Dynamic, Spontaneous Blistering of Substrate-Supported Graphene in Acidic Solutions

We report that for monolayer and few-layer graphene on common silicon and glass substrates, acidic solutions induce fast, spontaneous generation of solution-enclosing blisters/bubbles. Using interference reflection microscopy, we monitor the blister-generating process in situ and show that at pH < similar to 2, nanoscale to micrometer-sized graphene blisters, up to similar to 100 nm in height, are universally generated with high surface coverages on hydrophilic, but not hydrophobic, surfaces. The spontaneously generated blisters are highly dynamic, with growth, merging, and reconfiguration occurring at second-to-minute time scales. Moreover, we show that in this dynamic system, graphene behaves as a semipermeable membrane that allows the relatively free passing of water, impeded passing of the NaCl solute, and no passing of large dye molecules. Consequently, the blister volumes can be fast and reversibly modulated by the solution osmotic pressure.

Automated summary

This study reports that acidic solutions can induce the fast generation of solution-enclosing blisters on monolayer and few-layer graphene on silicon and glass substrates. The graphene blisters are nanoscale to micrometer-sized and are universally generated on hydrophilic surfaces. The blisters are highly dynamic and can be modulated by solution osmotic pressure.