Structural and mechanical properties of dendrimer-mediated thin films

Dendrimers are three-dimensional, globular, highly branched macromolecules made up of a central core surrounded by repetitive units all enclosed by a terminal group shell. They can be synthesized with highly controllable sizes (they are monodisperse) determined by the core type, extent of branching, and nature of the end groups, in the range from a few to several tens of nm in diameter. Dendrimers also assemble into monolayers on technologically interesting substrates using simple cleaning, dipping, and rinsing procedures. In this condensed monolayer phase dendrimers can act as surfactants mediating the growth of ultraflat films, and, create novel nanomechanical, adhesive, frictional, and tribological behavior. We have recently reported on the dramatically enhanced quality (superior flatness and adhesion) of metal films deposited on dendrimer monolayers. Different tribological responses are also observed in dendrimer-mediated metal thin films. To better understand metal/dendrimer/substrate interactions and how they determine the distinct physical, mechanical, and chemical properties of the resulting dendrimer-based nanocomposites, we are examining the structure and nanomechanical response of metal films formed with and without dendrimer mediation by atomic force, lateral force, and force modulation microscopy. (c) 2005 American Vacuum Society.