Browsing by Author "McAteer, Daniel"

Now showing 1 - 9 of 9
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    Compatibility assessment of thermoplastic formulations
    (2016-07-01) McAteer, Daniel; Weaver, M.; Blair, L. H.; Flood, Nathan; Gaulter, Sally E.
    Prior to the large-scale preparation of any new chemical formulation an assessment of the potential reactivity between the components must be carried out. This practice, which is common to many fields including pharmaceutical science, is particularly essential in the case of energetic formulations whose chemical incompatibility may result in an unexpected and potentially explosive decomposition. The common method used to investigate incompatibility is to heat 1:1 (w/w) formulations and evaluate the variation in their thermal stability with respect to the neat, pristine explosive. The techniques used are: differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), vacuum stability and heat flow calorimetry. As trends in energetics move towards safer formulations the components are more commonly selected for their high thermal stability and low sensitivity to initiation. However, recently prepared thermoplastic formulations which incorporate a thermally stable explosive, 2,2’,4,4’,6,6’-hexanitrostilbene (HNS II), and a selection of high-melting-point thermoplastics produced anomalous results during their compatibility assessment leading to the suggestion that historical tests originally devised for less thermally stable materials, such as N,N’,N’’-trinitro-1,3,5-triazacyclohexane (RDX), may not be directly transferable to the newer generations of insensitive explosive formulations.
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    Development of metal-organic framework (MOF) sensors for landmine detection
    (AMA Service GmbH, 2019-07-19) Humphreys, Lisa; Wilson, Ian; McAteer, Daniel; Pons, Jean-François
    Rural populations in Colombia are significantly affected by anti-personnel mines used by revolutionary armed forces. These mines typically contain ammonium nitrate (AN) based explosive compositions. The international community is committed to tackling the danger posed by landmines and other improvised explosive devices (IEDs). This involves the removal of explosive materials installed in areas of conflict. Current technologies used for humanitarian demining can be separated into three distinct categories; metal detection, mechanical clearance, and detection using trained animals [1]. Metal detection is deemed to be most effective but as plastic-bodied IEDs are now also in use other detection approaches must be sought after. Cranfield University, Universidad Nacional de Colombia and Oxford University have proposed the development of a device capable of detecting AN based IEDs using an optoelectronic sensor. The goal of the project is to establish the scientific validity of the new sensing method for the detection of explosive materials found in landmines and IEDs, and to demonstrate its usefulness in locating buried explosive devices. This will entail optimising the sensitivity and selectivity of the sensor. A systematic series of MOFs comprising transition metal acetates/chlorides and terephthalic acid derivatives as linkers has been synthesised and structurally characterised. Cobalt and copper based salts have been paired with numerous organic ligands to create MOFs which have been responsive to concentrations of ~100 ppm ammonia in aqueous conditions. The developed MOFs have also been assessed for their response to ammonia in the gas phase and at representative concentrations throughout the project.
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    The development of Novel, Low Sensitivity, Gas-generating Formulations for Hotwire Ignited Devices
    (2013-04) McAteer, Daniel; Akhavan, Jacqueline; Contini, Alessandro
    A novel, low sensitivity, gas-generating composition was developed to replace an existing primary explosive, potassium picrate, for use in a generic squib device. The novel composition was based on energetic materials researched from the open literature. The chosen materials were synthesised or purchased and combined in order to produce formulations which would reproducibly ignite when contacted with a hotwire. The formulations were assessed for their chemical compatibility and homogeneity by small-scale hazard testing, differential scanning calorimetry (DSC) and nuclear magnetic resonance (NMR) spectroscopy. The compositions were test fired within squibs coupled to a pressure bomb and the pressure generation and rise time was measured using a piezoelectric gauge.
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    Low hazard small-scale synthesis and chemical analysis of high purity nitroglycerine (NG)
    (Royal Society of Chemistry, 2015-10-06) Contini, Alessandro E.; Flood, Nathan; McAteer, Daniel; Mai, Nathalie; Akhavan, Jacqueline
    A previously reported two-phase (99.5% fuming nitric acid/dichloromethane) batch method to prepare high purity 1,2,3-propanetriyl trinitrate (nitroglycerine, NG) was evaluated, simplified and adapted specifically for low hazard small-scale synthesis. The purity of the product, as determined by NMR spectroscopy, HPLC and IR spectroscopic analysis was found to be greater than 99%. The quick synthetic method is highly recommended when small amounts of highly pure NG are required for analytical and related purposes in the absence of a microreactor.
