title: An ellipsometry study of silica nanoparticle layers at the water surface.
abstract: We have studied silica nanoparticle layers spread at the air/water interface. The surface pressure of the layers has been determined in a Langmuir trough via two orthogonal Wilhelmy plates. We observed significant differences in surface pressure according to the preparation protocol: layers spread then compressed or layers obtained after successive spreading steps. We also studied the two types of layers by multiple angle of incidence ellipsometry. We introduce a two-layer model which enables us to evaluate the radius of interfacial aggregates and their contact angle with the air/water interface.
authors.affiliation: Laboratoire de Physique des Solides, Université Paris-Sud, UMR CNRS 8502, Bâtiment 510, 91405 Orsay cedex, France.
authors.forename: Duyang
authors.initials: D
authors.lastname: Zang
authors.forename: Antonio
authors.initials: A
authors.lastname: Stocco
authors.forename: Dominique
authors.initials: D
authors.lastname: Langevin
authors.forename: Bingbo
authors.initials: B
authors.lastname: Wei
authors.forename: Bernard P
authors.initials: BP
authors.lastname: Binks