Stimulated Transitions of Directed Nonequilibrium Self-Assemblies

Area of Science:

• Polymer Science
• Materials Science
• Chemical Engineering

Background:

• Stimulus-responsive polymers typically undergo morphological changes under varying conditions.
• Transformations triggered at constant conditions, requiring metastable states, are less explored.
• Metastable states can either relax to equilibrium or be frozen upon returning to equilibrium.

Purpose of the Study:

• To investigate triggered transformations in polymers at constant conditions.
• To explore the potential of functional nonequilibrium macromolecular systems for on-demand material property changes.
• To introduce a novel diblock copolymer system for triggered micellar transformations.

Main Methods:

• Synthesis of a diblock copolymer with hydrophilic and pressure/temperature-responsive blocks.
• Induction of micellar transformations by temperature deflection.
• Induction of micellar transformations by temporary hydrostatic pressure application.

Main Results:

• The diblock copolymer system demonstrated micellar transformations.
• Transformations were triggered by deviations from equilibrium/nonequilibrium states.
• Both temperature changes and hydrostatic pressure initiated distinct micellar behaviors.

Conclusions:

• Functional nonequilibrium macromolecular systems can achieve on-demand transformations.
• Metastable states are key to triggering polymer transformations at constant conditions.
• The introduced diblock copolymer system offers a platform for novel responsive materials.