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1.
Bruce Salter Jeffery Owens Ryan Hayn Rashelle McDonald Eileen Shannon 《Journal of Materials Science》2009,44(8):2069-2078
Recent interest in the treatment of textiles for chemical and biological agent defense has led to the creation of materials
that contain N-chloramide moieties. These materials have demonstrated efficacy against weaponizable bacteria, mustard, and VX, as well as
possessing antimicrobial properties against nuisance organisms that cause conditions such as athlete’s foot or molds. Here,
N-chloramides have been attached to Nomex? intended for use as self-decontaminating regenerable military textiles. The materials were assayed for content of active
oxidizing agent, and tested for efficacy against 2-chloroethyl ethyl sulfide and Demeton-S, simulants for mustard and VX,
respectively. The decomposition products for each reaction were identified as well as reaction pathways to form each by-product
as correlated to analogous products of mustard and VX. Furthermore, the rate constant for the neutralization of each simulant
on the reactive material was calculated from data collected by GC-MS and ATR-FTIR real-time studies. 相似文献
2.
Mahato TH Singh B Srivastava AK Prasad GK Srivastava AR Ganesan K Vijayaraghavan R 《Journal of hazardous materials》2011,192(3):1890-1895
Present study investigates the potential of CuO nanoparticles calcined at different temperature for the decontamination of persistent chemical warfare agent sulphur mustard (HD) at room temperature (30 ± 2 °C). Nanoparticles were synthesized by precipitation method and characterized by using SEM, EDAX, XRD, and Raman Spectroscopy. Synthesized nanoparticles were tested as destructive adsorbents for the degradation of HD. Reactions were monitored by GC-FID technique and the reaction products characterized by GC-MS. It was observed that the rate of degradation of HD decreases with the increase in calcination temperature and there is a change in the percentage of product of HD degradation. GC-MS data indicated that the elimination product increases with increase in calcination temperature whereas the hydrolysis product decreases. 相似文献
3.
Activated carbon of surface area 1100 m2/gm is impregnated with 4% sodium hydroxide plus 3% Cr(VI) as CrO3 with and without 5% ethylene diamine (EDA), 4% magnesium nitrate and 5% ruthenium chloride by using their aqueous solutions. These carbons are characterized for surface area analysis by BET conventional method and exposed to the vapours of sulphur mustard (HD) at room temperature (30 degrees C). After 24 h, the reaction products are extracted in dichloromethane and analyzed using gas chromatography and mass spectrometry (GC-MS). Hemisulphur mustard, thiodiglycol, 1,4-oxathiane are observed to be the products of reaction between sulphur mustard and NaOH/CrO3/C system, whereas on NaOH/CrO3/EDA/C system HD reacted to give 1,4-thiazane. On Mg(NO3)2/C system it gave hemisulphur mustard and thiodiglycol. On RuCl3/C system it degraded to divinyl sulphone. Residual sulphur mustard is observed along with reaction products in all systems studied. Reaction mechanisms are also proposed for these interesting surface reactions. Above-mentioned carbons can be used in filtration systems for protection against hazardous gases such as sulphur mustard. 相似文献
4.
A gas chromatograph coupled with an atomic emission detector was used to identify and to determine the products formed on oxidation of sulfur mustard. The oxidation rate and the resulting oxidates were studied in relation to oxidant type and reaction medium parameters. Hydrogen peroxide, sodium hypochlorite, sodium perborate, potassium monopercarbonate, ammonium peroxydisulfate, potassium peroxymonosulfate (oxone), and tert-butyl peroxide were used as oxidants. Oxidations were run in aqueous media or in solvents of varying polarities. The oxidation rate was found to be strongly related to oxidant type: potassium peroxymonosulfate (oxone) and sodium hypochlorite were fast-acting oxidants; sodium perborate, hydrogen peroxide, ammonium peroxydisulfate, and sodium monopercarbonate were moderate oxidants; tert-butyl peroxide was the slowest-acting oxidant. In non-aqueous solvents, the oxidation rate was strongly related to solvent polarity. The higher the solvent polarity, the faster the oxidation rate. In the acid and neutral media, the mustard oxidation rates were comparable. In the alkaline medium, oxidation was evidently slower. A suitable choice of the initial oxidant-to-mustard concentration ratio allowed to control the type of the resulting mustard oxidates. As the pH of the reaction medium was increased, the reaction of elimination of hydrogen chloride from mustard oxidates becomes more and more intensive. 相似文献
5.
