Asymmetric self-assembly of oppositely charged composite microgels and gold nanoparticles

Research output: Contribution to journalArticle


The electrostatically driven self-assembly of oppositely charged gold nanoparticles (Au NPs) and polystyrene/poly(N-isopropylacrylamide) (PS/PNIPAm) core-shell microgels (CSMs) has been investigated. The co-assembly was accomplished by addition of smaller Au NPs to CSMs in dilute conditions up to a number ratio of about 1 : 1, when the suspension is destabilized. A combination of different techniques (i.e. turbidimetric titration, electrophoretic mobility, UV-visible spectroscopy, dynamic light scattering and microscopy techniques) were used to investigate the association between the two particles and the stability of the different mixtures. Hereby we demonstrate that the size ratio between the two particles (about 4 to 1) and the asymmetric character of the association result in the formation of electrostatic hybrid complexes, analogous to dipolar colloidal molecules, which further rearrange into finite sized clusters for number ratios N(AuNPs)/N(CSMs) < 1.


  • Jerome J. Crassous
  • Pierre-Eric Millard
  • Adriana M. Mihut
  • Frank Polzer
  • Matthias Ballauff
  • Peter Schurtenberger
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Physical Chemistry
Original languageEnglish
Pages (from-to)1648-1656
JournalSoft Matter
Issue number5
Publication statusPublished - 2012
Publication categoryResearch