title: Adsorption-desorption oscillations of nanoparticles on a honeycomb-patterned pH-responsive hydrogel surface in a closed reaction system.
abstract: A new type of pH-responsive hydrogel surface with varying nanoparticle adsorptivities was fabricated to form a micro-patterned film. To increase its responsivity to environmental pH changes, we incorporated graphene oxide (GO) into a poly(methacrylic acid)-polyethylene glycol copolymer. Incorporating GO in the pH-responsive hydrogel significantly increased the adsorption-desorption responsivity of Ag nanoparticles on the gel surface. A pH oscillator in a closed reaction system composed of BrO3(-)-Fe(CN)6(4-)-SO3(2-) facilitated the self-oscillating adsorption-desorption of Ag nanoparticles on the GO-incorporated gel surface. The reversible adsorption-desorption of Ag nanoparticles on the patterned hydrogel surface in response to pH oscillations was determined using UV-visible spectroscopy in aqueous solution. The observed heterogeneous oscillations indicated that the adsorptivity of the gel surface can be reversibly changed on the patterned pH-responsive gel. This phenomenon is similar to various natural biological systems.
authors.affiliation: Department of Chemistry and Nanoscience and Engineering, Institute of Basic Science, Inje University, Obang 607, Gimhae City, South Korea. chemhds@inje.ac.kr.
authors.forename: Ji Ho
authors.initials: JH
authors.lastname: Jang
authors.forename: M
authors.initials: M
authors.lastname: Orbán
authors.forename: Shutao
authors.initials: S
authors.lastname: Wang
authors.forename: Do Sung
authors.initials: DS
authors.lastname: Huh
mesh_terms: D000327:Adsorption; D006108:Graphite / Q000737:chemistry; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D013499:Surface Properties
chemical_list: D010087:Oxides; D011109:Polymethacrylic Acids; C099679:poly(methacrylic acid-ethylene glycol); D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D012834:Silver; D011092:Polyethylene Glycols; D006108:Graphite