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PEG‐Based Microgels Formed by Visible‐Light‐Mediated Thiol‐Ene Photo‐Click Reactions
Author(s) -
Fraser Andrew K.,
Ki Chang Seok,
Lin ChienChi
Publication year - 2014
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.201300731
Subject(s) - polymerization , pulmonary surfactant , polymer chemistry , chemistry , aqueous solution , monomer , chemical engineering , aqueous two phase system , photoinitiator , solvent , ene reaction , polymer , organic chemistry , biochemistry , engineering
Step‐growth PEG‐based microgels are produced via three liquid–liquid two‐phase suspension polymerization systems: i) hexane with surfactants Span80/Tween80; ii) mineral oil with surfactant Pluronic F‐68; and iii) surfactant‐free dextran‐rich aqueous solution. Following short vortexing to create monomer droplets, microgels are polymerized by a visible‐light‐initiated thiol‐ene photo‐click reaction using eosin‐Y as the only photoinitiator. The use of hexane as the organic phase and Span‐80/Tween‐80 as the surfactants leads to PEG microgels with entrapped solvent droplets that dissolve rapidly with time. Microgels polymerized in mineral oil with surfactant Pluronic F‐68 contain no entrapped droplets and are more uniform with smaller sizes. Visible‐light‐cured step‐growth thiol‐ene microgels can also be photopolymerized in a surfactant‐free aqueous two‐phase system. The sizes of the microgels formed in aqueous phase are one order of magnitude smaller than those formed in organic solvent. Dual‐layer microgels are also prepared using two‐step thiol‐ene reactions.