Gaseous Detonation Synthesis Of Nano-carbon Materials With Carbonyl Iron

Two kinds of carbon nanomaterials with special structure were successfully synthesized from acetylene gas,oxygen and nonacarbonyldiiron by gaseous detonation,the products were characterized by XRD,TEM,VSM,Raman,BET,DSC/TGA and so on.Firstly,the parameters of detonation reaction were calculated by C-J theory,Z-N-D model and thermodynamics law.Oxygen balance analysis and explosion concentration limit analysis were performed,and the feasibility of gaseous detonation synthesis of carbon nanomaterials was theoretically analyzed.Through the thermal decomposition experiment of nonacarbonyldiiron,the decomposition of nonacarbonyldiiron under the experimental conditions be explained which laid a foundation for the follow-up experiment.Gaseous detonation tube,a self-made carbonyl iron reactor,acetylene,oxygen and nonacarbonyldiiron were used to carry out several groups of experiments of different proportions and concentrations and two kinds of typical products were produced.One kind is carbon-encapsulated iron nanoparticles with 5nm diameter,another kind is carbon nanomaterials with capsule shape.The main variable that affects the species of the product is the numerical value of n(Fe2(CO)9)/ n(C2H2),when the numerical value of n(Fe2(CO)9)/ n(C2H2)?40%,the products are almost all carbon-encapsulated iron nanoparticles and when the numerical value of n(Fe2(CO)9)/ n(C2H2)?1%,the products are almost all carbon nanomaterials with capsule shape.The average diameter of carbon-encapsulated iron nanoparticles is 4.5nm which has wave absorbing property,and it is composed of carbon,?-Fe and ?-Fe.After heat treatment at 673 K,the saturation magnetization is greatly improved and the products act a good paramagnetic performance in 300 K,?-Fe changed to ?-Fe and the carbon shell structure is still in good condition.Carbon nanomaterial with capsule shape is amorphous carbon with a tendency to graphitization,and it has a larger specific surface area.The pore structure of carbon capsule nanomaterial is mainly a slit hole formed by particle accumulation with strong adsorption capacity.