Wettability(find instruments to measure wettability here) Definition: Wettability or wetting is the actual process when a liquid spreads on (wets) a solid substrate. Wettability can be estimated by determining the contact angle or calculating the so called spreading coefficient. Summary/Description: The shape of a liquid front in contact with a solid substrate is determined by the interfacial forces of the participating phases as was shown for the contact angle. Wettability of a surface by a liquid is the actual process of spreading. One can qualitatively determine the wetting with the contact angles i.e. when the contact angles are low this means good wetting, and when the contact angles are high this means non-wetting conditions.
Spreading Complete Partial γsl = γsv Negligible Non-wetting wetting wetting wetting A quantitative measure of wetting is the Spreading coefficient, which is the energy difference between the solid substrate with the contacting gas and liquid phases.
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