KINETICS OF SELF-ASSEMBLED SILANE MONOLAYERS AT VARIOUS TEMPERATURES - EVIDENCE OF 2D FOAM

We have observed stages in the formation of self assembled n-octadecyl trichlorosilane monolayers on silicon wafers at different temperatures using atomic force microscopy (AFM). We use the 2D phase diagram term inology to constitute the observed phases. At low temperatures: the su rface is successively covered by a gas, liquid expanded and liquid con densed phases. In this case, coexistence between the gas and liquid ex panded phases is evidenced by a foam-like pattern, comparable with the liquid expanded phase of Langmuir films with inclusion of 2D gas bubb les. Both transitions are first order. At high temperatures, only the gas -->, liquid expanded transition is observed. (C) 1998 Elsevier Sci ence S.A. All rights reserved.