Contact angle measurement of free-standing square-millimeter single-layer graphene.

ABSTRACT: Square millimeters of free-standing graphene do not exist per se because of thermal fluctuations in two-dimensional crystals and their tendency to collapse during the detachment from the substrate. Here we form millimeter-scale freely suspended graphene by injecting an air bubble underneath a graphene monolayer floating at the water-air interface, which allowed us to measure the contact angle on fully free-standing non-contaminated graphene. A captive bubble measurement shows that free-standing clean graphene is hydrophilic with a contact angle of 42° ± 3°. The proposed design provides a simple tool to probe and explore the wettability of two-dimensional materials in free-standing geometries and will expand our perception of two-dimensional materials technologies from microscopic to now mi

SUBMITTER: Prydatko AV 

PROVIDER: S-EPMC6180012 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature