Fig. 1
Polyzwitterionic brushes and water film stability. a Dry and wet thicknesses of the poly(sulfobetaine methacrylate) (PSBMA) brushes hdry,wet measured using ellipsometry and atomic force microscopy (AFM) for different polymerization times. b–d The presence of a stable hydration layer beneath the oil droplet can be confirmed using reflection interference contrast microscopy. e Sideview image of the oil droplet. f–h In the absence of a stable water film, solid–oil contact can clearly be seen. i Sideview image of the oil droplet. Scale bars are 50 μm for c and g, 10 μm for d and h, and 0.5 mm for e and i. The droplets are held in place by a capillary tube
