1. Long Range Interactions beyond first neighbour
Intermolecular forces organizing complex fluids
…Laboratory experiments for challenging predictive theories.
4-The equation of state of lipids in the multi-lamellar vesicle state in the presence of additives
..charged lipids.. ,plus salts and non-electrolytes

2. With free counter-ion :Charged lipids
Measuring EOS is a way to test the validity of colloidal electrostatics
1,2-Dioleoyl-sn-Glycero-3-Phospho-L-serine-N-sodium salt
Formula:
Molar Mass = 810
Structural charge = 1e/molecule
B. Demé (2002) : Giant Collective Fluctuations of Charged Membranes at the Lamellar-to-Vesicle Unbinding Transition

3. With free counter-ion :Charged lipids
Measuring EOS is a way to test the validity of colloidal electrostatics
1,2-Dioleoyl-sn-Glycero-3-Phospho-L-serine-N-sodium salt
Formula:
Molar Mass = 810
Structural charge = 1e/molecule
B. Demé (2002) : Giant Collective Fluctuations of Charged Membranes at the Lamellar-to-Vesicle Unbinding Transition

4. With added salt (« buffer » ) : e-kdw
What theory says : counter-ion entropy inducethe osmotic pressure
D*= dw+2t dw 2t
Without added salt
With added salt (« buffer » ) : e-kdw

5. Mg Cl2 P/P0=33% Mg NO3 P/P0=53% Na Cl P/P0=75% K Cl P/P0=80% K2SO410
K Cl
P/P0=80%
Ba Cl
P/P0=85%
K2SO4
P/P0=95%
B. Demé, Langmuir, Part II, 18, 2002,

6. Evolution of SAXS pattern versus dilution
B. Demé, Langmuir Part I:, 18, 2002,

7. Form factor of a single DOPS bilayer (SAXS)
B. Demé, M. Dubois, Th. Gulik-Krzywicki and Th. Zemb, Langmuir Part I:, 18, 2002,

8. Extract teh structure factor (powder average)5
Extract teh structure factor (powder average)
X-rays
Neutron
B. DeméLangmuir Part I:, 18, 2002,

9. 6
DOPS 30%
DOPS 14%
DOPS 5 %

10. « Diluted state »: spontaneous vesicles (inside/outside counter- ion distribution difference)*
*= M. Dubois et al. Langmuir (1991)

11. « OYSTER » STATE CHARACTERISTICS:
kc≈ 0.06 dw/Lb => x= t.ekc=200nm
d=30 nm; s=80nm;2t=4nm ld > 100nm; lG-C = 1nm; Lb = 0.7nm
B. Demé, M. Dubois, Th. Gulik-Krzywicki and Th. Zemb, Langmuir Part I:, 18, 2002,

12. « MICROSTARUCTURES » WHILE DECREASING OSMOTIC PRESSURE9
« MICROSTARUCTURES » WHILE DECREASING OSMOTIC PRESSURE
B. Demé, , Langmuir Part I:, 18, 2002,

13. B. Demé, Langmuir, Part II, 18, 2002, 997-1004

14. Vapor pressure
Data for DPPG from Cowley et al, 1978
Osmotic stress using PEG 110
B. Demé, M. Dubois, Th. Gulik-Krzywicki and Th. Zemb
Langmuir, Part II, 18, 2002,

15. In cationic lipids, thory overestimates the osmotic pressure, ???14
In cationic lipids, thory overestimates the osmotic pressure, ???
DDAB
DOPS

16. DDAB avec deux plateaux15
DDAB avec deux plateaux

17. M. Dubois, Th. Zemb , Current Opinion in Coll. and Interf. Sci

18. Charged layers in the presence of added salts
The two first are obesrved experimentally
D. Andelmann (1995) «Electrostatic properties of membranes » 

19. What theory says at saturation plus added salt :
M. Dubois. « Osmotic pressures in lamellar phases
in the presence of added salt » (1992)

20. Addition of small solutes: DMPC + SUGAR ? 2 cases:
Lipids with sugar in the « interlayer » water
Addition of small solutes:
DMPC + SUGAR ?
2 cases:
-excess water: zero pressure
- in the linear swelling regime

21. « Where » is the sugar gone ?
B. Demé, J. Applied Cryst. (2000 ) 33,

22. Sugar adsortion equilibria : partial release of bound water
Demé, B: Hydration forces between bilayers in the presence of dissolved
or surface-linked sugars (2011)

23. 20% DMPC with added glucose and fructose

24. 20% DMPC with added glucose and fructose

25. Demé, B (2002) : Swelling of lecithin lamellar phases
Swelling AND peak broadening the stack is observed at eqiilibrium
Demé, B (2002) : Swelling of lecithin lamellar phases
in the presence of small carbohydrates

26. Force balance in the presence of solute at 20% lecithin
Demé, B (2002) : Swelling of lecithin lamellar phases
in the presence of small carbohydrates

27. Equation of state when the solvent is a glucose solution
Hydration force and
undulation increase ?
DMPC/glucose/dextran/H2O quaternary samples in excess sugar solution

28. What we have learnt for non-electrolytes :
Measuring EOS is a way to test force balance for bilayers van der Waals, hydration, electrostatic, depletion + steric entropic… (.. But lateral equation of state is needed in anisotropic systems…) Water soluble additives: -are either dissolved or adsorbed (steric) -always change the van der Waals forces -may induce softening and undulations - change the hydration force ?
B. Demé (2011) Hydration forces bewteen bilayers in the presence of dissolved or surface-linked sugars