Ionic Strength Responsive Sulfonated Polystyrene Opals

Luca Nucara*, Vincenzo Piazza, Francesco Greco, Valentina Robbiano, Valentina Cappello, Mauro Gemmi, Franco Cacialli, Virgilio Mattoli

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Stimuli-responsive photonic crystals (PCs) represent an intriguing class of smart materials very promising for sensing applications. Here, selective ionic strength responsive polymeric PCs are reported. They are easily fabricated by partial sulfonation of polystyrene opals, without using toxic or expensive monomers and etching steps. The color of the resulting hydrogel-like ordered structures can be continuously shifted over the entire visible range (405-760 nm) by changing the content of ions over an extremely wide range of concentration (from about 70 μM to 4 M). The optical response is completely independent from pH and temperature, and the initial color can be fully recovered by washing the sulfonated opals with pure water. These new smart photonic materials could find important applications as ionic strength sensors for environmental monitoring as well as for healthcare screening.

Original languageEnglish
Pages (from-to)4818-4827
Number of pages10
JournalACS Applied Materials & Interfaces
Issue number5
Publication statusPublished - 8 Feb 2017
Externally publishedYes


  • colloids
  • core-shell particles
  • ionic strength sensors
  • polyelectrolytes
  • stimuli-responsive opals

ASJC Scopus subject areas

  • Materials Science(all)

Fields of Expertise

  • Advanced Materials Science

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