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The addition of solid nanoparticles to soft materials such as liquid crystals or organic polymers deeply modifies and can significantly enhance the properties of the composite material compared to the soft material alone. This project will study the effects of filling liquid crystals and polymers with nanoparticles, which result in the appearance of novel nanoscale structures, modification of physical properties such as macroscale rheology, and novel phenomena absent in the bulk material. Nematic liquid crystals filled with inorganic nanoparticles are stable dispersions that permit switching between a transparent and a scattered state, both of which are stable without external electric field. Mechanical and morphological properties in nanocomposites are affected by the alignment and orientation of the dispersed nanostructures relative to the polymer matrix, which is commonly composed of flexible polymers. Using rigid polymers, such as in a liquid crystalline polymer matrix, could provide better control of the alignment of nanorod fillers and affect the final nanocomposite's mechanical and morphological properties. We are investigating different aspects of the relationship between molecular structure and physical properties in an extremely broad frequency window by using powerful techniques such as ultra broadband dielectric spectroscopy, static light scattering, photon correlation spectroscopy, Brillouin light scattering, and Differential Scanning Calorimetry. We are also studying the phase behavior and rheological properties of nanocomposites of carbon nanotubes in a liquid crystalline polymer matrix to identify critical properties in the processing of these systems. Loading nanorods can improve mechanical properties, but as concentration increases, additional defects are introduced, creating a multidomain structure and hindering alignment of the polymer matrix. Therefore, the primary focus is on the effect of nanorod concentration on the phase behavior and dynamic viscoelastic properties. The latter will contribute to fundamental understanding of the molecular dynamics and the interactions between nanorods and rodlike polymers. Scaling arguments for rheological properties and phase transitions to be incorporated into molecular models are being sought.