Preparation and characterization of inverted opals

Abstract

The aims of this study were the preparation and the characterization of optical materials based on three dimensional ordered arrays of colloidal latex particles, which are also called colloidal crystals (CCs). Although these multilayered latex particles arrays do not exhibit a photonic bandgap (PBG), the fabrication and the research of the optical properties of CCs based on polymeric colloidal particles are not only useful as templates to synthesize PCs but also because, due to their composition and their structure, they could present very interesting applications, such as those derived of the interaction with light (difraction, interference, scattering, absorption, inhibition, ...), maximal packing density, maximal structural stability, maximal catalytic and reactivity inside them and the ability to create media for information storage (pre{formatted substrates), among others. Lots of different techniques and sources of knowledge contribute to develop and explain the photonic phenomena. Physicists, chemists and engineers work together in the photonic field. This interdisciplinary nature of the problem enriches it. The main ideas of polymerization and colloidal crystallization are commented in the Introduction. In chapter 1, not only modified emulsion and dispersion poly- merization techniques based in styrene and acrylate monomers, but also the surface functionalization and the purification and characterization of the colloidal latex particles synthesized are explained in detail. In chapter 2, the fabrication of 3D ordered arrays of colloidal particles by vertical deposition and sedimentation methods, and the investigation of the optical properties and crystalline structure of the colloidal crystals by spectroscopy, optical microscopy and optical diffraction techniques are explained. Finally, the conclusions of the study are reported in the last chapter.