We report on on all-polymer photonic crystals having different dimensionality. One-dimensional photonic crystals i.e. Distributed Bragg Reflectors (DBR) made of cellulose acetate and ZnO-polystyrene (PS) nanocomposites or Poly(p-phenyleneoxide) (PPO) have been prepared. When such structures are exposed to solvent vapors, remarkable photonic band gap spectral shifts can be observed due to free-volume effects (in the case of ZnO:PS nanocomposite) or to the peculiar crystallization properties of PPO.[1, 2] Such findings indicate that polymer DBR can be successfully used as low cost gas sensors. A variation of the 1D DBR structure is provided by the microcavity where a layer breaking the periodicity is inserted in the middle of the DBR structure.[3] When such structural defect is made by photochromic poly[[4-pentyloxy-3’-methyl-4’(6-methacryloxyhexyloxy)]azobenzene], strong photomodulation effects can be observed upon induced photoisomerization. Such microcavities show reversible spectral shifts larger than those so far reported in inorganic systems [4] indicating the quality of both the polymer mirrors and photochromic azo derivative. Monodisperse polymer and silica microspheres with an engineered structure (surface chemistry, core-shell structure, insertion of fluorophore and/or metal nanoparticles) are used to prepare compact monolayers of spheres and artificial opals. The 2D structures, whose optical response is tuned by sphere diameter are used both as template for grazing evaporation of half-moon shaped plasmonic nanostructures as well as for their peculiar light diffraction properties. Artificial opals (3D photonic crystals) made with core-shell microspheres containing fluorescent molecules allows to observe directional enhanced light emission.[5] [1] P. Lova, et al., Phys. Status Solidi C 2014, DOI: 10.1002/pssc.201400209. [2] C. Daniel, et al., Chem. Mater. 2011, 23, 3195. [3] G. Canazza, et al., Laser Phys. Lett. 2014, 11, 035804. [4] R. Piron, et al., Appl. Phys. Lett. 2000, 77, 2461. [5] K. Sparnacci, et al., J. Nanomater. 2012, 2012, 980541
E. Bozzoni, S. Congiu, S. Gazzo, R. Knarr III, F. La Rosa, G. Manfredi, et al. (2015). Polymer Photonic Crystal Structures.
Polymer Photonic Crystal Structures
LANZI, MASSIMILIANO;ZUCCHERI, GIAMPAOLO
2015
Abstract
We report on on all-polymer photonic crystals having different dimensionality. One-dimensional photonic crystals i.e. Distributed Bragg Reflectors (DBR) made of cellulose acetate and ZnO-polystyrene (PS) nanocomposites or Poly(p-phenyleneoxide) (PPO) have been prepared. When such structures are exposed to solvent vapors, remarkable photonic band gap spectral shifts can be observed due to free-volume effects (in the case of ZnO:PS nanocomposite) or to the peculiar crystallization properties of PPO.[1, 2] Such findings indicate that polymer DBR can be successfully used as low cost gas sensors. A variation of the 1D DBR structure is provided by the microcavity where a layer breaking the periodicity is inserted in the middle of the DBR structure.[3] When such structural defect is made by photochromic poly[[4-pentyloxy-3’-methyl-4’(6-methacryloxyhexyloxy)]azobenzene], strong photomodulation effects can be observed upon induced photoisomerization. Such microcavities show reversible spectral shifts larger than those so far reported in inorganic systems [4] indicating the quality of both the polymer mirrors and photochromic azo derivative. Monodisperse polymer and silica microspheres with an engineered structure (surface chemistry, core-shell structure, insertion of fluorophore and/or metal nanoparticles) are used to prepare compact monolayers of spheres and artificial opals. The 2D structures, whose optical response is tuned by sphere diameter are used both as template for grazing evaporation of half-moon shaped plasmonic nanostructures as well as for their peculiar light diffraction properties. Artificial opals (3D photonic crystals) made with core-shell microspheres containing fluorescent molecules allows to observe directional enhanced light emission.[5] [1] P. Lova, et al., Phys. Status Solidi C 2014, DOI: 10.1002/pssc.201400209. [2] C. Daniel, et al., Chem. Mater. 2011, 23, 3195. [3] G. Canazza, et al., Laser Phys. Lett. 2014, 11, 035804. [4] R. Piron, et al., Appl. Phys. Lett. 2000, 77, 2461. [5] K. Sparnacci, et al., J. Nanomater. 2012, 2012, 980541I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
