Roughness-Mediated SI-Fe⁰CRP for Polymer Brush Engineering toward Superior Drag Reduction

Area of Science:

• Polymer Chemistry
• Materials Science
• Surface Engineering

Background:

• Surface-initiated iron(0)-mediated controlled radical polymerization (SI-Fe⁰CRP) offers a low-toxicity, biocompatible method for fabricating polymer coatings.
• Current Fe(0)-based catalysts face limitations due to lower surface dissociation activity compared to Cu(0).

Purpose of the Study:

• To enhance the grafting rate of SI-Fe⁰CRP by modifying the iron(0) surface.
• To explore the controllability of roughness-mediated SI-Fe⁰CRP for complex polymer architectures.
• To evaluate the performance of resulting polymer coatings for marine applications.

Main Methods:

• Mechanical polishing of Fe(0) plates to alter surface roughness.
• Surface-initiated iron(0)-mediated controlled radical polymerization (SI-Fe⁰CRP) to grow polymer brushes.
• Characterization of polymer brush growth rates and properties.
• Assessment of water adhesion and drag reduction performance.

Main Results:

• Polishing the Fe(0) surface increased the polymer brush growth rate from 0.14 to 3.3 nm min^-1.
• Demonstrated precise control over polymer brush architecture, including multicompartment and triblock brushes.
• Resulting polymer coatings exhibited low water adhesion (0.097 mN) and a 52% drag reduction rate.

Conclusions:

• Surface roughness modification is an effective strategy to enhance SI-Fe⁰CRP efficiency.
• This method allows for the creation of advanced polymer brushes with tunable properties.
• The developed polymer coatings show significant potential for biocompatible marine drag reduction.