scholarly journals Modified-TiO2 Photocatalyst Supported on β-SiC Foams for the Elimination of Gaseous Diethyl Sulfide as an Analog for Chemical Warfare Agent: Towards the Development of a Photoreactor Prototype

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 403
Author(s):  
Armelle Sengele ◽  
Didier Robert ◽  
Nicolas Keller ◽  
Valérie Keller
Keyword(s):  
Photocatalytic Oxidation ◽  
Chemical Warfare Agents ◽  
Chemical Warfare Agent ◽  
Chemical Warfare ◽  
Diethyl Sulfide ◽  
Tio2 Photocatalysts ◽  
Doped Tio2 ◽  
Model Molecule ◽  
Warfare Agents ◽  
Oxidation Efficiency

In the context of the increase in chemical threat due to warfare agents, the development of efficient methods for destruction of Chemical Warfare Agents (CWAs) are of first importance both for civilian and military purposes. Amongst possible methods for destruction of CWAs, photocatalytic oxidation is an alternative one. The present paper reports on the preparation of Ta and Sn doped TiO2 photocatalysts immobilized on β-SiC foams for the elimination of diethyl sulfide (DES) used as a model molecule mimicking Yperite (Mustard Gas) in gaseous phase. Photo-oxidation efficiency of doped TiO2 catalyst has been compared with TiO2-P25. Here, we demonstrate that the Sn doped-TiO2 with a Polyethylene glycol (PEG)/TiO2 ratio of 7 exhibits the best initial activity (up to 90%) but is deactivates more quickly than Ta doped-TiO2 (40% after 800 min). The activity of the catalysts is strongly influenced by the adsorption properties of the support, as β-SiC foams adsorb DES and other sulfur compounds. This adsorption makes it possible to limit the poisoning of the catalysts and to maintain an acceptable conversion rate even after ten hours under continuous DES flow. Washing with NaOH completely regenerates the catalyst after a firs treatment and even seems to “wash” it by removing impurities initially present on the foams.

scholarly journals Acid is a potential interferent in fluorescent sensing of chemical warfare agent vapors

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Shengqiang Fan ◽  
Genevieve H. Dennison ◽  
Nicholas FitzGerald ◽  
Paul L. Burn ◽  
Ian R. Gentle ◽  
...  
Keyword(s):  
Chemical Warfare Agents ◽  
Chemical Warfare Agent ◽  
Chemical Warfare ◽  
Standard Laboratory ◽  
Care Needs ◽  
Fluorescent Sensing ◽  
Sensing Systems ◽  
Sensing Material ◽  
Fluorescence Change ◽  
Warfare Agents

AbstractA common feature of fluorescent sensing materials for detecting chemical warfare agents (CWAs) and simulants is the presence of nitrogen-based groups designed to nucleophilically displace a phosphorus atom substituent, with the reaction causing a measurable fluorescence change. However, such groups are also basic and so sensitive to acid. In this study we show it is critical to disentangle the response of a candidate sensing material to acid and CWA simulant. We report that pyridyl-containing sensing materials designed to react with a CWA gave a strong and rapid increase in fluorescence when exposed to Sarin, which is known to contain hydrofluoric acid. However, when tested against acid-free diethylchlorophosphate and di-iso-propylfluorophosphate, simulants typically used for evaluating novel G-series CWA sensors, there was no change in the fluorescence. In contrast, simulants that had been stored or tested under a standard laboratory conditions all led to strong changes in fluorescence, due to acid impurities. Thus the results provide strong evidence that care needs to be taken when interpreting the results of fluorescence-based solid-state sensing studies of G-series CWAs and their simulants. There are also implications for the application of these pyridyl-based fluorescence and other nucleophilic/basic sensing systems to real-world CWA detection.

Effects of incorporating regioisomers and flexible rotors to direct aggregation induced emission to achieve stimuli-responsive luminogens, security inks and chemical warfare agent sensors

2020 ◽  
Vol 56 (55) ◽  
pp. 7633-7636 ◽  
Author(s):  
Laxmi Raman Adil ◽  
Parameswar Krishnan Iyer
Keyword(s):  
Photophysical Properties ◽  
Chemical Warfare Agents ◽  
Design Strategy ◽  
Chemical Warfare Agent ◽  
Chemical Warfare ◽  
Simple Design ◽  
Stimuli Responsive ◽  
Aggregation Induced Emission ◽  
Flexible Rotors ◽  
Warfare Agents

A simple design strategy to convert ACQ materials into bright AIE luminogens is demonstrated. Unique differences in photophysical properties were observed among them which gave rise to stimuli responsive behaviour and sensor for chemical warfare agents.

The ionization process of chemical warfare agent simulants in low temperature plasma ionization

2020 ◽  
Vol 26 (5) ◽  
pp. 341-350
Author(s):  
Baoqiang Li ◽  
Jinglin Kong ◽  
Lin Zhang ◽  
Wenxiang Fu ◽  
Zhongyao Zhang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Chemical Warfare Agents ◽  
Chemical Warfare Agent ◽  
Chemical Warfare ◽  
Collision Induced Dissociation ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Plasma Ionization ◽  
Warfare Agents ◽  
Protonated Molecules

