Encapsulation of high explosives using nanoporous materials for desensitization

김은영 중앙대학교 대학원 2020 국내석사

고폭 화약은 짧은 시간의 화학반응에서 화학반응에서 고온 및 고압의 기체와 많은 에너지를 방출하는 방출하는 물질 이다. 이러한 화약에는 대표적으로 RDX, HMX, TNT가 있고 이들의 특징은 민감성과 민감성과 폭발 성능으로 설명할 수 있다. 일반적으로 고 성능의 화약은 민감한 특성을 지니고 지니고 저 성능의 화약은 둔감한 특성을 지닌다 . 따라서 고 성능의 화약에 대해서는 폭발 성능을 그 대로 유지한 상태로 민감한 특성을 줄이는 것이 매우 중요하다 중요하다 . 화약은 합성된 직후에 재결정 단계를 거쳐 불순물을 제거한다 . 이때 급작스러운 상변화에 변화에 의해 내부 공극이 형성된다 . 내부 공극은 외부로부터 오는 충격 및 마찰에 쉽게 수축하며 수축하며 폭발 개시를 일으키게 된다 . 화약의 일부분에서 일어난 폭발 개시는 화약 전체로 퍼져 비 의도성 폭발을 야기한다 . 그러므로 화약의 민감성을 줄이기 위해서는 내부 공극을 줄이거 나 화약이 받는 외부 충격을 완화시켜야 한다 . 화약의 둔감화 는 대부분 마이크로 사이즈 의 화약을 나노사이즈화 하여 내부 공극을 줄여 실현되고 있다 . 이 이외에도 표면 개질 과 충격 완화를 위한 물질 첨가에 첨가에 대한 연구도 활발히 진행되고 진행되고 있다 . 이번 실험에서는 3차원 구조와 구조와 넓은 기공 크기를 갖는 metal organic frameworks (MOFs)를 이용하여 RDX의 둔감화를 진행하였다 진행하였다 . 나노 다공성 물질인 물질인 MOF에 함침함으로써 내부 공 극을 줄일 수 있고 3차원 구조가 구조가 외부로부터 오는 충격을 완화시켜줄 수 있다 . 그리고 화 약의 함침량에 영향을 줄 수 있는 요인에 대해 알아보고 함침 과정을 최적화하였다 . 이를 통해 제작된 샘플에 대하여 충격 및 마찰 감도 시험을 진행하 였고 민감한 특성의 개선을 확인하였다. High explosives (HE) containing –NO2, -ONO2, and –NHNO2 groups can emit light, heat, sound, pressure, and large energy for a short time. The properties of explosives can be explained by their detonation performance and sensitivity, which are in a trade-off relationship. In general, explosives with high power of detonation are sensitive to external impact. It is therefore very important to develop explosives that can operate in the desired conditions while maintaining the original performance of explosives. In particular, the representative high explosives such as cyclotetramethylene-tetranitromine (High Melting Explosives (HMX), C4H8N8O8) and cyclotrimethylene trinitramine (Research Department Explosives (RDX), C3H6N6O6) are manufactured in a micro-size during the recrystallization process and the internal voids generated in this process act as hot spots causing unintentional explosions. Typically, there are two ways to desensitize explosives, reducing the size of the internal pores by reducing the particle size of the explosives and relieving the external impact of the explosives by adding inert materials. In this experiment, both of these options were used by using metal organic frameworks (MOFs) with a 3D structure and large pore volume. The size of the internal voids was reduced by encapsulation in nanoporous MOFs so that internal voids were diminished. In addition, the impact from the outside was alleviated by encapsulating the explosives inside MOFs with a rigid 3D structure. This study proposes a method to improve the insensitivity while maintaining the high power of detonation by encapsulating high explosives into various nanoporous MOFs having a high specific surface area and pore volume. At this time, studies were conducted on factors that could affect the amount of encapsulation, and it was confirmed that the sensitivity was reduced through an evaluation of sensitivity.

폭발사고시 효과적인 과학수사 방법에 관한 연구

전상근 경북대학교 수사과학대학원 2005 국내석사

Accidents and terrorist acts that utilize explosives have a great influence on society and thus require a prompt investigation for the arrest of the culprit. However, such investigations are often met with difficulties due to the vastness of the crime scene, restrictions on approaching the scene, fragility of the evidence, complexity of investigation, and the lack of expertise. In spite of such facts, scientific investigation regarding explosives have not been widely studied in Korea. Therefore, the focus of this research primarily concerns the effective scientific investigation methods in cases of accidents that involve chemical explosives. Although the a systematic investigation method is at the heart of scientific investigation in cases of explosive accidents, it is only at its rudimentary stage. Therefore, in this research, a systematic investigation method is put forth for the scene investigation, the documentation of the scene, and the collection and processing of evidence. Further, I have set forth a 'scene investigation check list' the ensure a thorough scene investigation and to promote an exhaustive evidence collection that would guarantee the admissibility of such evidence in court. The above efforts were aimed at simplifying the currently complicated investigation system. In the future, a guidebook that can be generally applied to accidents involving explosives in Korea ought to be produced, a continual systematic education and integrated training excises for investigators ought to be established, laws that require additives in explosives ought to be instituted so that the type, components, and source of explosives can be identified, and lastly, a database that contain information on former explosion accidents, trends, and techniques of criminal activities that involve explosion accidents should be compiled.

