Enhancing Membrane Adhesion to Polymeric Substrates via Plasma Treatment

Area of Science:

• Materials Science
• Surface Chemistry
• Polymer Engineering

Background:

• Achieving strong adhesion between porous polymeric membranes and substrates is vital for membrane device functionality.
• Low surface energy of polymers and small membrane pore sizes hinder effective bonding and mechanical interlocking.
• Plasma treatment is a common surface modification technique, but its efficacy on nanoporous membranes is underexplored.

Purpose of the Study:

• To investigate the effectiveness of low-pressure plasma treatment in enhancing the adhesion between poly(ethersulfone) (PES) membranes and polypropylene (PP) substrates.
• To quantify the adhesion improvement using T-peel tests and imaging analysis.
• To understand the synergistic effects of chemical bonding and mechanical interlocking on interfacial adhesion.

Main Methods:

• Poly(ethersulfone) (PES) membranes with 20 nm and 200 nm pore sizes were plasma-treated along with polypropylene (PP) substrates.
• Treatment parameters included specific power, duration, and gas flow rate.
• Thermomechanical bonding was performed on treated surfaces, followed by T-peel testing and imaging analysis to quantify adhesion.

Main Results:

• Plasma treatment significantly improved adhesion between PES membranes and PP substrates for both 20 nm and 200 nm pore sizes.
• Oxygen-containing plasmas yielded the greatest adhesion enhancement.
• The adhesion improvement was substantially greater for porous membranes compared to nonporous films, highlighting the role of mechanical interlocking.

Conclusions:

• Low-pressure plasma treatment effectively enhances interfacial adhesion between porous polymeric membranes and thermoplastic substrates.
• A synergistic effect between chemical bonding and mechanical interlocking contributes to improved interfacial fracture toughness.
• This approach offers a valuable strategy for optimizing membrane bonding processes in various applications.