Evidence of piezoelectricity in SWNT-polyimide and SWNT-PZT-polyimide composites

Nanotechnology offers opportunities to reenergize the area of smart materials by addressing their current shortfalls and expanding their application range. For example, sensors based on polymer nanocomposites would provide a new paradigm for lightweight structural health monitoring for broad aeronautics and space applications. Deployable structures such as inflatable antennae and space mirrors will benefit from the incorporation of multifunctional lenses employing smart, articulating materials. In this paper, an approach to enhance the piezoelectricity of polyimides through the addition of lead zirconate titanate (PZT) particles and single-wall carbon nanotubes (SWNT) is presented. The dielectric and electrical properties of the composites are investigated as a function of SWNT volume content. The dynamic and static mechanical properties are presented to assess the effect of the inclusions on the macro-scale properties of the nanocomposites. It is found that the SWNTs increase the dielectric, piezoelectric, and mechanical properties of the polyimide matrix. Addition of the SWNT in the PZT/polyimide composites facilitates poling and results in an increase of the piezoelectric properties of the three-phase composite.