Reactive Polymorphic Nanoparticles: Preparation via Polymerization-Induced Self-Assembly and Postsynthesis...

Area of Science:

• Polymer Chemistry
• Materials Science
• Nanotechnology

Background:

• Polymerization-induced self-assembly (PISA) is a powerful technique for creating nanostructures.
• Developing new monomers for PISA can expand the range of accessible morphologies and functionalities.
• Reactive monomers offer opportunities for post-synthesis modification of nanoparticles.

Purpose of the Study:

• To investigate the use of 2,3,4,5,6-pentafluorobenzyl methacrylate (PFBMA) as a core-forming monomer in PISA.
• To explore the synthesis of well-defined nanoparticles with tunable morphologies using PFBMA.
• To demonstrate post-synthesis modification and cross-linking of PFBMA-based nanoparticles.

Main Methods:

• Ethanolic reversible addition-fragmentation chain transfer (RAFT) dispersion polymerization.
• Chain extension of poly[poly(ethylene glycol) methyl ether methacrylate] (pPEGMA) with PFBMA.
• Post-synthesis modification of PFBMA cores via thiol-para-fluoro substitution.
• Core cross-linking of nanoparticles using dithiol.

Main Results:

• pPEGMA-pPFBMA nanoparticles formed spheres, worms, and vesicles via PISA.
• Worm phases exhibited thermo-reversible gelation and morphological transitions.
• Successful post-synthesis modification of PFBMA cores with monothiols (up to 94% conversion).
• Core cross-linking prevented nanoparticle dissociation and altered thermo-responsive behavior.

Conclusions:

• PFBMA is a versatile reactive monomer for PISA, enabling the creation of diverse nano-object morphologies.
• Post-synthesis modification and cross-linking provide pathways to stabilize and functionalize nanoparticles.
• PFBMA offers a simple route to well-defined nano-objects with retained morphologies, comparable to nonreactive monomers.