Model for athermal enhancement of molecular mobility in solid polymers by light

Area of Science:

• Polymer Physics
• Materials Science
• Photochemistry

Background:

• Molecular motion in polymers is typically frozen below the glass transition temperature (T_{g}).
• Viscoelastic properties of polymers change dramatically near T_{g}.
• Understanding sub-T_{g} molecular dynamics is crucial for polymer applications.

Purpose of the Study:

• To develop a model explaining light-induced enhancement of molecular mobility in polymers below T_{g}.
• To propose experiments correlating light absorption with material properties.
• To investigate the mechanism of molecular mobility enhancement via photoisomerization.

Main Methods:

• Theoretical modeling of light-matter interactions in polymers.
• Experimental proposals to measure light absorption effects on polymer dynamics.
• Analysis of photoisomerization-induced changes in molecular mobility.

Main Results:

• Demonstrated a model for light-induced molecular mobility enhancement below T_{g}.
• Showed that light absorption can drastically reduce relaxation times in polymers.
• Observed significant decreases in polymer viscosity, reaching the viscous flow regime.

Conclusions:

• Light absorption, particularly through photoisomerization, provides a powerful method to control polymer dynamics below T_{g}.
• The developed model offers insights into the relationship between light absorption and material properties.
• This work paves the way for developing photosensitive polymers for light-to-mechanical energy transduction.