Dynamical study on the blasting with one-free-face to utilize AN-FO explosives : 硝油爆藥類를 活用한 單一自由面發波의 力學的 硏究

허전 The Chosun Uinversity 1972 국내박사

發破에 있어서 穿孔配置는 發破效果에 影響을 미치는 가장 重要 한 要素中의 하나이다. Burn Cut의 爆發의 여러 要素에 關한 硏究는 Brown, Cook等에 依해 發表된 바 있으나 本 硏究에 있어서는 Burn-Cut와 Pyramid-Cut의 穿孔配置의 對比와 爆源과 自由面 사이의 力學的 應力 解析에 重點을 두어 伊勝 敎援가 展開한 理論에서 다루지 않은 適正穿孔配置에 依한 Burn-Gut의 效果를 連結시켰다. 從來의 理論에 依하면 .準- 自由面 發破에 있어서는 壓縮應力外 에 自由面에서 反射되는 引張應力의 影響을 追加로 받는바 本 新穿孔 配置에 依한 Burn-Cut는 自由面數의 增加와 距離의 縮小를 피하므로 이 效果는 더욱 增大된다. 이와 같은 效果를 爲해서는 다음 두가지 点을 考慮해야 한다. 첫째 心技孔의 無裝藁孔은 補助應力을 크게 하기 爲해해 可能한 大口徑으로 깊게 穿孔해야 한다. 둘째 각 心技孔間의 距離를 接近시켜 完全 發破를 期해야 한다. 그 까닭은 口徑이 增加됨에 따라 2次 自由面은 넓어지고 거리가 가까울수록 製藥孔과 無製藥孔 사이의 引張應力은 더욱 發達되기 때문이다. 先進國에서는 心□孔사이의 距離를 4 "로. 함이 理想的 이라고 알려지고 있으나 本實驗에 依하면 더욱 近接될수록 破壞巖石이 增加되고 掘進長도 깊어짐이 밝혀졌다. 나아가서는 掘進長을 더욱 增大시키기 爲해 Burn-Cut로 부터 large hole Burn-Gut를 開發하여 發破回數 max 7回/日로서 1發破堂 3.1 m까지 試圖 함으로서 高速度掘進의 起源을 마련했다. 또한 大口徑 Burn-Cut에서는 큰 抵抗을 극복하기 위해 金□硝 油爆藥을 使用함이 더욱 效果的임이 立證�榮� 最初 低廉한 □格과 取扱安全으로 각광을 시작한 AN-FO는 비료용 또는 産業用 硝安에 燃料油를 混合한 것으로서 雷管의 起爆前 에는 鈍感하나 Gelatine Dynamite 等의 瀑發性 銳感劑에 依해 發破孔內에서 일단 起爆되면 從來의 硝安爆藥에 相當한 威力을 發揮한다. AN-FO 爆劑의 性能에 關해서는 많은 報告가 있었으나 本 實驗에 依하면 硝油混合比는 粉狀은 93.5 : 6,5 . Prill狀은 94 : 6이 最適이며 粉狀 An-FO는 Prill 狀 AN-FO보다 恒常 爆速이 높다. 또한 起爆感度 ,衝擊感度.,摩擦感度 等 諸感度는 他火藥에 比해 몸시 鈍感하며 傳爆性을 Prill 狀이 粉狀보다 優秀함을 얻었다. 發破後 Gas도 良好하며 AN-PO는 製造後 7日 前後가 最大 效果를 갖는다. 從來 AN-FO는 지난 여러해 동안 露天掘에만 使用하여 왔으나 筆者는 AN-FO의 基礎性能試驗을 土台로 이를 利用한 新種爆劑로서 金屬硝油爆藥과 水中爆藥을 發展시켰다. 金屬硝油의 爆藥은 AN-FO와 A1 金屬粉末의 混合物이며 水中爆藥은 從來爆藥과 AN-FO로 製造한 바 이에 關해서는 附錄에 記述 했다. 本 硏究에 있어서는 單一自由面 發破에 있어서 硝油爆藥類를 活用한 바 그 效果가 매우 良好하였음을 確認하였다. Drilling position is one of the most important factors affecting on the blasting effects. There has been many reports on several blasting factors of burn-cut by Messrs. Brown and cook, but in this study the author tried to compare drilling positions of burn-cut with pyramid-cut, and also to correlate burn-cut effects of drilling patterns, not being dealt by prof. Ito in his theory, which emphasized on dynamical stress analysis between explosion and free face. According to former theories, there break out additional tensile stress reflected at the free face supplemented to primary compressive stress on the blasting with one-free-face. But with these experimented new drilling patterns of burn-cut, more free faces and nearer distance of each drilling holes make blasting effects greater than any other methods. To promote the above explosive effect rationally, it has to be considered two important categories under-mentioned. First, unloaded hole in the key holes should be drilled in wider diameter possibly so that it breaks out greater stress relief. Second, possibly key holes should have closer distances each other to result clean blasting. These two important factors derived from experiments with, theory of that the larger the dia. of the unloaded hole, it can be allowed wider secondary free faces and closes distances of each holes make more developed stress relief, between loaded and unloaded holes. It was suggested that most ideal distance between holes is about 4˝ clearance in U.S.A., but the author, according to the experiments, it results that the less distance allow, the more effective blasting with increased broken rock volume and longer drifted length can be accomplished. Developed large hole burn-cut method aimed to increase drifting length technically under the above considerations, and progressive success resulted to achieve maximum 7 blasting cycles per day with 3.1m drifting length per cycle. This achievement originated high-speed-drifting works, and it was also proven that application of Metallic AN-FO in large hole burn-cut method overcomes resistance of one-free-face. AN-FO which was favored with low price and safety handling is the mixture of the fertilizer or industrial Ammonium-Nitrate and fuel oil and it is also experienced that it shows insensible property before the initiation, but once it is initiated by the booster, it has equal explosive power of Ammonium Nitrate Explosive (ANE). There were many reports about AN-FO. On AN-FO mixing ratio, according to these experiments, powdered AN-FO, 93.5:6.5 and prilled AN-FO, 94:6 are the best ratios. Detonation, shock, and friction sensitivities are all more insensitive than any other explosives. Residual gas is little toxic. On initiation and propagation of the detonation test, prilled AN-FO is more effective than powdered AN-FO. AN-FO has the best explosion power at 7 days elapsed after it has mixed. While AN-FO was used at open pit in past years prior to other conditions, the author developed new improved explosives, Metallic AN-FO and Underwater explosive, based on the experiments of these fundamental characteristics by study on its usage utilizing AN-FO. Metallic AN-FO is the mixture of AN-FO and Al, Fe-Si powder, and Underwater explosive is made from usual explosive and AN-FO. The explanations about them are described in the appendix. In this study, it is confirmed that the blasting effects of utilizinng AN-FO explosives are very good.

