scholarly journals A Novel Trace-Level Ammonia Gas Sensing Based on Flexible PAni-CoFe2O4 Nanocomposite Film at Room Temperature

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3077
Author(s):  
Rima D. Alharthy ◽  
Ahmed Saleh
Keyword(s):  
Room Temperature ◽  
Gas Sensing ◽  
Oxidative Polymerization ◽  
Portable Devices ◽  
Trace Level ◽  
Humidity Effect ◽  
Sensor Performance ◽  
Wearable Electronic ◽  
Relative Humidity Effect

In this study, we developed a new chemi-resistive, flexible and selective ammonia (NH3) gas sensor. The sensor was prepared by depositing thin film of polyaniline-cobalt ferrite (PAni-CoFe2O4) nanocomposite on flexible polyethylene terephthalate (PET) through an in situ chemical oxidative polymerization method. The prepared PAni-CoFe2O4 nanocomposite and flexible PET-PAni-CoFe2O4 sensor were evaluated for their thermal stability, surface morphology and materials composition. The response to NH3 gas of the developed sensor was examined thoroughly in the range of 1–50 ppm at room temperature. The sensor with 50 wt% CoFe2O4 NPs content showed an optimum selectivity to NH3 molecules, with a 118.3% response towards 50 ppm in 24.3 s response time. Furthermore, the sensor showed good reproducibility, ultra-low detection limit (25 ppb) and excellent flexibility. In addition, the relative humidity effect on the sensor performance was investigated. Consequently, the flexible PET-PAni-CoFe2O4 sensor is a promising candidate for trace-level on-site sensing of NH3 in wearable electronic or portable devices.

scholarly journals Preparation and Gas Sensing Properties of PANI/SnO2 Hybrid Material

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1360
Author(s):  
Qiaohua Feng ◽  
Huanhuan Zhang ◽  
Yunbo Shi ◽  
Xiaoyu Yu ◽  
Guangdong Lan
Keyword(s):  
Hybrid Material ◽  
Room Temperature ◽  
Tin Dioxide ◽  
Gas Adsorption ◽  
Gas Sensing ◽  
Oxidative Polymerization ◽  
Environmental Pollutants ◽  
Decomposition Temperature ◽  
Benzene Vapor ◽  
Thermo Gravimetric Analyzer

A sensor operating at room temperature has low power consumption and is beneficial for the detection of environmental pollutants such as ammonia and benzene vapor. In this study, polyaniline (PANI) is made from aniline under acidic conditions by chemical oxidative polymerization and doped with tin dioxide (SnO2) at a specific percentage. The PANI/SnO2 hybrid material obtained is then ground at room temperature. The results of scanning electron microscopy show that the prepared powder comprises nanoscale particles and has good dispersibility, which is conducive to gas adsorption. The thermal decomposition temperature of the powder and its stability are measured using a differential thermo gravimetric analyzer. At 20 °C, the ammonia gas and benzene vapor gas sensing of the PANI/SnO2 hybrid material was tested at concentrations of between 1 and 7 ppm of ammonia and between 0.4 and 90 ppm of benzene vapor. The tests show that the response sensitivities to ammonia and benzene vapor are essentially linear. The sensing mechanisms of the PANI/SnO2 hybrid material to ammonia and benzene vapors were analyzed. The results demonstrate that doped SnO2 significantly affects the sensitivity, response time, and recovery time of the PANI material.

Influence of Catalyst Loading Method on Titania-Based Optical Hydrogen Gas Sensing Properties

2013 ◽  
Vol 582 ◽  
pp. 210-213 ◽  
Author(s):  
Junichi Hamagami ◽  
Ryo Araki ◽  
Shohei Onimaru ◽  
G. Kawamura ◽  
Atsunori Matsuda
Keyword(s):  
Palladium Catalyst ◽  
Room Temperature ◽  
Gas Sensing ◽  
Hydrogen Gas ◽  
Catalyst Loading ◽  
Sensing Properties ◽  
Precise Control ◽  
Sensor Performance ◽  
Loading Method ◽  
Gas Sensing Properties

We reported that titania ceramic coating loaded with palladium catalyst worked as an optical hydrogen gas sensor at room temperature. The palladium metal of this sensor worked as a catalyst not only for room-temperature operation but also for high selectivity to hydrogen gas. Precise control of metal/ceramic interface between the titania and the palladium was very important in order to improve the sensor performance such as sensitivity, response time, recovery time. Influence of a difference in palladium-catalyst loading method (photodeposition and sputtering) on the optical hydrogen gas sensing properties for the titania-based sensor was investigated. It was found that the catalytic loading process significantly affected the optical hydrogen characteristics of the titania-based coating.

