Infrared absorption studies of two different types of self-assembled monolayers: Alkanethiols deposited from aqueous solution and surface confined polymerization of polymethyl-methacrylate (PMMA) using metal overlayer attenuated total reflectance (ATR) an

This dissertation deals with the infrared spectral analysis of two different types thiol systems interacting with a gold surface to form self-assembled monolayers (SAMs). In the first study, hexanethiol was deposited from a saturated aqueous solution onto a poly-crystalline gold surface and studied with the technique of Attenuated Total Reflectance Spectroscopy (ATR). The ATR system used in this experiment is a multi-bounce system employing a zinc selenide crystal with an evaporated layer of gold deposited on it.;The second set of experiments involves characterization of polymethyl-methacrylate, (PMMA), "Polymer Brushes". Atom Transfer Radical Polymerization (ATRP) is used to directly grow polymers from a SAM of end-terminated bromopropionyl-ester thiol initiators that have been pre-assembled onto a Au (111) surface. The analysis of the polymer and initiator samples uses a different type of ATR spectroscopy, a single-bounce, hemispherical germanium crystal set-up (GATR) which is specifically designed to look at monolayer and sub-monolayer coverages of organic species on metals or semi-conductor surfaces.;For both the alkanethiol system and the Polymer Brush system, band assignments for the IR spectra are made. In the case of hexanethiol, a comparison of the CH stretching region (2800--3100 cm-1) is made against the longer chain thiol, decanethiol. The comparison of these two spectra suggest a difference in SAM environment which is consistent with what is described in the literature. Some observations concerning the stability of metal surfaces in the ATR overlayer technique are presented. For the Polymer Brush experiments a comparison of the CH stretching region of the C6 initiator vs. the C11 initiator used in this study, again shows that the longer alkyl chain and its associated inter-chain attraction energy of 5 kJ/mole, per added methylene group leads to a SAM for the C11 initiator which has a more crystalline environment than the shorter chain C6 initiator. This difference in SAM environment is found to be consistent with observations for SAM formation on Au by straight chain alkanethiolates and for variously substituted ω - n - Alkoxy - alkanethiolates, which the initiators more closely resemble.