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

Abstract

Ammonium perchlorate (AP) needs to be combined with nano-metal oxides to improve its thermal decomposition performance when applied to propellant, but with reduced safety performance. Herein, inspired by the rapid gelation of sodium alginate (Na-A) in the presence of metal ions to produce well-dispersed metal oxides after calcination, a novel “droplet and solution contact assembly” (DSCA) method is proposed and applied to prepare spherical AP/cobalt alginate (Co-A) composites. In spherical composite, Co-A forms a three-dimensional network structure and AP particles are uniformly and tightly filled in the network structure of Co-A, exhibitng outstanding safety performance. During the thermal decomposition process of it, Co-A thermally decomposes into evenly dispersed nano-Co3O4 and solves the facilely gathering trouble of nano-Co3O4, further results in an enhanced catalytic effect in thermal decomposition. In addition, compared with conventionally used methods for the spherification of composites, such as spray drying and electrospray methods, the method provides simpler, safer preparation conditions without high-temperature or high-voltage, which can be applied for mass production. Moreover, the atomization method is improved by replacing traditional atomization instrument with a hand-held high-velocity air spray gun, reducing the cost of the experiment and improving the convenience of the experiment. This study offers a new perspective for the design and systhesis of spherical composites.