1. ADSORPTION

2. Surface Activity of Solutes Solute, c  oo Solutes that decrease surface tension are called “surfactants”  Solute, c

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4. Adsorption More solute we have less surface tension (free energy) is - favorable As a result solute concentrates onto surface - adsorption More solute we have more surface tension (free energy) is - unfavorable Solute is repelled by surface 

5. Specific Adsorption  - thickness of adsorption layer Solute concentration, c Surface concentration, c  Surface area,  “Volume” of adsorption layer, .  Specific adsorption, 

6. Adsorption Isotherms  Langmuir isotherm (for a solution) (for a gas) c or p  max

7. More Adsorption Isotherms  c or P    (a) Langmuir(b) Multilayer formation (c) “Positive cooperativity” (d) Hysteresis first layer