title: The synergistic effect of the combined thin multi-walled carbon nanotubes and reduced graphene oxides on photothermally actuated shape memory polyurethane composites.
abstract: We evaluated the synergistic effect of the hybrid-type nanocarbon, consisting of 1D thin-walled carbon nanotubes (TWNTs) and 2D reduced graphene oxide (RGO), on the shape memory performance of hyperbranched polyurethane composites. The shape recovery of the resulting composites was activated via a photothermal process using a near-infrared laser. The best laser-induced shape recovery performance was achieved for the composites with a 7/3 of TWNT/RGO ratio and a 1wt.% of nanocarbon content. Such result can be explained by good dispersion of TWNTs and RGO in the hyperbranched polymer as well as three-dimensionally enhanced interconnection between carbon nanotubes and graphenes. The optically active TWNTs with a high optical absorption section exhibited high ability of transferring laser-induced thermal energy to polymer matrix whereas RGO provided a high mechanical property to polymer matrix. The tensile modulus and electrical conductivity of the composites also showed a similar dependence on the TWNT/RGO composition ratio as the photothermal shape recovery. Our study demonstrated an effective conversion from light, thermal to mechanical work by irradiating shape memory polymer composite containing hybrid-type fillers using a near-infrared laser.
authors.affiliation: Department of Organic and Nano System Engineering, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Dong Hun
authors.initials: DH
authors.lastname: Yi
authors.affiliation: Department of Organic and Nano System Engineering, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Yoo
authors.affiliation: Department of Organic and Nano System Engineering, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Sibdas Singha
authors.initials: SS
authors.lastname: Mahapatra
authors.affiliation: School of Polymer Science and Engineering, Chonnam National University, Gwangju 500-757, Republic of Korea. Electronic address: yak@jnu.ac.kr.
authors.forename: Yoong Ahm
authors.initials: YA
authors.lastname: Kim
authors.affiliation: Department of Organic and Nano System Engineering, Konkuk University, Seoul 143-701, Republic of Korea. Electronic address: jwcho@konkuk.ac.kr.
authors.forename: Jae Whan
authors.initials: JW
authors.lastname: Cho
keywords: Actuator; Carbon nanotube; Graphene; Photothermal; Shape memory polymer