Dynamics in Polymeric Thin Films

Missouri University Of Science And Technology, Rolla MO

Investigators

Abstract

The object of the proposed research is to characterize and understand the behavior, especially the dynamics (molecular motion), of thin-film polymers on solid surfaces. Characterization of the properties of the polymers is crucial to an understanding of how various devices work. Ultimately, the properties of devices containing polymers can be improved if the behavior and their roles are understood. These determinations become even more crucial as the size of the devices, and hence the thickness of the polymer films, becomes smaller. The properties of the very-thin polymer films will be studied with a variety of techniques including, mainly, nuclear magnetic resonance spectroscopy (NMR), and also modulated differential scanning calorimetry (MDSC), Fourier-transform infra-red spectroscopy (FTIR), and other techniques. The chemical/spectroscopic results will be correlated, when possible, to physical property studies, such as the measurement of adhesion strength in thin films. The intellectual merit of the proposed research is based on the understanding of the very complex phenomena in polymer thin films. Their dynamics are difficult to quantify with many of the techniques that are applied to chemical systems because of the thinness and opacity of the surface systems. The use of these complementary techniques will give unprecedented detail to the characterization of the dynamics of adsorbed polymers, especially through the use of twodimensional exchange deuterium NMR of adsorbed polymers. The segmental dynamics of the polymer chains will be interpreted in terms of distributions of correlation times and the results of the distributions will be used to determine the state of the polymer films. The broader impact of this research lies in the impact of the research itself on the technology, education and training of students, and the transfer of this knowledge to the scientific community and the public. The work to be performed will aid device makers in designing better systems for advanced applications that include thin polymer films. These applications are in electronic materials, sensors, particle stabilization, and composites fields, to name just a few. Knowledge of how material properties, such as adhesion, vary as a function of thickness allows the prediction and, indeed, avoidance of failure of these devices. The students educated through this research will be exposed to a wide variety of experiences, often from synthesis through the measurement of mechanical properties. They will develop an invaluable interdisciplinary background that will assist in making them more effective employees in complex technological fields. The scientific community and public at-large will also benefit through the activities of the PI in professional societies focused on improving and disseminating knowledge. This includes strong components of public outreach. In addition, the PI's scientific activities will enhance his own outreach to the community through involvement in and service to the important field of education.