ABSTRACT
Bubble formation at solid–liquid interfaces has long been of interest. Robert Boyle’s observation of a bubble in the eye of a viper, which had been placed in an evacuated chamber, is perhaps the earliest reported record. It has been convincingly demonstrated that the presence of nuclei in solution or on solid surfaces is a prerequisite for bubble formation. For studies of heterogeneous surfaces, there are obvious statistical advantages in dealing with a large ensemble of particles, particularly when bulk properties like colloid stability are to be predicted. Empirical, hydrophobic attractions are usually described using a single- or double-exponential term where one or two decay lengths are invoked. There are several reported AFM tapping-mode observations of “nanobubbles” on surfaces immersed in aqueous solutions reported to date, involving silane-treated silica or glass surfaces treated with silanes, cleaved mica, and pyrolytic graphite.
