LAUSR

Abstract Barium hydroxide octahydrate (BHO) will randomly pulverize and expand into a white powder during phase transformation, causing the container to deform or even rupture. This phenomenon seriously affects the practical application of BHO, but there is no research on the powdery expansion of BHO in the existing literature. In order to study the causes and influencing factors of the powdered expansion of BHO, the white powder, BHO and Barium carbonate (BC) were characterized by microscopic morphology and infrared spectrum, and the effect of additives on BHO crystallization was also investigated. The results show that the powdered expansion of BHO is its physical property, and no new substance will be produced during the expansion process, the expansion rate of BHO is 25%, as the cooling rate decreases, the probability of BHO powdered expansion increases; when the melting temperature of BHO reaches above 90 °C, the degree of undercooling will increase significantly, and the probability of powdered expansion increases. By adding hydroxyethyl cellulose, soluble starch and sodium dodecyl sulfonate, the radial expansion of BHO could be reduced to some extent, but it could not be prevented from happening.