Starch-stimulated aerobic degradation of explosives : microbial consortia development and soil applicability

Khan, Muhammad Imran Graduate School, Yonsei University 2015 국내박사

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)와 2,4,6-trinitrotoluene(TNT)는 전 세계적으로 사용되는 주요 화약물질로서, 이들에 의한 환경 오염은 생물학적 독성과 환경 내 잔류성 때문에 심각한 환경 문제로 인식되고 있다. 화약물질을 분해하기 위한 미생물 자원으로 호기성 질소 고정 미생물 군집제재가 고려되기도 하였으나, 화약물질 자체보다 독성이 높은 분해산물의 완전한 무기화는 성공하지 못하였다. 본 연구의 목적은 (i) 질소 고정 조건에서 대상 화약물질과 전분을 동시에 주입하여 새로운 RDX, TNT 분해 미생물 군집제재 개발, (ii) 생분해 시 발생하는 분해 산물과 미생물 군집 구조의 특성 분석, (iii) 전분을 이용해서 선택적 배양된 호기성 화약물질 분해 미생물 군집제재의 토양 적용성 평가 등이다. 질소 고정 조건에서 전분과 대상 화약물질이 함께 존재하는 경우, 화약물질의 호기성 생분해가 효과적으로 촉진되었다. 전분을 기질로 이용한 계대배양을 통해서 RDX를 완전 분해하는 호기성 미생물군집제재 (MI), TNT완전 분해하는 호기성 미생물군집제재(MIK), 그리고 혐기성에서 RDX 분해하는 군집제재 (IK)를 성공적으로 획득하였다. 호기성 미생물군집제재들은 RDX와 TNT를 완전 분해해서 무해한 최종산물들을 생산하는 무독성화의 정도가 전분을 첨가 하였을 때 더 향상됨을 알 수 있었다. 반면 혐기성 미생물 군집제재의 경우 독성 니트로소 산물의 누적이 관찰되었다. 16S rRNA 유전자를 대상으로 한 파이로시퀀싱 분석 결과, 전분과 화약물질의 공동투여로 활성화한 호기성 분해 미생물들이(MI의 경우Rhizobium, MIK의 경우 Methylophilus) 질소 고정과 연계되어 있고, 이러한 연계가 화약물질 무독화의 향상에 기여했을 가능성을 제시하였다. 실제 토양에 미생물군집제재를 적용한 마이크로코즘 실험에서는 개발된 호기성 미생물 군집제제가 토양 조건에서 RDX를 완전 무해화함을 확인하였다. 본 연구결과, 전분과 화약물질의 동시 주입이 호기성 화약물질 분해와 분해부산물의 무독화를 증진하는 효과가 있음이 밝혀졌다. 또한 획득한 신규 미생물 군집제재들은 화약물질 오염에 의한 지중환경의 유해성 감소를 위한 유용한 자원으로 활용될 것이다. Contamination by explosive compounds such as hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and 2,4,6-trinitrotoluene (TNT) and their degradation products is a serious environmental concern because of their toxicity to biological systems and their persistence in the environment. Although use of aerobic nitrogen-fixing microbial consortia has been considered a promising microbial resource for explosive degradation, its complete explosive mineralization has yet to be achieved. In this dissertation work, the research objectives were to; (i) develop novel RDX- and TNT-degrading microbial consortia by co-addition of starch with target explosives under nitrogen-fixing conditions, (ii) explore their biodegradation intermediates and microbial community characteristics, and (iii) examine the applicability of the developed starch-stimulated aerobic microbial consortia in soil under laboratory conditions. Under nitrogen-fixing condition, aerobic explosive biodegradation was found to be effectively stimulated by the co-addition of starch with each target explosive. Two aerobic microbial consortia (MI and MIK with RDX and TNT biodegradation abilities, respectively) and an anaerobic RDX-degrading consortium (IK) were successfully enriched through sub-culturing in series with starch addition. Complete explosive detoxification via ring cleavage and mineralization was achieved by the starch-stimulated aerobic consortia while formation of toxic nitroso-derivatives was observed by the anaerobic consortium. Pyrosequencing targeting bacterial 16S rRNA genes suggested that, in the aerobic consortia, the potentially novel aerobic explosive degraders stimulated by starch and explosives (Rhizobium for MI and Methylophilus for MIK) may have been involved in the improved explosive detoxification in association with nitrogen fixation. In the following laboratory soil microcosm experiments, the applicability of the developed aerobic consortium (MI) in soil RDX bioremediation was supported. In conclusion, the findings from this work suggest that the co-addition of starch with target explosive is an effective way to stimulate aerobic explosive degradation and to enhance explosive detoxification under nitrogen-fixing conditions, and that the newly developed aerobic consortia are valuable microbial resources for rhizoremediation and bioremediation of explosive-contaminated subsurface environment.

