Superior EMI shielding behavior of multi-layer structure of PVDF based laminated nanocomposite material by controlling the size and distribution of W-type hexaferrite magnetic nanofillers therein

The effects of size and distribution of magnetic filler materials with different loading percentages inside PVDF matrix having mono-layer and multi-layer structures for the modulation of EMI shielding behavior are discussed in the present report. W-type hexaferrites are prepared using the sol-gel method, followed by the manually mortared and ball-milled techniques and embedded inside the PVDF matrix separately. Phase analysis and morphological studies are performed and discussed herein to understand the effect of ball mill technique, over the manually mortared process of W-type hexaferrites. Magnetic and dielectric studies are performed and the influence of the ball mill technique on magnetic and dielectric behavior of nanofillers as well as nanocomposite systems are discussed. Various physical properties of the nanocomposite films are performed within the range of 8-12 GHz. Significant modulations of complex permeability and the complex permittivity with size, distribution and loading percentage of the W-type hexaferrite inside PVDF matrix are found and the effect of impedance matching on EMI shielding behavior are also discussed. EMI shielding behavior of the resultant W-type hexaferrite-PVDF films in the 8-12 GHz frequency region shows the modulations of their absorption and/or reflection effectiveness due to the variation of the size, distribution and loading percentage of magnetic filler materials inside PVDF matrix. Both mono-layer and multi-layer structures of W-type hexaferrite-PVDF films are considered and the effect of thickness on the various parts of EMI shielding behavior is also reported.