Stimuli-responsive thiol-epoxy networks with photo-switchable bulk and surface properties

Area of Science:

• Polymer Chemistry
• Materials Science
• Photochemistry

Background:

• Thiol-epoxy networks are versatile materials with tunable properties.
• Controlling material properties with light offers advanced fabrication possibilities.
• Photocleavable groups enable light-induced degradation and modification of polymer networks.

Purpose of the Study:

• To synthesize photo-responsive thiol-epoxy networks using o-nitrobenzyl chemistry.
• To demonstrate light-induced control over bulk and surface properties of these networks.
• To achieve photolithographic patterning of thiol-epoxy materials.

Main Methods:

• Synthesis of photo-responsive thiol-epoxy networks via photobase-catalyzed click chemistry.
• Incorporation of photolabile o-nitrobenzyl ester (o-NBE) groups.
• Utilizing a photolatent base and photosensitizer for temporal and spectral control of curing.
• Employing UV exposure for network degradation and surface modification.

Main Results:

• Successful synthesis of photo-responsive thiol-epoxy networks.
• Demonstrated light-induced switching of wettability, solubility, and crosslink density.
• Achieved positive tone micropatterning through photolithography.
• Localized changes in surface wettability were induced by UV exposure.

Conclusions:

• o-Nitrobenzyl chemistry provides a versatile platform for creating photo-responsive polymer networks.
• Light can be used to precisely control material properties and enable advanced patterning techniques.
• These photo-responsive networks offer potential for applications requiring tunable surface and bulk characteristics.