Photoactuating of materials designed for haptic aid-tablets for visually impaired people based on styrene-b-isoprene-b-styrene block copolymer nanocomposites

Abstract

In this study, the photoactuation of styrene-b-isoprene-b-styrene (SIS) block copolymer containing multiwalled carbon nanotubes (MWCNT) is shown. In order to improve dispersion, the MWCNT were ovalently modified either by polystyrene chains or cholesteryl chloroformate. The composites were prepared by solution technique and in the form of prestretched stripes were tested by dynamic mechanical analysis (DMA) in iso-strain mode. The actuation stress produced in response to irradiation was monitored. The pre-stretching of the stripes should impose the orientation of the polymer hains and carbon nanotubes, which was proved by transmission electron microscopy (TEM). The impact of the various pre-stretching conditions of the stripes as well as constant preload of the DMA was tudied. Both the actuation contraction and expansion was observed. The highest actuation expansion stress observed was 14 kPa, while the contraction exhibited the highest stress of 3 kPa.