• Textile Coloration and Finishing
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• v.32 no.1
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• pp.51-56
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• 2020

This study aims to pursue the multi-functional textile finishing method to detoxify chemical warfare agent by simply treating the well-known antimicrobial agent, chitosan, to cotton fabric. For this purpose, DFP(diisopropylfluorophosphate) was sele cted as a chemical warfare agent simulant and cotton fabric was treated with 0.5, 1.0, and 2wt% chitosan solution in 1wt% acetic acid. DFP decontamination properties of the chitosan treated cotton fabrics were evaluated and compared with the untreated cotton fabric. The chitosan treated cotton fabrics showed better DFP decontamination than the untreated cotton. Decontamination properties of the chitosan treated cotton fabrics improved with the increased chitosan solution used. Especially, the cotton fabrics treated with 2wt% chitosan solution showed 5 times more DFP decontamina tion than the untreated cotton fabrics. This suggested that the chitosan treated fabric has potential to be used as a material for protective clothing with chemical warfare agent detoxifying and antimicrobial properties.

• Textile Coloration and Finishing
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• v.33 no.1
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• pp.1-9
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• 2021

This study aims to prepare the fabric with detoxification properties against chemical warfare agent by the simple treatment. For this purpose, polypropylene non-woven fabric(PP) was treated with polyethyleneimine(PEI) and guanidinylated PEI and detoxification properties of the guanidinylated PEI treated PP were evaluated using diisopropylfluorophosphate(DFP), as a chemical warfare agent simulant, and compared with the untreated and PEI treated PP. The half-lives of DFP on guanidinylated PEI treated PP and untreated PP were 334 min and 714 min, respectively. The half-life of DFP with guanidinylated PEI treated PP was 53.22% shorter than with untreated PP. This result shows that guanidine group in guanidinylated PEI treated PP was acted as a base catalyst for hydrolysis of DFP and decreased half-life of DFP. Therefore, it is expected that guanidinylated PEI treatment can be an simple pathway to prepare the detoxification fabric material for protective clothing against chemical warfare agents.

• Textile Coloration and Finishing
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• v.32 no.2
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• pp.73-79
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• 2020

Pursuing the fabric materials for military chemical warfare protective clothing with the improved detoxification properties, this study investigated the simple and effective cotton treatment method using pad-dry-cure process and 3-aminopropyltrimethox ysilane(APTMS) solution for surface amination. Detoxification properties of the untreated and treated cotton fabrics were evaluated via decontamination of chemical warfare agent simulant, DFP(diisopropylfluorophosphate). The surface aminated cotton fabric increased the rate of the hydrolysis of DFP by the factor of 3 and the decontamination ratio reached 88.2% after 24h. Therefore, the surface amination of the cotton fabric with APTMS can be an effective pathway to prepare the material for protective clothing against chemical warfare agents.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.2
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• pp.210-217
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• 2022

Chemical warfare agents(CWA) such as nerve agents and vesicating agents show lethality by skin contamination. Skin protection, therefore, is one of the top priorities to deal with the growing threat from CWA. In an attempt to develop the most effective topical skin protectant(TSP), candidate substances including PFPE(perfluorinated polyether), PTFE(polytetrafluoroethylene), glycerin, and polysaccharides were evaluated in forms of various formulations against nerve agent simulant DMMP(dimethylmethyl phosphonate) penetration. The protective efficacy of the formulation against DMMP penetration was estimated as the onset time of color change of the KM9 chemical agent detection paper. Based on this study, it was found that several PFPE- and glycerin-based formulations exhibit remarkably superior efficacy as a protective cream. This protective cream is expected to be used as TSP for military application after further research.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.1967-1971
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• 2013

Aim of our study is finding adsorbents suitable for pre-concentration of chemical warfare agents (CWAs). We considered Tenax, bare silica and polydimethylsiloxane (PDMS)-coated silica as adsorbents for dimethyl methylphosphonate (DMMP) and dipropylene glycol methyl ether (DPGME). Tenax showed lower thermal stability, and therefore, desorption of CWA simulants and decomposition of Tenax took place simultaneously. Silica-based adsorbents showed higher thermal stabilities than Tenax. A drawback of silica was that adsorption of CWA simulant (DMMP) was significantly reduced by pre-treatment of the adsorbents with humid air. In the case of PDMS-coated silica, influence of humidity for CWA simulant adsorption was less pronounced due to the hydrophobic nature of PDMS-coating. We propose that PDMS-coated silica can be of potential importance as adsorbent of CWAs for their pre-concentration, which can facilitate detection of these CWAs.

• Korean Chemical Engineering Research
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• v.52 no.3
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• pp.360-365
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• 2014

Vapor-phase hydrogen peroxide(VPHP) has been used as a sterilant in the field of medical and pharmaceutical application due to low corrosive than chlorine contained sterilant. In addition, it is well known that VPHP is effective for decontamination of chemical warfare agents by adding ammonia gas. In this study, the decontamination efficiency was confirmed about CEPS, DFP and dimethoate as simulants of HD, GD and VX using VPHP respectively. For this purpose, VPHP generated from self configured device was injected into decontamination chamber and maintained for reaction time. After the decontamination, the residues are analyzed by GC/MS and decontamination efficiency was calculated. Through by-product for each simulants, the similarities in reaction mechanism of chemical warfare agents were confirmed. CEPS was completely decontaminated at 30% relative humidity within 60 min. By adding ammonia gas, DFP and dimethoate were completely decontaminated within 30 and 150 min respectively.

