The invention provides a preparation method of electromagnetic composite hollow microspheres, relates to a preparation method of a composite hollow material and aims to solve the problems of poor
conductivity,
high density and high falling possibility of magnetic particles of the existing composite hollow material. The preparation method comprises the following steps: 1, preparing
polystyrene microspheres; 2, dispersing the
polystyrene microspheres in concentrated
sulfuric acid, and sulfonating; 3, preparing a magnetic Fe3O4 nano
particle suspension; 4, adding the sulfonic-group-containing SPS microspheres and the Fe3O4 nano
particle suspension into a water solution; 5, adding
ethanol and
ammonia water, and dropwisely adding ethyl
orthosilicate; 6, adding into a PVP-containing
ethanol solution, and stirring; and 7, mixing an
aniline solution with the PVP modified magnetic microspheres, dropwisely adding
ammonium persulfate,
drying, adding N,N-
dimethylformamide, and soaking. For the prepared hollow microspheres, the
conductivity is 0.01-1.0 S / cm, the density is low, and the magnetic particles are less prone to fall; and the hollow microspheres are mainly used in the fields of light-weight electromagnetic materials, photonic crystals, wave-absorbing materials and the like.