A Spectrophotometric Study of Red Pyrotechnic Flame Properties Using Three Classical Oxidizers: Ammonium Perchlorate, Potassium Perchlorate, Potassium Chlorate

Abstract

Abstract. Red pyrotechnic flames are mostly produced using strontium compounds. Flame color quality is dependent on the chemical composition of the mixture. The emission spectrum produced by strontium monohydroxide (SrOH) and strontium monochloride (SrCl) species in red colored flames was measured, analyzed, and compared.

Oxidizer Ratio and Oxygen Balance Influence on the Emission Spectra of Green‐Colored Pyrotechnic Flames

“…This leads to the hypothesis that strontium (or strontium oxide) has a higher affinity to react with halogens or OH species in the flame than barium. However, in a similar manner to the strontium system, which was analyzed previously,16 NH 4 ClO 4 was found to increase the color purity of the flame due to the formation of the preferred BaCl emitter and quenching of the BaO continuum (group A).…”

“…In the second group (group B), the ratio of oxidizers was fixed: The amount of NH 4 ClO 4 was 1.24 higher than that of Ba(NO 3 ) 2 . This particular ratio was observed to be optimum for red flames in previous work with a similar pyrotechnic system 16. It is known that compositions producing a reductive flame are best for colored flame production 14.…”

“…The latter produce strong emissions in the UV/Vis range3,4 with excellent dominant wavelengths regarding colored flame production. In our previous work, NH 4 ClO 4 was found to be a superior oxidizer/chlorine donor for red‐colored flame pyrotechnics 16. It was interesting to evaluate how NH 4 ClO 4 performs in a similar group of barium green‐flame formulations.…”

“… Dependence of burning rate on chemical composition. The dotted line is taken from previous experiments using an identical system with Sr(NO 3 ) 2 instead of Ba(NO 3 ) 2 16…”

Color‐Changing Sparks from Rare Earth Metal Powders

“…Consequently, even elements with higher boiling points than erbium may provide element-specifically emitting stages. Jennings-White gives a survey on potential candidates for pyrotechnic applications throughout the periodic Table [12] and recent examples include boron, [13][14][15] cesium compounds, [16,17] copper iodide [18] and copper complexes [19] as well as copper-based blue strobe compositions, [20,21] new formulations based on lithium, [22,23] and sodium salts, [24] detailed investigations of composition based on barium [25] and strontium [26] salts as well as calcium [27] and strontium tetrazolates, [28] and indium [29] metal. Typical radiation trace of sparks based on different burning stages given in literature [11] and element-specific colored stage observed for erbium.…”