The study of sublimation rates and nucleation and growth of tnt and petn on silica and graphite surfaces by optical and atomic force microscopy and ellipsometry

摘要

Optical and atomic force microscopy (AFM) were used to study the structure and crystallization kinetics of 2,4,6-trinitrotoluene (TNT) and pentaerythritol tetranitrate (PETN) vapor deposited on silica, Muscovite mica and highly oriented pyrolytic graphite (HOPG) surfaces. Under ambient conditions, the deposited TNT and PETN on these surfaces are in supercooled liquid droplet forms. Dendritic-like crystal nucleation and growth are found for both TNT and PETN on a silica surface after the exposure to the air for 16 and 48 h, respectively. A plate-like solid TNT is also observed int he depletion zone between the grown crystals and the supercooled liquid droplet region. Both AFM and DSC measurements suggest that thest plate-like TNT films are amorphous.