Interaction between poly(ethylene glycol) and two surfactants investigated by diffusion coefficient measurements

Area of Science:

• Colloid and Surface Chemistry
• Polymer Science
• Biophysical Chemistry

Background:

• Polymer-surfactant interactions are crucial in various applications, including drug delivery and material science.
• Understanding these interactions at a molecular level informs the design of advanced functional materials.

Purpose of the Study:

• To investigate the interaction between low molecular weight poly(ethylene glycol) (PEG) and micelles of two distinct surfactants.
• To determine if PEG forms complexes with zwitterionic (C(14)DMAO) and non-ionic (C(12)E(5)) surfactant micelles.

Main Methods:

• Dynamic Light Scattering (DLS) was employed to analyze particle size and diffusion.
• Fluorescence Recovery After Pattern Photobleaching (FRAPP) was used to track the diffusion of surfactant-polymer complexes.
• Experiments utilized either an amphiphilic fluorescent probe or a fluorescent-labeled PEG molecule.

Main Results:

• FRAPP experiments confirmed that PEG forms a complex with C(14)DMAO micelles.
• Consistent diffusion coefficients were obtained using both micelle-based and polymer-based fluorescent probes, indicating complex formation.
• Similar interactions were observed between PEG and C(12)E(5) micelles.

Conclusions:

• Low molecular weight PEG interacts with both zwitterionic (C(14)DMAO) and non-ionic (C(12)E(5)) surfactant micelles in dilute solutions.
• These findings demonstrate the formation of surfactant-polymer complexes, relevant for understanding self-assembly and solution behavior.