Temperature Dependence of Surface Nanobubbles

The temperature dependence of nanobubbles was investigated experimentally using atomic force microscopy. By scanning the same area of the surface at temperatures from 51 degrees C to 25 degrees C it was possible to track geometrical changes of individual nanobubbles as the temperature was decreased. Interestingly, nanobubbles of the same size react differently to this temperature change; some grow whilst others shrink. This effect cannot be attributed to Ostwald ripening, since the growth and shrinkage of nanobubbles appears to occur in distinct patches on the substrate. The total nanobubble volume per unit area shows a maximum around 33 degrees C, which is comparable with literature where experiments were carried out with increasing temperature. This underlines the stability of surface nanobubbles.