Effect of sol-gel processing parameters on structure of zirconia
| Reference | Presenter | Authors (Institution) | Abstract |
|---|---|---|---|
| 17-018 | Débora Guimarães da Silva | Silva, D.G.(Federal University of Minas Gerais); Paraguay, L.F.(Federal University of Minas Gerais); Vasconcelos, W.L.(Federal University of Minas Gerais); | A lot of methods have been explored for synthesizing zirconia, including precipitation, sol-gel, thermal decomposition and hydrothermal treatment. Among these, the sol-gel method is considered to be a promising way to produce homogenous sols and gels whit modified physico-chemical properties. The present study reports the experimental results upon the effect of sol-gel parameters such as molar ratios of water () and catalyst () on the sol’s rheology and zirconia’s structure. Zirconia sols were synthesized via sol-gel process using zirconium n-propoxide as precursor, n-propanol as solvent, glacial acetic acid as a catalyst and inhibitor and deionized water for the hydrolysis. The gels were obtained after the sol solution be aged and dried at 60°C for seven days. The thermal decompositions characteristics of the gels were measured by thermogravimetric analysis (TGA) and differential scanning calorimetric analysis (DSC) in air atmosphere with a heating rate of 10°C/min from 30°C up to 900°C. The samples were calcined in air in a muffle furnace at 400°C for 20 hours with a heating rate of 1°C/min. The chemical status of zirconium in the two as-obtained powders, at 60°C and after calcination at 400°C, was analyzed by Fourier transform-infrared spectroscopy (FT-IR). The sample’s crystalline phase was characterized by an X-ray diffractometer (DRX). The morphology and porosity of final product were also studied trough scanning electron microscopy (SEM) and nitrogen adsorption/desorption measurements. The specific surface area was calculated by physisorption (SBET) and the pore size distribution was calculated by the density functional theory (DFT) method. |
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