High-Frequency Viscoelastic Bandgaps and Thermal Transport in Organic-Inorganic Nanolaminates: Phonons Meet Mechanics

Thursday, March 7 at 3:30pm

Toomey Hall, 140
400 W. 13th St., Rolla, MO 65409

You're invited to a seminar with Dr. Pawel Keblinski, the chair of materials science and engineering at Rensselaer Polytechnic Institute, titled "High-Frequency Viscoelastic Bandgaps and Thermal Transport in Organic-Inorganic Nanolaminates: Phonons Meet Mechanics."

Abstract: Incorporating molecular nanolayers (MNLs) at inorganic interfaces offers promise for reaping unusual enhancements in fracture energy, thermal and electrical transport, as well as diffusion barrier characteristics. Using molecular dynamics simulations, we reveal that multilayering of MNL-bonded inorganic interfaces can result in high-frequency viscoelastic damping bandgaps that are tunable by the interfacial bonding characteristics. The analyses of interfacial vibrations indicate that the viscoelastic bandgap is an interfacial vibration effect that cannot be explained by weighted averages of bulk responses. Similarly, to the viscoelastic behavior, thermal transport in soft-hard nanolaminates can be tuned by the interfacial bonding. By comparing thermal conductivity of the nanolaminates with interfacial thermal conductance of corresponding individual interfaces, we concluded that thermal transport in these nanolaminates can be largely understood in terms of independent interfacial resistors connected in series. However, simulations of the propagation of individual phonons (high-frequency mechanical waves) across nanolaminates indicate rather complex multi-interface scattering process with clear interference effects – yet the interfacial thermal transport that represents an integrated contribution of all phonons behaves as if the interfaces were independent.

Biography: Dr. Pawel Keblinski received MS degree in Physics from Warsaw University in 1990 and PhD degree in Physics from Pennsylvania State University in 1995. After postdoctoral appointments at Argonne National Laboratory and Forschungszentrum Karlsruhe, Germany, he joined the faculty of the Materials Science & Engineering Department at Rensselaer Polytechnic Institute, Troy, NY. He currently serves as the Department Head. His research relies mainly on the use of classical molecular dynamics simulations to study structure-property relationships in interfacial materials, with a focus on thermal transport modeling. His work to date resulted in over 200 publications in peer-reviewed journals and associated H-index that exceeds his age. He is a recipient of a National Science Foundation Career Award, Humboldt Fellowship (Germany) and Marie Curie Fellowship (EU Commission/Poland). He is also a Fellow of the American Physical Society and Materials Research Society, and an Associate Editor of the Journal of Applied Physics.

Event Type

Meetings, Lectures and Conferences

Departments

College of Engineering and Computing, Mechanical and Aerospace Engineering

Group
Open to Public
Hashtag

#graduateseminar

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