Silica gels containing incorporated heteropolyacids (HPAs) were synthesized in acidic media by co-condensation of tetraethoxysilane (TEOS) with phosphotungstic or phosphomolybdic acids using sol-gel technique. Effect of the synthesis conditions on their structure and morphology was studied. Yields of modified materials were some lower as compared to non-modified silica gels. All materials were mesoporous but contained micropores in their structures. Presence of bands of Keggin’s structures in FT-IR spectra along with absence of XRD patterns of crystalline HPAs confirmed their fine incorporation into silica network. Particle sizes of modified materials were 800-1100 nm excepting for W-containing sample obtained with trimethylstearylammonium chloride. This unusual effect was attributed to stabilization of primary silica nanoparticles by interaction between surfactant and HPA. High ratio HPA/TEOS resulted in partial loss of porosity. Obtained results might be used for optimization of synthesis of effective catalysts and adsorbents containing HPAs in mesoporous structure.
Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etd-4425 |
Date | 01 May 2016 |
Creators | Adetola, Opeyemi |
Publisher | Digital Commons @ East Tennessee State University |
Source Sets | East Tennessee State University |
Language | English |
Detected Language | English |
Type | text |
Format | application/pdf |
Source | Electronic Theses and Dissertations |
Rights | Copyright by the authors. |
Page generated in 0.0131 seconds