Optical sensitisation of energetic crystals with gold nanoparticles for laser ignition

Abstract

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.

Initiation of CL‐20 Doped with Aluminum Nanoparticles by Using a Laser Pulse through an Optical Fiber

“…Although the addi-tion of carbon black powder remarkably improves near-infrared (NIR) absorption, the decrease in laser energy is less than that of aluminum and nickel. The addition of gold nanoparticles to cyclotrimethylenetrinitramine (RDX) can considerably enhance laser ignitibility and reduce the laser ignition threshold power from more than 45 W to 1 W by using a NIR diode laser [15]. However, the high mechanical sensitivity and instability of PETN have limited its application in weapon systems, and the initiation energy of RDXdoped nanoparticles with a short pulse laser is too high for optical fiber transmission.…”

Time Delay of Initiation of some Primary Explosives and Initiating Mixtures when Exposed to Continuous IR Laser Radiation

“…There is very little data on the time delays of laser initiation of EM. Studies of the effect of continuous laser radiation on EM have also been conducted for many years using different laser sources [7–19] that generate radiation at different wavelengths: CO 2 lasers (10.6 μm) [14, 17]; Ar lasers (0.514 μm) [11, 15–18]; neodymium double‐frequency lasers (0.532 μm) [9]; semiconductor lasers (0.78 – 1.3 μm) [7, 8, 10, 11, 13, 15, 18, 19], etc. Of practical interest is the effect of continuous laser radiation at near‐IR wavelengths of 0.8–2 μm [7–11, 13, 15, 18, 19], since such laser sources are widely used, compact, have high energy characteristics, and their radiation can be transmitted over long distances via an optical fiber.…”

“…A number of works show that ignition of secondary explosives cannot be achieved using continuous laser radiation of the IR and near‐IR ranges with a power of up to 10 W. In particular, in [7] and [11] it was possible to obtain only the local decomposition mode of secondary explosives, which was supported by laser radiation in spectral range of 0.8–1.9 μm. Currently, active research is being conducted on the mechanisms of laser initiation at these wavelengths, the possibility of increasing the efficiency of laser initiation by photosensitizing EM with the introduction of various photoabsorbing additives in the form of various nanoparticles and dyes [7, 10, 12, 13].…”

Pulsed laser irradiation of a nanoparticles sensitised RDX crystal

“…The study concluded that GNPs-embedded RDX crystals could be ignited by a low-power CW diode laser at the wavelength (e.g. 808nm) of GNP's surface plasmon resonance (SPR), while pure RDX crystals were unable to ignite [9,10]. For this mechanism, GNPs under laser irradiation absorb laser energy due to their SPR and typically heat up.…”