Polyaniline based Composite for Gas Sensors

In this research work, we have demonstrated the synthesis, spectroscopic characteristics, thermal behaviour and DC conductivity of a few nanostructured composites, substituted conducting polymers (ICPs) and composites of ICPs. The physical properties of aforementioned composites are significantly changed by the doping with HCl, H2SO4, HNO3, H3PO4, or acrylic acid. The charge transport properties of these polymeric materials have been studied in detail because of their potential application in gas sensors. In the current work, varieties of conducting polymer based materials such as PANI-ES/Cloisite 20A nanostructured composite, acrylic acid (AA) doped PANI polymer, N-substituted conducting polyaniline polymer, DL−PLA/PANI-ES composites, poly methyl methacrylate (PMMA) based polyaniline composite, and inorganic acid doped polyaniline are sucessfuly synthesized using aniline/aniline hydrochloride as precursors in acidic medium. Particularly, AA based synthesised PANI polymer was found with higher solubility The spectroscopic, thermal stability, enthalpy of fusion, room temperature DC conductivity and temperature dependent DC conductivity measurements with and without magnetic was carried out with as-synthesized materials. The FTR/ATR−FTIR spectra indicated the presence of different functional groups in the as-prepared composite materials. The UV−Visible absorption spectroscopic analysis showed the presence of polaron band suggesting PANI-ES form. The Room temperature DC conductivity, temperature variation DC conductivity (in presence and absence of magnetic field), and magnetoresistance (MR) of as-prepared conducting polyaniline based were analysed. The highest room temperature DC conductivity value was obtained from H2SO4 doped based composite materials and all prepared conductive composites were followed ohms law. The low temperature DC conductivity was carried out in order to study the semiconducting nature of prepared materials. The Mott type VRH model was found to be well fitted the conductivity data and described the density of states at the Fermi level which is constant in this temperature range. From MR plots, a negative MR was observed, which described the quantum interference effect on hopping conduction. We discuss different gas analytes i.e., NO2, LPG, H2, NH3, CH4, and CO of conducting polymer based materials.

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Preparation and Application of 2D MXene-Based Gas Sensors: A Review

Chemosensors ◽

10.3390/chemosensors9080225 ◽

2021 ◽

Vol 9 (8) ◽

pp. 225

Author(s):

Qingting Li ◽

Yanqiong Li ◽

Wen Zeng

Keyword(s):

Composite Materials ◽

Specific Surface ◽

Surface Area ◽

Gas Sensor ◽

Specific Surface Area ◽

Gas Sensors ◽

Room Temperature ◽

Gas Sensing ◽

Interlayer Spacing ◽

Preparation Methods

Since MXene (a two-dimensional material) was discovered in 2011, it has been favored in all aspects due to its rich surface functional groups, large specific surface area, high conductivity, large porosity, rich organic bonds, and high hydrophilicity. In this paper, the preparation of MXene is introduced first. HF etching was the first etching method for MXene; however, HF is corrosive, resulting in the development of the in situ HF method (fluoride + HCl). Due to the harmful effects of fluorine terminal on the performance of MXene, a fluorine-free preparation method was developed. The increase in interlayer spacing brought about by adding an intercalator can affect MXene’s performance. The usual preparation methods render MXene inevitably agglomerate and the resulting yields are insufficient. Many new preparation methods were researched in order to solve the problems of agglomeration and yield. Secondly, the application of MXene-based materials in gas sensors was discussed. MXene is often regarded as a flexible gas sensor, and the detection of ppb-level acetone at room temperature was observed for the first time. After the formation of composite materials, the increasing interlayer spacing and the specific surface area increased the number of active sites of gas adsorption and the gas sensitivity performance improved. Moreover, this paper discusses the gas-sensing mechanism of MXene. The gas-sensing mechanism of metallic MXene is affected by the expansion of the lamellae and will be doped with H2O and oxygen during the etching process in order to become a p-type semiconductor. A p-n heterojunction and a Schottky barrier forms due to combinations with other semiconductors; thus, the gas sensitivities of composite materials are regulated and controlled by them. Although there are only several reports on the application of MXene materials to gas sensors, MXene and its composite materials are expected to become materials that can effectively detect gases at room temperature, especially for the detection of NH3 and VOC gas. Finally, the challenges and opportunities of MXene as a gas sensor are discussed.

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Gas sensing properties of conducting polymer/Au-loaded ZnO nanoparticle composite materials at room temperature

Nanoscale Research Letters ◽

10.1186/1556-276x-9-467 ◽

2014 ◽

Vol 9 (1) ◽

Cited By ~ 21

Author(s):

Viruntachar Kruefu ◽

Anurat Wisitsoraat ◽

Adisorn Tuantranont ◽

Sukon Phanichphant

Keyword(s):

Composite Materials ◽

Conducting Polymer ◽

Room Temperature ◽

Gas Sensing ◽

Zno Nanoparticle ◽

Sensing Properties ◽

Gas Sensing Properties

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Table-like magnetocaloric effect around room temperature of antiperovskite composite materials based on Mn3Sn1-xGaxC

Materials Today Communications ◽

10.1016/j.mtcomm.2021.102379 ◽

2021 ◽

Vol 27 ◽

pp. 102379

Author(s):

Congji Jiang ◽

Jun Yan ◽

Xiangqian Wang ◽

Shijie Wei ◽

Pengli Liang ◽

...