Synthesis of bisnitropyrazolylmethane and dialkyl-dinitro-imidazolium as candidates for new high energy materials

김남태 서울대학교 대학원 2021 국내박사

The azole compounds substituted with nitro groups have a difficulty in that their explosive performance is improved but their nucleophilicity is decreased as electron-withdrawing nitro groups are additionally introduced. For this reason, it remains a challenging task to synthesize new high-energy materials (HEMs) via alkylation of the nitroazoles. In this thesis, the results of synthetic studies for new nitroazoles based HEMs are presented via their alkylation reactions using selected reagents with high electrophilicity or applying appropriate reaction conditions. First, the N,N'-methylene bridged coupling reaction of 4-chloro-3,5-dinitro-1H-pyrazole (ClDNP) 1 was studied. ClDNP 1 is known to have a difficulty for coupling reaction due to its reduced nucleophilicity. Bis(4-chloro-3,5-dinitro-1H-pyrazol-1-yl)methane 2 was obtained in a yield of 79% under reaction conditions in which highly electrophilic diiodomethane was used excessively. It is expected that these reaction conditions of using the excess alkylation reagent could be applied to the coupling reaction of the nitroazole-based material having reduced nucleophilicity. Compound 2 is expected to be a useful precursor of new HEMs because it is easy to change its reactive chloro groups with energetic functional groups. In fact, bis(4-azido-3,5-dinitro-1H-pyrazol-1-yl)methane 3 was obtained in 77% yield by substituting the chloro group of 2 with energetic azido group under mild reaction condition. Compound 3 is expected to be used as a new green primary explosive candidate as it has better thermal stability and explosive performance than DDNP (2-diazo-4,6-dinitrophenol), a widely used military primary explosive. Second, the synthesis of 4,5-dinitro-N,N'-dialkylimidazolium cations was studied by quaternizing 4,5-dinitroimidazoles via alkylation reactions. In the research field of energetic ionic liquids (EILs), dinitroimidazoles have been reported to be unable to be quaternized due to the electron-withdrawing effect nitro groups substituted on them. In order to achieve this challenging task, it was necessary to select a more reactive alkylating reagent than methyl triflate. This challenge was overcome by using Meerwien’s reagents (R3OBF4) as more reactive alkylating reagents. As a result of quaternization reaction of 4,5-dinitro-1H-imidazole 4 and 1-methyl-4,5-dinitro-1H-imidazole 5 using