• Journal of Sensor Science and Technology
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• v.28 no.3
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• pp.139-145
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• 2019

Precautionary detection of chemical warfare agents (CWAs) has been an important global issue mainly owing to their toxicity. To achieve proper detection, many studies have been conducted to develop sensitive gas sensors for CWAs. In particular, metal-oxide semi-conductors (MOS) have been investigated as promising sensing materials owing to their abundance in nature and excellent sensitivity. In this review, we mainly focus on various MOS-based gas sensors that have been fabricated for the detection of two specific CWA simulants, 2-chloroethyl ethyl sulfide (2-CEES) and dimethyl methyl phosphonate (DMMP), which are simulants of sulfur mustard and sarin, respectively. In the case of 2-CEES, we mainly discuss $CdSnO_3-$ and ZnO-based sensors and their reaction mechanisms. In addition, a method to improve the selectivity of ZnO-based sensors is mentioned. Various sensors and their sensing mechanisms have been introduced for the detection of DMMP. As the reaction with DMMP may directly affect the sensing properties of MOS, this paper includes previous studies on its poisoning effect. Finally, promising sensing materials for both gases are proposed.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.6
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• pp.828-835
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• 2014

GC-TSQ CI technique was applied for analysis of samples for the $32^{nd}$ OPCW proficiency test. Eight chemical weapon convention(CWC) related chemicals were identified by product ion mode analysis with GC-TSQ in the samples. Choice of specific precursor ion made it possible to supply selective total ion chromatograms(TICs) of target molecule. GC-TSQ CI anaylsis technique was useful method for chemical warfare agent verification because analysis selectivity was improved by choice of mother molecule as precursor ion and gave mass spectra.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.4
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• pp.133-140
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• 2008

The purpose of this study is to provide response methods to minimize the damage from chemical terrorism in a naturally ventilated indoor system using several types of dispersion simulations. Three chemical warfare agents such as sarin(GB), phosgene and chlorine gas which have high potential to be used in terror or to be involved with accidents were selected in this simulation. Fire dynamic simulation based on Large Eddy Simulation which is effective because of less computational effort and detailed expression of the dispersion flow was adopted to describe the dispersion behavior of these agents. When the vent speed is 0.005m/s, the heights of 0.1 agent mass fraction are 0.9m for sarin, 1.0m for phosgene and 1.1m for chlorine gas, and the maximum mass fraction are 0.27 for all three agents. However, when the vent speed is increased to 0.05m/s, the heights of 0.1 agent mass fraction become 1.6m for all three agents and maximum mass fraction inside the room increase to 0.70 for sarin, 0.58 for phosgene and 0.53 for chlorine gas. It is shown that molecular weight of the agents has an important role for dispersion, and it is important to install ventilation system with height less than 1.6m to minimize the damage from chemical toxicity.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.148.2-148.2
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• 2013

We prepared hydrophobic PDMS-coated porous silica as pre-concentration adsorbent for chemical warfare agents (CWAs). Since CWAs can be harmful to human even with a small amount, detecting low-concentration CWAs has been attracting attention in defense development. Porous silica is one of the promising candidates for CWAs pre-concentration adsorbent since it is thermally stable and its surface area is sufficiently high. A drawback of silica is that adsorption of CWAs can be significantly reduced due to competitive adsorption with water molecule in air since silica is quite hydrophilic. In order to solve this problem, hydrophobic polydimethylsiloxane (PDMS) thin film was deposited on silica. Adsorption and desorption of chemical warfare agent (CWA) simulants (Dimethylmethylphosphonate, DMMP and Dipropylene Glycol Methyl Ether, DPGEM) on bare and PDMS-coated silica were studied using temperature programed desorption (TPD) with and without co-exposing of water vapor. Without exposure of water vapor, desorbed amount of DMMP from PDMS-coated silica was twice larger than that from bare silica. When the samples were exposed to DMMP and water vapor at the same time, no DMMP was desorbed from bare silica due to competitive adsorption with water. On the other hand, desorbed DMMP was detected from PDMS-coated silica with reduced amount compared to that from the sample without water vapor exposure. Adsorption and desorption of DPGME with and without water vapor exposing was also investigated. In case of bare silica, all the adsorbed DPGME was decomposed during the heating process whereas molecular DPGME was observed on PDMS-coated silica. In summary, we showed that hydrophobic PDMS-coating can enhance the adsorption selectivity toward DMMP under humid condition and PDMS-coating also can have positive effect on molecular desorption of DPGME. Therefore we propose PDMS-coated silica could be an adequate adsorbent for CWAs pre-concentration under practical condition.