Nanocomposite photoactuators based on an ethylene vinyl acetate copolymer filled with carbon nanotubes

This paper reports strong, reversible actuation of nanocomposites on the base of ethylene vinyl acetate (EVA) filled with multiwalled (MWCNTs) and singlewalled carbon nanotubes (SWCNTs). The carbon nanotubes (CNTs) dispersion within the EVA matrix was ensured with pyrene-based compatibilizer and the alignment of the CNTs within a matrix was induced by shear stress to 50% applied as a prerequisite for unilateral photo-actuation. The CNT dispersion within EVA matrix was characterized by transmission electron microscopy (TEM). The dependence of the actuation stress as a function of CNTs concentration, energy and intensity of light was studied. Stress variation of actuation and relaxation were evaluated. The photo-actuation responses showed contraction under illumination up to 170 kPa for EVA-CNTs-based nanocomposites. Repeatability of photo-actuation process up to 100 cycles was observed. High optical-to- mechanical energy conversion factor (ηM) of 55 MPa W-1 for EVA nanocomposite containing 0.1 wt.% MWCNTm during illumination by red light-emitted diode (LED) is reported. © 2013 Elsevier B.V. All rights reserved.