Photoinduced phase separation and morphology control in amphiphilic dimer melts

Area of Science:

• Materials Science
• Polymer Chemistry
• Soft Matter Physics

Background:

• Amphiphilic dimer melts exhibit complex phase behavior.
• Photosensitive bonds offer a route to dynamic control over molecular interactions.

Purpose of the Study:

• Investigate phase separation kinetics in amphiphilic dimers with photosensitive bonds.
• Analyze the formation of multiscale morphologies under light-induced cycling.
• Explore potential applications in material science.

Main Methods:

• Dissipative particle dynamics (DPD) simulations.
• Quenching below critical temperature.
• Alternate light-on/light-off cycles to control bond cleavage/reformation.

Main Results:

• Light-on cleaves bonds, triggering phase separation; light-off reforms bonds, inducing mixing.
• Formation of multiscale morphologies driven by competing mixing-demixing.
• System exhibits mass fractal characteristics during off-cycles.
• Structure factor shows peaks indicating bulk morphology development.
• Length scale follows power-law growth across viscous and inertial hydrodynamic regimes.

Conclusions:

• Light-controlled reversible bond dynamics enable tunable phase separation and morphology.
• The system's dynamic behavior is crucial for creating complex structures.
• Potential applications include hydrophobic agents, melanin synthesis, and emulsion stabilization.