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Gale, Robert Swinfen (1965) The nucleation and growth of bubbles in supersaturated solutions of gases in viscous liquids. Doctoral thesis, Northern Polytechnic.
The work arose from the need to improve the understanding of the factors determining bubble growth in the preparation of cellular polymers. In many of these systems bubbles grow in supersaturated solutions of gases in viscous liquids and gas diffusion in the liquid surrounding the bubble is an important factor. Previous theoretical work on bubble growth has been largely concerned with vapour bubbles growing in superheated one-component systems in which the growth is controlled by heat diffusion in the liquid phase. In this thesis the relevance of the above work, particularly that of SCRIVEN (1959, 1962), to the systems of present interest is reviewed; the final equations are presented in a form in which the ambiguities are eliminated and the physical significance of the variables is more clearly seen.
In the experimental portion of the present work, the growth rates of single bubbles, in liquids supersaturated with gas, have been measured over a wide range of conditions; the times for bubbles to grow to 0.5 mm diameter ranged from 0.02 to 1,200 seconds. Supersaturation pressures ranged from ca. 0.1 atm. to ca. 10 atm. with both carbon dioxide and nitrogen, and the liquid phase viscosity was varied between 2 and 1000 stokes.
The experimental results agree with the predictions of the Scriven theory in the time-dependence of bubble diameter and in the dependence of the growth rate constant on the dimensionless supersaturation parameter (volume of gas phase produced when unit volume of liquid phase gives up its supersaturation). The experimental values of growth rate constant differ from the predictions of the theory by up to ca. 20 per cent. These deviations are attributed to the fact that the experimental bubbles grew in tangential contact with a flat plate, whereas the theory applies to bubbles growing with spherical symmetry in an infinite extent of liquid phase.
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