title: Adsorption of alkylthiol-capped gold nanoparticles onto alkylthiol self-assembled monolayers: an SPR study.
abstract: The kinetics of alkylthiol-capped gold nanoparticle (RS/Au-NP) adsorption to alkylthiol/Au self-assembled monolayers (RS/Au-SAMs) has been studied using SPR (surface plasmon resonance) spectroscopy. Variation of the alkylthiol chain terminus (CH3, COOH) and solvent (H2O, hexane) provides insight into the relative importance of solvation energies (in the context of surface energies) and RS/Au-NP structure on adsorption kinetics. The kinetics, fitted to the Langmuir kinetic model, yield adsorption and desorption rate constants. DeltaG(ads) derived from kinetic data are compared to calculated values of work of adhesion (W(adh)), derived from the corresponding surface energies. The absence of a deltaG(ads) - W(adh) correlation arises because the measured kinetics are not reporting the approach to equilibrium and/or because there are factors (i.e., local chain packing defects, surface hydration differences, or particle-particle interactions) not accounted for in calculated W(adh) values.
authors.affiliation: Department of Chemistry and the FQRNT Center for Self-Assembled Chemical Structures, McGill University, 801 Sherbrooke St. West, Montreal, Quebec, Canada H3A 2K6.
authors.forename: Michal
authors.initials: M
authors.lastname: Goren
authors.forename: Natalie
authors.initials: N
authors.lastname: Galley
authors.forename: R Bruce
authors.initials: RB
authors.lastname: Lennox