Controlling the Sensitivity of Pentaerythritol Tetranitrate to Visible Laser Radiation by the Addition of ZnO:Ag Nanopowder

The laser initiation threshold energy densities (the laser sensitivity) of pentaerythritol tetranitrate (PETN) containing a nanostructured zinc oxide powder doped with silver (ZnO:Ag) are studied in the article. The second harmonic radiation of a pulsed Nd:YAG laser with a wavelength of 532 nm and a CW laser diode with a wavelength of 450 nm are used for initiation. The ZnO:Ag nanopowder can potentially provide photoinitiation of PETN by the photochemical mechanism. The initiation thresholds via pulsed laser initiation are compared with compositions of PETN and gold nanoparticles, which have similar optical characteristics but are chemically inert. The absorption spectra of materials in the UV, visible, and near-IR spectral regions are studied. The threshold of the laser initiation of the explosion of the PETN–ZnO:Ag composite by pulsed radiation is lower than one-third of the threshold of initiation of the PETN-nanogold composite, which has similar values of optical density. The addition of 1% mass of ZnO:Ag for the first time makes it possible to initiate PETN reliably (without failures) by the radiation of a low-power visible laser diode. The results and their comparison with the published data allow us to make a reasonable assumption on the contribution of the photochemical stages to the laser initiation of the PETN–ZnO:Ag composite by visible laser radiation.