Prasad GK Mahato TH Singh B Ganesan K Pandey P Sekhar K 《Journal of hazardous materials》2007,149(2):460-464
Detoxification reactions of sulphur mustard, a deadliest chemical warfare agent were studied on the surface of zinc oxide nanorods at room temperature (32+/-2 degrees C) and the data was compared with that of the bulk ZnO. Prior to the reaction, the nanorods of zinc oxide were synthesized by the hydrothermal method and subsequently characterized by XRD, SEM, TG, N(2) BET, FT-IR. The data revealed the formation of nanorods with diameter ranging from 100 nm to 500 nm with length in microns. Obtained nanomaterial along with bulk ZnO were tested as reactive sorbent for the detoxification of sulphur mustard. Reaction was monitored by GC-FID technique and the reaction products were characterized by GC-MS. Data explores the role of hydrolysis and elimination reactions in the detoxification of sulphur mustard and it also reveals that zinc oxide nanorods and bulk ZnO show the half lives of 8.48 h, 24.75 h in the first 12h and 122.47 h, 177.29 h from 12h to 48 h of the reaction. 相似文献
6.
Methyl salicylate (MeS) has a rich history as an inert physical simulant for the chemical warfare agents sulfur mustard and soman, where it is used extensively for liquid- and vapor-permeation testing. Here we demonstrate possible utility of MeS as a reactivity simulant for chlorine-based decontaminants. In these experiments MeS was reacted with sodium hypochlorite varying stoichiometry, temperature, reaction time, and pH. No colored oxidation products were observed; however, chlorination of the aromatic ring occurred ortho (methyl 3-chlorosalicylate) and para (methyl 5-chlorosalicylate) to the position bearing the -OH group in both the mono- and disubstituted forms. The monosubstituted para product accumulated initially, and the ortho and 3,5-dichloro products formed over the next several hours. Yields from reactions conducted below pH 11 declined rapidly with decreasing pH. Reactions run at 40 °C produced predominantly para substitution, while those run at 0 °C produced lower yields of ortho- and para-substituted products. Reactions were also carried out on textile substrates of cotton, 50/50 nylon-cotton, and a meta aramid. The textile data broadly reproduced reaction times and stoichiometry observed in the liquid phase, but are complicated by physical and possibly chemical interactions with the fabric. These data indicate that, for hypochlorite-containing neutralizing agents operating at strongly alkaline pH, one can expect MeS to react stoichiometrically with the hypochlorite it encounters. This suggests utility of MeS in lieu of such highly hazardous surrogates as monochloroalkyl sulfides as a simulant for threat scenarios involving the stoichiometric decomposition of sulfur mustard. Specifically, the extent of coverage of the simulant on a fabric by the neutralizing agent can be directly measured. Similar reactivity toward other halogen oxidizing agents is likely but remains to be demonstrated. 相似文献
7.
The products formed from the degradation of the blister agent sulfur mustard [bis(2-chloroethyl) sulfide] on concrete were identified using gas chromatography with mass spectrometry detection (GC/MSD), (1)H NMR, 2D (1)H-(13)C NMR and (13)C solid state magic angle spinning (SSMAS) NMR. In situ and extraction experiments were performed. Sulfur mustard was detected in the in situ (13)C SSMAS samples for 12 weeks, whereas less than 5% of the sulfur mustard was detected in extracts from the concrete monoliths after 8 days. Sulfonium ions and (2-chloroethylthio)ethyl ether (T) were observed on the in situ samples after a period of 12 weeks, whereas vinyl species and bis(2-chloroethyl) sulfoxide were observed in the extracts of the concrete monoliths within 24h. The differences between the extraction and the SSMAS data indicated that the sulfur mustard existed in the concrete in a non-extractable form prior to its degradation. Extraction methods alone were not sufficient to identify the products; methods to identify the presence of non-extractable degradation products were also required. 相似文献
8.
