Particle Size and Surface Area Analysis of Amorphous and Crystalline Boron

Abstract

Abstract : Surface areas were measured and scanning electron microscopy (SEM) photographs were obtained from seven boron particle samples used in recent boron particle combustion experiments. Some significant differences were seen between the manufacturer claimed particle sizes and the distributions obtained from the SEM photographs. In those samples with large particle size distributions, calculated surface areas differed significantly from measured surface areas and it is clear that a single particle diameter parameter is inadequate to describe the corresponding surface area of the true particle size distribution. In general, the particle size distribution estimates taken from SEM yield lower surface areas than were measured. Further data on the purity of the samples are necessary to determine whether the phase or purity of the boron particle has an effect on the efficiency of boron particle combustion.