https://doi.org/10.1007/s100510050170
Thermodynamics and X-ray studies of 2-alcohol monolayers at the air water interface
1
Laboratoire de Spectrométrie Physique (UMR 5588) , Université Joseph Fourier-CNRS,
BP 87, 38402 St Martin d'Hères, France
2
Laboratoire de Physique des Solides (URA 2) ,
Université Paris-Sud, Bat. 510, 91405 Orsay Cedex,
France
3
Laboratoire de Physico-Chimie des Surfaces et Interfaces,
Institut Pierre et Marie Curie, 11
rue P. et M. Curie, 75005 Paris, France
Corresponding author: a Anne.RENAULT@ujf-grenoble.fr
Received:
11
April
1997
Revised:
18
August
1997
Accepted:
9
October
1997
Published online: 15 January 1998
We investigate monolayers of 2-alcohols (2-C9 to 2-C16) obtained by placing a drop of pure alcohol at the water surface. These alcohols are chiral molecules and we study the racemic mixtures. By ellipsometry and surface tension measurements we are able to characterize the 2D crystallization-melting transition with temperature. We find a first order transition. Using X-ray under grazing incidence we show that the racemic mixture crystallizes at 2D on a hexagonal cell. We find a parity effect on the lateral pressure at the transition and on the stability of the Bragg peak. We compare all results with those observed for 1-alcohols.
PACS: 61.10.-i – X-ray diffraction and scattering / 64.70.Dv – Solid-liquid transitions / 68.10.Cr – Surface energy (surface tension, interface tension, angle of contact, etc.)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1998