Methods of deposition and characterization of thin films of amphiphiles

Deposition of monolayers of amphiphiles has been done by allowing Langmuir layers to vertically descend (vertical descent method, VDM) slowly, followe d by soft-landing onto a substrate kept immersed in the subphase. Two types of troughs (conical and rectangular) have been used. Troughs of different dimensions and materials (Teflon and Perplex) have been used in order to as certain generality of the method. Representative results an reported here. Films of stearic acid (SA), arachidic acid (AA), L-alpha-distearoyl phospha tidyl choline (DSPC) and modified metallated porphyrin have been prepared. Ordering of the molecules has been examined using atomic force microscopy ( AFM) and fluorescence spectroscopy wherever applicable. (C) 1999 Elsevier S cience S.A. All rights reserved.