Preparation and Electromagnetic Shielding Properties of MoO2-NC/Polyvinylidene Fluoride Composites
The rapid developments of modern electronic information technologies have brought great convenience to human life.Meanwhile,they also produce serious electromagnetic interference problems that not only affect the normal use of electronic equipment,but also endanger human health.In view of this,it is urgent to develop high-performance electromagnetic shielding materials to solve the electromagnetic radiation pollution.In this paper,one-dimensional MoO2-NC heterogeneous nanomaterials were successfully prepared by simple hydrothermal method,in-situ chemical oxidation polymerization and high temperature carbonization process.Then the flexible polyvinylidene fluoride(PVDF)was filled with this nanomaterial.A series of MoO2-NC/PVDF composites with different mass fractions of MoO2-NC were fabricated by simple solution mixing and hot-pressing techniques,then their electromagnetic shielding properties were investigated.The results show that the polypyrrole(PPy)precursor is pyrolyzed to carbon material and MoO3 is reduced to MoO2 by the carbothermal reduction method after high temperature treatment,which greatly improves the electric conductivity of nanofillers.The electric conductivity of MoO2-NC could reach133.67 S/cm at 20 MPa,which is 28 times higher than that of the sample before calcination.When the mass fraction of MoO2-NC is 40%,the composite possesses excellent electromagnetic shielding performance.The highest total shielding efficiency of the composites could reach up to 32.2 dB in the X-band,which is 60%higher than that of commercial standard(20 dB).It indicates that MoO2-NC owns the potential to be used as the high-efficiency electromagnetic shielding filler.
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