Degree Name
MS (Master of Science)
Program
Chemistry
Date of Award
5-2016
Committee Chair or Co-Chairs
Aleksey N. Vasiliev
Committee Members
Dane Scott, Gregory W. Bishop
Abstract
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.
Document Type
Thesis - unrestricted
Recommended Citation
Adetola, Opeyemi, "Immobilization of Heteropolyacids in Silica Gel" (2016). Electronic Theses and Dissertations. Paper 3050. https://dc.etsu.edu/etd/3050
Copyright
Copyright by the authors.
Included in
Analytical Chemistry Commons, Environmental Chemistry Commons, Materials Chemistry Commons