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ADSORPTION. Surface Activity of Solutes. Solute, c. . . o. Solute, c. Solutes that decrease surface tension are called “surfactants”. Here is me. I am trying to get your attention now. . . Adsorption. More solute we have more surface tension (free energy) is - unfavorable
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Surface Activity of Solutes Solute, c o Solute, c Solutes that decrease surface tension are called “surfactants”
Adsorption More solute we have more surface tension (free energy) is - unfavorable Solute is repelled by surface More solute we have less surface tension (free energy) is - favorable As a result solute concentrates onto surface - adsorption
Specific Adsorption Surface area, - thickness of adsorption layer “Volume” of adsorption layer, . Solute concentration, c Surface concentration, c Specific adsorption,
Adsorption Isotherms Langmuir isotherm max (for a solution) c or p (for a gas)
More Adsorption Isotherms (a) Langmuir (b) Multilayer formation first layer c or P c or P (c) “Positive cooperativity” (d) Hysteresis c or P c or P