Journal of Polymer Science Part B: Polymer Physics, Vol.48, No.22, 2355-2365, 2010
Shear Piezoelectricity in Single-Wall Carbon Nanotube/Poly(gamma-benzyl-L-glutamate) Composites
Single-wall carbon nanotubes (SWCNTs) have been added to high molecular weight poly(gamma-benzyl-L-glutamate), or PBLG, to evaluate their effects on the polymer's shear piezoelectricity. While the addition of SWCNTs increased various PBLG physical properties such as electrical conductivity, dielectric constant, several mechanical properties, and electrostriction coefficient, the shear piezoelectricity remained constant up to a 0.3 wt % SWCNT concentration. The composite crystallinity, orientation, and SWCNT alignment (measured by X-ray diffraction, birefringence, and polarized Raman spectroscopy, respectively) were found to be constant up to this same concentration, corroborating the shear piezoelectric findings. PBLG composites made with acid-treated (and therefore less electrically conductive) SWCNTs exhibited similar shear piezoelectric behavior, indicating that neither the SWCNT type, concentration (up to the percolation threshold), nor electrical conductivity influences PBLG shear piezoelectricity. (C) 2010 Wiley Periodicals, Inc.(dagger) J Polym Sci Part B: Polym Phys 48: 2355-2365, 2010
Keywords:biopolymers;nanocomposites;polypeptides;sensors;shear piezoelectricity;single wall carbon nanotube (SWCNT)