  The stretching of brushes of long polymers grafted to a planar surface is
investigated byMonte Carlo simulations in the limit of very high grafting
densities, as achieved in recent experiments. The monomer density profiles are
shown to deviate considerably from the parabolic limiting form predicted by
self-consistent field theory. A rapid transition is observed from parabolic to
fully stretched polymers, characterized by a dramatic change in the end-monomer
height distribution and by a clear cross-over in the slope of the brush height
versus scaled grafting density.
