Gelation via ion exchange in discotic suspensions

Phys Rev Lett. 2012 Jun 15;108(24):247802. doi: 10.1103/PhysRevLett.108.247802. Epub 2012 Jun 15.

Abstract

The phase behavior of charged disk suspensions displays a strong dependence on ionic strengths, as the interplay between excluded volume and electrostatic interactions determines the formation of glasses, gels, and liquid crystal states. The various ions in natural soil or brine, however, could present additional effects, especially considering that most platelet structures bear a momentous ion-exchange capacity. Here we observed how ion exchange modulates and controls the interaction between individual disks and leads to unconventional phase transitions from isotropic gel to nematic gel and finally to nematic liquid crystals.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Colloids / chemistry*
  • Gels / chemistry*
  • Liquid Crystals / chemistry*
  • Osmolar Concentration
  • Phase Transition
  • Quaternary Ammonium Compounds / chemistry
  • Static Electricity
  • Suspensions / chemistry*
  • Zirconium / chemistry

Substances

  • Colloids
  • Gels
  • Quaternary Ammonium Compounds
  • Suspensions
  • zirconium phosphate
  • Zirconium
  • tetrabutylammonium