1. Thermodynamics of surfaces and interfaces
Atkins (ed. 10): §16C C.4
Atkins (ed. 9): §
Atkins (ed. 8): §
Study Guide: P.14

2. Na2ClO3 crystals in solution

3. Large crystals grow; small crystals dissolve
T = 1 day 3

4. Large crystals grow; small crystals dissolve
Wilhelm Ostwald
Ostwald ripening
(1896)
T = 0
T = 1 day 4

5. Equilibrium: one single crystal
T = 1 day
10 days
30 days 5

6. Equilibrium: one single crystal
T = 1 day
10 days
30 days 6

7. Gibbs-Thomson effect
Interfacial (free) energy between two phases

8. Gibbs-Thomson effect Interfacial (free) energy between two phases
relevant for P >1
P =1
P =2,3
P =2,3

9. Laplace equation γ r
out in
equilibrium

10. Laplace equation γ r γ
r+dr
equilibrium
Laplace
equation

11. Surface tension γ

13. Surface tension and capillary action
Pressure of
liquid column
of height h
Laplace equation
equilibrium
capillary action

14. Surface tension and capillary action

15. Surface tension and wetting
specific
work (J/m2)
of adhesion
(γ is always trying to reduce the corresponding surface)
horizontal
Force (N/m)
balance
(equilibrium)

16. Surface tension and wetting}
Work (J/m2)
Force (N/m)
partial dewetting
partial wetting

18. Kelvin equation (nucleation barrier for condensation)γ
Pout
Laplace equation
Pin l g
equilibrium
constant T
Kelvin equation

19. barrier for nucleation of phase α from phase β
reason: interface energy between new and old phase
classical nucleation theory
assume spherical nucleus, radius r
driving force:
surface free energy: γ
molar volume: Vm γ β α
Free energy
gain
cost

20. nucleation barrier
nucleation barrier and critical radius
nucleation barrier depends on supersaturation (Δμ = σ)
-low σ: no nucleation
-high σ: easy nucleation