Counterion-induced reversibly switchable transparency in smart windows

Chang Hwan Lee, Ho Sun Lim, Jooyong Kim, Jeong Ho Cho

Research output: Contribution to journalArticle

25 Citations (Scopus)


Smart windows that can reversibly alternate between extreme optical characteristics via clicking counteranions of different hydration energies were developed on glass substrates through the facile spray-casting of poly[2-(methacryloyloxy)ethyltrimethylammonium chloride-co-3-(trimethoxysilyl) propyl methacrylate]. The optical transmittance was either 90.9% or 0% over the whole spectral range when alternately immersed in solutions containing thiocyanate (SCN-) or bis(trifluoromethane)sulfonimide (TFSI -) ions, respectively. The extreme optical transitions were attributed to formation of microporous structures via the molecular aggregation of polyelectrolyte chains bearing TFSI- ions in methanol. Because the smart windows were either highly transparent toward or completely blocking of incident light upon direct counterion exchange, this kind of nanotechnology may provide a new platform for efficiently conserving on energy usage in the interior of buildings.

Original languageEnglish
Pages (from-to)7397-7403
Number of pages7
JournalACS Nano
Issue number9
Publication statusPublished - 2011 Sep 27

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'Counterion-induced reversibly switchable transparency in smart windows'. Together they form a unique fingerprint.

  • Cite this