• Title/Summary/Keyword: Chemiresistors

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Nerve-Agent Selective Chemiresistors Fabricated by Oxime Decorated Polypyrrole Layer on Cellulose Paper (셀룰로오스 종이 상에 Oxime 도입된 polypyrrole 층을 제조한 신경작용제 선택적 화학저항 센서)

  • Changhoon Jeon;Taihwan Ha
    • Journal of the Korea Institute of Military Science and Technology
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    • v.27 no.4
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    • pp.528-534
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    • 2024
  • In continuous research of detecting highly toxic chemical warfare agents to ensure preparedness for the future battlefield, flexible and wearable sensor platforms with high sensitivity are still demanding. Herein we demonstrate a facile fabrication of polypyrrole-based chemiresistors on cellulose paper for the detection of nerve gas simulants. In order to optimize electrical properties of sensor platform, conducting polymer made of polypyrrole were first synthesized on flexible cellulose paper and interdigitated electrodes were formed thereon. Following confirmation of polypyrrole and/or oxime moiety through FT-IR analyses, electrical characteristics were measured in the various ratio of monomers between simple pyrrole and oxime-modified one. Typically for the optimized chemiresistor(2:8 molar ratio of simple pyrrole and oxime-modified one), eleven species of chemical warfare agents were examined and enhanced conductivity(104~105 order) was observed for three simulants(diethyl cyanophosphonate, diisopropyl fluorophosphonate and diethyl chlorophosphonate), which was mainly attributed to intermolecular hydrogen bonding, while no significant responses was recorded against sixteen common volatile organic chemicals.

Ionic Liquid/Styrene-Acrylonitrile Copolymer Nanofibers as Chemiresistor for Alcohol Vapours

  • Kim, Min-Jae;Kang, Eun-Soo;Park, Dong-Wha;Shim, Bong-Sup;Shim, Sang-Eun
    • Bulletin of the Korean Chemical Society
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    • v.33 no.9
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    • pp.2867-2872
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    • 2012
  • SAN/$BMIPF_6$ nanofibers were fabricated by an electrospinning process and used as chemiresistors for sensing alcohol vapours. A hydrophobic and air-stable ionic liquid, $BMIPF_6$, was used to impart electrical conductivity to insulating SAN nanofibers. The effects of $BMIPF_6$ addition on the morphology of the nanofibers were explained in terms of surface tension, viscosity and conductivity. After exposing the SAN/$BMIPF_6$ nanofibers collected on an interdigitated electrode to alcohol vapours (ethanol, 1-propanol and 1-butanol), the resistance of the nanofibers decreased due to adsorption of alcohol molecules. The electrospun SAN/$BMIPF_6$ nanofibers sensor exhibited good sensitivity and reproducibility.

Recent Advances and Trends in Filters for Highly Selective Metal Oxide Gas Sensors (산화물 반도체형 가스센서의 선택성 향상을 위한 필터 연구 동향 및 전략)

  • Seong-Yong Jeong
    • Journal of Sensor Science and Technology
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    • v.33 no.1
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    • pp.48-55
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    • 2024
  • Metal-oxide-based semiconductor gas sensors are widely used because of their advantages, such as high response and simple sensing mechanism. Recently, with the rapid progress in sensor networks, computing power, and microsystem technology, sensor applications are expanding to various fields, such as food quality control, environmental monitoring, healthcare, and artificial olfaction. Therefore, the development of highly selective gas sensors is crucial for practical applications. This article reviews the developments in novel sensor design consisting of sensing films and physical and chemical filters for highly selective gas sensing. Unlike conventional sensors, the sensor structures with filters can separate the sensing and catalytic reactions into independent processes, enabling selective and sensitive gas sensing. The main objectives of this study are directed at introducing the role of various filters in gas-sensing reactions and promising sensor applications. The highly selective gas sensors combined with a functional filter can open new pathways toward the advancement of high-performance gas sensors and electronic noses.