title: Graphene/phase change material nanocomposites: light-driven, reversible electrical resistivity regulation via form-stable phase transitions.
abstract: Innovative photoresponsive materials are needed to address the complexity of optical control systems. Here, we report a new type of photoresponsive nanomaterial composed of graphene and a form-stable phase change material (PCM) that exhibited a 3 orders of magnitude change in electrical resistivity upon light illumination while retaining its overall original solid form at the macroscopic level. This dramatic change in electrical resistivity also occurred reversibly through the on/off control of light illumination. This was attributed to the reversible phase transition (i.e., melting/recrystallization) behavior of the microscopic crystalline domains present in the form-stable PCM. The reversible phase transition observed in the graphene/PCM nanocomposite was induced by a reversible temperature change through the on/off control of light illumination because graphene can effectively absorb light energy and convert it to thermal energy. In addition, this graphene/PCM nanocomposite also possessed excellent mechanical properties. Such photoresponsive materials have many potential applications, including flexible electronics.
authors.affiliation: Department of Biomedical Engineering, Wisconsin Institute for Discovery, and Materials Science Program, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States .
authors.forename: Yunming
authors.initials: Y
authors.lastname: Wang
authors.forename: Hongyi
authors.initials: H
authors.lastname: Mi
authors.forename: Qifeng
authors.initials: Q
authors.lastname: Zheng
authors.forename: Zhenqiang
authors.initials: Z
authors.lastname: Ma
authors.forename: Shaoqin
authors.initials: S
authors.lastname: Gong
keywords: form-stable phase change material; graphene; photoresponsive; polymer nanocomposites; reversible electrical resistivity