Atmospheric pressure plasma graft polymerization of polyethylene glycol for hydrophilic surface modification

Overview

This solution is an atmospheric-pressure plasma graft polymerization process for applying a very thin polyethylene glycol (PEG) layer to surfaces. The surface is first activated by plasma—either dielectric barrier discharge or gliding arc, depending on the shape and size of the object—then coated with fine PEG powder and briefly exposed to plasma to initiate graft polymerization. The resulting hydrophilic surface can achieve static water contact angles of 30° or lower.

Technical specifications

How it works:

• Surface activation using atmospheric-pressure plasma (DBD or gliding arc), selected based on object geometry and scale.
• Application of very thin PEG powder coating.
• Short plasma exposure triggers graft polymerization, binding PEG to the activated surface.
• Surface properties are characterized through contact angle measurement and related testing to verify uniformity and treatment quality.

Key features and benefits:

• Achieves strongly hydrophilic surfaces with static water contact angles of 30° or less.
• Atmospheric-pressure operation avoids vacuum chambers and supports treatment of varied object shapes and sizes.
• Uses a very thin polymer coating, preserving the geometry and bulk properties of the substrate.
• Combines surface modification and characterization capabilities, enabling integrated process development.

Development considerations:

• Treatment parameters must be adapted to the surface properties, geometry, and number of specimens.
• Pretreatment conditions and PEG powder application need to be optimized for each target object.
• Final surface performance depends on polymerized layer uniformity and adhesion.

Technology readiness level

The process is at an early technology readiness level (approximately TRL 3–4). A clear hypothesis and validation plan are in place: determine pretreatment conditions, apply PEG powder, execute plasma graft polymerization, and evaluate coated objects. The next stage is systematic validation on representative parts to confirm contact angle performance and surface consistency.