Transport of Heat, Mass and Charge in Nanostructured Materials

When materials are nanostructured in the 1-100 nm range, fundamental length scales related to transport are often crossed.  In the case of heat transport by phonons, the dominant wavelength at room temperature is typically in the 1-10 nm range.  Hence, by nanostructuring to this length scale, thermal transport can be modulated in unprecedented ways.   Here I will discuss our observations to reduce thermal conductivity below the “alloy limit” as well as reaching the upper limits of phonon conductance. What has eluded the community is the lower limit, which is likely to occur due to Anderson localization. That is the focus of our current work.

The van der Waals, electrostatic or steric forces between liquid molecules and between liquid-solid interfaces fall in the range of 1-10 nm.  When liquids are confined to these length scales, they undergo a variety of transitions that control the liquid, ionic and macromolecular transport, as well as liquid-vapor phase transitions.  This talk will discuss what we discovered in nanofluidics, which is forming the basis for new research to probe ions, solvation shells and macromolecules in nanofluidic channels.

Finally, I will discuss our current research to use a new class of oxide material for catalysis of a few redox reactions that are important in energy science. This research will also underscore the need for new experimental probes to study catalysis and surface reactions at nanoscales.