Insights into Photopolymerization at the Nanoscale Using Surface Plasmon Resonance Imaging

Area of Science:

• Nanofabrication
• Polymer Chemistry
• Surface Science

Background:

• Near-field photopolymerization (NFPP) utilizes surface plasmon resonance (SPR) for advanced nanofabrication.
• The evanescent wave in NFPP enables nanometer-scale control over polymer thickness.
• Real-time monitoring of NFPP processes is crucial for understanding and optimizing fabrication.

Purpose of the Study:

• To present a novel multi-spectral SPR instrument for real-time imaging of polymer growth during NFPP.
• To investigate the influence of irradiance, dye concentration, and initiator concentration on NFPP kinetics and threshold energy.
• To elucidate the role of oxygen inhibition in near-field versus far-field photopolymerization.

Main Methods:

• Development and application of a multi-spectral surface plasmon resonance instrument.
• Real-time monitoring of polymer growth with nanometer sensitivity during NFPP.
• Systematic investigation of NFPP parameters including irradiance, dye, and initiator concentrations.

Main Results:

• Achieved real-time imaging of polymer growth during NFPP with nanometer sensitivity.
• Quantified the effects of irradiance, dye, and initiator concentrations on NFPP threshold energy and kinetics.
• Demonstrated that oxygen inhibition significantly impacts near-field photopolymerization more than far-field.

Conclusions:

• The developed multi-spectral SPR instrument enables precise, real-time monitoring of NFPP.
• Understanding the kinetics and threshold energy is key to optimizing NFPP for nanofabrication.
• Oxygen inhibition is a critical factor in NFPP, requiring specific strategies for mitigation.