Mechanical stimulation of energetic materials at the nanoscale

Abstract

The initiation of energetic materials by mechanical stimuli is a critical stage of their functioning, but remains poorly understood. Using atomic force microscopy (AFM) we explore the microscopic initiation behavior...

Can the Sublimation Enthalpy Be Obtained Using Atomic Force Microscopy with Heating? A PETN Nanofilm Case

“…Although the morphological changes described above are to be thermally induced, there are some reports of PETN crystallization in response to the mechanical stimulation using an AFM probe. ,, Previously, we tried to mechanically affect energetic crystals including PETN by scratching them with an AFM probe in lithography mode . The dendritic microcrystals of PETN produced on the Si substrate were treated with a similar approach, which caused the creation of the lithographic scratch and the appearance of spherical particles having several hundreds of nm in size at the point of mechanical stimulation (Figure a).…”

“…The response of the PETN films to the local mechanical stimulation was studied by the AFM−lithography method, which enables the creation of scratches on the sample surface using an AFM probe. 14 For mechanical impact on a specific area, an AFM investigation in contact mode with a large pressing force of the probe was carried out. Both types of mechanical stimulation, i.e., scratches and impacts, were conducted with HA_NC probes.…”

“…16,17,22 Previously, we tried to mechanically affect energetic crystals including PETN by scratching them with an AFM probe in lithography mode. 14 The dendritic microcrystals of PETN produced on the Si substrate were treated with a similar approach, which caused the creation of the lithographic scratch and the appearance of spherical particles having several hundreds of nm in size at the point of mechanical stimulation (Figure 6a). No changes of this structure with time were detected; therefore, its response to direct stimulation with an AFM probe is found to be similar to the one exhibited previously with significantly larger monocrystals.…”

“…No changes of this structure with time were detected; therefore, its response to direct stimulation with an AFM probe is found to be similar to the one exhibited previously with significantly larger monocrystals. 14 Another way to mechanically affect the sample is a prolonged investigation of a certain surface area in contact mode with a large pressing force of the AFM probe. Continuous investigation of the 50 μm × 50 μm area of the PETN film on the Si substrate in that manner led to the destruction and almost complete disappearance of the crystals from the area within 2 h. However, further examination revealed an accumulation of PETN particles framing the stimulation area (Figure 6c).…”

Spiers Memorial Lecture: Mechanochemistry, tribochemistry, mechanical alloying – retrospect, achievements and challenges

“…The mechanoexcitation of lattice vibrations, and the subsequent transfer of the energy from phonons to molecular vibrations to drive bond breaking are the main points of the model developed by A. Michalchuk et al which describes how a mechanical impact can cause a chemical transformation, such as the decomposition of energetic materials. 325–330…”