The laser ignition of explosives is safer and more environmentally beneficial than electric ignition systems, but optical sensitisers must be present to facilitate heating by optical absorption. We investigated, for the first time, the optical sensitisation of cyclotrimethylenetrinitramine (RDX) crystals by doping them with gold nanoparticles to enhance laser ignitibility using a near-infrared diode laser. RDX crystals physically coated with gold nanoparticles or recrystallised from a solution containing gold nanoparticles were tested for optical sensitisation by micro-imaging with a scanning electron microscope, and high-speed video was used to experimentally observe the enhanced laser ignitibility. The gold nanoparticles achieved effective optical sensitisation and significantly enhanced the laser ignitibility of RDX, reducing the laser ignition threshold power from more than 45 W to as little as 1 W. Our results show that gold nanoparticles are effective as optical sensitisers for the ignition of energetic materials using a small, low-power diode laser.

Crystalline polymers such as b-cyclodextrin( bCD) can be modified with polyethylene glycol (PEG) diglycidyl ether cross-linkers (262, 394, 500 Da). In this work, the authors show that the quantity and length of the PEG soft segments influencet he solubility and malleability of the products, which are water soluble and easily converted to nitrated analoguesu nder standard reaction conditions. Inert and nitrated derivatives containing longer PEG segmentsshowed the ability to self-heal. The degree of cross-linking and de-composition temperatures ande nergies dependedo nt he quantity andl ength of the soft segment. Nitrated crosslinked bCD containingl ongerP EG segmentsd id not ignite following an electrostatic discharge of 4.5 J. The chemical stabilityo fbCD/PEG bindersw as testedb yh eat flow calorimetry at 80 8C. The balanced incorporation of soft PEG and rigid bCD segmentsw as found to improve the processability of cross-linked bCDsa nd desensitised their nitratedd erivatives, offering new solutions for inert and energetic binders.

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