http://matdl.org/repository/ Materials Digital Library en Fez 1.3 http://blogs.law.harvard.edu/tech/rss http://matdl.org/repository/view/matdl:207 The study of thin films on the nanometer or Ångstrom scale has a great deal of applications in materials science. Within this field, there is much interest in the interactions between organic molecules and a variety of substrates, as the mechanisms of many of these interactions are not well understood. Silicon substrates are often used to study such interactions due to the ease with which their surfaces can be chemically modified to suit an experiment. In this experiment, silicon wafers were coated with a self-assembled monolayer (SAM) of octadecyltrichlorosilane (OTS). Heptane was used to wet the surface of this new substrate. The procedure for growing these layers will be briefly described. X-ray and neutron reflectometry are powerful techniques that can elucidate the thickness and roughness of thin films. X-ray reflectometry is used in this experiment to probe these characteristics of the heptane film on the OTS layer. The behavior of such films is extremely sensitive to temperature stability, making temperature control of paramount importance in this experiment. It is critical that the temperature be stable across the substrate to ensure that the film is the uniform over the entire sample. The measures that were taken to ensure temperature stability of the sample within 1mK will be explained. The wetting behavior of heptane on OTS as a function of temperature will be examined and the results compared to those of recent ellipsometry studies of alkane wetting behavior on silane-covered silicon substrates. Thu, 21 Sep 2006 13:54:47 Jacques, Teresa