Methods for stability assessment of electrically conductive membranes

Area of Science:

• Materials Science
• Chemical Engineering
• Membrane Technology

Background:

• Electrically conductive membranes (ECMs) exhibit surface properties that change during operation due to passivation.
• These changes can significantly impact ECM performance, necessitating standardized quantification methods.
• Current research lacks consistent approaches to evaluate ECM stability under operational conditions.

Purpose of the Study:

• To establish three standardized methods for assessing the electrochemical, chemical, and physical stability of ECM coatings.
• To evaluate the stability of ECMs synthesized using carbon nanotubes (CNTs) and polyvinyl alcohol (PVA).
• To provide a framework for consistent performance comparisons in the ECM research field.

Main Methods:

• Electrochemical stability assessed via anodic oxidation.
• Mechanical stability quantified using surface scratch testing.
• Physical stability evaluated by measuring component leaching (PVA) during separation processes.

Main Results:

• Anodic oxidation effectively probed the electrochemical stability of ECMs.
• Scratch test depth indicated the mechanical stability of the membrane coatings.
• Quantification of PVA leaching provided insights into physical stability.

Conclusions:

• The proposed methods offer a standardized approach to assess ECM stability.
• These fundamental measurements are critical for evaluating ECMs for industrial applications (MF, UF, NF, RO).
• The methods are extendable to various types of ECMs and membrane filtration processes.