title: Multilayered composite microgels synthesized by surfactant-free seeded polymerization.
abstract: We report on a simple and rapid method to produce multilayered composite microgels. Thermosensitive microgels were synthesized by aqueous free radical precipitation polymerization using N-isopropylacrylamide (NIPAm) as a monomer. Using the microgels as cores, surfactant-free seeded polymerization of an oil-soluble monomer, glycidyl methacrylate (GMA), was carried out at 70 °C, where the microgels were highly deswollen in water. All of the oil-soluble monomers were polymerized, and the resultant polymers were attached on the pre-existing microgel cores, resulting in hard shell formation. It is worth mentioning that secondary particles of oil-soluble monomers have never been formed during the polymerization. The composite microgels were characterized by electron microscopy and dynamic light scattering. In particular, X-ray photoelectron spectroscopy (XPS) measurements revealed that the surface of the composite microgels was composed of a hydrogel layer, although microgel cores were covered by polyGMA shell. The mechanism of the trilayered composite microgel formation will be discussed.
authors.affiliation: Graduate School of Textile Science & Technology, Shinshu University, 3-15-1, Tokida, Ueda 386-8567, Japan. d_suzuki@shinshu-u.ac.jp
authors.forename: Daisuke
authors.initials: D
authors.lastname: Suzuki
authors.forename: Tomoyo
authors.initials: T
authors.lastname: Yamagata
authors.forename: Masaki
authors.initials: M
authors.lastname: Murai