Photoinduced Proton-Transfer Polymerization: A Practical Synthetic Tool for Soft Lithography Applications

Area of Science:

• Polymer Chemistry
• Materials Science
• Photochemistry

Background:

• Fabricating micro- and nanosized polymeric patterns is crucial for advanced applications.
• Existing photopolymerization methods face limitations in versatility and control over surface properties.

Purpose of the Study:

• To develop a versatile photopolymerization method for micro- and nanosized polymeric patterns.
• To demonstrate tunable surface chemistry, including antibiofouling properties, through post-patterning modification.

Main Methods:

• Utilizing proton-transfer photopolymerization via the thiol-epoxy click reaction.
• Employing a photolabile guanidine base (diazabicycloundecene, DBU) complexed with ketoprofen.
• Inducing photodecarboxylation upon 365 nm illumination to release DBU and initiate polymerization.
• Modifying the resulting poly(β-hydroxyl thio-ether) surface chemistry via alkylation.

Main Results:

• Successful fabrication of cross-linked poly(β-hydroxyl thio-ether) micro- and nanopatterns.
• Demonstrated ability to alter surface chemistry through thio-ether linkage alkylation.
• Creation of a novel sulfonium/carboxylate-based zwitterionic motif with bromoacetic acid.
• Endowment of significant antibiofouling capacity to the micropatterns.

Conclusions:

• Proton-transfer photopolymerization offers a versatile route for micro/nanopattern fabrication.
• The developed method allows for precise control over surface functionalities.
• The zwitterionic modification provides a promising strategy for creating antibiofouling surfaces.