Solubilization, microstructure, and thermodynamics of fully dilutable U-type Brij microemulsion.

Area of Science:

• Colloid and Surface Chemistry
• Physical Chemistry
• Materials Science

Background:

• Microemulsions are thermodynamically stable, isotropic liquid mixtures of oil, water, and surfactant.
• Understanding microemulsion phase behavior is crucial for applications in drug delivery, enhanced oil recovery, and nanotechnology.
• Brij 96-based U-type microemulsions offer unique properties influenced by formulation components.

Purpose of the Study:

• To characterize U-type microemulsions formed with Brij 96.
• To investigate the impact of cosurfactant type, oil chain length, and dilution on microemulsion properties.
• To elucidate the microenvironment and water solubilization behavior within these systems.

Main Methods:

• Phase behavior mapping with various oils.
• Conductivity measurements to study percolation phenomena.
• Optical microscopy for visualizing droplet and liquid crystal equilibrium.
• Absorption spectroscopy using hydrophilic and hydrophobic probes (Methyl orange, Nile red).
• Fourier Transform Infrared (FT-IR) spectroscopy to analyze water state and dissolution.

Main Results:

• Phase diagrams were established for different oil systems.
• Volume-induced conductance percolation was observed across various cosurfactants (n2-n6 alcohols).
• Energetics of alcohol transfer to the interface were quantified via the dilution method.
• Microenvironment polarity and water solubilization were analyzed using spectroscopic probes and FT-IR.

Conclusions:

• The study provides a comprehensive characterization of Brij 96-based U-type microemulsions.
• Cosurfactant and oil properties significantly influence microemulsion phase behavior and characteristics.
• The research offers valuable insights into the structure, dynamics, and water interaction within these complex fluid systems.