A simple and economical chemical neutralization method is developed against highly toxic chemical warfare agent's viz. sulfur mustard (SM), sesquimustard, and their homologues/analogous. The method involves treatment of chemical warfare agents with sodium in inert solvents. This destruction method of sulfur mustards release innocuous products via desulfurization reactions. The products were characterized by GC-MS technique. The method is suitable in particular, for bulk destruction of heel of mustard stockpiles. 相似文献
9.
Kinetics of degradation of sulphur mustard (HD) on the surface of NaOH/CrO3/C, NaOH/CrO3/EDA/C and RuCl3/C systems has been examined by using gas chromatography technique by extracting and analyzing the residual HD periodically. The carbons were prepared by impregnating activated carbon with 4% sodium hydroxide plus 3% Cr(VI) as CrO3 with and without 5% ethylene diamine (EDA) and 5% ruthenium chloride by using their aqueous solutions. Obtained carbons were characterized for surface area analysis by BET conventional method. Kinetic plots reveal that the observed reactions are fast at the initial stages, slow at the later stages and progress to a steady state indicating the first order behavior. Effect of moisture on kinetic rate is also observed. In the case of NaOH/CrO3/C system the rate constant is decreased from 13.36 to 5.53 x 10(-2) h(-1) and half life is increased from 5.2 to 12.54 h while moisture content is increased from 1.9% to 11.2%. Whereas, the rate constant of HD degradation reaction is decreased from 10.4 to 4.14 x 10(-2) h(-1) and half life is increased from 6.7 to 16.72 h while moisture content is increased from 2.1% to 10.8% on NaOH/CrO3/EDA/C. Reaction on RuCl3/C system also behaves in the similar manner. Extracted reaction products were characterized by GC/MS and it is found that on NaOH/CrO3/C, HD degrades to hemisulphur mustard, thiodiglycol and 1,4-oxathiane. Whereas, on NaOH/CrO3/EDA/C, HD is degraded to 1,4-thiazane and it is degraded to divinyl sulphone on RuCl3/C. All these investigations reveal that above mentioned carbons can be used in nuclear, biological and chemical (NBC) filtration systems for protection against sulphur mustard. 相似文献
10.
Numerous methods are used for destruction of sulfur mustard. Oxidation is one of those methods. There have been only limited data concerning application of the advanced oxidation technologies (AOTs) for mustard destruction available before. In this study sulfur mustard oxidation rate depending on kind of the oxidative system and process parameters used was assessed using selected AOT. The following were selected for mustard oxidation: ozone (O(3)), UV light (UV), hydrogen peroxide (H(2)O(2)); double systems: UV/O(3), UV/H(2)O(2), and O(3)/H(2)O(2); a triple system: O(3)/H(2)O(2)/UV and Fenton reaction. Effectiveness of the selected AOT methods has been evaluated and the most suitable one for mustard destruction was chosen. Using ozone in various combinations with hydrogen peroxide and UV radiation mustard can be destroyed much quicker comparing to the classical oxidizers. Fast mustard oxidation (a few minutes) occurred in those systems where ozone alone was used, or in the following combinations: O(3)/H(2)O(2), O(3)/UV and O(3)/H(2)O(2)/UV. When those advanced oxidation technologies are used, mustard becomes destroyed mainly in course of the direct oxidation with ozone, and reactions of mustard with radicals formed due to ozone action play a secondary role. Rate of sulfur mustard oxidation in the above mentioned ozone-containing oxidative systems decreases with pH value increasing from 2 to 12. Only when pH value of reaction solutions is close to pH 5, mustard oxidation rate is minimal, probably due to "disappearance" of radicals participating in oxidation in this pH. Sulfur mustard can be most effectively destroyed using just ozone in pH 7. In that case mustard destruction rate is only slightly lower than the rate achieved in optimal conditions, and the system is the simplest. 相似文献
11.
Fabrication of TiB2/TiC composites by the directional reaction of titanium with boron carbide 总被引:4,自引:0,他引:4
Dense TiB2/TiC composites were fabricated by the directional reaction of molten titanium with boron carbide preform. The reaction between pure molten titanium and boron carbide preform could not progress due to reaction choking. However, when a few weight per cent of nickel were added in the titanium, the reaction progressed continuously and resulted in TiB2/TiC composites. A gradient of grain sizes was observed in the reaction products. The processing temperature affected the microstructure of the reaction products rather than the reaction rate. The degree of grain-size gradient in the reaction product increased with the processing temperature. 相似文献
12.