The application of low-temperature plasma ionization technology in the chemical warfare agent detection was mostly focused on the research of rapid detection methods. Limited studies are available on the ionization process of chemical warfare agents in low temperature plasma. Through the intensity of protonated molecules of dimethyl methylphosphonate (DMMP) in different solvents including methanol, deuterated methanol (methanol-D4), pure water, and deuterium oxide (water-D2), it was concluded that the water molecule in the air provides the hydrogen ion (H+) needed for ionization. The product ion spectra and the collision-induced dissociation processes of protonated molecules of nerve agent simulants, including DMMP, diethyl methanephosphonate (DEMP), trimethyl phosphate (TMP), triethyl phosphate (TEP), tripropyl phosphate (TPP), and tributyl phosphate (TBP) were analyzed. Results revealed that H+ mostly combined with phosphorus oxygen double bond (P = O) in the low-temperature plasma ionization. By analyzing the peak intensity distribution of product ions of protonated molecules, the presence of proton and charge migration in the low temperature plasma ionization and collision-induced dissociation were researched. This study could provide technical guidance for the rapid and accurate detection of chemical warfare agents through low temperature plasma ionization-mass spectrometry.

scholarly journals Detoxification Properties of Guanidinylated Chitosan Against Chemical Warfare Agents and Its Application to Military Protective Clothing

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1461 ◽  
Author(s):  
Woong Kwon ◽  
Euigyung Jeong
Keyword(s):  
Acetic Acid ◽  
Cotton Fabric ◽  
Protective Clothing ◽  
Water Solution ◽  
Chemical Warfare Agents ◽  
Treatment Method ◽  
Chemical Warfare Agent ◽  
Chemical Warfare ◽  
Warfare Agents ◽  
First Time

This study investigates the detoxification properties of guanidinylated chitosan against chemical warfare agents and its application to the preparation of military protective clothing. Guanidinylated chitosan was synthesized by chitosan guanidinylation with cyanamide. The detoxification properties of the guanidinylated chitosan were then evaluated using a chemical warfare agent simulant, called diisopropylfluorophosphate (DFP). Cotton fabric was treated with 1 wt.% of guanidinylated chitosan in acetic acid and water solution using the simple and conventional textile treatment method of pad–dry–cure. The detoxification properties of the guanidinylated chitosan-treated cotton fabric were evaluated to investigate the application of guanidinylated chitosan to the preparation of military protective clothing. Subsequently, 71.3% of DFP was hydrolyzed to non-hazardous diisopropylhydrogenphosphate (DHP) in 2 h because of the base organocatalytic activity of 0.02 g guanidinylated chitosan itself. Moreover, 60.1% of DFP was hydrolyzed by the catalytic activity of the guanidinylated chitosan-treated cotton fabric, which contained only 0.0002 g of guanidinylated chitosan. This result shows that the guanidinylated chitosan itself has detoxification properties for hydrolyzing DFP to DHP, and its detoxification properties can be more efficient when applied to cotton fabric because it showed 84.3% of the detoxification properties with only 1 wt.% of guanidinylated chitosan. For the first time, this study shows that guanidinylated chitosan has considerable detoxification properties and can be used as an agent to prepare protective clothing.

scholarly journals Nanomaterials and Cross-Cutting Technologies for Fostering Smart Electrochemical Biosensors in the Detection of Chemical Warfare Agents

2021 ◽  
Vol 11 (2) ◽  
pp. 720
Author(s):  
Fabiana Arduini
Keyword(s):  
Flexible Electronics ◽  
Wearable Sensors ◽  
Chemical Warfare Agents ◽  
Chemical Warfare Agent ◽  
Chemical Warfare ◽  
Electrochemical Biosensors ◽  
Novel Technologies ◽  
Fast Detection ◽  
Warfare Agents ◽  
Timely Fashion

The smart, rapid, and customizable detection of chemical warfare agents is a huge issue for taking the proper countermeasures in a timely fashion. The printing techniques have established the main pillar to develop miniaturized electrochemical biosensors for onsite and fast detection of nerve and mustard agents, allowing for a lab on a chip in the chemical warfare agent sector. In the fast growth of novel technologies, the combination of miniaturized electrochemical biosensors with flexible electronics allowed for the delivery of useful wearable sensors capable of fast detection of chemical warfare agents. The wearable microneedle sensor array for minimally invasive continuous electrochemical detection of organophosphorus nerve agents, as well as the wearable paper-based origami functionalized with nanomaterials for mustard agents in the gas phase, represent two examples of the forefront devices developed in the chemical warfare agent detection field. This review will highlight the most promising electrochemical biosensors developed by exploiting nanomaterials and cross-cutting technologies for the fabrication of smart and sensitive electrochemical biosensors for the detection of chemical warfare agents.

Rapid, In-Situ Detection of Chemical Warfare Agent Simulants and Hydrolysis Products in Bulk Soils by Low-Cost 3D-Printed Cone Spray Ionization Mass Spectrometry

The Analyst ◽  
2021 ◽  
Author(s):  
Hilary M. Brown ◽  
Trevor J. McDaniel ◽  
Karan R. Doppalapudi ◽  
Christopher C. Mulligan ◽  
Patrick Fedick
Keyword(s):  
Low Cost ◽  
Chemical Warfare Agents ◽  
Chemical Warfare Agent ◽  
Chemical Warfare ◽  
Ionization Mass ◽  
Chemical Weapons Convention ◽  
Warfare Agents ◽  
3D Printed ◽  
In Situ Detection

Chemical warfare agents (CWAs) are toxic chemicals that have been used as disabling or lethal weapons in war, terrorist attacks, and assassinations. The Chemical Weapons Convention (CWC) has prohibited the...

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