pH-Responsive Nanogels Generated by Polymerization-Induced Self-Assembly of a Succinate-Functional Monomer
Ruiling Du1,2, Lee A Fielding1,2
1Department of Materials, School of Natural Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
Macromolecules
|April 29, 2024
Summary
Researchers developed novel pH-responsive colloidal nanogels using a new reversible addition-fragmentation chain-transfer (RAFT)-mediated polymerization-induced self-assembly (PISA) method. These stable nanogels exhibit tunable sizes and reversible swelling in response to pH changes.
Area of Science:
- Polymer Chemistry
- Materials Science
- Nanotechnology
Background:
- pH-responsive materials are crucial for controlled release and smart applications.
- Developing novel synthesis routes for functional nanogels remains an active research area.
- Polymerization-induced self-assembly (PISA) offers a versatile platform for nanoparticle synthesis.
Purpose of the Study:
- To synthesize novel pH-responsive colloidal nanogels with tunable properties.
- To explore a new reversible addition-fragmentation chain-transfer (RAFT)-mediated aqueous emulsion PISA route.
- To investigate the pH-responsiveness and colloidal stability of the synthesized nanogels.
Main Methods:
- Synthesis of a poly(potassium 3-sulfopropyl methacrylate) (PKSPMA50) macromolecular chain-transfer agent (macro-CTA) via RAFT solution polymerization.
- Chain-extension with 2-(methacryloyloxy) ethyl succinate (MES) monomer via RAFT-mediated aqueous emulsion PISA at pH 2.
- Characterization of nanogel size, particle size distribution, pH-responsiveness, and thermal stability.
Main Results:
- Colloidal nanogels with tunable diameters (66-150 nm) and narrow particle size distributions were successfully prepared.
- The nanogels exhibited well-defined pH-responsiveness, swelling upon increasing pH.
- Nanogels demonstrated reversible size changes with pH cycling and maintained colloidal stability up to 70 °C.
Conclusions:
- A novel and efficient RAFT-mediated aqueous emulsion PISA route was established for pH-responsive nanogel synthesis.
- The synthesized nanogels offer tunable sizes and excellent pH-responsive swelling behavior.
- These nanogels show promise for applications requiring stimuli-responsive and stable colloidal systems.
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