Carbon nanotube and polyaniline composite actuators

Abstract

The actuation of single-wall carbon nanotube (CNT) mat, electrically conducting polyaniline (PAn) film and a composite of these two materials has been investigated in NaNO3 (1 M), NaCl (1 M, 3 M) and HCl (1 M) solutions. The expansion/contraction patterns of the PAn, CNT and CNT/PAn samples are similar in these solutions. Fabrication of the CNT/PAn samples by coating PAn (CNT:PAn= 3:1 by weight) substantially enhanced the actuation strain (0.2 - 0.5 %) of the CNT/PAn composite from a low actuation strain (0.06%) of the CNT mat. This result indicates that the addition of PAn to CNT can increase the strain while the Young's modulus E of the PAn coated CNT bundles could be maintained near the E value of CNT bundles (~640 GPa). In other words, the PAn component contributes to a high strain value while the CNT component to high Young's modulus. The combination of these two factors would result in high actuation stresses produced by CNT/PAn composite actuators.