title: Controlled release using a polymer stereocomplex capsule through the selective extraction and incorporation of one capsule shell component.
abstract: Isotactic poly(methyl methacrylate) (it-PMMA)/syndiotactic poly(methacrylic acid) (st-PMAA) stereocomplex hollow capsules were fabricated by the deposition of stereocomplex films of it-PMMA and st-PMAA on silica particles by alternate layer-by-layer assembly and the subsequent removal of the silica particles with aqueous HF. The selective extraction of st-PMAA from the it-PMMA/st-PMAA stereocomplex capsule shells was successfully carried out by immersion in a pH 6-9 aqueous solution. The incorporation of st-PMAA into the resulting porous capsule shells was performed by immersion in an acetonitrile/water (1/1) solution of st-PMAA. The controlled release of an encapsulated dye from the it-PMMA/st-PMAA hollow capsules was achieved by combining the selective extraction of st-PMAA from the capsule shells and the incorporation of st-PMAA into the resulting porous shells.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita 565-0871, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kida
authors.forename: Masataka
authors.initials: M
authors.lastname: Mouri
authors.forename: Kenta
authors.initials: K
authors.lastname: Kondo
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Akashi
mesh_terms: D002214:Capsules; D003692:Delayed-Action Preparations; D011109:Polymethacrylic Acids / Q000737:chemistry* / Q000302:isolation & purification*; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D016062:Porosity; D013237:Stereoisomerism
chemical_list: D002214:Capsules; D003692:Delayed-Action Preparations; D011109:Polymethacrylic Acids; C030613:polymethacrylic acid; D019904:Polymethyl Methacrylate