Data evento: 
Venerdì, 12 Settembre, 2014 - 15:00 to 17:00

Aula Seminari - Dipartimento di Scienze di Base ed Applicate per l'Ingegneria

Titolo: Microwave characterization of polymer composites modified with nanoscale objects

Autore: Dr. Jan Obrzut

Affiliazione: Material Measurement Laboratory, National Institute of Standards and Technology

Gaithersburg, MD 20899, U.S.A.


As part of a collaborative NIST-wide nano-manufacturing program, we are developing  methods sensitive to nanoscale structure and properties, which are suitable for the manufacturing environment, and which have been rigorously validated theoretically and by detailed experimental measurements. Our objective is to develop metrologies that illuminate the extent to which morphology and functionalization by nanoscale modifiers can affect the overall response of composite materials to microwave radiation. Our research particularly focuses on determining certain collective universal transport properties of percolated networks, which have demonstrated extraordinary enhancements.  We are also concerned with how light, stress, and other environmental exposures alter these properties and the practical potential of such property measurements to anticipate material failure.

In this presentation I will describe some of our recent research results and discuss the topics mentioned above.

Non classical microwave resonant absorption from semi-continuous metallic nano-particles near percolation coverage in films that are only 7 – 10 nm thick.
Mechanisms of degradation of polymer-carbon-nanotube composite during accelerated weathering by UV radiation.  We have observed that after a certain dose of radiation, a compact, highly conducting layer of carbon nanotubes is formed on the composite surface, which shields the material from further degradation. 

I will also describe an inline, real-time, non-contact microwave measurement sensor that we are developing jointly with our industry partners to characterize the quality and electrical properties of nano-carbon engineered light-weight materials for RF, EMI and Space applications, as well as our involvement in IEC standards and in the  FP7 EU Project  for large area graphene production.

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