Phase and Morphology in Mixed CuO-WO3 Films for Chemical Sensing

2002 ◽  
Vol 751 ◽  
Author(s):  
A. El Madi ◽  
B. Meulendyk ◽  
R. S. Pilling ◽  
G. Bernhardt ◽  
R. J. Lad ◽  
...  
Keyword(s):  
Gas Phase ◽  
Surface Segregation ◽  
Organophosphorus Compounds ◽  
Chemical Warfare Agents ◽  
Phase Changes ◽  
Highly Sensitive ◽  
Warfare Agents ◽  
Phase Sensor ◽  
Semiconducting Metal Oxide

ABSTRACTSemiconducting metal oxide (SMO) chemiresistive sensors are highly sensitive toward a broad range of hydrocarbons. To develop a gas phase sensor with selectivity toward organophosphorus compounds, such as chemical warfare agents and pesticides, we have developed dosimeters based upon a poisoning mechanism. Here, we report the growth and characterization of WO3 thin films, modified with Cu2O. XPS data show that exposure to phosphonate compounds leads to accumulation of phosphate on the surface, together with dramatic changes in the surface segregation of copper. We present XRD and XPS results to characterize the phase changes following growth, annealing, and exposure to phosphonate compounds. The correlation between sensor response and phosphorous accumulation shows that the highest activity occurs at intermediate coverages of Cu2O, in the15–25 Å range, on 500 Å WO3 films.

scholarly journals Highly sensitive SERS quantification of organophosphorous chemical warfare agents: A major step towards the real time sensing in the gas phase

2018 ◽  
Vol 267 ◽  
pp. 457-466 ◽  
Author(s):  
Marta Lafuente ◽  
Ismael Pellejero ◽  
Víctor Sebastián ◽  
Miguel A. Urbiztondo ◽  
Reyes Mallada ◽  
...  
Keyword(s):  
Real Time ◽  
Gas Phase ◽  
Chemical Warfare Agents ◽  
Chemical Warfare ◽  
Major Step ◽  
The Real ◽  
Highly Sensitive ◽  
Warfare Agents

Review about structure and evaluation of reactivators of Acetylcholinesterase inhibited with neurotoxic organophosphorus compounds

2020 ◽  
Vol 27 ◽  
Author(s):  
José Daniel Figueroa-Villar ◽  
Elaine C. Petronilho ◽  
Kamil Kuca ◽  
Tanos C. C. Franca
Keyword(s):  
Organophosphorus Compounds ◽  
Chemical Warfare Agents ◽  
Nerve Impulse ◽  
Limited Capacity ◽  
New Agents ◽  
Long Time ◽  
Warfare Agents ◽  
Comprehensive Search ◽  
Pharmacology And Toxicology ◽  
The Many

Background: Neurotoxic chemical warfare agents can be classified as some of the most dangerous chemicals for humanity. The most effective of those agents are the organophosphates (OPs) capable of restricting the enzyme acetylcholinesterase (AChE), which in turn controls the nerve impulse transmission. When AChE is inhibited by OPs, its reactivation can be usually performed through cationic oximes. However, until today it has not been developed one universal defense agent, with complete effective reactivation activity for AChE inhibited by any of the many types of existing neurotoxic OPs. For this reason, before treating people intoxicated by an OP, it is necessary to determine the neurotoxic compound that was used for contamination, in order to select the most effective oxime. Unfortunately, this task usually requires a relative long time, raising the possibility of death. Cationic oximes also display a limited capacity of permeating the blood-brain barrier (BBB). This fact compromises their capacity of reactivating AChE inside the nervous system. Methods: We performed a comprehensive search on the data about OPs available on the scientific literature today in order to cover all the main drawbacks still faced in the research for the development of effective antidotes against those compounds. Results: Therefore, this review about neurotoxic OPs and the reactivation of AChE, provides insights for the new agents’ development. The most expected defense agent is a molecule without toxicity and effective to reactivate AChE inhibited by all neurotoxic OPs. Conclusion: To develop these new agents it is necessary the application of diverse scientific areas of research, especially theoretical procedures as computational science (computer simulation, docking and dynamics); organic synthesis; spectroscopic methodologies; biology, biochemical and biophysical information; medicinal chemistry, pharmacology and toxicology.

scholarly journals Development of Cotton Nonwoven Composite Fabric for Toxic Chemical Decontamination and Characterization of its Adsorption Capabilities

2013 ◽  
Vol 8 (1) ◽  
pp. 155892501300800 ◽  
Author(s):  
Utkarsh Sata ◽  
Eugene Wilusz ◽  
Steve Mlynarek ◽  
Gopal Coimbatore ◽  
Ronald Kendall ◽  
...  
Keyword(s):  
Department Of Defense ◽  
Chemical Warfare Agents ◽  
Toxic Chemical ◽  
Thermogravimetric Analyzer ◽  
Chemical Decontamination ◽  
Military Applications ◽  
Warfare Agents ◽  
Individual Protection ◽  
Gravimetric Procedure

