Light-responsiveness of C12E6/polymer complexes swollen with dodecane.

Area of Science:

• Polymer Science
• Colloid and Surface Science
• Photochemistry

Background:

• Azobenzene-modified polymers (AMPs) show potential as light-responsive emulsifiers.
• Controlling emulsion properties via light offers novel applications.
• Understanding the photoresponse mechanism is crucial for optimizing performance.

Purpose of the Study:

• Investigate the association behavior of AMPs with surfactant micelles swollen with dodecane.
• Elucidate the role of dodecane and micelle size on AMPs binding and photoresponse.
• Provide insights into the mechanism of light-triggered emulsion inversion.

Main Methods:

• Dynamic Light Scattering (DLS) to determine micelle size.
• UV Spectrophotometry to monitor azobenzene conformation changes.
• Capillary Electrophoresis (CE) to analyze complex formation.

Main Results:

• Micelle size was tunable (4-8 nm radii) by varying dodecane content.
• AMPs binding to micelles is influenced by transfer energy and loop formation energy, both found to be weak.
• UV irradiation significantly reduced AMPs-surfactant association, especially in swollen micelles.

Conclusions:

• The photoresponse of AMPs/surfactant complexes is modulated by micelle composition and curvature.
• Light-induced weakening of AMPs binding is a key factor in phototriggered emulsion inversion.
• These findings support the use of AMPs for light-controlled emulsions and related colloidal systems.