Tran Thi Nga, Piogé Sandie, Fontaine Laurent, Pascual Sagrario
Institut des Molécules et Matériaux du Mans, UMR 6283 CNRS-Le Mans Université, Avenue Olivier Messiaen, Le Mans Cedex, 72085, France.
Macromol Rapid Commun. 2020 Jul;41(13):e2000203. doi: 10.1002/marc.202000203. Epub 2020 Jun 5.
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.
基于聚（N-丙烯酰甘氨酰胺）（PNAGA）的氢键合上临界溶液温度（UCST）热敏纳米凝胶，通过光可逆加成-断裂链转移介导的聚合诱导自组装（光-RAFT PISA）在水分散体中合成，使用N，N'-亚甲基双丙烯酰胺作为交联剂，聚（寡聚乙二醇甲基醚丙烯酸酯）作为稳定剂和大分子链转移剂（宏观CTA）。在低温（3°C）下紫外光照射1小时内，可高效制备出具有窄多分散性的高度稳定球形纳米凝胶，直至单体完全转化。通过动态光散射和紫外可见分光光度法评估，基于PNAGA的纳米凝胶的热敏行为表现出与预期UCST行为相对应的可逆加热诱导溶胀和冷却诱导收缩。通过改变NAGA光-RAFT PISA中单体与宏观CTA的初始摩尔比和交联剂的用量，可以调节纳米凝胶的流体动力学直径、溶胀率和相变温度。
