Advantages and Practice
Unlike a Du Nuoy ring, no correction factors are required when calculating surface tensions when using the Wilhelmy plate, assuming a zero contact angle. In addition, because the plate is not moved during measurements, the Wilhelmy plate allows accurate determination of surface kinetics on a wide range of timescales and it displays low operator variance. In a typical plate experiment, the plate is lowered to the surface being analyzed until a meniscus is formed, and then raised so that the bottom edge of the plate lies on the plane of the undisturbed surface. If measuring a buried interface, the second (less dense) phase is then added on top of the undisturbed primary (denser) phase in such a way as to not disturb the meniscus. The force at equilibrium can then be used to determine the absolute surface or interfacial tension.
Read more about this topic: Wilhelmy Plate
Famous quotes containing the words advantages and/or practice:
“To become aware in time when young of the advantages of age; to maintain the advantages of youth in old age: both are pure fortune.”
—Johann Wolfgang Von Goethe (1749–1832)
“It is accordance with our determination to refrain from aggression and build up a sentiment and practice among nations more favorable to peace ... that we have incurred the consent of fourteen important nations to the negotiation of a treaty condemning recourse to war, renouncing it as an instrument of national policy.”
—Calvin Coolidge (1872–1933)