title: Precise Actuation of Bilayer Photomechanical Films Coated with Molecular Azobenzene Chromophores.
abstract: Bilayer photomechanical films are fabricated by depositing one layer of molecular azobenzene chromophores onto flexible low-density polyethylene substrates. The photoinduced bending and unbending behavior of five azobenzene derivatives including azobenzene, 4-hydroxy-azobenzene, 4-((4-hydroxyphenyl)diazenyl)bezoitrile, 4-((4-methoxyph-enyl)diazenyl)phenol, and 4-(phenyldiazenyl)phenol is systematically studied by considering the incident light intensity and the thickness of the coated chromophore layers. Precise control of photoinduced curling of the bilayer film is successfully achieved upon irradiation with two beams of UV light, and the curled films can be recovered by thermal relaxation in the dark. The easily fabricated bilayer films show fast photomechanical response, strong photoinduced stress, and stability similar to crosslinked polymeric films.
authors.affiliation: State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang, 621010, China.
authors.forename: Ziyi
authors.initials: Z
authors.lastname: Liu
authors.affiliation: State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang, 621010, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Tang
authors.affiliation: State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang, 621010, China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Xu
authors.affiliation: School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang, 621010, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing, 100871, China.|Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing, 100871, China.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Yu
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D055668:Photochemical Processes; D014466:Ultraviolet Rays
chemical_list: D001391:Azo Compounds; C009850:azobenzene
keywords: actuators; azobenzenes; photoactive materials; photomechanics