Regioselective Seeded Polymerization in Block Copolymer Nanoparticles: Post-Assembly Control of Colloidal Features

Area of Science:

• Colloid and Polymer Science
• Materials Chemistry
• Nanotechnology

Background:

• Post-assembly modifications are crucial for tailoring block copolymer (BCP) particle properties.
• Current methods often struggle to simultaneously control particle shape, morphology, and chemical functionality.
• Simultaneous control over these features is essential for advanced material applications.

Purpose of the Study:

• To develop a versatile method for simultaneous control over BCP particle shape, morphology, and chemical functionality.
• To adapt the concept of seeded polymerization for use in phase-separated BCP particles.
• To demonstrate regioselective monomer polymerization within specific BCP domains.

Main Methods:

• Transferring the concept of seeded polymerization to phase-separated BCP particles.
• Utilizing regioselective polymerization of monomers within distinct BCP domains.
• Demonstrating the method in striped polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) ellipsoids.

Main Results:

• Achieved regioselective polymerization of styrene within PS domains, increasing lamellar thickness up to 5-fold.
• Observed changes in particle shape, specifically an increase in aspect ratio, due to asymmetric lamellar morphology.
• Successfully introduced azide functionalities selectively into PS domains using 4-vinylbenzyl azide co-monomer.

Conclusions:

• The developed method offers a simple and versatile approach for creating multifunctional BCP colloids.
• This technique allows for simultaneous control over particle shape and chemical functionalization from a single batch of pre-formed particles.
• The regioselective polymerization strategy opens new avenues for designing complex colloidal materials.