Adsorption-desorption oscillations of nanoparticles on a honeycomb-patterned pH-responsive hydrogel surface in a closed reaction system

Phys Chem Chem Phys. 2014 Dec 14;16(46):25296-305. doi: 10.1039/c4cp03083d. Epub 2014 Oct 22.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Graphite / chemistry
  • Hydrogel, Polyethylene Glycol Dimethacrylate / chemistry*
  • Hydrogen-Ion Concentration
  • Metal Nanoparticles / chemistry*
  • Oxides / chemistry
  • Polyethylene Glycols / chemistry
  • Polymethacrylic Acids / chemistry
  • Silver / chemistry
  • Surface Properties

Substances

  • Oxides
  • Polymethacrylic Acids
  • poly(methacrylic acid-ethylene glycol)
  • Hydrogel, Polyethylene Glycol Dimethacrylate
  • Silver
  • Polyethylene Glycols
  • Graphite