Because of the current threat of toxic chemicals and chemical warfare agents, personal protection is important for soldiers and first responders, as well as the civilian population. This paper describes the development of a cotton non-particulate nonwoven composite fabric and the evaluation of its adsorption capability for protection against toxic chemical ingress which can be harmful or lethal. In addition, this paper focuses on the evaluation of toxic chemical adsorption capabilities of various chemical protective substrates that have the potential to be used in military applications. The development of a three-layered cotton based decontamination wipe and its adsorption of 0.1 % w/v pinacolyl methylphosphonate in butanol, is presented. Adsorption is quantified using a modified gravimetric procedure developed using a thermogravimetric analyzer. The results demonstrate the adsorption performance of a new cotton-based, non-particulate flexible composite that has a high potential to be used as a portable decontamination wipe. This research is unique in the area of individual protection and addresses the requirements of the U.S. Department of Defense (DoD) for seeking and evaluating highly efficient, non-particulate, and skin-friendly materials that provide necessary chemical protection while minimizing any discomfort or irritation.

scholarly journals Enzymatic Degradation of Organophosphorus Pesticides and Nerve Agents by EC: 3.1.8.2

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1365
Author(s):  
Marek Matula ◽  
Tomas Kucera ◽  
Ondrej Soukup ◽  
Jaroslav Pejchal
Keyword(s):  
Catalytic Activity ◽  
Organophosphorus Compounds ◽  
Organophosphorus Pesticides ◽  
Chemical Warfare Agents ◽  
Enzyme Commission Number ◽  
Nerve Agents ◽  
Organophosphorus Acid Anhydrolase ◽  
Warfare Agents ◽  
Heavy Burden ◽  
Medical Countermeasures

The organophosphorus substances, including pesticides and nerve agents (NAs), represent highly toxic compounds. Standard decontamination procedures place a heavy burden on the environment. Given their continued utilization or existence, considerable efforts are being made to develop environmentally friendly methods of decontamination and medical countermeasures against their intoxication. Enzymes can offer both environmental and medical applications. One of the most promising enzymes cleaving organophosphorus compounds is the enzyme with enzyme commission number (EC): 3.1.8.2, called diisopropyl fluorophosphatase (DFPase) or organophosphorus acid anhydrolase from Loligo Vulgaris or Alteromonas sp. JD6.5, respectively. Structure, mechanisms of action and substrate profiles are described for both enzymes. Wild-type (WT) enzymes have a catalytic activity against organophosphorus compounds, including G-type nerve agents. Their stereochemical preference aims their activity towards less toxic enantiomers of the chiral phosphorus center found in most chemical warfare agents. Site-direct mutagenesis has systematically improved the active site of the enzyme. These efforts have resulted in the improvement of catalytic activity and have led to the identification of variants that are more effective at detoxifying both G-type and V-type nerve agents. Some of these variants have become part of commercially available decontamination mixtures.

Broad-Spectrum Liquid- and Gas-Phase Decontamination of Chemical Warfare Agents by One-Dimensional Heteropolyniobates

2016 ◽  
Vol 55 (26) ◽  
pp. 7403-7407 ◽  
Author(s):  
Weiwei Guo ◽  
Hongjin Lv ◽  
Kevin P. Sullivan ◽  
Wesley O. Gordon ◽  
Alex Balboa ◽  
...  
Keyword(s):  
Gas Phase ◽  
Broad Spectrum ◽  
Chemical Warfare Agents ◽  
Chemical Warfare ◽  
One Dimensional ◽  
Warfare Agents

scholarly journals Insight into the Synthesis and Characterization of Organophosphorus-Based Bridged Triazine Compounds

Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2672 ◽  
Author(s):  
Khalifah A. Salmeia ◽  
Antonia Neels ◽  
Dambarudhar Parida ◽  
Sandro Lehner ◽  
Daniel Rentsch ◽  
...  
Keyword(s):  
Gas Phase ◽  
Organophosphorus Compounds ◽  
Triethyl Phosphite ◽  
Molecular Structures ◽  
Composition Analysis ◽  
Char Formation ◽  
Flame Inhibition ◽  
High Yields ◽  
Insight Into

In this article, we report the synthesis of 2,4,6-substituted s-triazine-based organophosphorus compounds via a two-step process, which enables their production in high yields, and with a high purity as solids. In the first step, a Michaelis–Arbuzov rearrangement of cyanuric chloride with triethyl phosphite afforded 2,4,6-trisdiethoxyphosphinyl-1,3,5-triazine (HEPT). Subsequently, the nucleophilic substitution reaction on the triazine carbon was achieved, owing to the electron-withdrawing ability of the phosphonate groups. This characteristic of HEPT facilitated its derivatization with bi-functional amines, producing novel P–C containing bridged triazine organophosphorus compounds. The molecular structures of all of the compounds were confirmed by NMR spectroscopy, CHN elemental analysis, and single crystal X-ray analysis. In the thermogravimetric analysis in an N2 environment, >33% char formation was observed for the bridged compounds. The chemical composition analysis of the char obtained under the oxidative thermal decomposition of the bridged compounds confirmed the presence of phosphorus- and nitrogen-enriched species, which indicate their function in the condensed phase. Comparatively, the detection of HPO and H–C≡P in the gas phase during the pyrolysis of the bridged compounds can act as a source for PO•, which is known for its gas phase flame inhibition reactions. The synergy of significant char formation and the generation of intermediates leading to PO• during pyrolysis makes these molecules promising flame-retardant additives.

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