Preparation of BaTiO3-MWNT/polyvinylidene fluoride three-phase composites with novel dielectric behavior

A three-phase composite with multiwall carbon nanotube (MWNT) and BaTiO₃ particles embedded into polyvinylidene fluoride (PVDF) is prepared by using a flocculation and hot-molding technique, which is eco-friendly compared with solution method avoiding the pollution of solvent to the air. The uniform dispersion of fillers in matrix is realized and the dielectric constant is as high as 924 at 10² Hz when the volume concentrations of MWNT and BaTiO₃ are 0.02 and 0.2, respectively, which is four times larger than that of MWNT/PVDF composite with 2 vol% MWNT prepared by solution method (epsiv=231). Meanwhile, the incorporation of the third phase decreases the dielectric loss abruptly (672rarr67 at 10² Hz). This phenomenon can be explained well by employing the interaction between two kinds of fillers and the evolutions of microcapacitance structure.