Reducing the γ'-Particle Size in CMSX-4 for Membrane Development

Area of Science:

• Materials Science
• Chemical Engineering
• Pharmaceutical Technology

Background:

• Premix membrane emulsification is used for lipophilic drug delivery systems.
• Current polycarbonate/polyester membranes suffer from fouling and waste.
• Nickel-based single crystalline superalloy CMSX-4 offers a fouling-resistant alternative.

Purpose of the Study:

• To optimize metallic membrane fabrication for improved droplet size distribution.
• To investigate the effect of heat treatment on CMSX-4 microstructure for membrane applications.
• To identify heat treatment parameters for controlled γ'-particle size and morphology.

Main Methods:

• Fabrication of CMSX-4 metallic membranes.
• Implementation of varied heat treatment protocols: cooling rates (water vs. air), precipitation holding time, and temperature.
• Microstructural analysis of γ/γ' phases, focusing on γ'-particle size and morphology.

Main Results:

• Air cooling promotes well-aligned, cubic γ'-particles, superior to water quenching's irregular structures.
• Reduced precipitation temperature and holding time lead to smaller γ'-particles.
• An optimal protocol yielded γ'-particles of 224 ± 52 nm with favorable morphology for membrane fabrication.

Conclusions:

• Heat treatment significantly influences CMSX-4 microstructure, impacting membrane performance.
• Air cooling and controlled precipitation offer a viable route to tune γ'-particles for enhanced metallic membranes.
• Optimized CMSX-4 membranes present a durable and efficient platform for lipophilic drug emulsification.