Catalytic Performance Of ZnO Modified Graphene Nanosheets For The Thermal Decomposition Of Ammonium Perchlorate

Ammonium perchlorate is the oxidant in solid propellants,and it is also the most high-energy component in the propellant.The thermal decomposition performance of ammonium perchlorate has a great influence on the combustion characteristics of solid propellants.Using a burning rate catalyst to improve the thermal decomposition performance of ammonium perchlorate is one of the effective methods to improve the combustion characteristics of solid propellants.The carbon material has a certain activity to catalyze the thermal decomposition of ammonium perchlorate,but due to its limited defect sites,the catalytic performance still needs to be improved.Therefore,this thesis uses a combination of ball milling and atomic layer deposition to obtain a highperformance ZnO modified graphene nanosheet composite catalyst.The catalytic performance and mechanism of ZnO modified graphene nanosheet were studied.The application in solid propellant was explored,which provided technical support for the application of new combustion rate catalyst in solid propellant field.First,using graphene nanosheets as a raw material,modified graphene nanosheets are prepared by a ball milling method.The influence of ball milling speed and ball milling time on the microscopic morphology,defect state and degree of agglomeration of graphene nanosheets is studied.Studies have shown that,compared with the original graphene nanosheets,the modified graphene nanosheets have a better catalytic effect,which can increase the heat release of pure AP from 376 J/g to 1223 J/g,and the heat release is more concentrated.The temperature corresponding to the main exothermic peak of thermal decomposition is 326 ℃,which is close to the temperature of 315 ℃corresponding to the low-temperature decomposition peak of pure AP thermal decomposition.Secondly,in order to further improve the catalytic effect of the modified graphene nanosheets,atomic layer deposition technology is used to deposit ZnO nanoparticles on the surface of the modified graphene nanosheets to obtain a ZnO modified graphene nanosheet composite material.And study the effect of atomic layer deposition process on ZnO modified graphene nanosheet composites.When the deposition cycle is 100 cycles,the composite material has the best catalytic effect on the thermal decomposition of AP,the heat release increased from 1223 J/g to 2076 J/g,and the heat release is also relatively concentrated,and the temperature corresponding to the high and low temperature decomposition peaks is only different 12 ℃.Finally,the burning rate catalyst is added to the solid propellant.The ZnO modified graphene nanosheet composite material improves the burning rate of the propellant to a certain extent,increasing it from 2.15 cm/s to 2.23 cm/s,and can Significantly reduce its ignition power,reducing it from 3.36 W to 2.35 W.The research work has verified the advantages and great potential of ZnO modified graphene nanosheet composites as a new burning rate catalyst in the field of solid propellants.