fig3

Figure 3. WCA measurements on suspended graphene. (A) (i) Schematic and picture of the captive bubble method for measuring the WCA on suspended graphene; (ii) Surface energy balance at the triple line indicated by the Neumann’s triangle; (iii) Measured WCA as a function of relative humidity of air^[70]; (B) (i) Schematic of micro-droplets on graphene that is supported by a hole-patterned substrate; (ii) ESEM image of a water droplet on graphene that is supported by an Au/carbon substrate with a 70° tilt angle of sample stage with respect to the electron beam; (iii) ESEM image of a water droplet on clamped, suspended graphene with a 70° tilt angle^[15]; (C) (i) ESEM image of droplets condensed on monolayer graphene sitting on a trench; (ii) ESEM image of droplets with and without contact with the substrate-supported region; (iii) WCA statistics on supported and suspended monolayer and multilayer graphene^[71]. Figures are adapted from references^[15,70,71] with permission. ESEM: Environmental scanning electron microscope; WCA: water contact angle.