Berlin 2012 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 8: Poster: Nanoparticles and Composite Materials

CPP 8.47: Poster

Montag, 26. März 2012, 17:30–20:00, Poster A

AFM investigations of surface properties of 2, 4, 6 trinitrophenol (TNP) crystal at the nanoscale — •Alexander Kovalev¹ and Heinz Sturm^{1, 2} — ¹BAM - Fed. Inst. Materials Res. - Div. Nanotribology and Nanostructuring, 12205 Berlin — ²TU Berlin, IWF, 10587 Berlin

Knowledge of the behaviour of energetic materials (EM) subjected to phenomena at the nanometre scale is a main key to better understanding the nature of initiation processes of an explosion. The chemical-mechanical decomposition of EM is not fully understood, and the initial decomposition steps are not firmly established, but the model of hotspot formation is generally accepted. The initial size of a hotspot is comparable with molecular dimensions of EM. It is evident that the real origin of ignition should be explored at the nanometre scale, and such possibility are provided by atomic-force microscopy (AFM) techniques. Here, we report on the direct initiation of the hotspot formation on surfaces of 2, 4, 6-trinitrophenol (TNP) single crystals by the AFM tip. The immediate AFM imaging of the selected region revealed the destructive changes of TNP crystals, and allows a first estimate of the evolution of hotspot phenomenon at the initial stage. The direct observation of the nanoscale surface restructuring of TNP crystal during the AFM scanning has been explored. Our results reveal the instability of TNP molecules at the border of molecular layers at normal ambient condition. Based on the explored properties of TNP crystal a mechanism of hotspot formation at the nanoscale is proposed.