title: One-pot template-free synthesis of monodisperse hollow hydrogel microspheres and their resulting properties.
abstract: Monodisperse poly(methacrylic acid/ethyleneglycoldimethacrylate) (MAA/EGDMA) hollow microcapsules, which exhibit pH-responsive behavior, are prepared by diffusion of cationic surfactants and hydrophobic interaction. During the association of the negatively charged hydrogel microspheres and an oppositely charged surfactant (cetyltrimethylammonium bromide, CTA(+)B), the hydrophobic polymer-surfactant complexes that form are separated from the internal water; consequently, a hollow structure can be formed. Confocal laser scanning microscopy, UV spectro-scopy and zeta potential are employed to study the formation of the hollow structure during the diffusion of the cationic surfactant. The controlled release behavior of methylene blue as a model drug from the as-prepared poly(MAA/EGDMA) microcapsules with a hollow structure is investigated under different pH conditions. The hollow structure can be retained, even during repetitive pH changes.
authors.affiliation: Department of Chemical Engineering, College of Engineering, Hanyang University, Seoul, 133-791, Republic of Korea.
authors.forename: Hyung-Seok
authors.initials: HS
authors.lastname: Lim
authors.forename: Eunji
authors.initials: E
authors.lastname: Kwon
authors.forename: Moonjoo
authors.initials: M
authors.lastname: Lee
authors.forename: Young
authors.initials: Y
authors.lastname: Moo Lee
authors.forename: Kyung-Do
authors.initials: KD
authors.lastname: Suh
mesh_terms: D002214:Capsules; D020100:Hydrogels / Q000138:chemical synthesis* / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008689:Methacrylates / Q000737:chemistry*; D018613:Microscopy, Confocal; D008863:Microspheres; D011109:Polymethacrylic Acids / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D002214:Capsules; D020100:Hydrogels; D008689:Methacrylates; D011109:Polymethacrylic Acids; C030613:polymethacrylic acid; C004919:ethylene dimethacrylate
keywords: hollow structure; pH-responsive hydrogels; release behavior; shell thickness