Home – Home – Jornals – Chemistry for Sustainable Development 2016 number 2

Dependencies of the critical energy density of the initiation of explosive decomposition of PETN-Co nanocomposite on nanoparticle radius and the duration of the pulse of the first harmonics of neodymium laser were calculated using the microfocal model of thermal explosion. For each pulse duration, the minimal values of the critical energy density for the initiation and the corresponding radii of nanoparticles were determined. The calculation was carried out in two versions: 1) with the coefficient of absorption efficiency equal to 1, which is independent of nanoparticle radius; 2) taking into account the dependence of absorption efficiency coefficient on the radius of cobalt nanoparticle in a transparent matrix with the refractive index equal to 1.54 (PETN), calculated within the framework of Mie theory. For pulse duration shorter than 100 ns, calculation results differ substantially: neglect of the regularities of absorption by cobalt nanoparticles leads to a decrease in the minimal energy density by a factor of more than 17 for pulse duration 0.1 ns, while taking into account the dependence of the coefficient of absorption efficiency on particle radius, the energy threshold in this range decreases only by a factor of 3. The account of the dependence of laser pulse absorption efficiency coefficient on nanoparticle radius allows solving the paradox of small particles.