Effects of Nanoscale Voids on the Sensitivity of Model Energetic Materials

1995 ◽  
Vol 418 ◽  
Author(s):  
C. T Whitea ◽  
J. J. C. Barretta ◽  
J. W. Mintmirea ◽  
M. L. Elert ◽  
D. H. Robertson

AbstractBecause of its importance in designing safer, more reliable explosives the shock to detonation transition in condensed phase energetic materials has long been a subject of experimental and theoretical study. This transition is thought to involve local hot-spots which represent regions in the material which couple efficiently to the shock wave leading to a locally higher temperature and ultimately initiation. However, how at the atomic scale energy is transferred from the shock front into these local “hot spots” remains a key question to be answered in studies of the predetonation process. In this paper we report results of molecular dynamics simulations that suggest that even nanometer scale defects can play an important role in the shock to detonation transition.

MRS Advances ◽  
2018 ◽  
Vol 3 (8-9) ◽  
pp. 463-468 ◽  
Author(s):  
Alexandre F. Fonseca ◽  
Douglas S. Galvão

ABSTRACTIn spite of years of intense research, graphene continues to produce surprising results. Recently, it was experimentally observed that under certain conditions graphene can self-drive its tearing and peeling from substrates. This process can generate long, micrometer sized, folded nanoribbons without the action of any external forces. Also, during this cracking-like propagation process, the width of the graphene folded ribbon continuously decreases and the process only stops when the width reaches about few hundreds nanometers in size. It is believed that interplay between the strain energy of folded regions, breaking of carbon-carbon covalent bonds, and adhesion of graphene-graphene and graphene-substrate are the most fundamental features of this process, although the detailed mechanisms at atomic scale remain unclear. In order to gain further insights on these processes we carried out fully atomistic reactive molecular dynamics simulations using the AIREBO potential as available in the LAMMPS computational package. Although the reported tearing/peeling experimental observations were only to micrometer sized structures, our results showed that they could also occur at nanometer scale. Our preliminary results suggest that the graphene tearing/peeling process originates from thermal energy fluctuations that results in broken bonds, followed by strain release that creates a local elastic wave that can either reinforce the process, similar to a whip cracking propagation, or undermine it by producing carbon dangling bonds that evolve to the formation of bonds between the two layers of graphene. As the process continues in time and the folded graphene decreases in width, the carbon-carbon bonds at the ribbon edge and interlayer bonds get less stressed, thermal fluctuations become unable to break them and the process stops.


2021 ◽  
Author(s):  
Nadire Nayir ◽  
Mert Y. Sengul ◽  
Anna L. Costine ◽  
Petra Reinke ◽  
Siavash Rajabpour ◽  
...  

2019 ◽  
Vol 21 (24) ◽  
pp. 13099-13108 ◽  
Author(s):  
Susanna Monti ◽  
Jiya Jose ◽  
Athira Sahajan ◽  
Nandakumar Kalarikkal ◽  
Sabu Thomas

Functionalized gold nanoparticles for antibiotic drug delivery: from the nanoscale to the atomic scale.


2016 ◽  
Vol 18 (12) ◽  
pp. 8730-8738 ◽  
Author(s):  
Nerea Epelde-Elezcano ◽  
Virginia Martínez-Martínez ◽  
Eduardo Duque-Redondo ◽  
Inés Temiño ◽  
Hegoi Manzano ◽  
...  

The aggregation process of pyronin Y (PY) dye into thin films of different smectite clays, LAPONITE® and saponite, is deeply studied by means of electronic absorption and fluorescence spectroscopy and by molecular dynamics simulations.


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