Analysis and Comparison of Vapor and Liquid Deposition of Pyrrole on Wool Fiber

2009 ◽  
Vol 87-88 ◽  
pp. 468-473 ◽  
Author(s):  
Xin Jin ◽  
Yong Yue Wang ◽  
Chang Fa Xiao
Keyword(s):  
Vapor Phase ◽  
Room Temperature ◽  
Oxidative Polymerization ◽  
Composite Fiber ◽  
Granular Structure ◽  
Deposition Technique ◽  
Electrical Stability ◽  
Vapor Phase Deposition ◽  
Liquid Deposition

Polypyrrole/wool composite fiber was prepared by in situ oxidative polymerization from vapor phase and liquid phase pyrrole at room temperature, by using FeCl3 as catalyst. The effect of deposition technique on the surface morphology, mechanical properties and the electrical stability of fibers were discussed. The result showed that deposition technique has a strong effect and fiber prepared by vapor phase deposition has much fine and small granular structure, lower resistance, better mechanical property and electrical stability.

Fabrication of Polyaniline-Coated Carbon Nanotubes Conducting Wire Nanocomposite for NH3 Gas Sensors at Room Temperature

2012 ◽  
Vol 554-556 ◽  
pp. 661-666
Author(s):  
Kan Kan ◽  
Chun Sheng Chen ◽  
Guang Xin Zhang ◽  
Chao Jiang ◽  
Li Li ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Room Temperature ◽  
Gas Sensing ◽  
Oxidative Polymerization ◽  
Composite Films ◽  
Ammonium Persulfate ◽  
Coating Method ◽  
Conducting Wire ◽  
Coated Carbon ◽  
Higher Sensitivity

The nanocomposite of polyaniline (PAni)-coated Carbon nanotubes (CNT) for NH3gas sensing application are presented in this paper. The nanorods of PAni/CNT nanocomposite was synthesized by chemical oxidative polymerization of aniline using ammonium persulfate in acidic medium. The aniline was adsorbed in CNT by vacuum absorption method. The morphologies and properties of the nanocomposite have been characterized by SEM, XRD and FTIR respectively. Thin sensor of PAni/CNT nanorods was prepared by spin coating method. Finally, the response of these composite films for NH3gas was evaluated by monitoring the change in electrical resistance at room temperature. With compared to the pure PAni and CNT, tSubscript texthe nanorods of PAni/CNT composite films show a higher sensitivity.

Well-Defined Blackberry-Like Polypyrrole Microspheres via Chemical Oxidative Polymerization in the Presence of Functional Floating Bead as In Situ Dopant

2014 ◽  
Vol 904 ◽  
pp. 159-163 ◽  
Author(s):  
Jia Ping Lao ◽  
Chao Yang ◽  
Hao Dao Mo ◽  
Yu Ping Li ◽  
Li Min Zang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Electrical Conductivity ◽  
Sulfonic Acid ◽  
Room Temperature ◽  
Oxidative Polymerization ◽  
High Electrical Conductivity ◽  
Chemical Oxidative Polymerization ◽  
Inorganic Substrate ◽  
Thermal Stability Of

Functional floating bead (F-FB), prepared by anchoring the organic sulfonic acid on the surface of the blackberry-like structural FB, was used as both the inorganic substrate and the in situ dopant for the in situ chemical oxidative polymerization of pyrrole to obtain the plypyrrole/functional floating bead (PPy/F-FB) nanocomposite material. The composites possess high electrical conductivity at room temperature. Thermogravimetric analysis shows that the thermal stability of PPy/F-FB composites was enhanced and these can be attributed to the retardation effect of sulfonic acid-functionalized FB as barriers for the degradation of PPy. The morphology of PPy/FB composites showed the well-defined blackberry-like morphology.

