CHARACTERIZATION OF THE MELTING-CRYSTALLIZATION TRANSITION OF ALCOHOLMONOLAYERS AT THE AIR WATER INTERFACE BY POLARIZATION MODULATION INFRARED REFLECTION-ABSORPTION SPECTROSCOPY/

Monolayers of 1- and 2-alcohols of varying lengths have been studied a t the water surface using polarization modulation infrared reflection absorption spectroscopy, Al the melting of the monolayer, we observe f or all compounds a sudden increase of the conformational defects. In t he liquid phase the alkyl chains contain gauche defects whereas they a re all-trans in the solid phase, In addition, the chains are vertical or tilted by a few degrees with respect to the normal to the surface a nd the anchorage of molecules at the water surface is ensured by hydro gen bonding. (C) 1998 Elsevier Science B.V.