An ellipsometry study of silica nanoparticle layers at the water surface

Duyang Zang (1) , Antonio Stocco (2) , Dominique Langevin (3) , Bingbo Wei (1) , Bernard P Binks (4)

1 NPU - Northwestern Polytechnical University [Xi'an]
2 LPS - Laboratoire de Physique des Solides
3 Laboratoire de Physique des Solides
4 University of Hull [United Kingdom]

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.

Domaines: Matière Molle [cond-mat.soft]

Duyang Zang, Antonio Stocco, Dominique Langevin, Bingbo Wei, Bernard P Binks. An ellipsometry study of silica nanoparticle layers at the water surface. Physical Chemistry Chemical Physics, 2009, 11 (41), pp.9522-9. ⟨hal-00785456⟩