ИСТИНА

The synthesis methods of nanomaterials mostly provide them in the form of dispersed systems. However, high surface energy and topochemical reactions in dispersed systems lead to agglomeration of nanoparticles and clusters, which significantly affects their physicochemical properties and limits their applications. We see the solution of this problem in the development of new synthesis methods that make it possible to obtain nanomaterials with stable physicochemical and structural properties. One of these areas are the porous materials and nanostructures, in which 1D or 2D nanoparticles form stable contact interfaces and combined into a 3D network. Our research was focused on the study of the following processes: 1. Low-temperature oxidation (T <300 ° C) in a humid gas environment of the surface of binary liquid metal solutions Me (Al), where Me = Hg, Ga, In, Bi, Sn, Pb; 2. The mechanism of formation and growth of highly porous monolithic 3D nanostructures consisting of aluminum oxyhydroxides (PMAO) at the liquid metal surface; 3. Evolution of the chemical composition, structure and morphology of the basic elements of the 3D structure – the nanofibrils during annealing in the temperature range 25 - 1700 °C. During high-temperature annealing monolithic 3D structure of PMOA is preserved, while the samples dimensions decreasing isotropically. The range of the density changes from ~0.02 to ~3 g / cm3, the porosity decreases from 99 to 25% and the specific surface decreases more than 100 times. We proposed a simple physical model, describing quantitatively the evolution of the 3D structure and nanofibril's morphology in the temperature range 25 - 1700 °C. Annealing of PMOA provides additional opportunities for the development of new technologies for practical use. Nanocomposites based on PMAO are a universal basis for the creating functional nanomaterials with a wide range of potential applications: nonlinear optics (photonic crystals, optical elements IR, THz, and GHz), sensor devices. There is a successful experience of using PMOA nanocomposites in photocatalysis: purification of water and air from organic pollution, photodestruction of microorganisms and bacteria.