喷涂聚脲弹性体用端氨基聚醚的合成与表征 总被引:4,自引:0,他引:4
采用氨基丁酸酯法合成了可用于喷涂聚脲弹性体的高活性端氨基聚醚。整个反应分为酯化和氨化两步,并用红外光谱、核磁共振、元素分析对两步的产物分别进行了表征,最后探讨了影响端氨基聚醚颜色、黏度及转化率的主要因素。 相似文献
13.
Decomposition of cumene hydroperoxide (CHP) was undertaken in a free radical chain reaction. The peroxyl group is very active and unstable, while the remainder of the molecule is inert. CHP reacted with various concentrations of dilute sodium hydroxide as a catalyst to cleave at ambient and decomposition temperature. The products were verified by GC/MS, and were quantitatively analyzed by chromatography. CHP cleaved heterolytic with NaOH at 250 degrees C, whose major product was dimethylphenyl carbinol (DMPC); however, the main products become acetophenone and alpha-methylstyrene by cleaved homolytic pathway. The catalytic concentrations of NaOH significantly affected the branch ratios of DMPC under decomposition. Based on the experimental results, a radical cleavage mechanism was proposed. To sum up, the reaction parameters, such as temperature, Lewis base, etc., could affect the incompatibilities and decomposition pathways for proper CHP cleavage process. In addition, exothermic onset temperatures (T0) and heat of decomposition (Delta Hd) of incompatible mixtures and CHP itself were studied by differential scanning calorimetry (DSC). Comparisons of T0, Delta Hd and peak power were assessed to corroborate the severity of thermal hazards. From the decay rate of CHP concentration, the reaction order was determined to be 0.5, and the Arrhenius parameters were measured as Ea=92.1 kJ/mol and frequency factor A=2.42 x 10(10)min(-1). 相似文献
14.
Study of the co-pyrolysis of biomass and plastic wastes 总被引:1,自引:0,他引:1
Filipe Paradela Filomena Pinto Ibrahim Gulyurtlu Isabel Cabrita Nuno Lapa 《Clean Technologies and Environmental Policy》2009,11(1):115-122
This work aimed to study the recovery of two types of waste by the process of pyrolysis. The obtained results show that the
adding of a plastic mix improves the overall efficiency of the slow pyrolysis of pine. Therefore, it was possible to achieve
higher liquid yields and less solid product than in the classic slow pyrolysis carbonization of biomass. The obtained liquids
showed heating values similar to that of heating fuel oil. The gas products had energetic contents superior to that of producer
gas, and the obtained solid fractions showed heating values higher than some coals. There were also identified some typical
products of fast biomass pyrolysis used as raw material in several industries. The effects of experimental conditions in product
yield and composition were also studied. The parameters that showed higher influence were (with its increase): reaction time
on gas product composition (increase of the alkane content) and on liquid composition (increase in aromatics content); reaction
temperature on product yield (decrease of liquid yield with increase of solids and gases) and on gas product composition (increase
in alkane content); initial pressure on liquid composition (increase in the aromatics content) and mainly the pine content
of the initial mixture on products yield (increase of gas and solid yield with a decrease in liquids) and on the gas product
composition (favouring CO and CO2 formation).
An erratum to this article can be found at 相似文献
15.
Two new reagents, NDTE (2,5-dihydroxyphenylacetic acid, 2,5-bis-tetrahydropyranyl ether p-nitrophenyl ester) and HLTE (homogentisic gamma-lactone tetrahydropyranyl ether), are described for the chemical derivatization of primary and/or secondary amines to form an electrochemically active product. These reagents undergo reaction with the aforementioned analytes to form a product possessing the hydroquinone moiety, thus allowing for reversible electrochemical detection at mild oxidation potentials. The reactivity of each reagent was demonstrated by using N-ethylbenzylamine (EBzA) and the dipeptide isoleucine leucine methyl ester as model analytes. The investigation included the isolation and identification of the intermediates and final products from derivatization of EBzA. These isolated standards were subsequently characterized with respect to electrochemical properties by means of cyclic voltammetry. In LC-EC experiments, the concentration limit of detection (CLOD) of the purified EBzA product was determined to be 5 nM (100 fmol) at a detection potential of +200 mV vs Ag/AgCl ([Cl-] = 3 M). The CLOD values obtained by LC-EC after derivatization of aqueous solutions of EBzA and Ile-Leu-OMe with NDTE were 25 nM (250 fmol) and 250 nM (2.5 pmol), respectively. 相似文献
16.
