title: Quantitatively modeling the equilibrium properties of thiol-decorated gold nanoparticles.
abstract: We employ a molecular mean-field theory to quantitatively understand the sizes, surfactant surface coverage, and size fluctuations of gold nanocrystals decorated with thiol surfactants of different chain lengths. Our model assumes that surfactant-coated nanoparticles are equilibrium structures. We find that packing constraints experienced by the surfactant tails are less significant for more curved (smaller) particles. This effect enables us to rationalize the experimental observations/deductions that the thiol coverage per unit area increases with decreasing particle size. The reduction of surface coverage with increasing size also explains the fact that size polydispersity increases with increasing nanoparticle size. We find that increasing the length of the surfactants results in larger nanoparticles.
authors.affiliation: Department of Chemical Engineering, Columbia University, New York, New York, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Tambasco
authors.forename: Sanat K
authors.initials: SK
authors.lastname: Kumar
authors.forename: Igal
authors.initials: I
authors.lastname: Szleifer
mesh_terms: D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008956:Models, Chemical; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: D013438:Sulfhydryl Compounds; D006046:Gold