triethyloxonium tetrafluoroborate (Et3O+BF4-), 1,3-diethyl-4,5-dinitro-1H-imidazol-3-ium tetrafluoroborate ([1,3-diEt-4,5-diNO2-Im][BF4]) 6 and 3-ethyl-1-methyl-4,5-dinitro-1H-imidazol-3-ium tetrafluoroborate ([3-Et-1-Me-4,5-diNO2-Im][BF4]) 7 were obtained. Newly obtained compounds 6 and 7 are expected to be used as precursors for new HEMs via metathesis reaction with energetic anions. In fact, two new HEMs candidates, 1,3-diethyl-4,5-dinitro-1H-imidazol-3-ium 2,4,5-trinitroimidazol-1-ide ([1,3-diEt-4,5-diNO2-Im][2,4,5-triNO2-Im]) 8, 3-ethyl-1-methyl-4,5-dinitro-1H-imidazol-3-ium 2,4,5-trinitroimidazol-1-ide ([3-Et-1-Me-4,5-diNO2-Im][2,4,5-triNO2-Im]) 9 were also obtained via anion metathesis reaction with energetic 2,4,5-trinitroimidazolate anion. Compound 9 showed the promising properties as a new insensitive HEM because of its excellent insensitivity and more powerful explosive performance than those of TNT (2,4,6-trinitrotoluene). 아졸계 화합물에 다수의 니트로기가 치환될 경우, 폭발성능은 향상되지만, 증가된 전자끌기 유발효과로 인해 친핵성이 저하되어 알킬화 반응으로 새로운 구조의 고에너지 물질을 합성하는 시도들이 어려움을 겪어왔다. 본 논문에서는 반응조건의 조절과 높은 친전자성을 가진 알킬화 반응 시약의 사용을 통해 기존 합성이 어려운 것으로 보고된 새로운 고에너지 물질들을 합성한 결과를 제시한다. 첫째로, 2개의 강한 활성감소 치환기인 니트로기와 1개의 약한 활성감소 치환기인 염소기가 치환되어 기존 메틸렌 결합으로 커플링 반응이 어려운 것으로 보고된 4-chloro-3,5-dinitro-1H-pyrazole (ClDNP) 1의 커플링 반응을 통해 새로운 고에너지 물질 합성을 시도하였다. 친전자성이 높은 디할로메텐인 디아이오도메테인을 과량으로 사용한 반응조건에서 ClDNP로부터 bis(4-chloro-3,5-dinitro-1H-pyrazol-1-yl)methane 2을 79%의 수율로 얻을 수 있었다. 이러한 과량 반응조건은 친핵성이 저하된 니트로아졸계 물질의 커플링 반응에 적용할 수 있을 것으로 기대된다. 또한, 아지도화 반응을 통해 염소기를 고에너지기인 아지도기로 치환하여 새로운 1차 폭발물 후보로서 bis(4-azido-3,5-dinitro-1H-pyrazol-1-yl)methane 3을 77% 수율로 얻을 수 있었다. 실측 및 계산을 통해 분석된 3의 물성은 군사적으로 널리 사용되는 1차 폭발물인 DDNP (2-diazo-4,6-dinitrophenol)보다 우수한 열적 안정성과 폭발성능을 가진 것으로 확인되었다. 둘째로, 2개의 강한 활성화 치환기인 니트로기 치환으로 N,N’-디알킬화 반응이 어려운 것으로 보고된 4,5-dinitro-1H-imidazole 4와 1-methyl-4,5-dinitro-1H-imidazole 5를 quaternization하여 새로운 에너지 이온성 액체(energetic ionic liquids, EILs)를 합성하였다. 강한 친핵성을 가진 것으로 보고된 Meerwein 시약을 사용하여 무수조건에서 반응하여 새로운 EILs인 1,3-diethyl-4,5-dinitro-1H-imidazol-3-ium tetrafluoroborate 6과 3-ethyl-1-methyl-4,5-dinitro-1H-imidazol-3-ium tetrafluoroborate 7를 각각 얻을 수 있었다. 이 반응조건은 활성감소 치환기로 인해 친핵성이 저하된 헤테로고리 화합물의 quaternization에 적용 가능할 것으로 기대된다. 또한, 폭발성능을 가진 potassium 2,4,5-trinitroimidazol-1-ide로 음이온 metathesis하여 새로운 고에너지 물질인 3-diethyl-4,5-dinitro-1H-imidazol-3-ium 2,4,5-trinitroimidazol-1-ide 8와 3-ethyl-1-methyl-4,5-dinitro-1H-imidazol-3-ium 2,4,5-trinitroimidazol-1-ide 9을 각각 얻을 수 있었다. 이 중에서, 화합물 9은 대표적인 고에너지 물질인 TNT에 비해 우수한 둔감성과 폭발성능을 동시에 갖춘 것으로 확인되었다.

염기성 가수분해와 아임계수 추출을 이용한 화약류 오염 토양의 처리

신동식 울산대학교 대학원 2013 국내석사

국문요약 염기성 가수분해와 아임계수 추출을 이용한 화약류 오염 토양의 처리 울산대학교 대학원 건설환경공학과 신동식 대표적 화약류인 TNT (2,4,6-trinitrotoluene)는 동?식물 및 미생물에 대한 독성이 존재하고 돌연변이와 유전자 변이를 일으키며 피부자극, 호흡기 장애, 빈혈 및 간에 대한 발암 가능 물질 (carcinogen class C)로 알려져 있다. US EPA는 DNT (2,4-dinitrotolune), TNT, RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine)를 발암 가능 물질과 priority pollutant로 분류하여 관리하고 있다. 본 연구에서는 니트로기(-NO2)를 보유한 화약류가 염기성 환경에서 가수분해된다는 가정 하에 pH 11 이상 조건에서 화약류 오염 토양을 처리하였다. 또한 아임계수 추출을 이용하여 화약류 물질을 분해 추출하였다. 염기성 가수분해를 통하여 DNT 오염토양 (10 mg/kg)은 pH 12에서 60 분 반응 하였을 때 완전 분해되었다. TNT 오염토양 (5 mg/kg)의 경우 pH 12 이상에서 반응시간 10 분 안에 토양내의 TNT가 완전 분해되었고, RDX (25 mg/kg) 오염토양은 pH 12 이상에서 초기반응 시간 10분에서 RDX가 완전 분해되었다. DNT 및 TNT 오염토양의 pseudo-first-order rate constant는 pH 12인 경우 각각 0.085 min-1, 0.1 min-1 였으며 약 1 order 정도 차이를 보였다. RDX 오염토양 (0.7 min-1)의 경우는 DNT 오염토양 및 TNT 오염토양에 비하여 pH 12인 경우 약 6-7 배 높은 pseudo-first-order rate constant 값을 보였다. 아임계수 추출 실험 결과 DNT 오염토양은 초기 농도 (50 mg/kg) 대비하여 250~300 ℃에서 60 분 반응 하였을 때 완전히 분해되었다. RDX (255 mg/kg) 오염토양은 200 ℃ 일 때 반응시간 120분에서 완전 분해되었다. 그에 비해서 TNT 오염토양 (200 mg/kg)의 경우 250 ℃ 이상에서 40분 이상 반응할 때 토양내의 TNT가 완전 분해되었다. 염기성 가수분해 및 아임계수 추출 조건에서 화약류 오염토양과 용액의 실험 비율을 각각 1:4, 1:3으로 조절 하였을 때 전체적인 분해효율은 40~60% 감소하였다. DNT, TNT, RDX로 오염된 토양의 염기성 가수분해 정도를 평가한 결과 pH 12 이상의 경우 3시간 이내에 완전히 분해되었다. 또한 화약류로 오염된 토양과 물의 비율이 염기성 가수분해의 정도를 증가시키는데 매우 중요한 요소였으며 토양과 물의 비율이 1:6 이상이었을 경우 완전한 제거를 관찰하였다. 염기성 가수분해와 마찬가지로 토양과 물의 비율은 아임계수 추출에 중요한 요소였으며 1:5 이상이었을 때 토양내의 화약류가 완전분해가 되었다. ABSTRACT Treatment of explosive-contaminated soils using alkaline hydrolysis and subcritical water degradation Dong-Sik Shin Department of Civil & Environmental Engineering Graduate School, University of Ulsan 2,4-Dinitrotoluene (DNT), 2,4,6-trinitrotoluene (TNT), hexahydro-1, 3, 5-trinitro-1, 3, 5-triazine (RDX) are toxic to plants, animals, and microorganism. Due to this reason, they are classified as possible carcinogens (Class C) and priority pollutants by US EPA. In this study, we investigated alkaline hydrolysis and subcritical water degradation of the explosives via a series of batch experiments. The results indicated that DNT and TNT in contaminated soils (10 and 5 mg/kg, respectively) were completely hydrolyzed at pH 12 in 60 and 10 min, respectively. RDX in contaminated soil (25 mg/kg) was also fully decomposed at pH 12 in 10 min. The pseudo-first-order hydrolysis rate constants for DNT, TNT, and RDX in contaminated soils were 0.085, 0.1, and 0.7 min-1 at pH 12, respectively. It appears that pH 12 is a critical pH to enhance the alkaline hydrolysis. Through subcritical water degradation, DNT in contaminated (50 mg/kg) soil was completely removed at 250~300℃ in 60 min. RDX and TNT in contaminated soils (255 and 200 mg/kg, respectively) were also completely decomposed at 200 ℃ in 120 min and 250 ℃ in 40 min, respectively. For both alkaline hydrolysis and subcritical water degradation, the soil-to-water ratio affected the degradation efficiency. When the ratio was increased to 1:4 and 1:3, the decomposition efficiency was decreased by 40~60%. The critical soil-to-water ratios to maintain constant degradation rates were 1:5 and 1:6 for alkaline hydrolysis and subcritical water degradation, respectively. Our results suggest that alkaline hydrolysis and subcritical water degradation can effectively treat explosive-contaminated soils.

Role of Energy Localization on Chemical Reactions at Extreme Conditions

Hamilton, Brenden W Purdue University ProQuest Dissertations & Theses 2022 해외박사(DDOD)

