Supramolecular Structure in Liquid Mixtures: Insights from Light Scattering Analysis" (62 characters)

1. Supramolekulárna štruktúra v roztokoch a zmesiach kvapalín_______________________Seminár ÚEF 25.septembra 2007

2. 1.) M. Sedlák: Large-Scale Supramolecular Structure in Solutions of Low Molar Mass Compounds and Mixtures of Liquids: I. Light Scattering Characterization. J. Phys. Chem. B, 110 (9), 4329 -4338, 2006.2.) M.Sedlák: Large-Scale Supramolecular Structure in Solutions of Low Molar Mass Compounds and Mixtures of Liquids: II. Kinetics of the Formation and Long-Time Stability. J. Phys. Chem. B, 110 (9), 4339 -4345, 2006.3.) M. Sedlák: Large-Scale Supramolecular Structure in Solutions of Low Molar Mass Compounds and Mixtures of Liquids: III Correlation with molecular properties and interactions. J. Phys. Chem. B, 110 (9), 13976-13984, 2006.M. Sedlák: Large-scale supramolecular structure in solutions of polar and ionic molecules and macromolecules, ESF Exploratory workshop: self-assembly of guanosine, Bled, Slovenia, 13.9. -15.9.2006M. Sedlák: Large-scale supramolecular structures,First Annual (Inaugural) Conference onThe Physics, Chemistry and Biology of Water 2006, Brattleboro, Vermont, USA, 26.10. -29.10., 2006

4. r r g(r) - pair correlation function

5. Static and Dynamic Laser Light Scattering SLS: Space resolution ~ 1/q q: scattering vector q = (4n/0)sin(/2) r ~ 1/q ~ 20 - 2 000 nm DLS resolution: Space: 1 - 5 000 nm Time: 100 ns - seconds

6. Static Light Scattering Measured quantities: • angular dependence I()or I(q), q = (4n/0)sin(/2) yields: structural information d ~ 1/q ~ 20 - 2000 nm • absolute values I(0) yields: particle mass particle interactions

7. Dynamic Light Scattering Measured quantity • frequency dependence I(f) f/f0 = 10 - 107Hz / 1015Hz = 10-8- 10-14

8. Time autocorrelation of scattering signal  ~ 100ns - seconds Various types of dynamics: Spatial resolution via dynamics: • translational diffusion Diffusion ~ 1/R • rotational diffusion 1 nm - 5000 nm • non-diffusive relaxations

9. I/IB = Af + As Df = coupled diffusion of cations and anions (Nernst-Hartley) M. Sedlák, in ”Physical Chemistry of Polyelectrolytes” (T. Rageva ed.), Marcel Dekker, New York, 2001, p.1-58 M. Sedlák, Langmuir 15 (1999), 4045-4051. 0.4 M MgSO4 (aqueous)

10. Rationale • Large inhomogenities in refractive index must exist (large means ~ q-1 >> molecular dimensions or intermolecular distances) • These are responsible for the slow dynamics • Due to inhomogenities in the local concentration of solute and/or due to inhomogenities in the local arrangement of asymmetric solute molecules

11. Light scattering characterization of large-scale inhomogeneous structure Random two-phase system (Debye-Bueche model)? Spatial correl. function <n(0)n(r)> ~ e-r/a Discrete structures • self-similar (fractal) ? • asymmetric (depolarized scattering) ? • spherical or close-to-spherical

12. Spherical or close-to-spherical discrete objects Size distribution by ORT Optimized regularization technique (O. Glatter et al.)

13. 20 000 g

14. Number of solute particles per domain R = 30 nm R = 300 nm Lower estimate ~ 104~ 107 Upper estimate ~ 106 ~ 109

15. 0.5 0.4 0.3 0.2 0.1 0.0 5 4 3 2 1 0 acetic acid H2O + acid I / IB (90°) I / IB (90°) H2O 0 2 4 6 8 10 12 t, min 0 10 20 30 40 t, min Kinetics of the supramolecular domain formation H2O + acetic acid c = 6 mass % of acid

16. 8 6 4 2 0 8 1 0.1 0.02 300 225 150 75 AS (37.5°) Rh, nm AS 0 0 100 200 300 t, days 0.0 0.2 0.4 0.6 0.8 sin 2(/2) Kinetics of the supramolecular domain formation H2O + DMSO c = 10.5 mass % of DMSO

17. 200 100 10 1 0.1 200 100 10 1 0.1 As / Af As / Af 0.0 0.2 0.4 0.6 0.8 sin 2(/2) 0.0 0.2 0.4 0.6 0.8 sin 2(/2) Monovalent (1:1) electrolytesMultivalent electrolytes c = 0.4M Effect not due to Coulomb attraction • no correlation with ion valency • no correlation with solvent dielectric permittivity KCl in water NaI in water KI in water KI in glycerine KI in ethyleneglycol KI in dimethylformamide KI in dimethylsulfoxide Aqueous solutions: AlCl36H2O Al(NO3)39H2O MgSO47H2O CdSO48/3H2O and Al2(SO4)318H2O As= 0 KI in methanol As= 0 KI in acetonitrile As= 0 MgSO47H2O in methanol

18. Comparison of osmotic coefficients  of monovalent and multivalent salts in selected solvents. . Simple ion pairing due to Coulomb attraction • correlation with ion valency • correlation with solvent dielectric permittivity

19. Aqueous solutions of citric acidionized to different degrees:no ionization (), 4% (), 38% (), 60% (), and 90% ionization () Effect not due to Coulomb attraction • no correlation with ion valency citric acid

20. Scattering from supramolecular domains in aqueous solutions of selected non-ionic solid compounds urea pyrogallol hydroquinone D-glucose saccharose c = 4.5 mass %

21. Scattering from supramolecular domains in aqueous liquid mixtures dimethylsufoxide dioxane acetonitrile acetic acid methanol ethanol ethyleneglycol glycerol

22. 10 5 1 0.5 0.4 0.3 0.2 0.1 0.0 methanol-benzene methanol-benzene g(1)(t) I / IB t A(t), a.u. 0.0 0.2 0.4 0.6 0.8 1.0 sin 2(/2) -4 -3 -2 -1 0 1 2 log (t, ms) Mixtures of nonpolar or weakly polar compounds

23. Mixtures of strongly polar compounds

24. Protic mixtures: at least one component protic O-H, N-H, S-H, Halogen-H

25. urea

26. water methanol As/Af (37.5°)As/Af  0.4M KI 6.5 0.92 0 0.79 0.12M KBr 10.2 0.93 0 0.81 0.4M MgSO47H2O 118 0.57 0 0.20 10 mass % dioxane 155 ---- 0 ---- 20 mass % acetonitrile > 30 ---- 0 ---- 1 0.1 0.1 0.01 10 1 0.3 10 1 0.3 1 0.1 0.03 I / IB I / IB I / IB I / IB I / IB 0.0 0.2 0.4 0.6 0.8 sin 2(/2)

27. Scattering from supramolecular domains in dioxane mixtures water ethyleneglycol glycerol 10 1 0.1 0.01 AS 0.0 0.2 0.4 0.6 0.8 sin 2(/2) As = 0 methanol As = 0 ethanol

28. glucose dextran

29. Dakujem Vám za pozornost