Hybrid microspheres with alternating layers of a polymer and metal nanoparticles

We studied the optical properties of hybrid multilayer microspheres (HMMs). We prepared multilayer particles with alternating radial layers of gold nanoparticles (NPs) and poly(methyl methacrylate) and achieved control over particle size, the thickness of particle layers, and the surface coverage of gold NPs. We showed the ability to tune the spectral characteristics of the HMMs, which was based on frequency dispersion of the dielectric constant of polymer-metal NP structures. Good agreement between experimental and theoretical extinction properties of the HMMs was obtained. In comparison with multilayer structures synthesized solely from polymers, hybrid multilayer microspheres have a larger refractive layer contrast between adjacent layers, which is important for practical applications in optoelectronic devices. Key words: hybrid polymer-inorganic materials, polymer microspheres, gold nanoparticles, optical properties, extinction spectra. On a etudie les proprietes optiques de microspheres multicouches hybrides (MMH). On a prepare les particules a multicouches comportant des couches radiales alternantes de nanoparticules (NP) d'or et de poly(methacrylate de methyle) et on a pu controler la taille des particules des couches et la surface de la couverture des nanoparticules d'or. On a pu controler les caracteristiques spectrales des microspheres multicouches hybrides en ajustant la frequence de dispersion de la constante de dielectrique des structures des nanoparticules polymere-metal. On a obtenu un bon accord entre les proprietes d'extinction experiinentales et theoriques des microspheres multicouches hybrides. Par comparaison avec les structures multicouches synthetisees uniquement a partir de polymeres, les microspheres multicouches hybrides possedent un plus grand contraste de refraction par couche entre les couches, propriete importante pour les applications pratiques dans les appareils optoelectroniques. Mots-cles : materiaux hybrides polymere-inorganique, microspheres de polymere, nanoparticules d'or, proprietes optiques, spectres d'extinction. [Traduit par la Redaction] doi: 10.1139/V09-172
Introduction Polymer microspheres with a multilayer onion-like structure possess optical properties that are useful in photonic crystals, (1-2) optical data storage, (3-4) biometrics, (5,6) and, sensing and single-particle optical limiting. [...]