NANOITSELF · Advanced functional nanocomposites by cooperative self assembly

Advanced functional nanocomposites by cooperative self assembly

Project context and objectives The general aim of the project is to systematically study the preparation of hybrid organic-inorganic nanomaterials obtained from self-assembled surfactant systems. These hybrid nanocomposite materials may have very important technological applications in photovoltaic devices. Work performed An experimental study of phase behaviour and structure of surfactant self-assemble aggregates was carried out. Surfactant systems were selected and Sol-Gel reactions were carried out in the presence of organic compounds. Surfactant aggregates were used both as solubilisers and as structure director agents. After the reactions, hybrid organic-inorganic nanocomposites were obtained in the form of films on solid substrates. These hybrid nanomaterials were characterised from the point of view of their structural, optical and electrical properties, analysing the influence of parameters such as morphology, size and the chemical nature of the nanodomains, and their degree of ordering. Small-angle X-ray scattering (SAXS), scanning and transmission electron microscopy (SEM, TEM), and solid-state nuclear magnetic resonance (NMR) spectroscopy were used for characterisation, obtaining information of compositions, structures, and distributions of inorganic and organic materials. Cooperative self-aggregation of surfactant and inorganic species has allowed the control of structures and interactions of active components in the mesostructured hybrid organic-inorganic materials. Molecular-level differences in the interactions among the surfactant molecules, titania frameworks and conjugated polymer guest species were shown to be correlated with the macroscopic photoluminescence and photovoltaic properties in cubic mesostructured titania films containing conjugated polymers. These cubic nanostructured films of titania-surfactant-conjugated polymer exhibit fast photoluminescence decay rates and high photocurrent generation. These results have evidenced efficient electron transfer at the inorganic-organic interfaces and high photovoltaic device efficiencies. Main results Films of mesostructurally ordered conjugated polymer-titania nanocomposites have been obtained. They have been characterised and their photovoltaic properties have been evaluated. The chemical compositions and structures of these nanomaterials have shown to be very important on their photovoltaic properties. Expected final results and their potential impacts Molecular understanding of the compositions and chemical interactions at organic inorganic interfaces are shown to enable the design, synthesis and control of the photovoltaic properties of hybrid functional materials. The results provide opportunities to better control physicochemical interactions at interfaces, thereby yielding selection criteria for the design and syntheses of hybrid functional materials with improved photovoltaic properties. The potential impact can be huge, since new organic-based photovoltaic devices can become a substitute for the current silicon-based photovoltaics. Moreover, the fundamental analysis of molecular compositions and structures at organic-inorganic interfaces, and their correlations to technologically important macroscopic opto-electronic properties, are expected to be applicable to hybrid materials in general. Organic-inorganic nanocomposites may have applications in biotechnology, catalysis, separation and extraction processes, energy conversion applications, controlled release and drug delivery, among others.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз