Keggin-type aluminum nanoclusters: synthesis, structural characterization and environmental implications

• Main Author: Abeysinghe, Samangi
• Other Authors: Forbes, Tori Z.
• Format: Others
• Language: English
• Published: University of Iowa 2012
• Subjects: aluminum hydrolysis; Keggin cluster; supramolecular; X-ray diffraction; Chemistry
• Online Access: https://ir.uiowa.edu/etd/2430; https://ir.uiowa.edu/cgi/viewcontent.cgi?article=4558&context=etd

Hydrolysis products of aluminum that exist in aqueous solutions play an important role in controlling the fate and transport of contaminants and are also used for coagulants to purification of wastewater streams. Adsorption of contaminants such as heavy metals and organics are widely recognized, but the molecular level understanding of the mechanism of action has not been clearly defined. In this research we present the crystallization, structural characterization and chemical characterization of three novel Keggin-type aluminum polycations including ((Al(IDA)H2O)2(Al30O8(OH)60(H2O)22)(2,6 NDS)4(SO4)2Cl4(H2O)40) (Al32-IDA),[(Cu(H2O)2(µ2-OH)2)2(Al2(µ4-O)8(Al28(µ2-OH)50(µ3-OH)6(H2O)26(2,6-NDS)9(H2O)52]-(CuAl30) and [(Zn(NTA)H2O)2(Al(NTA)(µ2-OH)2)2(Al30(µ2-OH)54(µ3-OH)6(µ4-O)8(H2O)20(2,6-NDS)5(H2O)64]-(ZnAl32) where IDA = iminodiacetic acid, NTA- Nitrilotriacetic acid, and 2,6 NDS = 2,6 napthalene disulfonate. These compounds are the first ever reported Keggin-type aluminum species that have been functionalized with organics and heavy metal cations. Structural characterization of these compounds was done by means of single crystal X-ray diffraction along with FTIR, TGA, SEM/EDS and PXRD techniques for chemical characterization. This study provides more insight into the coagulation process and can be employed in developing optimized coagulants for enhanced water purification.