title: Gas-like adhesion of two-dimensional materials onto solid surfaces.
abstract: The adhesion of two-dimensional (2D) materials onto other surfaces is usually considered a solid-solid mechanical contact. Here, we conduct both atomistic simulations and theoretical modeling to show that there in fact exists an energy conversion between heat and mechanical work in the attachment/detachment of two-dimensional materials on/off solid surfaces, indicating two-dimensional materials adhesion is a gas-like adsorption rather than a pure solid-solid mechanical adhesion. We reveal that the underlying mechanism of this intriguing gas-like adhesion is the configurational entropy difference between the freestanding and adhered states of the two-dimensional materials. Both the theoretical modeling and atomistic simulations predict that the adhesion induced entropy difference increases with increasing adhesion energy and decreasing equilibrium binding distance. Our findings provide a fundamental understanding of the adhesion of two-dimensional materials, which is important for designing two-dimensional materials based devices and may have general implications for nanoscale efficient actuators.
authors.affiliation: Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai University, Shanghai, 200072, People's Republic of China. guozhengrong@shu.edu.cn.
authors.forename: Zhengrong
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai University, Shanghai, 200072, People's Republic of China.|State Key Laboratory of Ocean Engineering, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China.
authors.forename: Tienchong
authors.initials: T
authors.lastname: Chang
authors.affiliation: Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai University, Shanghai, 200072, People's Republic of China.
authors.forename: Xingming
authors.initials: X
authors.lastname: Guo
authors.affiliation: School of Engineering, Brown University, Providence, Rhode, Island, 02912, USA.
authors.forename: Huajian
authors.initials: H
authors.lastname: Gao
mesh_terms: D000327:Adsorption; D001696:Biomechanical Phenomena; D019277:Entropy; D008958:Models, Molecular; D013499:Surface Properties