Retardation and flow at the glass transition.

Area of Science:

• Physics
• Materials Science
• Chemistry

Background:

• Understanding the transition from reversible jumps to irreversible flow is crucial in materials science.
• Existing models often simplify the complex dynamics of structural changes.

Purpose of the Study:

• To model the crossover from back-and-forth jumps to no-return jumps in viscous flow.
• To characterize this transition using an ensemble of double-well potentials.

Main Methods:

• Utilizing an ensemble of double-well potentials with finite decay probability.
• Characterizing the ensemble by the Kohlrausch-exponent (β) of time-dependent response.
• Applying the model to existing shear and dielectric experimental data.

Main Results:

• Successfully modeled the transition from reversible to irreversible dynamics.
• The Kohlrausch-exponent (β) effectively describes the short-time response characteristics.
• The model shows good agreement with literature shear and dielectric data.

Conclusions:

• The double-well potential ensemble model provides a robust framework for understanding flow transitions.
• The Kohlrausch-exponent is a key parameter for quantifying this dynamic crossover.
• This approach offers insights into the behavior of various materials exhibiting viscous flow.