Acid monolayer functionalized iron oxide nanoparticle catalysts

dc.contributor.authorIkenberry, Myles
dc.date.accessioned2014-01-27T19:20:02Z
dc.date.available2014-01-27T19:20:02Z
dc.date.graduationmonthMay
dc.date.issued2014-01-27
dc.date.published2014
dc.description.abstractSuperparamagnetic iron oxide nanoparticle functionalization is an area of intensely active research, with applications across disciplines such as biomedical science and heterogeneous catalysis. This work demonstrates the functionalization of iron oxide nanoparticles with a quasi-monolayer of 11-sulfoundecanoic acid, 10-phosphono-1-decanesulfonic acid, and 11-aminoundecanoic acid. The carboxylic and phosphonic moieties form bonds to the iron oxide particle core, while the sulfonic acid groups face outward where they are available for catalysis. The particles were characterized by thermogravimetric analysis (TGA), transmission electron microscopy (TEM), potentiometric titration, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), inductively coupled plasma optical emission spectrometry (ICP-OES), X-ray photoelectron spectrometry (XPS), and dynamic light scattering (DLS). The sulfonic acid functionalized particles were used to catalyze the hydrolysis of sucrose at 80˚C and starch at 130˚C, showing a higher activity per acid site than the traditional solid acid catalyst Amberlyst-15, and comparing well against results reported in the literature for sulfonic acid functionalized mesoporous silicas. In sucrose catalysis reactions, the phosphonic-sulfonic nanoparticles (PSNPs) were seen to be incompletely recovered by an external magnetic field, while the carboxylic-sulfonic nanoparticles (CSNPs) showed a trend of increasing activity over the first four recycle runs. Between the two sulfonic ligands, the phosphonates produced a more tightly packed monolayer, which corresponded to a higher sulfonic acid loading, lower agglomeration, lower recoverability through application of an external magnetic field, and higher activity per acid site for the hydrolysis of starch. Functionalizations with 11-aminoundecanoic acid resulted in some amine groups binding to the surfaces of iron oxide nanoparticles. This amine binding is commonly ignored in iron oxide nanoparticle syntheses and functionalizations for biomedical and catalytic applications, affecting understandings of surface charge and other material properties.
dc.description.advisorKeith L. Hohn
dc.description.degreeDoctor of Philosophy
dc.description.departmentDepartment of Chemical Engineering
dc.description.levelDoctoral
dc.description.sponsorshipKansas National Science Foundation's Experimental Program for Stimulating Competitive Research, National Science Foundation, Kansas State Center for Sustainable Energy,
dc.identifier.urihttp://hdl.handle.net/2097/17060
dc.language.isoen_US
dc.publisherKansas State University
dc.rights© the author. This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/
dc.subjectIron oxide nanoparticle
dc.subjectGreen chemistry
dc.subjectCarbohydrate hydrolysis
dc.subjectSolid acid catalyst
dc.subject.umiChemical Engineering (0542)
dc.subject.umiChemistry (0485)
dc.titleAcid monolayer functionalized iron oxide nanoparticle catalysts
dc.typeDissertation

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