Influence of surface modification of carbon nanotubes on interactions with polystyrene-b-polyisoprene-b-polystyrene matrix and its photo-actuation properties

Abstract

The influence of various surface modification of multiwalled carbon nanotubes (MWCNT) on preferential interactions with individual phases of the linear triblock copolymer polystyrene-b-polyisoprene-b-polystyrene (SIS) and the photo-actuation ability, reproducibility, and stability of the composite was investigated. The preferential interactions of MWCNT were achieved with covalent modification of MWCNT surface either with cholesteryl groups (MWCNT-chol) or with short polystyrene chains (MWCNT-PS). The specific interactions were investigated by dynamic mechanical analysis. The activation energy of glass transition of the polystyrene phase in the MWCNT-PS/SIS composite increased significantly compared with the neat SIS matrix, while the incorporation of MWCNT-chol resulted in selective increase of activation energy of glass transition of the polyisoprene phase. The best reproducible and stable photo-actuation behavior was obtained during irradiation of the composite containing low content of MWCNT-PS.