# Identifying the Thermal Barriers of Glass Aging via Isoconversional Analysis

## TL;DR

This paper uses isoconversional analysis to study how thermal barriers change as glasses age and approach equilibrium.

## Contribution

The study reveals that aging in glasses involves increasing thermal barriers, linked to α-relaxation at later stages.

## Key findings

- Aging kinetics involve increasing activation barriers as relaxation proceeds.
- Initial and intermediate aging stages involve lower thermal barriers than α-relaxation.
- Different mechanisms mediate glass aging at early and late stages.

## Abstract

We employ isoconversional
analysis to gain insights on aging time-dependent
thermal barriers in glasses evolving toward equilibrium. This is applied
to glasses of different natures, including small molecules and polymers.
Our analysis indicates that as relaxation proceeds, equilibration
kinetics involves increasingly larger activation barriers. The latter
equals that of the α-relaxation at the final stage of aging.
In contrast, the relatively low thermal barriers at the initial and
intermediate stages of aging indicate that mechanisms different from
the α-relaxation mediate aging in these conditions. We discuss
the nature of these mechanisms in the light of the complexity of glass
aging.