Piezoelectric composite forming and its characterization

Physical properties of PVDF blends with a multiwalled carbon nanotube (MWCNT) have been characterized. Surface of MWCNT was functionalized to enable the nanotubes to be randomly well-dispersed in the PVDF matrix. The blend samples were drawn and/or poled at high voltage and high temperature. X-rayu analysis coupled with differential scanning calorimetry suggests that the nanotubes alter crystal formation within the polymer. For drawn samples, the elevation of piezoelectric β-form crystal was increased with MWCNT addition, but soon reached a plateau. Undrawn samples show monotonous increase of β-phase content with MWCNT amount when subjected to poling. Other physical properties showed similar behavior of steady increase with MWCNT amount.