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Fragility and basic process energies in vitrifying systems.

Martinez-Garcia JC, Rzoska SJ, Drozd-Rzoska A, Starzonek S, Mauro JC - Sci Rep (2015)

Bottom Line: Finding the fundamental meaning of fragility is the 'condicio sine qua' for reaching the long expected conceptual breakthrough in this domain.The limited adequacy of broadly used so far semi-empirical relationships between fragility and the activation energy is shown.Results presented remain valid for an arbitrary complex system and collective phenomena if their dynamics is described by the general super-Arrhenius relation.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Biochemistry, University of Berne, Freiestrasse 3, Berne CH-3012, Switzerland.

ABSTRACT
The concept of 'fragility' constitutes a central point of the glass transition science serving as the 'universal' metric linking previtreous dynamics of qualitatively distinct systems. Finding the fundamental meaning of fragility is the 'condicio sine qua' for reaching the long expected conceptual breakthrough in this domain. This report shows that fragility is determined by the ratio between two fundamental process energies, viz. the activation enthalpy and activation energy. The reasoning, avoiding any underlying physical model, is supported by the experimental evidence ranging from low molecular weight liquids and polymers to plastic crystals and liquid crystals. All these lead to the new general scaling plot for dynamics of arbitrary glass former. The limited adequacy of broadly used so far semi-empirical relationships between fragility and the activation energy is shown. Results presented remain valid for an arbitrary complex system and collective phenomena if their dynamics is described by the general super-Arrhenius relation.

No MeSH data available.


Related in: MedlinePlus

The experimental tests of the relationship between the ‘classical’ fragility metric m and the new metric M = ΔHa(Tg)/ΔEa(Tg) − 1.Results are for selected glass forming LMW, P, ODC and LC systems (see Table 1).
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f2: The experimental tests of the relationship between the ‘classical’ fragility metric m and the new metric M = ΔHa(Tg)/ΔEa(Tg) − 1.Results are for selected glass forming LMW, P, ODC and LC systems (see Table 1).

Mentions: The experimental confirmation of the behavior predicted by eq. (10) is given in Figure 2. It is notable that eq. (10), showing also the link of m to basic process energies, indicates also the uncertainty introduced by the prefactor τ0 or η0 in SA eq. (2). The summary of characteristics for aforementioned experimental systems is given in Table 1.


Fragility and basic process energies in vitrifying systems.

Martinez-Garcia JC, Rzoska SJ, Drozd-Rzoska A, Starzonek S, Mauro JC - Sci Rep (2015)

The experimental tests of the relationship between the ‘classical’ fragility metric m and the new metric M = ΔHa(Tg)/ΔEa(Tg) − 1.Results are for selected glass forming LMW, P, ODC and LC systems (see Table 1).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4321169&req=5

f2: The experimental tests of the relationship between the ‘classical’ fragility metric m and the new metric M = ΔHa(Tg)/ΔEa(Tg) − 1.Results are for selected glass forming LMW, P, ODC and LC systems (see Table 1).
Mentions: The experimental confirmation of the behavior predicted by eq. (10) is given in Figure 2. It is notable that eq. (10), showing also the link of m to basic process energies, indicates also the uncertainty introduced by the prefactor τ0 or η0 in SA eq. (2). The summary of characteristics for aforementioned experimental systems is given in Table 1.

Bottom Line: Finding the fundamental meaning of fragility is the 'condicio sine qua' for reaching the long expected conceptual breakthrough in this domain.The limited adequacy of broadly used so far semi-empirical relationships between fragility and the activation energy is shown.Results presented remain valid for an arbitrary complex system and collective phenomena if their dynamics is described by the general super-Arrhenius relation.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Biochemistry, University of Berne, Freiestrasse 3, Berne CH-3012, Switzerland.

ABSTRACT
The concept of 'fragility' constitutes a central point of the glass transition science serving as the 'universal' metric linking previtreous dynamics of qualitatively distinct systems. Finding the fundamental meaning of fragility is the 'condicio sine qua' for reaching the long expected conceptual breakthrough in this domain. This report shows that fragility is determined by the ratio between two fundamental process energies, viz. the activation enthalpy and activation energy. The reasoning, avoiding any underlying physical model, is supported by the experimental evidence ranging from low molecular weight liquids and polymers to plastic crystals and liquid crystals. All these lead to the new general scaling plot for dynamics of arbitrary glass former. The limited adequacy of broadly used so far semi-empirical relationships between fragility and the activation energy is shown. Results presented remain valid for an arbitrary complex system and collective phenomena if their dynamics is described by the general super-Arrhenius relation.

No MeSH data available.


Related in: MedlinePlus