Stability of Voids Formed in Cavities at Liquid-Solid Interfaces
Jeffrey W. Bullard
A thermodynamic model is developed of the free energy of gas-filled voids formed within cavities on solid surfaces covered by a liquid. Capillary effects are assumed to be the only important contributions to the free energy, and expressions are derived for the free energy as a function of the air void size, the relative surface free energy densities involved, and the geometry of the cavity. The results of the model are (1) construction of stability diagrams that map the most stable void configuration versus the wetting properties of the various solid surfaces involved, and (2) estimates of the work required to liberate a void of a given size. The model can give qualitative insight into the stability of coating defects on uneven surfaces, and also can be used to prescribe possible surface treatments for reducing the work required to remove voids from the system.
Stability of Voids Formed in Cavities at Liquid-Solid Interfaces, Journal of Colloid and Interface Science, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=860525
(Accessed February 24, 2024)