The University of Massachusetts Amherst
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Electrostatic adsorption of hematite nanoparticles on self assembled monolayer surfaces

TitleElectrostatic adsorption of hematite nanoparticles on self assembled monolayer surfaces
Publication TypeJournal Article
Year of Publication2013
AuthorsLau BLT, Huang R, Madden AS
JournalJournal of Nanoparticle Research
Start Page1873
Date Published08/2013
KeywordsSolid-water interface Quartz crystal microgravimetry (QCM) Atomic force microscopy (AFM) Scanning electron microscopy (SEM)

Deposition of nanoparticles (NPs) on different environmental surfaces has important implication on their fate and transport in aquatic systems. This study quantitatively and kinetically analyzed the adsorption of hematite (α-Fe2O3) NPs (HNPs) onto self-assembled monolayer modified surfaces using QCM, AFM, and SEM. Experiments were conducted to study the immobilization of two different sizes of HNPs onto gold substrate and surfaces modified with 1-mercapto-11-undecanoic acid and cysteine. It is shown that the extent and rate of HNPs adsorption onto substrate surfaces can be modulated electrostatically. Control over the surface coverage of the adsorbed HNPs has been demonstrated by pH variation. Size-dependent adsorption kinetics was observed, with the 79 nm HNPs adsorbed 2–3 times faster than the 116 nm HNPs.