SI-PET-RAFT in flow: improved control over polymer brush growth

Area of Science:

• Polymer Chemistry
• Surface Science
• Materials Science

Background:

• Surface-initiated photoinduced electron transfer-reversible addition-fragmentation chain transfer (SI-PET-RAFT) is a versatile method for synthesizing polymer brushes.
• Existing SI-PET-RAFT methods have limitations in growth control and scalability.

Purpose of the Study:

• To improve control over SI-PET-RAFT polymerizations using continuous flow conditions.
• To demonstrate enhanced polymer brush growth and enable the synthesis of complex polymer architectures.

Main Methods:

• Surface-initiated photoinduced electron transfer-reversible addition-fragmentation chain transfer (SI-PET-RAFT) polymerization in a continuous flow setup.
• Characterization using X-ray photoelectron spectroscopy, ellipsometry, and atomic force microscopy (AFM).
• Single-molecule force spectroscopy for molecular weight and thickness correlation.

Main Results:

• Continuous flow SI-PET-RAFT achieved significantly prolonged linear polymer brush growth (up to 250 nm) compared to no-flow conditions (<50 nm).
• Demonstrated improved polymerization control, enabling the construction of diblock polymer brushes.
• Established a linear correlation between polymer brush molecular weight and dry thickness.

Conclusions:

• Continuous flow conditions offer superior control and scalability for SI-PET-RAFT polymerizations.
• This advancement facilitates the synthesis of well-defined polymer brushes and complex polymer structures.
• The findings provide a foundation for advanced surface modification applications.