Gözenekli Bazı Nano Malzemelerin Akışkan (Gaz/Sıvı) Depolama Potansiyelleri Üzerine Ar-Ge Çalışmaları

Abstract

In this thesis, the storage of fluids in porous natural and artificial nanomaterials, which have the potential to be a solution to energy storage and environmental pollution problems, which is one of the essential needs of today, is examined. Varieties of natural zeolite extracted from the Maitobinsky region of Kazakhstan, the shells of chicken, ostrich, and pigeon eggs are grown in our country, and porous metal oxide materials (SiO₂, TiO₂, MnO₂ ve CeO₂) with micro and nano-scale sizes, which are chemically synthesized at temperatures of 410-450-500 °C, were investigated within the scope of this thesis. The effects of synthesis temperature differences on metal oxide nanostructures were determined. In the first stage, the nano morphologies of the samples which have suitable morphologies for fluid storage were determined, then the H₂, CO₂, N₂, and H₂O sorption potentials of these samples were examined. As a result of the analyses, besides the 1-3D simple morphologies of the examined materials; it has been shown that they can have complex structure models such as a core-shell, fractal, and elliptical cylinder. It indicates that the porous materials focused on these studies; can have the properties of sorbing and storing methane, which is one of the main causes of global warming, carbon-based gases that play an important role in environmental pollution, and toxic chemicals (arsenic, mercury, chromium, lead, cyanide, nickel, etc.) which are found in drinking water. In addition, it has been shown by the studies carried out within the scope of this thesis that these materials can be used for energy storage and have hydrogen storage properties. In this context, the fluid-holding properties of the studied materials have been determined for the first time in the literature by X-Ray scattering (SAXS: Small Angle X-Ray Scattering and WAXS: Wide Angle X-Ray Scattering) methods, including sensitive structural findings up to the electron density difference. The amount of stored fluid in the porous structures was associated with the difference between pore and electron density, surface area changes, and visualized in three dimensions by ab-initio methods. For the first time in the literature, the fluid storage potentials of the materials were determined in the range of their radius of gyration (Rg), with the SAXS method. Accordingly, it was concluded that the natural zeolite, which was determined to be in clinoptilolite structure, had a maximum of 17.2% nitrogen, 7.1% hydrogen, and 20.7% water holding potential by volume. When the egg shells were examined similarly, it was understood that the chicken, pigeon, and ostrich egg shells had respectively 24.0 % 20,3 %, and 16.9 % max. hydrogen storage potentials by volume. Focused on TiO₂ synthesized at 410-500°C and was concluded that they have CO₂, H₂, and water vapor storage potential. The highest hydrogen storage potential was determined TiO₂ sample with 24.9% by volume, which was synthesized at 410°C. These findings were supported by Fourier Transform Infrared (FTIR) spectrometry and scanning electron microscopy (SEM) measurements at molecular and microscopic scales. As a result of these studies, structural density fluctuations for industrial applications of simultaneously examined samples could be traced with SAXS and WAXS methods. Furthermore, it was emphasized that standardization and quality studies could be carried out with this method in the production of materials and before use.