Seawater-Boosting Surface-Initiated Atom Transfer Radical Polymerization for Functional Polymer Brush Engineering

Area of Science:

• Polymer Chemistry
• Materials Science
• Surface Science

Background:

• Iron-mediated surface-initiated reversible deactivation radical polymerization (Fe0 SI-RDRP) offers a low-toxicity, biocompatible route to functional polymer surfaces.
• Previous limitations in Fe0 SI-RDRP were attributed to the poor activity of iron-based catalysts, hindering widespread application.
• The development of efficient polymerization techniques is crucial for advanced materials and energy applications.

Purpose of the Study:

• To enhance the activity of iron(0)-mediated surface-initiated atom transfer radical polymerization (Fe0 SI-ATRP) using readily available reaction media.
• To investigate the efficiency and scope of Fe0 SI-ATRP in seawater for producing well-defined polymer brushes.
• To demonstrate a practical application of the synthesized polymer brushes in energy conversion devices.

Main Methods:

• Utilized iron(0)-mediated surface-initiated atom transfer radical polymerization (Fe0 SI-ATRP) with seawater as the reaction medium.
• Compared polymerization results in seawater versus deionized water.
• Synthesized tetrablock polymer brushes to demonstrate chain-end fidelity.
• Fabricated polymer-brush-gated ion-selective membranes for osmotic energy conversion.

Main Results:

• Fe0 SI-ATRP in seawater exhibited significantly enhanced activity, leading to rapid polymer brush formation (up to 31.5 nm min-1) with minimal monomer consumption.
• No polymer brush formation was observed in deionized water, highlighting the crucial role of seawater.
• The synthesized polymer brushes demonstrated excellent chain-end fidelity, enabling the creation of complex block copolymer structures.
• The fabricated ion-selective membranes achieved high power densities (5.93 W m-2) for osmotic energy conversion, surpassing benchmarks.

Conclusions:

• Seawater is an effective and simple medium for dramatically enhancing Fe0 SI-ATRP, overcoming previous catalyst limitations.
• This method provides a rapid and efficient route to well-defined polymer brushes with high chain-end fidelity.
• The developed polymer-brush-based membranes show significant promise for efficient osmotic energy conversion applications.