Controlling the Location and Spatial Extent of Nanobubbles Using Hydrophobically Nanopatterned Surfaces
Hatsopoulos Microfluids Laboratory, Department of Mechanical Engineering, Department of Material Science and Engineering, and Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, and Polymer Science and Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003
Received June 11, 2005
Revised July 29, 2005
The presence of nanobubbles-as imaged with tapping-mode atomic force microscopy-is controlled using nanopatterned surfaces possessing repeating patterns of polystyrene (hydrophobic domains) and poly(methyl methacrylate) (hydrophilic domains). For nanobubbles to be present, we find that, in addition to controlling the degree of surface hydrophobicity, it is important for the spatial dimensions of the hydrophobic domains on the nanopatterned surface to be commensurate with the equilibrium topology of the nanobubbles.