Layered Poly(ethylene-co-vinyl acetate)/Poly(ethylene-co-vinyl alcohol) Membranes with Enhanced Water Separation...

Area of Science:

• Materials Science
• Polymer Science
• Chemical Engineering

Background:

• Developing advanced membranes for selective separation of water and gases is crucial for industrial applications.
• Existing membranes often face challenges with selectivity, stability, or cost-effectiveness.
• Tuning membrane properties through surface modification offers a pathway to enhanced performance.

Purpose of the Study:

• To create and characterize a novel three-layered membrane with selective barrier properties.
• To investigate the influence of microstructure and surface chemistry on separation performance.
• To evaluate the potential of these membranes for water and gas separation applications.

Main Methods:

• Fabrication of a three-layered EVOH/EVA/EVOH membrane via surface hydrolysis of a dense EVA membrane.
• Characterization of membrane microstructure (amorphous EVA, semicrystalline EVOH) and surface properties.
• Measurement of gas and water permeation kinetics and selectivity at 25 °C.

Main Results:

• The three-layered membrane exhibited tunable hydrophilic/hydrophobic balance and selective barrier properties.
• High selectivity values were achieved for H2O/O2 (∼11,900) and H2O/N2 (∼48,000) due to specific polymer-water interactions.
• The membrane structure demonstrated excellent stability without delamination.

Conclusions:

• The developed three-layered EVOH/EVA/EVOH membranes possess superior selectivity for water over gases.
• The unique microstructure and tunable surface chemistry contribute to their enhanced separation capabilities.
• These membranes show significant potential for applications in food packaging and gas dehydration.