Versatile Surface Modification of Hydrogels by Surface-Initiated, Cu⁰-Mediated Controlled Radical Polymerization

Area of Science:

• Materials Science and Engineering
• Polymer Chemistry
• Surface Science

Background:

• Hydrogel functionalization is crucial for advanced material applications.
• Existing methods for polymer brush grafting onto hydrogels can be complex or inefficient.
• Controlled radical polymerization offers precise control over polymer chain growth.

Purpose of the Study:

• To introduce and validate a novel surface-initiated controlled radical polymerization (SI-CRP) method using a copper (Cu⁰) plate.
• To demonstrate the versatility of SI-Cu⁰ CRP for grafting diverse polymer brushes onto hydrogel surfaces.
• To create functional hydrogel surfaces with tailored properties such as hydrophobicity, lubricity, and thermal responsiveness.

Main Methods:

• Utilized a copper (Cu⁰) plate in direct contact with initiator-functionalized hydrogel surfaces.
• Employed ambient conditions, a ligand, and monomer for polymerization.
• Leveraged the Cu⁰ plate's ability to consume oxygen and act as a catalyst source for rapid polymer chain growth.

Main Results:

• Successfully grafted a wide variety of polymer brushes onto hydrogel surfaces via SI-Cu⁰ CRP.
• Demonstrated the rapid growth of hydrogel-bound polymer chains under mild, ambient conditions.
• Synthesized three distinct functional hydrogel surfaces: hydrophobic, lubricious, and thermally switchable.

Conclusions:

• SI-Cu⁰ CRP is a versatile and efficient technique for hydrogel surface modification.
• The method enables the creation of advanced hydrogel materials with tunable surface properties.
• This approach holds significant potential for developing new functional biomaterials and surfaces.