1 / 28

3. THE GLASS STATE AND THE GLASS TRANSITION : THERMODYNAMIC and KINETIC ASPECTS

3. THE GLASS STATE AND THE GLASS TRANSITION : THERMODYNAMIC and KINETIC ASPECTS. Differential Scanning Calorimetry. Differential Thermal Analysis. Is the glass transition a true thermodynamic phase transition ?.  T g depends on the cooling rate

donkor
Télécharger la présentation

3. THE GLASS STATE AND THE GLASS TRANSITION : THERMODYNAMIC and KINETIC ASPECTS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 3. THE GLASS STATE AND THE GLASS TRANSITION: THERMODYNAMIC and KINETIC ASPECTS

  2. Differential Scanning Calorimetry Differential Thermal Analysis

  3. Is the glass transition a true • thermodynamic phase transition ?  Tg depends on the cooling rate  Tg depends on the thermal history

  4. sub-Tg aging and annealing Tanneal .

  5. Phase transitions of 1st and 2nd order (Ehrenfest classification) Clausius-Clapeyron Ehrenfest

  6. Phase transitions of 1st and 2nd order (Ehrenfest classification)

  7. 1st-order, 2nd-order and Lambda-type transitions [ T1=T2 ; P1=P2 ; g1=g2 ] v1=v2 s1=s2 cp1  cp2 1  2 T1  T2 v1  v2 s1  s2 cp, , T   v1=v2 s1=s2 cp, , T  

  8. Ehrenfest relations Prigogine-Defay ratio must be = 1 if it were a phase transition with a single order parameter

  9. using Differential Scanning Calorimetry (DSC, TMDSC…) [J. M. Hutchinson, Thermochimica Acta 324 (1998) 165-174

  10. using Differential Scanning Calorimetry

  11. the fictive temperature Tf B2O3 [M. A. R. et al., J. Non-Cryst. Solids 221 (1997) 170]

  12. the fictive temperature Tf Ethanol [B. Kabtoul and M. A. R., Phys. Status Solidi A 208, 2249–2253 (2011)]

  13. the fictive temperature Tf  phenomenological Tool-Narayanaswamy-Moynihan (TNM) approach [ Tool, J. Am. Ceram. Soc. 29 (1946) 240. Narayanaswamy, J. Am. Ceram. Soc. 54 (1971) 491. Moynihan et al., J. Am. Ceram. Soc. 59 (1976) 12. ] • curve fitting method: • [I. M. Hodge, J. Non-Cryst. Solids 169 (1994) 211]

  14. THE KAUZMANN PARADOX EXCESS OF ENTROPY: TK

  15. W. Kauzmann, Chem. Rev.43, 219 (1948)

  16. THE KAUZMANN PARADOXNN 1.0

  17. STRONG AND FRAGILE GLASS-FORMING LIQUIDS 0 1

  18. Vogel-Tamman-Fulcher equation: (D: strength) fragility index m:

  19. STRONG AND FRAGILE GLASS-FORMING LIQUIDS C. A. Angell, J. Non-Cryst. Solids 102, 205 (1988)

  20. [I. Chang and H. Sillescu] Stokes-Einstein equation: [A. Einstein, Annalen der Physik 17, 549 (1905)]

  21. B2O3 v  o-terphenyl H

More Related