Novel kinetic trapping in charged colloidal clusters due to self-induced surface charge organization

Christian L. Klix, Ken-ichiro Murata, Hajime Tanaka*, Stephen R. Williams, Alex Malins, C. Patrick Royall

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)

25 Citations (Scopus)

Abstract

Colloidal clusters are an unusual state of matter where tunable interactions enable a sufficient reduction in their degrees of freedom that their energy landscapes can become tractable - they form a playground for statistical mechanics and promise unprecedented control of structure on the submicron lengthscale. We study colloidal clusters in a system where a short-ranged polymer-induced attraction drives clustering, while a weak, long-ranged electrostatic repulsion prevents extensive aggregation. We compare experimental yields of cluster structures with theory which assumes simple addition of competing isotropic interactions between the colloids. Here we show that for clusters of size 4 <= m <= 7, the yield of minimum energy clusters is much less than expected. We attribute this to an anisotropic self-organized surface charge distribution which leads to unexpected kinetic trapping. We introduce a model for the coupling between counterions and binding sites on the colloid surface with which we interpret our findings.

Original languageEnglish
Article number2072
Number of pages6
JournalScientific Reports
Volume3
DOIs
Publication statusPublished - 25 Jun 2013

Keywords

  • ENERGY LANDSCAPES
  • POLYMER MIXTURES
  • JANUS SPHERES
  • MODEL SYSTEM
  • RANGE
  • POTENTIALS
  • PARTICLES
  • DEPLETION
  • BEHAVIOR
  • ARREST

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