Keyword(s):

Composite Materials ◽

Magnetocaloric Effect ◽

Room Temperature

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Effect of Humidity on Gas Sensing Performance of Carbon Nanotube Gas Sensors Operated at Room Temperature

IEEE Sensors Journal ◽

10.1109/jsen.2020.3038647 ◽

2020 ◽

pp. 1-1

Author(s):

Mostafa Shooshtari ◽

Alireza Salehi ◽

Sten Vollebregt

Keyword(s):

Carbon Nanotube ◽

Gas Sensors ◽

Room Temperature ◽

Gas Sensing ◽

Sensing Performance

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Ultraviolet light-emitting diode-assisted highly sensitive room temperature NO2 gas sensor for low-temperature solution-processed ZnO/TiO2 nanorods decorated with plasmonic Au nanoparticles

Nanoscale ◽

10.1039/d1nr01001h ◽

2021 ◽

Author(s):

Soon-Hwan Kwon ◽

Tae-Hyeon Kim ◽

Sang-Min Kim ◽

Semi Oh ◽

Kyoung-Kook Kim

Keyword(s):

Gas Sensors ◽

High Performance ◽

Room Temperature ◽

Au Nanoparticles ◽

Light Emitting Diode ◽

Light Emitting ◽

No2 Gas Sensor ◽

Highly Sensitive ◽

Temperature Solution ◽

Semiconducting Metal Oxides

Nanostructured semiconducting metal oxides such as SnO2, ZnO, TiO2, and CuO have been widely used to fabricate high performance gas sensors. To improve the sensitivity and stability of gas sensors,...

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Thermal, Viscoelastic, Mechanical and Wear Behaviour of Nanoparticle Filled Polytetrafluoroethylene: A Comparison

Polymers ◽

10.3390/polym12091940 ◽

2020 ◽

Vol 12 (9) ◽

pp. 1940 ◽

Cited By ~ 1

Author(s):

Levente Ferenc Tóth ◽

Patrick De Baets ◽

Gábor Szebényi

Keyword(s):

Room Temperature ◽

Filler Content ◽

Research Work ◽

Tensile Modulus ◽

Al2o3 Content ◽

Wear Behaviour ◽

X Ray ◽

Mechanical Stirring ◽

Wear Analysis ◽

Sintering Method

In this research work, unfilled and mono-filled polytetrafluoroethylene (PTFE) materials were developed and characterised by physical, thermal, viscoelastic, mechanical, and wear analysis. The applied fillers were graphene, alumina (Al2O3), boehmite alumina (BA80), and hydrotalcite (MG70) in 0.25/1/4/8 and 16 wt % filler content. All samples were produced by room temperature pressing–free sintering method. All of the fillers were blended with PTFE by intensive dry mechanical stirring; the efficiency of the blending was analysed by Energy-dispersive X-ray spectroscopy (EDS) method. Compared to neat PTFE, graphene in 4/8/16 wt % improved the thermal conductivity by ~29%/~84%/~157%, respectively. All fillers increased the storage, shear and tensile modulus and decreased the ductility. PTFE with 4 wt % Al2O3 content reached the lowest wear rate; the reduction was more than two orders of magnitude compared to the neat PTFE.

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Gas Sensors Based on Mechanically Exfoliated MoS2 Nanosheets for Room-Temperature NO2 Detection

Sensors ◽

10.3390/s19092123 ◽

2019 ◽

Vol 19 (9) ◽

pp. 2123 ◽

Cited By ~ 13

Author(s):

Wenli Li ◽

Yong Zhang ◽

Xia Long ◽

Juexian Cao ◽

Xin Xin ◽

...

Keyword(s):

Gas Sensors ◽

High Performance ◽

Density Functional ◽

Room Temperature ◽

Mos2 Nanosheets ◽

Mechanical Exfoliation ◽

High Responsivity ◽

Recovery Behavior ◽

No2 Gas Sensors ◽

No2 Detection

The unique properties of MoS2 nanosheets make them a promising candidate for high-performance room temperature gas detection. Herein, few-layer MoS2 nanosheets (FLMN) prepared via mechanical exfoliation are coated on a substrate with interdigital electrodes for room-temperature NO2 detection. Interestingly, compared with other NO2 gas sensors based on MoS2, FLMN gas sensors exhibit high responsivity for room-temperature NO2 detection, and NO2 is easily desorbed from the sensor surface with an ultrafast recovery behavior, with recovery times around 2 s. The high responsivity is related to the fact that the adsorbed NO2 can affect the electron states within the entire material, which is attributed to the very small thickness of the MoS2 nanosheets. First-principles calculations were carried out based on the density functional theory (DFT) to verify that the ultrafast recovery behavior arises from the weak van der Waals binding between NO2 and the MoS2 surface. Our work suggests that FLMN prepared via mechanical exfoliation have a great potential for fabricating high-performance NO2 gas sensors.

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