Conjugated polymer infiltrated silica opals and the effect of nano-confinement on the luminescent spectra

Self assembled synthetic opals composed of spheres with 200-1500nm diameters were infiltrated with poly[2-methoxy5-(20-ethylhexyloxy)-l,4- phenylenevinylene] (MEH-PPV) and Poly [(m-phenylenevinylene)-co- (2,5-dioctoxy-pphenylenevinylene)] (PmPV) which are luminescent polymers. The luminescence spectra of the polymers was blue shifted when infiltrated deep into the nano-scopic opal pores relative to the luminescence spectra from thick films of the bulk polymers. Inverse composite plastic and luminescent polymer opals were constructed resulting in a significant blue shift in the peek luminescence of MEH-PPV from 568nm for the bulk polymer to 520nm in the inverse opal structure. We found mat the majority of the blue shifting observed could be explained by the formation of isolated polymer strands within the opals. Silica spheres were coated with MEH-PPV, dispersed in H 2o and coated with polyelectrolytes which recharged and sterically stabilized the colloidal surfaces. Luminescence spectra from individual and selfassembled silica spheres coated with MEH-PPV were also blue shifted.