Enhanced room temperature ammonia sensing properties of polypyrrole–zinc tin oxide nanocomposite

2020 ◽  
Vol 34 (17) ◽  
pp. 2050188
Author(s):  
Seyede Azadeh Hejazi Juybari ◽  
Hossain Milani Moghaddam
Keyword(s):  
Recovery Time ◽  
High Performance ◽  
Room Temperature ◽  
Gas Sensing ◽  
Oxidative Polymerization ◽  
Physicochemical Characterization ◽  
High Porosity ◽  
Sensing Properties ◽  
Ammonia Sensing ◽  
Zinc Tin Oxide

Polypyrrole (PPy)–Zn2SnO4 nanocomposites with different weight percentages (0–20%) of Zn2SnO4 were successfully prepared by chemical oxidative polymerization. The prepared nanocomposites were deposited on epoxy glass substrate using a spin coating technique and have been characterized using various techniques such as X-ray diffractometer, field emission scanning electron microscopy (FESEM) and Fourier transform infrared (FTIR) spectrometer. The physicochemical characterization confirmed well-formed dodecylbenzene (DBSA)-doped PPy–Zn2SnO4 nanocomposites with granular morphology and high porosity. Among various nanocompositions, DBSA-doped PPy–Zn2SnO4 (10 wt.%) nanocomposite was found to be highly sensitive towards NH3 vapor at room temperature i.e. with a chemiresistive response of 5.44% at 27 ppm with a reasonably fast recovery time of 76 s. Additionally, it shows a linear response and appropriate recovery time at all concentrations of NH3 vapor. The DBSA-doped PPy–Zn2SnO4 nanocomposite response is four times better than pure PPy toward NH3 vapor at room temperature. Therefore, it is expected that such material with excellent gas sensing properties at room temperature can be used for high-performance NH3 sensors.

Synthesis, Structural and Gas Sensing Properties of Nano-Branched Coaxial Polyaniline Fibers by Electrospinning

2012 ◽  
Vol 562-564 ◽  
pp. 308-311 ◽  
Author(s):  
Cheng Chun Tang ◽  
Rong Huang ◽  
Yun Ze Long ◽  
Bin Sun ◽  
Hong Di Zhang ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Oxidative Polymerization ◽  
Impedance Analysis ◽  
Ammonia Concentration ◽  
Ammonia Gas ◽  
Sensing Properties ◽  
Ammonia Sensing ◽  
Ppm Level ◽  
Polymerization Method

Polyaniline (PANI) is a promising functional polymer in the field of toxic gas detection. In this paper, nano-branched coaxial PANI fibers were grown on electrospun poly(methyl methacrylate) (PMMA) nanofibers by an in situ chemical oxidative polymerization method. The resultant PANI/PMMA fibers were characterized by scanning electronic microscopy and Raman spectrum analysis. The conductivity of an individual coaxial PANI/PMMA fiber is about 2.123 S/cm and that of the conducting PANI coating layer is about 21.8 S/cm. The ammonia sensing properties of the samples were tested by means of impedance analysis. The nano-branched PANI fibers can response significantly to low concentration of ammonia due to large specific surface area, and the sensitivity shows good linear relationship to the ammonia concentration of ppm level. These results indicate that nano-branched coaxial PANI fibers are promising candidate for detection of toxic ammonia gas.

A Study on the Properties of Polypyrrole Coated Polyester Fiber

2011 ◽  
Vol 221 ◽  
pp. 48-53 ◽  
Author(s):  
Jin Yun Xu ◽  
Xin Jin
Keyword(s):  
Room Temperature ◽  
Oxidative Polymerization ◽  
Composite Fiber ◽  
Granular Structure ◽  
Polyester Fiber ◽  
Conducting Materials ◽  
Polyester Fibers ◽  
Heating Treatment ◽  
Polypyrrole Composite

Polyester fibers are used in a great many textile and industrial materials, their undesirable electrical advantage bring about disadvantages. Direct polymerization of pyrrole on polyester fibers may provide useful tools for producing new conducting materials. Polyester/polypyrrole composite fiber was prepared by in situ oxidative polymerization from liquid phase pyrrole at room temperature. The result showed that deposition of pyrrole is an effective way to impart conductivity to polyester fiber. The Tg of coated polyester fiber decreased and the surface of Ppy coated polyester fiber displayed an evident granular structure. In addition, the Ppy coatings have good stability under washing and heating treatment, which demonstrate that polypyrrole has good affinity to polyester fiber.

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