Enhancing surface/interface activity and wettability via trimeric surfactant-containing mixtures

Area of Science:

• Colloid and Surface Science
• Supramolecular Chemistry
• Materials Science

Background:

• Surfactant aggregation behavior is crucial for applications like detergency, emulsification, and drug delivery.
• Understanding mixed surfactant systems, especially those involving synergistic interactions, is key to optimizing performance.
• Trimeric surfactants and their combinations with other surfactant types offer unique properties due to their complex structures.

Purpose of the Study:

• To investigate the aggregation behavior and synergistic effects of a trimeric surfactant (Citric-3C12) mixed with anionic-nonionic surfactants (9-EOS/12-EOS).
• To evaluate the impact of varying molar fractions on the mixed surfactant system's properties.
• To characterize the interfacial and micellar composition and adsorption behaviors.

Main Methods:

• Surface tension measurements
• Dynamic Light Scattering (DLS)
• Zeta potential analysis
• Cryo-Transmission Electron Microscopy (Cryo-TEM)
• Ideal mixing and regular solution models

Main Results:

• Negative interaction parameters (βσ and βm) indicate strong synergistic interactions.
• Mixed systems show significantly lower surface tension and critical micelle concentration (CMC) compared to individual surfactants.
• Surfactants form vesicles above CMC, with size decreasing upon charge neutralization.
• Enhanced oil-water interfacial activity and superior wettability on hydrophobic surfaces were observed.

Conclusions:

• The combination of trimeric cationic and anionic-nonionic surfactants exhibits significant synergy driven by electrostatic, hydrophobic, and hydrogen bonding interactions.
• The mixed surfactant systems demonstrate superior interfacial adsorption and wetting properties.
• These findings suggest potential applications in areas requiring enhanced surface activity and controlled self-assembly.