Oxygen-Tolerant Ab Initio Emulsion ATRP Driven by Red or Near-Infrared Light

Area of Science:

• Polymer Chemistry
• Green Chemistry
• Photochemistry

Background:

• Emulsion polymerization is a practical and eco-friendly method for polymer synthesis.
• Existing reversible deactivation radical polymerization (RDRP) in emulsion systems often requires significant surfactant or homogenization.
• Microemulsion and miniemulsion are common RDRP techniques but have limitations in scope and practicality.

Purpose of the Study:

• To develop a more practical and efficient RDRP method for emulsion polymerization.
• To demonstrate an oxygen-tolerant, light-driven emulsion ATRP system.
• To expand the applicability of RDRP in heterogeneous systems.

Main Methods:

• Utilized an ab initio emulsion atom transfer radical polymerization (ATRP) approach.
• Employed red or near-infrared (NIR) light as the driving force for polymerization.
• Used methylene blue (MB+) as a water-soluble photocatalyst, a hydrophilic initiator, and an interfacial ion-pair catalyst.

Main Results:

• Achieved highly efficient and oxygen-tolerant emulsion ATRP.
• Synthesized polymers with controlled molar masses (10,000–600,000 g/mol) and low dispersity (1.09 ≤ Đ ≤ 1.29).
• Demonstrated excellent chain-end fidelity and facile temporal control over the polymerization process.

Conclusions:

• The developed light-driven emulsion ATRP is a practical and efficient method for polymer synthesis.
• This technique overcomes limitations of previous RDRP methods in emulsion systems.
• Offers a greener and more versatile approach to controlled radical polymerization in heterogeneous media.