Droplet and solution contact assembled cobalt alginate for enhanced properties of ammonium perchlorate

Abstract

Ammonium perchlorate (AP), a widely used oxidizer in solid propellants, requires the incorporation of combustion catalysts to enhance its thermal decomposition efficiency. However, such modifications often compromise safety performance. Inspired by the rapid metal-ion-induced gelation of sodium alginate (Na-A), this study introduces a novel “droplet-solution contact assembly” strategy to encapsulate AP within a three-dimensional porous network framework derived from cobalt alginate (Co-A), thereby fabricating spherical AP/Co-A composites with simultaneously improved catalytic activity and safety. During thermal decomposition, Co-A breaks down into catalytically active nano-Co₃O₄ particles uniformly dispersed on a carbonized porous framework. The unique architecture facilitates efficient charge transfer and synergistically accelerates AP decomposition. In the event of collision and friction, the spherical morphology of AP/Co-A minimizes localized hot spot formation under mechanical stress, while the organic framework formed by Co-A functions as a spring-like buffer network to alleviate collision and friction energy, significantly enhancing the safety performance. The study provides a simple and safe preparation method for spherical composite materials and offers novel insights into its design.