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The rationale behind developing insensitive energetic compounds (IECs) for incorporation into insensitive munition (IM) formulations (rather than the alternative approach of desensitizing higher energy but sensitive compounds) is discussed. With the aim of selecting a maximum of 2–3 IECs suitable for use in insensitive explosive and propellant compositions, a survey of the literature on IECs published in the last 20 years was carried out. From around 50 candidates, a selection was made of eight prime candidates, all heterocyclic compounds (principally monocyclic or fused‐ring bicyclic compounds of the di‐ or triazine, triazole or oxadiazole classes), which displayed explosive performance significantly better than that of the ubiquitous IEC, TATB. The criteria for inclusion of compounds in these listings are described. Screening of the eight candidate compounds against further performance criteria reduced the list to five compounds which were evaluated in detail – these were: CL‐14 (5,7‐diamino‐4,6‐dinitrobenzofuroxan), ANPZ‐i (2,5‐diamino‐3,6‐dinitropyrazine), NNHT (2‐nitrimino‐5‐nitro‐hexahydro‐1,3,5‐triazine), NTAPDO (5‐nitro‐2,4,6‐triaminopyrimidine‐1,3‐dioxide), and PANT [4‐(picrylamino)‐5‐nitro‐1,2,3‐triazole]. A detailed analysis of scale‐up issues associated with each compound was then made, including cost and availability of precursors, hazards (chemical and explosive), effluent streams, and other scale‐up issues (e.g. materials of plant construction). A further downselection using these criteria gave the present short‐list comprising three compounds (the first three listed above) and further evaluation is in progress. The results of this study, funded by UK MOD, comprise the UK contribution to a nine‐nation European research collaboration in the EUCLID Common European Priority Area 14 “Energetic Materials”, as part of a five‐year project which commenced in October 2003.

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The enzyme-mediator-conducting polymer model provides a convenient charge transporting immobilization matrix for redox enzymes in potential biosensor constructions. This study considers the charge transport mechanism in the benzoquinone (Q)-polyaniline (Pani) system. An enhanced current can be obtained on Pani, compared with Pt, using Q as enzyme mediator. Two-electron redox pathways are available for the Q/H2Q (hydroquinone) system, but the kinetics limit this conversion. On Pt, one-electron equivalent is estimated. On Pani-modified electrodes, reduction of Q on Pani is a nearly reversible two-electron process at stationary electrodes at low pH. At rotating electrodes, the initial reaction occurs at the surface of the polymer at pH 1.1, but the second electron transfer is prevented by loss of the intermediate from the surface before it can migrate into the film. At stationary electrodes, the H2Q product is stabilized, possibly by the formation of a charge-compensating complex between the H2Q anion/radical and the polymer. At higher pH, charge transfer through the polymer is slow and no reduction of Q occurs on the outside of the film, instead occurring in a layer at the electrode limited by the exchange kinetics there. Promotion of the two-electron pathways on Pani is proposed as the source of current enhancement when Q is employed as an enzyme mediator.