Structural Design And Generator Properties Of BaTiO₃/CNT Flexible Organic Composite Materials

Dielectric elastomer is a new kind of smart material that is widely used to artificialmuscle, biomedicine, micro-robot, etc. Electrical output which can drive amicro-electronic products can be realized base on the inverse effect of dielectricelastomer and this is a hotspot in recent years, especially doping piezoelectric ceramicsinto PDMS which is a kind of silicone rubber with a very low Young modulus toenhance the dielectric property. In this paper, PDMS and PVDF which is a kind ofpolymer with ferroelectricity were chosen as matrix to research the structure, dielectricbehavior, generator performance of the BaTiO3/CNT flexible organic compositematerial.The synthesis and modification of the piezoelectric filler are the precondition toenhance the property of organic composite material. First, BaTiO3nanowire withdiameter of20nm was synthetized via hydrothermal method. According to XRD andSEM result, the purity of nanowire was high, and no impurity phase in it. Confirmed byRaman and SEM, CNT was grafted to the BaTiO3particle via CVD method. In thispaper, BaTiO3particle, BaTiO3nanowire, mechanical mixed nanowire and CNT, graftedBaTiO3particle were doped into the organic matrix to research their properties.The properties of PDMS matrix organic composite were studied, when the filler isBaTiO3particle, the voltage output first increases then stays as the BaTiO3particleloading increases, the max output is4.2V when the BaTiO3particle loading is10wt%;When the filler is BaTiO3nanowire, the voltage output first increases then decreases, themax output is5.7V when the BaTiO3nanowire loading is7.5wt%; When the filler isBaTiO3and CNT, the max output is7.3V when the CNT loading is1wt%; When thefiller is grafted BaTiO3particle, the max output is15.2V when the loading is7.5wt%,the voltage output is260%higher than the filler is BaTiO3particle; The enhancementattribute to the improvement of stress and charge deliver on the interface。The properties of PVDF matrix organic composite were studied, due to the lowflexibility, their generator performance were not good. Their dielectric property weretested, when the filler is BaTiO3particle, the dielectric constant increases as the loadingincreases, when the loading is10wt%, the max value is22at1kHz. The dielectric loss decreases as the loading increases; When the filler is BaTiO3nanowire, the dielectricconstant increases as the loading increases, the max value is16, the dielectric lossincreases as the loading increase; When the filler is grafted BaTiO3particle, thedielectric constant increases as the loading increases, when the loading is10wt%, themax value is27at1kHz,23%higher than the filler is BaTiO3particle, and the mostimportant is its dielectric loss stays at0.03at1kHz. Moreover, the max d33is13pC/Nwhen the filler is grafted BaTiO3particle; All the sample showed obviousferroelectricity.