200, 300, 400, 500 and 600 ppm). The sensitivity of PANI was observed to increase with the increase in the concentration of ammonia.
Sensors
Polyaniline (PANI) is a conducting polymer, widely used in gas-sensing applications. Due to its classification as a semiconductor, PANI is also used to detect reducing ammonia gas (NH3), which is a well-known and studied topic. However, easier, cheaper and more straightforward procedures for sensor fabrication are still the subject of much research. In the presented work, we describe a novel, more controllable, synthesis approach to creating NH3 PANI-based receptor elements. The PANI was electrochemically deposited via cyclic voltammetry (CV) on screen-printed electrodes (SPEs). The morphology, composition and surface of the deposited PANI layer on the Au electrode were characterised with electron microscopy, Fourier-transform infrared spectroscopy and profilometry. Prior to the gas-chamber measurement, the SPE was suitably modified by Au sputtering the individual connections between the three-electrode system, thus showing a feasible way of converting a conventional three-electrode...
Ammonia Gas Sensing Characteristics of Chemically Synthesized Polyaniline Matrix
Sensors & Transducers, 2010
In present investigations polyaniline matrix was synthesized by oxidative polymerization (chemically synthesized). The polyaniline matrix was prepared on Si- substrate. The active layer of PANI as a sensor was fabricated with the help of spin-coating technique. The structural insight into the synthesized polyaniline matrix was sought by Fourier Transform Infrared (FTIR) spectroscopy. The mechanism of formation of polyaniline was also confirmed by UV spectroscopy. The electrical conductivity was measured by four probe method at room temperature. Ammonia gas sensing characteristics of the synthesized polyaniline matrix was studied by measuring the change in electrical resistance on exposure to ammonia gas at different concentrations from 100 to 500 ppm. The polyaniline matrix exhibits excellent sensing behavior for ammonia gas.
In this work, the simple and inexpensive technique for the development of toxic gas(ammonia) sensor using conducting polymer films is described. The Polyaniline films were synthesized by of oxidative polymerization of aniline using ammonium peroxydisulfate on poly (methyl methacrylate) substrate. In the present investigation, HClO 4 (Perchloric acid) and PVA on PMMA substrate has been successfully synthesized PANI film by simple chemical polymerization technique. The synthesized Polyaniline films were characterized by using UV-visible, FTIR, SEM and the electrical conductivity. The ammonia sensing behaviour of the synthesized structure was studied by indigenously developed computer controlled gas chamber. The synthesized PANI structure shows excellent sensing behavior for 20-250 ppm of ammonia.
SYNTHESIS OF NANOSTRUCTURES OF POLYANILINE DOPED WITH INORGANIC DOPANT FOR SENSING AMMONIA
Nanostructured samples of polyaniline (PANI), doped with inorganic bismuth nitrate (Bi(NO3)3), have been synthesized employing chemical oxidative polymerization and electrodeposition. The influence of the process variation on the structure, room temperature electrical conductivity and on ammonia vapour sensing performance (response percentage and response time) has been investigated. The synthesized samples have been structurally characterized by transmission electron microscopy (TEM) UV-VIS and Fourier transform infrared (FTIR) spectra. TEM analysis reveals formation of nanorods and nanospheres of PANI. Polymerization produces nanospheres of PANI and electrodeposition leads to formation of nanorod-like structures. The conductivity of the prepared samples were measured as a function of time after exposure to ammonia indicating that the polymerized sample exhibit fast response (least response time), while the electrodeposited samples show sluggish response. Thus response percentages ...
ZnO assisted polyaniline nanofibers and its application as ammonia gas sensor
Sensors and Actuators B: Chemical, 2014
A novel route for the synthesis of polyaniline nanofibers in the presence of varying amounts of zinc oxide has been reported in this paper. The homogeneous PANI nanofibers were prepared through template approach, in which the ZnO nanoparticles were used as template. Structural, optical and morphological analysis of synthesized nanofibers was carried out using X-ray diffraction, UV-vis, IR spectroscopy and FESEM techniques. The thick films of the synthesized polyaniline powder were deposited on alumina substrate and their sensing response to ammonia gas was investigated. Optimum sensing response was achieved with PANI nanofibers synthesized in the presence of 30 wt% ZnO powder. The sensing response of fabricated sensor was proportional to the ammonia gas concentration and exhibited excellent selectivity toward ammonia gas.
Fabrication and characterization of polyaniline-based gas sensor by ultra-thin film technology
Sensors and Actuators B-chemical, 2002
Pure polyaniline (PAN) film, polyaniline and acetic acid (AA) mixed film, as well as PAN and polystyrenesulfonic acid (PSSA) composite film with various number of layers were prepared by Langmuir–Blodgett (LB) and self-assembly (SA) techniques. These ultra-thin films were characterized by ultraviolet–visible (UV–VIS) spectroscopy and ellipsometry. It is found that the thickness of PAN-based ultra-thin films increases linearly with the increase of the number of film layers. The gas-sensitivity of these ultra-thin films with various layers to NO2 was studied. It is found that pure polyaniline films prepared by LB technique had good sensitivity to NO2, while SA films exhibited faster recovery property. The response time to NO2 and the relative change of resistance of ultra-thin films increased with the increase of the number of film layers. The response time of three-layer PAN film prepared by LB technique to 20 ppm NO2 was about 10 s, two-layer SA film was about 8 s. The mechanism of sensitivity to NO2 of PAN-based ultra-thin films was also discussed.