Applications of Sol-Gel Processing

Abstract

The applications of sol-gel-made materials have largely expanded during the two last decades and a significant span of these applications is the subject of this chapter. A first domain concerns direct applications in the sol or in the gel state. The various types of gel shaping come next. The techniques reviewed here comprise coatings and thin films, fibers, and monoliths directly obtained from gel monoliths, or from gel-derived powder packing. Many applications are more technical. The applications being first addressed here are filtration membranes, thermal and acoustic insulation, insulating windows optically transparent in the visible spectrum, antireflective coatings, Cherenkov counters, luminescent materials, and absorbent or confinement media. Next come the electric and energy storage applications such as electrodes or batteries, also in superconductivity and environmental applications. More involved applications which are briefly reviewed concern the electronic, dielectric, or piezoelectric domains. Catalysis and biocatalysis are other important fields, altogether with the neighbor fields of sensors and biosensors. Biomedical applications, in particular implants, have beneficiated from significant sol-gel developments and they deserve a dedicated sections. In all these domains, the newly designed hybrid or mesostructured materials brought some noteworthy progress and these are summarized all along the various sections of this chapter.