High explosives represent a class of materials known as energetic materials, in which providing an external stimulus of impact, heat, and electric shock can result in rapid exothermic reactions. Hence, there has always been a considerable research focus into the development, production, optimization, and control of these materials, aiming to increase explosive capabilities while also decreasing overall sensitivity to ignition.The study of impact induced chemical initiation of explosives is an inherent multiscale problem that requires time and length scales not accessible by a single experiment or calculation. The works presented here provide a theoretical effort to contribute to bottom-up modeling of the physics and chemistry phenomena in reacting high explosives using molecular dynamics simulations. Focus will be placed how energy localizes in the molecular crystal TATB, an insensitive high explosive.The first energy localization topic covered is an intra-molecular localization and distribution of the kinetic energy. Molecular dynamics is inherently classical, which partition energy equally between all modes. However, most molecular explosives should follow a quantum description, where energy is partitioned between modes following the Bose-Einstein distributions. A semi-classical approximation called the 'quantum thermal bath' is applied here to study classical vs. quantum effects for both shock and thermal initiation of chemistry. These results show, not only the importance of the changes to specific heat, which is expected, but the influence of the zero-point energy on reactivity.The idea of energy localization is then expanded to the microstructural level, focusing on hotspots, which are areas of extreme temperature following interactions between a shockwave and the microstructure. To date, hotspots have been characterized and described by the localization of their temperature fields only. This work develops a description of the potential energy field in the hotspot, which is markedly different from the temperature field and cannot be predicted from it, as has been previously assumed. This latent potential energy, that is non-thermal, manifests from intra-molecular strain in which individual molecules in the hotspot become highly distorted. This strain energy is shown to be driven by plastic flow during the formation of the hotspot.Lastly, the influence of the latent PE in hotspots on chemical reactivity is assessed. Reactive molecular dynamics calculations of shock induced pore collapse creates a hotspot in which deformed molecules can be separately assessed from undeformed ones. Deformed molecules are shown to react faster, follow different ensemble statistics, and undergo different first step reaction pathways. To better study these deformation under equilibrium, the Many-Bodied Steered MD method is developed in which multiple deformation modes are explored. It is shown that different deformation paths in the same molecule leads to different mechanochemical accelerations of kinetics and a different alteration of first step reaction pathways.

보안검색장비 성능인증을 위한 폭발물 시뮬런트 개발

박서하 경상국립대학교 대학원 2022 국내석사

항공보안장비의 성능을 평가하는 기술 및 방법에는 다양한 방법이 있다. 특히 폭발물을 탐지하는 폭발물탐지장비(EDS) 및 폭발물흔적탐지장비(ETD)는 장비의 성능을 확인하기 위한 표준폭발물 시료가 필요하다. 폭발물은 외부의 자극이나 충격에 쉽게 반응을 일으키기 때문에 취급하기 매우 위험한 물질이다. 따라서 해외에서는 두 장비(EDS, ETD)의 성능시험에서 위험성이 높은 실제 폭발물보다 안정성이 확인된 폭발물 시뮬런트를 사용하도록 권장하고 있다. 국내 항공보안장비 성능인증제는 2018년 10월 25일에 시행되어 비교적 늦게 시작되었다. 이에 아직 표준화된 표준폭발물 시료가 국내에서 개발되지 않았다. 본 연구에서는 항공보안장비의 표준폭발물 시료로 사용될 수 있는 폭발물 시뮬런트를 개발하여 소개하고자 한다. 실험에 사용된 주요 물질은 페트롤라툼(Petrolatum)으로, 3종(TNT, RDX, PETN)의 폭발물 시뮬런트를 개발하였다. 완성된 폭발물 시뮬런트는 다양한 이화학분석(NMR, FT-IR, LC, TGA)을 통해 물리적 특성을 보여주며, 실제 두 장비(EDS, ETD)의 적용 가능성도 분석하였다. 하지만 폭발물 시뮬런트의 안정성 및 신뢰성을 높이기 위하여 추가적으로 낙하시험, 마찰강도시험, 먼지폭발시험 등의 분석이 필요하다. In the field of research, how to evaluate the performance of aviation security equipment is an interesting field. In particular, explosive detection systems(EDS) and explosive trace detection(ETD) that detect explosives require explosives to check the performance of the equipment. Explosives are very dangerous materials to handle because they easily react to external stimuli or shocks. Therefore, overseas, it is recommended to use explosive simulants that have been confirmed to be more stable than actual explosives at high risk in performance tests of both types of equipment(EDS and ETD). In this study, we intend to develop and introduce explosive simulants that can be used as standard explosive samples of aviation security equipment. The main material used in the experiment was Petrolatum, which developed three explosive simulants (TNT, RDX, and PETN). The completed explosive simulation shows physical properties through various physicochemical analyses (TGA, NMR, FT-IR, LC, etc.), and also analyze the applicability of the actual two equipment. However, to increase the stability and reliability of explosive simulants, additional analysis such as drop test, friction strength test, and dust explosion test is needed.

