GHz-THz Dynamics and the Glass Transition in Polymers

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Understanding the fundamentals of molecular motions is crucial for understanding many properties of polymers from macro- to nano- scale. Among various aspects of polymer dynamics the dynamics in the GHz-THz frequency range deserves particular attention because of its importance for applications in information and communication technologies and in photonics. The GHz-THz dynamics of polymeric systems in a broad temperature range, from deep in a solid state up to deep in a liquid state, is studied in this program. Three experimental techniques, light and neutron scattering and dielectric relaxation spectroscopy, are employed. This combination provides detailed microscopic information on the fast dynamics and helps to understand its relationship with macroscopic properties of polymers. This program will advance understanding of microscopic mechanisms behind GHz-THz properties of polymeric materials and molecular motions on a nanometer scale. It will create a solid experimental basis for developments of new theoretical approaches. Expected results will have significant implications on polymer science, and in broader aspect on dynamics of complex systems, Materials Science and Physics in general, and also on Biophysics through better understanding of bio-polymers dynamics. The program includes broad collaborations with a few groups in the US and in Europe.%%%Advanced knowledge of the GHz-THz dynamics has significant impact on design and synthesis of materials for current and future communication, information and computation technologies, on developments of materials for photonic applications, and on a progress in some bio-technologies. The proposed program has also significant impact on education of specialists for future technologies through active involvement of graduate and undergraduate students in this research, developments of graduate courses. Advances in the proposed directions will impact various fields of Materials Science, Physics and Biophysics. The proposed program promotes active international cooperation and collaboration with national multi-user facilities at NIST and ANL. ***