Surface characterization of nanostructured systems

Abstract

Publisher Summary Nanostructured systems have five different modes of aggregation: powder, aerogel, nanocrystalline film, polycrystalline film, and single crystal. This chapter deals with the surface characterization of these nanostructured systems. If one takes a 5nm typical particle and defines a surface at about 0.5 nm thickness, 50% of the volume can be defined as “surface.” The chapter bridges the gaps between the various aggregation modes and traces the development of some of the emerging collective properties. Most of the aggregation modes can be synthesized through sol-gel processing. Most of the demonstrations are confined to titanium dioxide (TiO 2 ) and barium titanate (BaTiO 3 ) aerogels and xerogels. The chapter provides schematic representation of the morphology of TiO 2 aerogels, as determined by various experimental techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), small angle neutron scattering (SANS), X-ray diffraction (XRD), BET ((Brunauer, Emmett and Teller) surface area measurements, and nitrogen absorption isotherms.