Photothermal decomposition of HNS at 532 nm

The photodecomposition of solid 2,2′,4,4′,6,6′-hexanitrostillbene (HNS) at 532 nm, induced by a 10-nanosecond (ns) laser, is investigated by an elaborately designed in situ X-ray photoelectron spectroscopy (I-XPS) experiment and steady-state Fourier transform IR (FTIR) spectroscopies. Numerical integration of the two-dimensional heat conduction equation indicates that the irradiated sample volume is effectively heated and photothermal decomposition takes place. Agreement of results between the I-XPS and FTIR suggests that the nitro-nitrite (NO2-ONO) isomerization is a main decomposition pathway for HNS.