Influence of nano Fe3O4 particles on the free volume and dielectric behaviour of Polyisobutyl methacrylate

Polyisobutyl methacrylate (PiBMA)/ferrous-ferric oxide (Fe 3 O 4 ) polymer nanodielectric films with different wt% of Fe 3 O 4 nanoparticles (from 0.2wt.% to 1.0wt.%) were prepared by solution casting technique. The effect of free volume on the dielectric properties of PiBMA/Fe 3 O 4 polymer nanodielectrics is also explored. The free volume parameters and AC conductivity of PiBMA/Fe 3 O 4 polymer nanodielectrics as a function of Fe 3 O 4 nanoparticle wt% exhibit an increasing trend. The DSC results suggest weak interfacial interaction between agglomerated Fe 3 O 4 nanoparticles and polymeric chains of PiBMA polymer. The dielectric constant ( ϵ ′ ) of PiBMA/Fe 3 O 4 polymer nanodielectrics increased as a function of free volume hole size and Fe 3 O 4 nanoparticle wt%. This is attributed to the increased interfacial polarization at the interface region and the orientation polarization effect of intrinsic dipoles. The increased electrochemical current of PiBMA/Fe 3 O 4 polymer nanodielectrics for 0.8wt.% and 1.0wt.% of Fe 3 O 4 nanofiller loading imply that the increased free volume favors the diffusion of electrolytic ions into PiBMA/Fe 3 O 4 polymer nanodielectrics.