Controllable Explosion of Nanobomb by Modifying Nanocontainer and External Shocks

Abstract

The effects of physicochemical modification of carbon nanotubes (CNTs) on the explosion dynamics of a nanobomb, comprising nitromethane confined in CNTs, were investigated using nonequilibrium reactive molecular dynamics and density functional theory (DFT) calculations. CNTs with chirality, nitrogen-doping, and monovacancy defect were utilized. All modifications commonly reduced the time for nanobomb bursting under thermal shock and led to an overall similar reaction pathway. Bursting time of chirality-modified nanobomb was shortened by inferior mechanical property, whereas nitrogen-doping and monovacancy modification reduced the time by increased chemical reactivity (i.e., facilitated attachment of reaction intermediates to the nanocontainer). DFT calculations showed that nitrogen-doping and introducing monovacancy defects lowered the activation energy and heat of formation of the Stone-Wales defects and induced high binding energy of the intermediates, whereas chirality modification alone was ineffective. In addition, decomposition of the nanobomb was initiated via another two heating methods (i.e., electric spark and electromagnetic induction). Under a continuous electric field, bursting of nanobomb with electromagnetic induction was much faster due to oscillating frequency. This theoretical exploration of the effects of physicochemical modification of the nanocontainer and the explosion-initiation methods on the explosion of nanobombs provides in-depth understanding of a confined nanostructured high-energy material.