Adsorption of citric acid on cerium oxide nanoparticles (nanoceria) : effects of pH, surface charge and aggregation

Content Provider	Semantic Scholar
Author	Siriwardane, Induni W.
Copyright Year	2012
Abstract	Recommended Citation Siriwardane, Induni Wathsala. "Adsorption of citric acid on cerium oxide nanoparticles (nanoceria) : effects of pH, surface charge and aggregation. ii To my ever loving parents for molding their 'little girl' into a 'strong woman', who can smile at every challenge on her way iii ACKNOWLEDGMENTS Foremost I would like to express my gratitude to my supervisor, Professor Vicki University of Iowa for their kind assistance provided. A special word of thanks should be given to all present and former Grassian group members for their kind support given to me throughout this period of one and half years. Especially I would like to thank Imali Mudunkotuwa, Thilini Rupasinghe and Dr. Larissa Stebanovna for their immense support. Furthermore I would like to thank all my colleagues here at Iowa for their helping hands for me. A special word of thank should be gone to my Sri Lankan friends here at UIowa for being with me and supporting with everything throughout this period. Last but not least I would like to thank my loving husband, parents and my family for encouraging me at every moment. The emotional strength you all gave me was the giant shade behind all my achievements. iv ABSTRACT Among a large number of engineered nanomaterials, CeO 2 nanoparticles (nanoceria) are of particular interest due to their unique oxidative, optical and electrical properties. With the increasing use of this important rare-earth metal oxide nanoparticle, there is the potential for it to be released in to the environment. Surface adsorbed ligands affect the surface chemistry of nanomaterials and thereby ultimately determine their fate and transformation in the natural environment. Citric acid is a naturally abundant organic acid, which can play an important role in determining the environmental fate of nanomaterials. This study focuses on citric acid adsorption onto nanoceria for three different particle diameters of 4, 9 and 39 nm. Both the details of surface adsorption of citric acid at different pH and its impact on nanoparticle behavior are explored. Speciation of adsorbed citric acid as a function of pH is probed using ATR-FTIR measurements, whereas HPLC and X-ray photoelectron spectroscopy are used to quantify the adsorption coverage. These results show that the surface speciation of citric acid differs from that of bulk solution at all pHs studied and the coordination to the surface as well as surface coverage is a function of particle size. Nanoparticle-nanoparticle interactions and …
File Format	PDF HTM / HTML
DOI	10.17077/etd.ygd6t1ba
Alternate Webpage(s)	http://ir.uiowa.edu/cgi/viewcontent.cgi?article=3330&context=etd
Alternate Webpage(s)	https://www.mobt3ath.com/uplode/book/book-1685.pdf
Alternate Webpage(s)	https://ir.uiowa.edu/cgi/viewcontent.cgi?article=3330&context=etd
Alternate Webpage(s)	https://ir.uiowa.edu/cgi/viewcontent.cgi?article=3330&context=etd&httpsredir=1&referer=
Alternate Webpage(s)	https://doi.org/10.17077/etd.ygd6t1ba
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article