Environmental characteristics of surface acoustic wave devices for sensing organophosphorus vapor

Park

et al. 2020

Sensors

G nerve agents are colorless, odorless, and lethal chemical warfare agents (CWAs). The threat of CWAs, which cause critical damage to humans, continues to exist, e.g., in warfare or terrorist attacks. Therefore, it is important to be able to detect these agents rapidly and with a high degree of sensitivity. In this study, a surface acoustic wave (SAW) array device with three SAW sensors coated with different sensing materials and one uncoated sensor was tested to determine the most suitable material for the detection of nerve agents and related simulants. The three materials used were polyhedral oligomeric silsesquioxane (POSS), 1-benzyl-3-phenylthiourea (TU-1), and 1-ethyl-3-(4-fluorobenzyl) thiourea (TU-2). The SAW sensor coated with the POSS-based polymer showed the highest sensitivity and the fastest response time at concentrations below the median lethal concentration (LCt50) for tabun (GA) and sarin (GB). Also, it maintained good performance over the 180 days of exposure tests for dimethyl methylphosphonate (DMMP). A comparison of the sensitivities of analyte vapors also confirmed that the sensitivity for DMMP was similar to that for GB. Considering that DMMP is a simulant which physically and chemically resembles GB, the sensitivity to a real agent of the sensor coated with POSS could be predicted. Therefore, POSS, which has strong hydrogen bond acid properties and which showed similar reaction characteristics between the simulant and the nerve agent, can be considered a suitable material for nerve agent detection.

Section: Design Of Saw Array Sensormentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

SAW Chemical Array Device Coated with Polymeric Sensing Materials for the Detection of Nerve Agents

Park

et al. 2020

Sensors

“…The structure of PMFOS is presented in Figure 2. [14]; (b) PLF [12]; (c) LSFA [13]; (d) PMPS [17]; (e) PMDFPS [18]; (f) DKAP [19,20].…”

Section: Introductionmentioning

confidence: 99%

“…A strongly acidic group found in the structure of many HBA polysiloxanes is hexafluoroisopropanol (HFIP) [ 12 , 13 , 14 , 15 , 16 ]. However, it shows a high affinity to water vapor that is always present in the environment.…”

Section: Introductionmentioning

confidence: 99%

Fluorophenol-Containing Hydrogen-Bond Acidic Polysiloxane for Gas Sensing-Synthesis and Characterization

et al. 2022

In this work, the synthesis of a new polysiloxane, poly {dimethylsiloxane-co-[4-(2,3-difluoro-4-hydroxyphenoxy) butyl] methylsiloxane} (dubbed PMFOS), is presented. This polymer exhibits high hydrogen bond acidity and was designed to be used as a sensor layer in gas sensors. The description of the synthetic route of the PMFOS has been divided into two main stages: the synthesis of the functional substituent 4-(but-3-en-1-yloxy)-2,3-difluorophenol, and the post-polymerization functionalization of the polysiloxane chain (methylhydrosiloxane-dimethylsiloxane copolymer) via hydrosilylation. The synthesized material was subjected to instrumental analysis, which confirmed its structure. The performed thermal analysis made it possible to determine some properties important for the sensor application, such as glass transition temperature and decomposition temperature. The results showed that PMFOS meets the requirements for materials intended for use in gas sensors based on acoustoelectric transducers.

Adv Materials Technologies

Recent Advancements in Development of Wearable Gas Sensors

Bag

Lee

2021

139

In the era of the Internet of Things, wearable technologies are expected to become an indispensable part of daily life. In recent times, highly sensitive, flexible, and stretchable electronic gas sensors are gaining tremendous interest due to their applicability in wearable electronics applications. The construction of wearable gas sensors are reviewed for real‐time, highly sensitive, and selective detection of hazardous gases at room temperature (RT) that can be laminated onto a human body or integrated with body‐worn textile or other consumer products, utilizing carbon nanomaterials, conductive polymers, 2D nanostructured materials, and their composites. Sensing materials, transduction techniques, and substrates for high‐performance wearable gas sensing are discussed in detail. The critical challenges for future development of wearable gas sensors are presented. Wearable gas sensors are believed to have great potential in environmental monitoring, healthcare, public safety, security, as well as food quality monitoring.