Controlling gold nanoparticle stability with triggerable microgels

Mohamad Azwani Shah Mat Lazim, Melanie Bradley, Julian Eastoe

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

The interaction of a photodegradable surfactant (PS, 4- hexylphenylazosulfonate, C6PAS) with microgels (MGs) of poly(2-vinyl pyridine) (MGA) in the protonated state (pH 3) has been investigated. Electrophoretic mobility measurements confirm that negatively charged PS interacts with positively charged MGA to formmixed PS-MG complexes. This was sensed by a decrease in the effective PS-MGA charge and a switch in sign of electrophoretic mobility, from positive to negative, with increasing PS concentration. After the addition of extra positive microgels (MGB), the system undergoes coflocculation. Incident UV irradiation was used to photolyze the anionic PS, effectively eliminating the headgroups, thereby lowering the electrostatic interactions between PS and MGA microgel networks. Consequently, a reversal of MGA charge occurred, leading to electrostatic repulsions and causing the MGs to reswell and redisperse, with both MGA and MGB now being positively charged and hence stabilized against coflocculation. Extending this approach, negatively charged gold nanoparticles (AuMES) have been incorporated into the PS-MGA complexes. Atomic absorption spectroscopy (AAS) showed that 100% of the AuMES particles were recovered after coflocculation of (PS-MGA)-AuMES complexes with MGB. Furthermore, approximately 75% of the AuMES could be redispersed after UV irradiation to restabilize the dispersion. This systemprovides an interesting method for phase separation and gold nanoparticle recovery for reuse and recycling.

Original languageEnglish
Pages (from-to)11779-11783
Number of pages5
JournalLangmuir
Volume26
Issue number14
DOIs
Publication statusPublished - 20 Jul 2010
Externally publishedYes

Fingerprint

Electrophoretic mobility
Gold
Irradiation
electrostatics
gold
Nanoparticles
Atomic spectroscopy
nanoparticles
irradiation
reuse
recycling
Coulomb interactions
Absorption spectroscopy
Surface-Active Agents
Phase separation
Pyridine
Recycling
Electrostatics
pyridines
absorption spectroscopy

ASJC Scopus subject areas

  • Electrochemistry
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Materials Science(all)
  • Spectroscopy

Cite this

Controlling gold nanoparticle stability with triggerable microgels. / Mat Lazim, Mohamad Azwani Shah; Bradley, Melanie; Eastoe, Julian.

In: Langmuir, Vol. 26, No. 14, 20.07.2010, p. 11779-11783.

Research output: Contribution to journalArticle

Mat Lazim, Mohamad Azwani Shah ; Bradley, Melanie ; Eastoe, Julian. / Controlling gold nanoparticle stability with triggerable microgels. In: Langmuir. 2010 ; Vol. 26, No. 14. pp. 11779-11783.
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