Fabrication and characterization of free-standing, flexible and translucent BaTiO3-P(VDF-CTFE) nanocomposite films

Free-standing and translucent nanocomposite films with good flexibility were fabricated using a spin-coating process. BaTiO3 nanoparticles with an average size of about 50 nm and P(VDF-CTFE) 91/9 mol.% copolymer were used as ceramic fillers and polymer matrix, respectively. Dense and uniform microstructure was obtained due to the good compatibility and homogeneous distribution of BaTiO3 nanoparticles in P(VDF-CTFE) matrix. It was experimentally found that the dielectric constant increased but the breakdown strength decreased with increasing volume fraction of BaTiO3. A dielectric constant of about 53 was obtained in the nanocomposite film with 40 vol.% of BaTiO3, which was about 4.4 times higher than that of the pure P(VDF-CTFE) film. A discharged energy-storage density of 4.9 J/cm3 was obtained in the nanocomposite film with 35 vol.% of BaTiO3 under 2000 kV/cm, which was about 2 times higher than that of the pure P(VDF-CTFE) film under the same electric field.