Effect of CeO2 nanoparticles on dielectric properties of PVB/CeO2 polymer nanodielectrics: a positron lifetime study

To produce a polymer nanodielectric material with low dielectric constant for high speed communication network cables, polymer nanodielectrics of Polyvinyl butyral (PVB) with (0.2, 0.4, 0.6, 0.8, and 1 wt%) of CeO2 nanoparticles are prepared. Cerium dioxide (CeO2) nanoparticles were synthesized by hydrothermal technique. The average size of CeO2 nanoparticles determined by Dynamic Light Scattering studies is 60 nm. The dependence of free volume and crystallinity on dielectric properties of PVB/CeO2 polymer nanodielectrics is explored. The positron lifetime parameters viz., o-Ps lifetime (tau(3)) and free volume size (V-f) show minimum value for 1.0 wt% of CeO2 nanoparticles loading. The reduced free volume is attributed to the increased chemical interaction between CeO2 nanoparticles and PVB side chain. The AC conductivity and dielectric constant of PVB/CeO2 polymer nanodielectrics are also decreased for 1.0 wt% of CeO2 nanoparticle loading. The reduced free volume restricts the ionic mobility of CeO2 nanoparticles and impedes dipoles mobility.