The Optimum of Preparation and Characterization of Aerogels like Hydrophobic Titania by Ambient Pressure Drying

Abstract:

The influence of different factors in the alcogel preparation process and ambient pressure drying process on packing density of hydrophobic TiO₂ aerogel synthesized by ambient pressure drying (APD) and the optimum preparation conditions were investigated by the orthogonal test with four-factor and three-level L₉(3⁴), respectively. The morphology and structural properties of hydrophobic TiO₂ aerogels with different density were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetry (TG), N₂ adsorption-desorption measurement and Scanning Electron Microscope (SEM). The results showed that the most important factors in the preparation process for TiO₂ aerogels with low-density under ambient pressure are aging time, the volume ratio of C₂H₅OH to TBT, ethanol immersion time and hydrophobic modification time. The optimized preparation conditions are that aging time is 24 h, the volume ratio of C₂H₅OH to TBT is (7+7) : 5, the volume ratio of H₂O to TBT is 1.7 : 5, the volume ratio of HAc to TBT is 1.7 : 5, ethanol immersion time is 24 h, hydrophobic modification time is 48 h, hexane solvent replacement time is 24 h and the drying temperature is 393 K. TiO₂ aerogels with density of 460 kg/m³ was obtained at the optimized conditions. TiO₂ aerogel with lower density displays higher specific surface area, porosity and pore volume as well as the larger pore size.

• Periodical: Advanced Materials Research (Volumes 1120-1121)
• Pages: 264-274
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1120-1121.264
• Online since: July 2015
• Authors: Jing Chen, Bo Zhang*, Ming Quan Wei, Jun Men, Guang Wu Miao
• Keywords: Ambient Pressure Drying, Density, Orthogonal Test, Titania Aerogels

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