Hydrogen‐Bonding UCST‐Thermosensitive Nanogels by Direct Photo‐RAFT Polymerization‐Induced Self‐Assembly in Aqueous Dispersion

• Published in: Macromolecular rapid communications. Vol. 41; no. 13; pp. e2000203 - n/a
• Main Authors: Tran, Thi Nga, Piogé, Sandie, Fontaine, Laurent, Pascual, Sagrario
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.07.2020; Wiley-VCH Verlag
• Subjects: Acrylamide; Addition polymerization; Assembly; Bonding; Chain transfer; Chemical Sciences; Crosslinking; Dispersion; Ethylene glycol; Irradiation; Light scattering; Low temperature; Macromolecules; Molecular chains; Monomers; nanogels; N‐Acryloyl glycinamide; Organic chemistry; Phase transitions; photoinitiation; Photon correlation spectroscopy; Polydispersity; Polyethylene glycol; Polymerization; Polymers; RAFT polymerization‐induced self‐assembly; Spectrophotometry; Swelling ratio; Transition temperature; Transition temperatures; Ultraviolet radiation; RAFT polymerization-induced self-assembly; N-Acryloyl glycinamide; nanogels; photoinitiation
• ISSN: 1022-1336; 1521-3927
• DOI: 10.1002/marc.202000203

Hydrogen‐bonding upper critical solution temperature (UCST) thermosensitive nanogels based on poly(N‐acryloyl glycinamide) (PNAGA) are synthesized by photo‐reversible addition‐fragmentation chain transfer mediated polymerization‐induced self‐assembly (photo‐RAFT PISA) in aqueous dispersion using N,N′‐methylenebis(acrylamide) as crosslinker and poly(oligo(ethylene glycol) methyl ether acrylate) as both stabilizer and macromolecular chain transfer agent (macro‐CTA). Highly stable, spherical nanogels with narrow polydispersity are efficiently produced up to complete monomer conversion within 1 h under UV irradiation at low temperature (3 °C). The thermosensitive behavior of PNAGA‐based nanogels, as assessed by dynamic light scattering and UV–vis spectrophotometry, exhibits reversible heating‐induced swelling and cooling‐induced shrinking corresponding to the expected UCST behavior. The hydrodynamic diameter, swelling ratio, and phase transition temperature of nanogels can be tuned by modifying the initial molar ratio of monomer‐to‐macro‐CTA and the amount of crosslinker in the photo‐RAFT PISA of NAGA. Well‐defined hydrogen‐bonding upper critical solution temperature (UCST) thermosensitive nanogels are synthesized through a direct photo‐reversible addition‐fragmentation chain transfer mediated polymerization‐induced self‐assembly in aqueous dispersion using UV‐light irradiation. Hydrodynamic diameter, volume‐swelling ratio, and UCST transition temperature of the resulting nanogels depend on the initial molar ratio of N‐acryloyl glycinamide monomer‐to‐poly(oligo(ethylene glycol) methyl ether acrylate) macromolecular chain transfer agent and the amount of N,N′‐methylenebis(acrylamide) crosslinker.