• Textile Coloration and Finishing
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• v.31 no.1
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• pp.33-41
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• 2019

In this report, nano-sized catalysts were introduced onto fabric surface to eliminate toxic chemicals assisted by physical adsorption. For chemical removal of toxic compounds, a series of zirconium-containing catalysts were synthesized and treated on fabric to catalyze the hydrolysis and oxidation of target molecules. Antimicrobial was also introduced for the research purpose to prove the compatibility of as-synthesized catalysts with other solutions. Zirconium ligated with hydroxyl group and MOF(Metal-Organic Frameworks) were exploited as catalyst for removal of toxic compounds, while zinc complex was used for an antimicrobial to culminate in a chemical shield. Once fabrics were functionalized, fabrics were washed 2 or 5 times for a washing durability test. The amount of catalyst in textile were measured by ICP-MS and weight increasing ratio of fabrics.

• Applied Chemistry for Engineering
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• v.32 no.5
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• pp.524-531
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• 2021

Depending on the type and amount of acid used as a modulator in the manufacturing process, the structural properties of UiO-66 can be modified and the adsorbability of chemical warfare agents can be enhanced. In this study, several acids as a modulator were used to synthesize UiO-66. Their properties were analyzed with FT-IR, XRD, titrator, and adsorption isotherms using chemical warfare agent simulant, DIMP. The UiO-66, structurally damaged by hydrochloric acid as a modulator, showed lower crystallinity and DIMP adsorption capacity and also smaller specific surface area and volume of voids compared to those of UiO-66, which was manufactured using acetic acid, and formic acid as a modulator. Additionally, UiO-66 which was synthesized by adding formic acid and hydrochloric acid as a modulator, showed the highest DIMP adsorption capacity and is likely to be used as an adsorbent for chemical warfare agent in the future.

• Carbon letters
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• v.13 no.2
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• pp.109-114
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• 2012

A nuclear, biological, chemical (NBC) canister was indigenously developed using active carbon impregnated with ammoniacal salts of copper (II), chromium (VI) and silver (I), and high efficiency particulate aerosol filter media. The NBC canister was evaluated against carbon tetra chloride ($CCl_4$) vapours, which were used as a simulant for persistent chemical warfare agents under dynamic conditions for testing breakthrough times of canisters of gas masks in the National Approval Test of Respirators. The effects of $CCl_4$ concentration, test flow rate, temperature, and relative humidity (RH) on the breakthrough time of the NBC canister against $CCl_4$ vapour were also studied. The impregnated carbon that filled the NBC canister was characterized for surface area and pore volume by $N_2$ adsorption-desorption isotherm at liquid nitrogen temperature. The study clearly indicated that the NBC canister provides adequate protection against $CCl_4$ vapours. The breakthrough time decreased with the increase of the $CCl_4$ concentration and flow rate. The variation in temperature and RH did not significantly affect the breakthrough behaviour of the NBC canister at high vapour concentration of $CCl_4$, whereas the breakthrough time of the NBC canister was reduced by an increase of RH at low $CCl_4$ vapour concentration.

• Applied Chemistry for Engineering
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• v.30 no.6
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• pp.719-725
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• 2019

In this study, activated carbon fibers were treated with oxygen plasma to investigate gas sensing properties of the dimethyl methylphosphonate (DMMP), which is a simulant gas of the chemical warfare agent, according to oxygen functional group contents. As the flow rate of oxygen plasma treatment increased, oxygen groups were introduced to the surface of activated carbon fibers from 6.90 up to 36.6%, increasing the -OH group which influences the DMMP gas sensing properties. However, as the flow rate of oxygen plasma increases, the specific surface area tends to decrease because etching on the surface of activated carbon fibers occurs due to active species generated during the oxygen plasma treatment. The resistance change rate of the DMMP gas sensor increased from 4.2 up to 25.1% as the oxygen plasma treatment flow rate increased. This is attributed to the hydrogen bonding between DMMP gas and introduced hydroxyl functional group on activated carbon fibers by the oxygen plasma treatment. Therefore, the oxygen plasma is considered to be one of the important surface treatment methods for detecting chemical warfare agents at room temperature.

• Textile Coloration and Finishing
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• v.32 no.2
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• pp.96-102
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• 2020

Recently, it was reported that chitosan or APTMS(3-aminopropyltrimethoxysila ne) treatment to cotton using the simple pad-dry-cure method has potential to prepare textile materials for military chemical warfare protective clothing. However, it is not confirmed which method is more efficient. Therefore, this study aims to quantitatively compare detoxification properties of chitosan treated cotton fabric with those of APTMS treated cotton fabric. Detoxification properties were evaluated using the well-known organic phosphorous nerve agent stimulant, diisopropylfluorophosphate(DF P). With the same amount of chitosan and APTMS on the surface of the cotton fabrics, APTMS treated cotton fabric exhibited 10% higher detoxification properties than chitosan treated cotton fabric based on the rate of DFP hydrolysis and half-live of DFP calculated from the DFP decontamination ratios of the treated cotton fabrics through time. Therefore, APTMS treatment can be more efficient method to prepare the textile materials for military protective clothing than chitosan treatment.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.1
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• pp.116-122
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• 2007

A 2-step process for the safe disposal of chemical warfare agents(agent hydrolysis followed by incineration In the submerged-quench incinerator) was studied to obtain basic data for the design of pilot plant in the future. Sample materials used for the hydrolysis reaction were sarin(GB), sulfur mustard (HD), and methylphosphonic difluoride(DF). The hydrolysates of these materials were thermally destroyed in a submerged-quench incineration system. Experimental conditions for achieving destruction efficiency of 99.99% in both steps were established and phosphoric acid was recovered from the waste water when destroying DF hydrolysate in the incinerator. Treated water could be reused as process water for the agent hydrolysis.

