Responsive
photonic crystals assembled from colloidal particles
have been increasingly utilized in detection and sensing devices owing
to their attractive ability to change color in response to external
conditions. Methods of semi-batch emulsifier-free emulsion and seed
copolymerization are successfully applied for the synthesis of monodisperse
submicron particles with a core/shell structure, a core being formed
by polystyrene or poly(styrene-co-methyl methacrylate) and a shell
being formed by poly(methyl methacrylate-co-butyl
acrylate). The particle shape and diameter are analyzed by the dynamic
light scattering method and scanning electron microscopy, and the
composition is investigated by ATR-FTIR spectroscopy. As shown by
scanning electron microscopy and optical spectroscopy, the thin-film
3D-ordered structures based on poly(styrene-co-methyl methacrylate)@poly(methyl
methacrylate-co-butyl acrylate) particles exhibited
the properties of photonic crystals with minimum number of defects.
For polymeric photonic crystal structures based on core/shell particles,
a pronounced solvatochromism with respect to ethanol vapor (less than
10 vol %) is observed. Moreover, the nature of the crosslinking agent
has a significant effect on the solvatochromic properties of 3D-ordered
films.