Preferential interaction of small-diameter metallic SWNTs with ferroelectric polymer

Abstract

Poly(vinylidene difluoride) (PVDF) blends with single-walled carbon nanotubes (SWNTs) have been prepared to investigate the interaction between nanotubes and polymer. The SWNTs are observed to form a good dispersion in the fluoropolymer matrix. Raman measurements showed sizable changes in the frequencies and intensities of SWNTs and PVDF in the composites compared with the values in pristine SWNTs and neat PVDF. This originates from the polymer's preferential interaction with metallic SWNTs (m-SWNTs), especially with small-diameter tubes, due to non-vanishing Fermi electrons and increased curvature-induced strain energy. In addition, the selective dispersion of m-SWNTs induced remarkable enhancement in the β-ferroelectric phase of PVDF as demonstrated by Fourier transform infrared spectroscopy (FTIR).