title: In situ assessment of the contact angles of nanoparticles adsorbed at fluid interfaces by multiple angle of incidence ellipsometry.
abstract: Here multiple angle of incidence ellipsometry was successfully applied to in situ assess the contact angle and surface coverage of gold nanoparticles as small as 18 nm, coated with stimuli-responsive polymers, at water-oil and water-air interfaces in the presence of NaCl and NaOH, respectively. The interfacial adsorption of the nanoparticles was found to be very slow and took days to reach a fairly low surface coverage. For water-oil interfaces, in situ nanoparticle contact angles agree with the macroscopic equilibrium contact angles of planar gold surfaces with the same polymer coatings, whilst for water-air interfaces, significant differences have been observed.
authors.affiliation: Université Montpellier 2, Laboratoire Charles Coulomb UMR 5221, F-34095, Montpellier, France. Antonio.Stocco@univ-montp2.fr.
authors.forename: Antonio
authors.initials: A
authors.lastname: Stocco
authors.forename: Ge
authors.initials: G
authors.lastname: Su
authors.forename: Maurizio
authors.initials: M
authors.lastname: Nobili
authors.forename: Martin
authors.initials: M
authors.lastname: In
authors.forename: Dayang
authors.initials: D
authors.lastname: Wang