AFM characterization of nanobubble formation and slip condition in oxygenated and electrokinetically altered fluids

► Gas-filled bubbles with nanosize dimensions were observed on hydrophobic surfaces with an AFM. ► The instability to image nanobubbles can be attributed to the surface charge and low roughness of OTS surface. ► Applying negative ions with the anti-static gun reduce the diameter of the nanobubbles in DI water on PS surface. ► The electrons are captured by the water molecules while the oxygen molecules are released to the air. ► Applied electric field to the PS surface, increased the size of nanobubbles while the total count decreased.