In this technique, a high intensity, high speed flash lamp is used to induce almost instantaneous heating of finely divided black body particles or filamentary materials immersed in transparent materials of various types.
Since only a few milliseconds elapse between initiation and quenching of the thermal reactions, the reaction intermediates do not undergo the usual degradation and condensation reactions which normally occur under longer exposure at high temperature conditions. Thus, information on the true reaction products should be forthcoming from studies using this new technique.
The work grew out of attempts to study photochemical reactions in polymers at higher and higher light intensities. The heating effect of the flash was soon found to exceed greatly the photochemical effect when insulated black bodies were present. This resulted from the high intensities used, and the use of a greater fraction of the lamp output by black body absorption as compared to photochemical absorption.
According to the authors, the new technique is applicable to the study of thermal reactions in solids, liquids, and gases. Basically, it utilizes black body heating of finely-divided or filamentary material to decompose either the black body itself or the