Recent scattering approaches to structure and dynamics of polymer nanocomposites

Abstract

The characterization of polymer nanocomposites on molecular length scales and timescales is a challenging task, which is also indispensable for the understanding of macroscopic material's properties. Neutron scattering is one of the techniques which are very well-suited for studying the structure and molecular motion in such soft matter systems. X-rays can also be used for the same purpose, however, with higher energy and thus a different focus on dynamics, where they are better suited for nanoparticle motion. In this mini-review, we aim at highlighting recent results in the field of polymer nanocomposites, including nanoparticle structure in various experimental systems, from model to industrial, and polymer and particle dynamics. This allows establishing the link between microscopic and macroscopic properties, in particular rheology.

Suppression of Segmental Chain Dynamics on a Particle’s Surface in Well-Dispersed Polymer Nanocomposites

“…Because of the high incoherent scattering cross section of hydrogen, quasielastic neutron scattering (QENS) , probes the single particle dynamic structure factor, S ( Q , E ), of the hydrogen atoms in the sample, providing information both on the time scale and the spatial characteristics of their motion over length scales from a few to tens of Angstroms and time scales from a few picoseconds to a few nanoseconds . Therefore, QENS was employed to gain insight on the polymer dynamics in PNCs. ,− The results of these studies show that the chain segmental dynamics progressively slow down with increasing NP content.…”

“…12,14,15 Moreover, neutron spin echo measurements have been used to propose models of the reduced mobility of the segments in the interfacial layer based on Rouse dynamics modified to account for the presence of topological constraints. 16,17 Because of the high incoherent scattering cross section of hydrogen, quasielastic neutron scattering (QENS) 18,19 probes the single particle dynamic structure factor, S(Q,E), of the hydrogen atoms in the sample, providing information both on the time scale and the spatial characteristics of their motion over length scales from a few to tens of Angstroms and time scales from a few picoseconds to a few nanoseconds. 20 Therefore, QENS was employed to gain insight on the polymer dynamics in PNCs.…”

Quantifying structure and dynamics of bound and bulk polymer in tailor-made rubber-silica nanocomposites

“…The versatility of such materials arises from the large number of tunable physico-chemical parameters at play. As shown by the recent review by Kruteva and co-workers [3], there is a vast literature on macroscopic mechanical properties and scattering studies on model systems, some of which are listed below. For polymers, the chemical nature as well as the length of the chain [4] or its conformation (linear, branched, etc .…”