Influence of cluster size and surface functionalization of ZnO nanoparticles on the morphology, thermomechanical and piezoelectric properties of P(VDF-TrFE) nanocomposite films

Few studies have been reported concerning the nanocomposites of copolymers of vinylidene difluoride and trifluoroethylene (P(VDF-TrFE)) with piezoelectric nanofillers. This study deals with the preparation and characterization of piezoelectric nanocomposite films based on P(VDF-TrFE) filled with several ZnO piezoelectric nanoparticles with different sizes and surface states. The influence of cluster size and surface state of ZnO nanoparticles on the morphology and electromechanical properties of (PVDF-TrFE) nanocomposite films is investigated. The dispersion of nanoparticles and the microstructure of nanocomposite are observed by Environmental Scanning Electron Microscope (ESEM) and Transmission Electron Microscopy (TEM). The crystallinity of the copolymer matrix is characterized by X-ray diffraction and Differential Scanning Calorimetry (DSC). The piezoelectric and mechanical properties are measured to evaluate the influence of cluster size and surface functionalization with respect to the P(VDF-TrFE) matrix. The nanocomposites filled with 10% nanoparticles showed an increase up to 25% of storage modulus while keeping a high piezoelectric activity. Furthermore, storage modulus of nanocomposites slightly linearly increased with decreasing cluster size of nanoparticles.