The photolysis and co-irradiated decomposition of barium and strontium azides

Shephard, Enid Gwendolyn

The photolysis and co-irradiated decomposition of barium and strontium azides

Doctoral Thesis

1974

Publisher

University of Cape Town

Department

Department of Chemistry

Faculty

Faculty of Science

Abstract

The effect of ultraviolet radiation on sieved powders and pellets of barium azide in the temperature range 27,0° - 135,0°C and of strontium azide in the temperature range 30,0° - l35,0°C has been studied. Decompositions in the temperature range 27,0°- 100,0°C for barium azide and 30,0° - 90,0°C for strontium azide have been termed photolytic decompositions, while reactions in the temperature range 110,0° - l35,0°C (the thermal decomposition temperature range) for both compounds have been termed co-irradiated decompositions. The ultraviolet light source used was a very high intensity 100 watt "point source" high pressure mercury arc lamp. The extent of decomposition was almost the same as a simple thermal decomposition. Kinetic analyses, activation energy determinations, studies of the dependence of reaction rates on light intensity, the effect of water vapour on the sample at various stages of reaction and the observance of the colour of the sample at various stages of reaction have been carried out. Analogous results were obtained for the two compounds. In the photolytic temperature range two distinct modes of decomposition are postulated to occur, the transition temperature occurring at 60,0°C for barium azide and at 50,0°C for strontium azide. During co-irradiation it is proposed that decomposition occurs via the expected thermal decomposition process and the photolytic mechanism or a slight variation thereof, above 60,0°C for barium azide and above 50,0°C for strontium azide.

Keywords

Chemistry

Reference:

Collections

PhD / Doctoral

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