R. E. Loehman F. M. Hosking B. Gauntt P. G. Kotula P. Lu 《Journal of Materials Science》2005,40(9-10):2319-2324
We are studying reactions of Ti, V, Zr, and Hf with ceramics as part of a program to understand fundamental reaction and bonding mechanisms in active metal brazing of ceramics. In this paper we present results of experiments with model systems comprising Ag alloys that contain different amounts of Hf or Zr that were reacted with sapphire or 99.6% alumina for different times and temperatures in a controlled atmosphere furnace. In these alloys the Ag functions as an inert solvent, which allowed us systematically to determine the effects of changes in concentration of the active element. We observed qualitative wetting and spreading tendencies of the alloys during heating and examined cross sections after cooling using electron analytical techniques. For all reaction times studied, the Hf/Ag alloys formed a discontinuous reaction layer, which was consistent with earlier high-resolution electron microscopy that showed sub-micrometer HfO2 particles embedded in the surfaces of the Al2O3 grains. By contrast, initial reaction of the Zr/Ag alloys with Al2O3 produced a continuous interface layer. With longer reaction times, the ZrO2 reaction product became much thicker and exhibited three distinct zones at the interface. The results suggest that the rate limiting step in the Zr/Ag reaction is the chemical reaction at the interface, whereas with Hf/Ag reaction diffusion of products away from the interface is rate limiting. 相似文献
17.
目的面向智能产品状态信息的视觉性表达,探讨提取、匹配与重组智能产品光效视觉特征的设计方法。方法以空气净化器的光效设计为例,根据产品符号学和认知心理学理论,基于视觉特征,运用限定式KJ法建立智能产品光效特征的要素清单,运用问卷与量表建立光效闪烁样式、闪烁频率与灯光亮度3个特征与智能产品状态信息相匹配的设计模型,最后通过匹配实验证明本方法在智能产品光效设计中的有效性。结果设计出针对空气净化器运行活跃、夜间睡眠、通知换芯和程序故障4种状态的光效。结论通过将智能产品光效视觉特征进行提取、匹配与重组,增强光效对智能产品状态信息的准确性表达。与此同时,将光效作为用户与产品沟通的媒介,以提升用户对智能产品状态的认知,并引导用户对智能产品作出相应的操作反馈。 相似文献
18.
Chlorine dioxide is a hypochlorite alternative disinfectant agent. In this context, we have determined the products formed in the reaction of ClO(2) with selected amino acids as model compounds that can be present in natural waters. The reaction of tryptophane, histidine and tyrosine (10 ppm each) with ClO(2) were studied at molar ratios ranging from 0.25 to 4 in the presence or absence of oxygen. It was found that in the absence of oxygen adding substoichiometric amounts of ClO(2) creates products that are structurally similar to the starting amino acids. Through a series of cascade reactions the initial product distribution gradually evolves toward simple, small carbon chain products that are far from the starting amino acid. The reaction product distribution revealed that chlorine dioxide can attack the electron-rich aromatic moieties as well as the nitrogen atom lone electron pair. Our study is relevant to gain knowledge on the reaction mechanism of ClO(2) with ubiquitous amino acids present in natural waters. 相似文献
19.
20.
This paper describes a microfluidic chip wherein the position and order of two immobilized enzymes affects the type and quantity of reaction products in the flowing fluid. Assembly of the chip is based on a self‐assembled monolayer presenting two orthogonal covalent capture ligands that immobilize their respective fusion enzyme. A thiol‐tagged substrate is flowed over a region presenting the first enzyme—which generates a product that is efficiently transferred to the second enzyme—and the second enzyme's product binds to an adjacent thiol capture site on the chip. The amount of the three possible reaction products is quantified directly on the chip using self‐assembled monolayers for matrix‐assisted laser desorption/ionization mass spectrometry, revealing that the same microsystem can be spatiotemporally arranged to produce different products depending on the device design. This work allows for optimizing multistep biochemical transformations in favor of a desired product using a facile reaction and analytical format. 相似文献