• Applied Chemistry for Engineering
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• v.34 no.6
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• pp.596-602
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• 2023

Chromium-based metal-organic frameworks (MIL-101(Cr)) were synthesized, and their potential use as a filling material for gas masks or protective clothing was assessed through adsorption experiments using diisopropyl methyl phosphate (DIMP) as a simulant for chemical warfare agents. MIL-101(Cr) was prepared using acetic acid (MIL-101(Cr)-A) and sodium hydroxide (MIL-101(Cr)-N) as modulators. The use of acetic acid as a modulator resulted in a larger specific surface area and a higher DIMP adsorption capacity. MIL-101(Cr)-A absorbed approximately 160% of its own weight of moisture when exposed to an environment with a relative humidity of 90% for 10 days, surpassing other adsorbents such as activated carbon. The DIMP adsorption capacity of MIL-101(Cr)-A decreased to about 40% of its initial adsorption capacity after 24 hours of exposure to an environment with a relative humidity of 90%. However, this capacity is still higher compared to that of activated carbon used in commercial gas masks, suggesting a high potential for future use as a filling material for gas masks or protective clothing.

• Applied Chemistry for Engineering
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• v.33 no.3
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• pp.296-301
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• 2022

Due to the fact that zirconium based metal-organic frameworks (Zr-MOFs), such as UiO-66, have a large specific surface area and excellent selective adsorption capacity, Zr-MOFs are gaining attention as materials that can provide protection from the attack of chemical warfare agents in battleground. However, most of the metal-organic frameworks have an issue of selective adsorption capacity degraded by water molecules when exposed to the atmosphere, because of the weak metal-organic ligand bonds and the presence of voids. Therefore, polydimethylsiloxane (PDMS), a representative hydrophobic polymer material, was coated on the surface of UiO-66 to enhance the sustainability of the diisopropyl methylphosphonate (DIMP) sorption capacity in the battleground condition. Through the analysis of surface structure and organic functional group distribution of PDMS coated UiO-66, silicon was confirmed to be evenly coated. The contact angle increased by over 30° for the PDMS coated UiO-66, indicating that the hydrophobicity was improved. In addition, both the UiO-66 and PDMS coated UiO-66 were used as adsorbents for DIMP, a similar chemical warfare agent, to investigate the durability of adsorption capacity in a high humidity environment. The PDMS coated UiO-66 showed higher durability of adsorption capacity for 20 days than that of pristine UiO-66.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.1
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• pp.122-128
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• 2014

Remote fourier transform infrared(FTIR) chemical imaging detection system allows detection and identification of gases in the atmosphere from long distances. In this paper, the appropriate field of view(FOV) of the FTIR imaging system was examined and the main performance of the system for the interferometer was described. For the determination of the FOV, simulations of gas dispersion range were performed with the NBC reporting and modeling software(NBC-RAMS) developed by ADD. As a result, minimum 192 mrad of FOV was required for the remote FTIR imaging system to visualize chemical warfare agents dispersed in several hundred meters. At the same time, 0.75 mrad of instantaneous field of view(IFOV) for a linear interferometer proper to take a FOV for the chemical agent imaging.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.2 s.17
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• pp.81-87
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• 2004

Semiconductor thick film gas sensors based on tin oxide are fabricated and their gas response characteristics are examined for four simulant gases of chemical warfare agent (CWA)s. The sensing materials are prepared in three different sets. 1) The Pt or Pd $(1,\;2,\;3\;wt.\%)$ as catalyst is impregnated in the base material of $SnO_2$ by impregnation method.2) $Al_2O_3\;(0,\;4,\;12,\;20\;wt.\%),\;In_2O_3\;(1,\;2,\;3\;wt.\%),\;WO_3\;(1,\;2,\;3\;wt.\%),\;TiO_2\;(3,\;5,\;10\;wt.\%)$ or $SiO_2\;(3,\;5,\;10\;wt.\%)$ is added to $SnO_2$ by physical ball milling process. 3) ZnO $(1,\;2,\;3,\;4,\;5\;wt.\%)$ or $ZrO_2\;(1,\;3,\;5\;wt.\%)$ is added to $SnO_2$ by co-precipitation method. Surface morphology, particle size, and specific surface area of fabricated sensing films are performed by the SEM, XRD and BET respectively. Response characteristics are examined for simulant gases with temperature in the range 200 to $400^{\circ}C$, with different gas concentrations. These sensors have high sensitivities more than $50\%$ at 500ppb concentration for test gases and also have shown good repetition tests. Four sensing materials are selected with good sensitivity and stability and are fabricated as a sensor array A sensor array Identities among the four simulant gases through the principal component analysis (PCA). High sensitivity is acquired by using the semiconductor thick film gas sensors and four CWA gases are classified by using a sensor array through PCA.