Gkermpoura Sandra, Obiols-Rabasa Marc, Iatridi Zacharoula, Tsitsilianis Constantinos
†Department of Chemical Engineering, University of Patras, 26504 Patras, Greece.
‡Division of Physical Chemistry, Department of Chemistry, Lund University, SE-221 00 Lund, Sweden.
ACS Appl Mater Interfaces. 2015 Jun 17;7(23):12411-21. doi: 10.1021/am507587s. Epub 2015 Jan 29.
We report the rheological and structural properties of a suspension comprising poly(ethylene oxide)-polystyrene-poly(ethylene oxide) core-shell micellar nanoparticles dispersed in 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid. A liquid to soft solid transition was observed at a copolymer concentration of 10 wt % above which an elastic soft material was formed, which was composed of non-ordered jammed core-shell micellar nanoparticles. In the soft solid state, a significant reduction in the size of the nanoparticles, approaching hard sphere behavior, was observed by small-angle X-ray scattering which is attributed to compression of the soft poly(ethylene oxide) coronas. The nonvolatile ionic liquid-based glassy soft solid formed exhibited remarkable thermal stability with a melting temperature of 141 °C at 20 wt % copolymer, which renders it suitable for applications involving elevated temperatures and/or reduced pressure where water-based formulations are inappropriate.
