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Opportunity at National Institute of Standards and Technology (NIST)

Structure and Dynamics of Polymer Nanocomposites Investigated by Neutron Scattering

Location

NIST Center for Neutron Research

RO# Location
50.61.01.C0408 Gaithersburg, MD

Please note: This Agency only participates in the February and August reviews.

Advisers

Name E-mail Phone
Faraone, Antonio afaraone@nist.gov 301.975.5254

Description

Addition of nanoparticles into polymer matrices remarkably changes mechanical, optical, and electrical properties relative to the host polymer. These materials, referred to as polymer nanocomposites,1 are already widely applied and are presently the focus of continuous research efforts because of the potentiality they offer in terms of tunability, responsiveness, and functionality. However, a satisfactory understanding of the structural and dynamical properties of these materials at the molecular level and the relationship with the macroscopic properties, e.g. rheology, is lacking. These complex and novel systems expose fundamental features of scientific interest such as confinement and nano-structuring effects.

We use neutron scattering methods to provide unique insight onto polymer conformation and motions, ought to the nanoscale resolution of these techniques as well as to the possibility to employ deuterium substitution and contrast matching techniques. Even in the presence of a dispersed nanophase, neutron techniques allow us to measure, fundamental structural and dynamical parameters, such as the radius of gyration, the Rouse rates and the tube reptation diameter, which are connected to the rheological properties of polymers melts.2 Through these studies we aim to gain a fundamental understanding of the interplay between the microscopic properties and macroscopic behavior of polymer composites.

1 S.K. Kumar, B.C. Benicewicz, R.A. Vaia, and K.I. Winey, 50th Anniversary Perspective: Are Polymer Nanocomposites Practical for Applications? Macromolecules, 50, 714 (2017).

2 E. Senses, S.M. Ansar, C.L. Kitchens, Y. Mao, S. Narayanan, B. Natarajan, and A. Faraone, “A. Small Particle Driven Chain Disentanglements in Polymer Nanocomposites” Phys. Rev. Lett., 118, 147801 (2017).

Keywords:
Polymers; composites; nanoparticles; neutron scattering; rheology

Eligibility

Citizenship:  Open to U.S. citizens
Level:  Open to Postdoctoral applicants

Stipend

Base Stipend Travel Allotment Supplementation
$72,030.00 $3,000.00
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