CRIM 2653 Lecture Notes - Lecture 7: Surface Tension, Contact Angle, Monolayer
6 May 2020
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Document Summary
Ym- mass of gas absorbed when the gas molecule is complete single layer. Assumptions made by languir: solid has a uniform surface, absorbed molecules do not interact, adsorbed molecules are localized at spefic active site, only a monolayer can be absorbed. Limitations: not uniform - rate of absorption depends on position of ga. Interact gas molecules interact via van der waals: move on the surface gas molecules move due to increase in temp, monolayers gases actually exist as multilatyers. Conttact angle: wettting is a phenomenon of the solid-liquid interface. If you add a drop of liquid to a solid, when it is spontaneously spread, it can be described as complete wetting. If you add a liquid to solid surface, and liquid forms. Globules, it can be described as incomplete wetting or no wetting. You define the spreading coefficient as the surface tension of old system and new system.
