BUBBLE-GROWTH IN CARBONATED LIQUIDS

The formation and growth of a bubble in a liquid is a subject that has been widely investigated. In the present study, bubble growth in carbonated liquids was investigated. A model cavity was developed at which bubble growth occurred as soon as the liquid became sufficiently oversaturated with gas. A theory based on Fick's first law was developed to describe this bubble growth at the cavity and to predict the moment of detachment from the latter. This theory was compared with two other available theories by F.C. Frank (Proc. R. Soc. London, 201 A (1950) 586), and F. van Voorst Vader, F. Erkens and M. van den Tempel (Trans. Faraday Soc., 60 (1964) 1170), describing the transport of molecules to a liquid surface driven by a concentration gradient. It appeared that by considering the geometrical changes that take place at the boundary layer during bubble growth, in combination with the penetration theory and by applying Fick's first law, it is possible to describe the observed bubble growth at a cavity more successfully than by means of the two theories of Frank and van Voorst Vader. Nevertheless, our theory can only be used if no convection is involved. The moment of detachment depends on the perimeter of attachment, the dynamic surface tension of the liquid and the wetting properties of the cavity. The developed theory was successfully applied by using a computer program to calculate the times needed for very small consecutive increases in bubble radius. In this way, transient phenomena such as bubble growth and detachment could be predicted.