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).