A microfluidic-multiwell platform for rapid phase mapping of surfactant solutions

Area of Science:

• Physical Chemistry
• Materials Science
• Chemical Engineering

Background:

• Understanding liquid formulation phase behavior is crucial for thermodynamics and applications.
• Surfactant solutions are widely used in industry and require detailed phase characterization.

Purpose of the Study:

• To develop and validate a microfluidic platform for rapid and precise measurement of solution phase behavior and metastability.
• To enable high-throughput screening of phase diagrams for various liquid formulations.

Main Methods:

• A microfluidic platform with a stepped temperature profile using a dual Peltier module.
• Automated multiwell plate injection and optical detection for solution phase mapping.
• U-shaped microchannels for assessing transformation reversibility and metastable zone width.

Main Results:

• The platform allows precise control over cooling/heating rates and temperature excursions for reproducible screening.
• Demonstrated rapid phase mapping of micellar (L1) to liquid crystalline lamellar (Lα) phase transitions in surfactant solutions.
• Validation of results with traditional methods like optical microscopy and small-angle neutron scattering.

Conclusions:

• The microfluidic platform offers a significant advancement for characterizing phase behavior and metastability of liquid formulations.
• This technology facilitates efficient and accurate screening of phase diagrams, crucial for industrial applications of surfactants.