Spectroscopic and Thermal Analysis of Explosive and Related Compounds Via Gas Chromatography/Vacuum Ultraviolet Spectroscopy (GC/VUV)

Cruse, Courtney Purdue University ProQuest Dissertations & Theses 2021 해외박사(DDOD)

Analysis of explosives (intact and post-blast) is of interest to the forensic science community to qualitatively identify the explosive(s) in an improvised explosive device (IED). This requires high sensitivity, selectivity, and specificity. Forensic science laboratories typically utilize visual/microscopic exams, spectroscopic analysis (e.g., Fourier Transform Infrared Spectroscopy (FTIR)) and gas chromatography/mass spectrometry (GC/MS) for explosive analysis/identification. However, GC/MS has limitations for explosive analysis due to difficulty differentiating between structural isomers (e.g., 2,4-dinitrotoluene, 2,5-dinitrotoluene and 2,6- dinitrotoluene) and thermally labile compounds (e.g., ethylene glycol dinitrate (EGDN), nitroglycerine (NG) and pentaerythritol tetranitrate (PETN)) due to mass spectra with very similar fragmentation patterns.The development of a benchtop vacuum ultraviolet spectrometer coupled to a gas chromatography (GC/VUV) was developed in 2014 with a wavelength region of 120 nm to 430 nm. GC/VUV can overcome limitations in differentiating explosive compounds that produces similar mass spectra. This work encompasses analysis of explosive compounds via GC/VUV to establish the sensitivity, selectivity, and specificity for the potential application for forensic explosive analysis. Nitrate ester and nitramine explosive compounds thermally decompose in the VUV flow cell resulting in higher specificity due to fine structure in the VUV spectra. These fine structures originate as vibronic and Rydberg transitions in the small decomposition compounds (nitric oxide, carbon monoxide, formaldehyde, water, and oxygen) and were analyzed computationally. The thermal decomposition process was further investigated for the determination of decomposition temperatures for the nitrate ester and nitramine compounds which range between 244 ºC and 277 ºC. Nitrated compounds were extensively investigated to understand the absorption characteristics of the nitro functional group in the VUV region. The nitro absorption maximum appeared over a wide range (170 - 270 nm) with the wavelength and intensity being highly dependent upon the structure of the rest of the molecule. Finally, the GC/VUV system was optimized for post-blast debris analysis. Parameters optimized include the final temperature of a ramped multimode inlet program (200 ºC), GC carrier gas flow rate (1.9 mL/min), and VUV make-up gas pressure (0.00 psi). The transfer line/flow cell temperature was determined not to be statistically significant.

Detonation Performance Analysis of Cocrystal and Other Multicomponent Explosives

Vuppuluri, Vasant S Purdue University ProQuest Dissertations & Theses 2019 해외박사(DDOD)

Development of novel energetic molecules is a challenging endeavor. Successful discovery and synthesis of a novel viable energetic molecule is an even more challenging endeavor. To qualify for scale-up in production, the molecule must undergo extensive characterization at the small scale and meet criteria for sensitivity, stability, toxicity, lifetime, etc. A failure to qualify for further scale-up can result in significant wasted investment. Cocrystallization of energetic materials is a potentially attractive route to development of new energetic materials because existing molecules can be used to create new materials that have tailored properties different from either coformer. A cocrystal is a combination of two crystalline monomolecular materials that yields a material with a unique crystal structure. While cocrystallization reduces the frontend investment ordinarily required for discovery of new energetic molecules, discovery of energetic cocrystals is not trivial. A number of energetic cocrystals have been reported that display attractive properties such as high density and improved thermal stability. However, the effect of cocrystal formation on larger scale properties, particuarly detonation properties, is not well-understood. Knowledge of these properties is important for understanding the potential improvements gained from pursuing discovery of cocrystals.A challenge with obtaining detonation properties is that most techniques typically require anywhere from hundreds of grams to several kilograms of material. For example, rate stick experiments typically have an L/D (length to diameter) ratio between 12 and 20. Even for ideal explosives, diameters used are typically at least two centimers in diameter. Such experimental configurations are poorly suited for materials in the early stages of development.In this work, comparative detonation velocity measurements were performed for select hexanitrohexaazaisowurtzitane (CL-20) cocrystals that have been reported in the past five years along with corresponding formulations or physical mixtures of the components. The detonation velocity measurements were performed using microwave interferometry, a well-established detonation velocity diagnostic. Using precisionmachined hardware and appropriate matching of booster charge to sample charge, it was shown with statistical analysis that well-resolved measurements of detonation velocity could be obtained with shot-to-shot variation in the range of 130 m/s. The detonation velocity for cyclotetramethylene tetranitramine (HMX) was obtained using this experimental technique to validate the method and estimated variation. It was demonstrated that detonation tests with good repeatability could be performed for the nearly ideal explosives considered.The experimental technique described above was performed first for a cocrystal of 1-methyl-3,5-dinitro-1,2,4-triazole (MDNT) and CL-20. Comparative measurements were performed for the cocrystal and physical mixture at a loading density of 1.4 g/cm3 . We chose a fixed loading density in order to isolate isolate effects other than loading density. The cocrystal was observed to detonate about 500 m/s faster than the physical mixture. In comparison, thermochemical equilibrium predictions showed that the cocrystal would detonate about 230 m/s faster than the physical mixture at this density. The enthalpy of formation for this cocrystal was double that of the physical mixture and this difference resulted in the predicted difference. Similar measurements were performed for the cocrystal of cyclotetramethylene tetranitramine (HMX) and CL-20 and CL-20/hydrogen peroxide (HP) solvate at the same loading density. The HMX/CL-20 cocrystal was observed to detonate about 300 m/s faster than the physical mixture.