Research Information System
Thesis Type: Postgraduate
Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey
Approval Date: 2019
Thesis Language: Turkish
Student: AYBÜKE MERVE KESİK
Supervisor: HABİBE CANAN CABBAR
Abstract:Silica aerogels are one of the most versatile materials available for technological and scientific applications because of their exceptional properties. However, as they possess polar OH groups on their surface the aerogels are moisture sensitive, which is one of the major obstacles to their large-scale commercialization. In order to solve this problem hydrophobic silica aerogels are synthesized. In this study, we aimed synthes of aerogel which have a high hydrophobicity via sol-gel method and drying at ambient pressure. Initially various surface modification agents were chosen to synthes hydrophobic aerogel. High hydrophobic properties obtained by surface modification using the trimethylchlorosilane agents with 142,25o contact angle. Then as another parameter, the acid and the base concentration was changed. Finally, to observe the effect of dimethylformamide on hydrophobicity, dimethylformamide was added in the base catalyst phase and aerogels were modified with trimethylchlorosilane. Characterization of aerogels was made. Brunauer-Emmett-Teller analyses were carried out for the measure of surface area, pore size and pore volume. The surface area values ranged from 455 m2/g to 974 m2/g. The hydrophobicity of aerogels was characterized with contact angle measurements. The contact angle values with using trimethylchlorosilane modified gels ranged from 134.89 to 142.25. Surface chemical modification of the aerogels was studied using Fourier Transform Infrared Spectroscopy, which gave information about the chemical bonding. With the Scanning Electron Microscope studies the pore and particle size and the pore characteristics were examined