We study coarse-grained continuum models for Langmuir monolayers by self-co
nsistent held theory and by Monte Carlo simulations. Amphiphilic molecules
are represented by stiff chains of monomers with one end grafted to a plana
r surface. In particular, we discuss the origin of successive fluid-fluid t
ransitions, the possible origin of tilt order and the factors which determi
ne the direction of tilt. (C) 1999 Elsevier Science B.V. All rights reserve
d.