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    Nitration of primary amines to form primary nitramines (Review)
    (2016-07-04) McAteer, Daniel; Pons, Jean-François; Wilson, I. I.; Cavaye, H.
    The nitration of primary amines to form primary nitramines is a rarely reported synthetic procedure which proceeds through a minimum of two steps. This is in stark contrast to the nitration of alcohols and secondary amines which is readily achievable by a number of methods in a single step. In general the primary amine must initially be activated to nitration as direct exposure to nitrating media tends to result in the formation of an ionic nitrate salt. This activation may be achieved through the use of a multitude of protecting groups that are stable to the nitrating conditions used thereafter. The review presented here is an attempt to bring together the published literature on this often overlooked synthetic procedure in energetic materials chemistry.
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    Nitrogen-14 NMR spectroscopic detection of explosophores in solution
    (Wiley, 2016-12-02) McAteer, Daniel; Akhavan, Jacqueline
    Nitrogen‐14 (14N) quadrupolar nuclear magnetic resonance (NMR) spectroscopy was used to detect and measure the chemical environment of various nitrogen nuclei located within the explosophore of many commonly studied explosives in solution (Figure 1). The values are presented here as a resource for researchers in the field who may find use in this non‐destructive and convenient analytical technique.
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    Practical colorimetry of 3-Nitro-1,2,4-Triazol-5-One
    (Wiley, 2018-10-30) Tennant, Mat; Chew, Siao Chien; Krämer, Tobias; Mai, Nathalie; McAteer, Daniel; Pons, Jean-François
    A field ready colorimetric method of quantifying the concentration of aqueous 3‐nitro‐1,2,4‐triazol‐5‐one (NTO), several orders of magnitude below its environmental toxicity level, has been developed. The test allows for the immediate evaluation of the level of contamination in aqueous solution without the need for analytical equipment such as high pressure liquid chromatography (HPLC). The observed colours have been explained by the different NTO species present over the range of pH; these observations are supported by modelling and experimental results.
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    Practical remediation of 3-nitro-1,2,4-triazol-5-one wastewater
    (Wiley, 2017-11-30) Chew, Siao Chien; Tennant, Mat; Mai, Nathalie; McAteer, Daniel; Pons, Jean-François
    Limiting environmental impact is a top priority for the chemical industry, and manufacturing practices need to be well controlled to avoid any potential contamination. In order to reduce waste streams during the processing of 3-nitro-1,2,4-triazol-5-one (NTO), potentially evironmental hazardous at concentrations of 1 g/l, we investigated the potential remediation and recycling of water using a wide range of commercial sorption media. We studied the effect of experimental conditions, including flow rate, initial contaminant concentration and temperature. This led to the selection of Amberlyst A26 OH in a batch process and Activated Carbon in continuous flow, as the most effective sorption methods. Using high performance liquid chromatography photodiode array detection (HPLC-PDA), NTO was quantified from solutions, before and after remediation, showing a complete removal from a 10 g/l NTO solution. Our purification method therefore appears to be suitable for the remediation of NTO-contaminated wastewater.
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    Written evidence into the use of Improvised Explosive Devices and their impact on the Humanitarian Space. Report to the All Party Parliamentary Group (APPG) on Explosive Weapons
    (2017-08-24) Cleary, Laura; Johnson, Steve; McAteer, Daniel; Turns, David; Wilkinson, Edith
    This report constitutes Cranfield’s School of Defence and Security response to the All Party Parliamentary Group on Explosive Weapons’ call for written evidence (dated 11 December 2015) into the use of Improvised Explosive Devices and their impact on the Humanitarian Space. The APPG expressed interest in three questions: - What are the main groups using IEDs that operate around the globe today and what types of IEDs do they employ? - What challenges do state governments and law enforcement agencies face in effectively monitoring and restricting the sale of dual use precursor materials used in making IEDs and the knowledge exchange between groups? - The level and extent of humanitarian harm caused by IEDs around the world?