Aging phenomena in polystyrene thin films

TL;DR

This study investigates aging effects in polystyrene thin films, revealing changes in capacitance related to thickness and dielectric permittivity, along with memory and rejuvenation phenomena during aging.

Contribution

It provides new insights into the aging behavior of polystyrene thin films, including the dependence on thermal history and the observation of memory and rejuvenation effects.

Findings

Real part of capacitance increases with aging time

Imaginary part of capacitance decreases with aging time

Aging effects depend on thermal history and show memory and rejuvenation

Abstract

The aging behavior is investigated for thin films of atactic polystyrene through measurements of complex electric capacitance. During isothermal aging process the real part of the electric capacitance increases with aging time, while the imaginary part decreases with aging time. This result suggests that the aging time dependence of the real and imaginary parts are mainly associated with change in thickness and dielectric permittivity, respectively. In thin films, the thickness depends on thermal history of aging even above the glass transition. Memory and `rejuvenation' effects are also observed in the thin films.