Metal-Polymer and Metal-Ceramic Colloidal Building Blocks for 3d Photonic Crystals

Photonic Crystals produce an imperative technological advantage over conventional electronic technologies. Crystals possessing a photonic band gap behave like semiconductors for light, offering the possibility that they may be manipulated in ways similar to electrons. We report the synthesis, coating and assembly of sub micron colloids, coated with silver nanoparticles. The colloids were coated by means of two methods: the Physical Embedding Method and the Layer-by-Layer (LbL) method. The Physical Embedding Method aims to co-condense the colloidal shell with metal nanoparticles that adsorb on the surface. The LbL Method envolves the sequential adsorption of oppositely charged polyelectrolytes in which ZnS colloids are coated with a positive polyelectrolyte, (PDADMAC) then negatively charged metal nanoparticles followed by another coating of PDADMAC and a final coating of a negative polyelectrolyte, (PSS). Energy Dispersive X-Ray Spectroscopy, a Scanning Electron Microscope and a Zeta Sizer were used to analyze and characterize the coated colloidal particles. The results reveal that a chemical modification needs to be applied to the Layer Embedding reaction and that the LbL Method using ZnS colloids and Ag nanoparticles was successful.