|Title||Electrostatic adsorption of hematite nanoparticles on self assembled monolayer surfaces|
|Publication Type||Journal Article|
|Year of Publication||2013|
|Authors||Lau BLT, Huang R, Madden AS|
|Journal||Journal of Nanoparticle Research|
|Keywords||Solid-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.