TY - JOUR
T1 - Chemical characterization of fluorinated/hydrogenated mixed monolayers grafted on gold nanoparticles
AU - Tirotta, Ilaria
AU - Calloni, Alberto
AU - Pigliacelli, Claudia
AU - Brambilla, Alberto
AU - Bussetti, Gianlorenzo
AU - Duò, Lamberto
AU - Metrangolo, Pierangelo
AU - Baldelli Bombelli, Francesca
PY - 2018/2/1
Y1 - 2018/2/1
N2 - Perfluorocarbons are omniphobic compounds as a consequence of their unique properties such as, e.g., high electronegativity, low polarizability, high ionization energy, and low surface tension. The possibility of combining such properties with the features of nanoscale materials promoted a recent upsurge in the production of fluorinated nanoparticles for application in different fields. Attainment of mixed fluorinated/hydrogenated stabilizing layers is also desired in some cases, but often the composition of the ligand mixture used in the exchange reaction is not reflected in the resulting monolayer. Thus, methodologies for determining the resulting chemical composition of the final mixed fluorinated/hydrogenated monolayers grafted on the nanoparticle (NP) surface are needed. Here we propose a combined Fourier Transform Infrared (FTIR) and X-ray Photoemission Spectroscopy (XPS) investigation for assessing the final chemical composition of a mixed monolayer of hydrogenated and fluorinated alkanethiols grafted on the surface of gold NPs obtained through two different synthetic routes. This analysis allowed the evaluation of the exchange efficiency of the two synthetic routes, and also, coupled with UV–vis studies, highlighted that the colloidal stability of the final NPs was not only dependent on the fluorinated/hydrogenated ratio but also on the chosen exchange route, which seems to influence the ligand organization on the mixed monolayer.
AB - Perfluorocarbons are omniphobic compounds as a consequence of their unique properties such as, e.g., high electronegativity, low polarizability, high ionization energy, and low surface tension. The possibility of combining such properties with the features of nanoscale materials promoted a recent upsurge in the production of fluorinated nanoparticles for application in different fields. Attainment of mixed fluorinated/hydrogenated stabilizing layers is also desired in some cases, but often the composition of the ligand mixture used in the exchange reaction is not reflected in the resulting monolayer. Thus, methodologies for determining the resulting chemical composition of the final mixed fluorinated/hydrogenated monolayers grafted on the nanoparticle (NP) surface are needed. Here we propose a combined Fourier Transform Infrared (FTIR) and X-ray Photoemission Spectroscopy (XPS) investigation for assessing the final chemical composition of a mixed monolayer of hydrogenated and fluorinated alkanethiols grafted on the surface of gold NPs obtained through two different synthetic routes. This analysis allowed the evaluation of the exchange efficiency of the two synthetic routes, and also, coupled with UV–vis studies, highlighted that the colloidal stability of the final NPs was not only dependent on the fluorinated/hydrogenated ratio but also on the chosen exchange route, which seems to influence the ligand organization on the mixed monolayer.
KW - Fluorine
KW - Gold nanoparticles
KW - Mixed monolayers
KW - Thiols
KW - XPS
UR - http://www.scopus.com/inward/record.url?scp=85039162651&partnerID=8YFLogxK
U2 - 10.1016/j.jfluchem.2017.12.014
DO - 10.1016/j.jfluchem.2017.12.014
M3 - Article
AN - SCOPUS:85039162651
SN - 0022-1139
VL - 206
SP - 99
EP - 107
JO - Journal of Fluorine Chemistry
JF - Journal of Fluorine Chemistry
ER -