Chain dynamics and nanoparticle motion in attractive polymer nanocomposites subjected to large deformations. Issue 43 (16th October 2017)

• Record Type: Journal Article
• Authors: Senses, Erkan; Tyagi, Madhusudan; Natarajan, Bharath; Narayanan, Suresh; Faraone, Antonio
• Is Part Of: Soft matter. Volume 13:Issue 43(2017)
• Page Start: 7922
• Page End: 7929
• Publication Date: 2017-10-16
• Subjects: Soft condensed matter -- Periodicals; 530.413
• DOI: 10.1039/c7sm01009e
• Languages: English
• ISSNs: 1744-683X

Abstract

Abstract : A neutron scattering investigation on polymer nanocomposites reveals shear-induced changes in segmental dynamics. Abstract : The effect of large deformation on the chain dynamics in attractive polymer nanocomposites was investigated using neutron scattering techniques. Quasi-elastic neutron backscattering measurements reveal a substantial reduction of polymer mobility in the presence of attractive, well-dispersed nanoparticles. In addition, large deformations are observed to cause a further slowing down of the Rouse rates at high particle loadings, where the interparticle spacings are slightly smaller than the chain dimensions, i.e. in the strongly confined state. No noticeable change, however, was observed for a lightly confined system. The reptation tube diameter, measured by neutron spin echo, remained unchanged after shear, suggesting that the level of chain–chain entanglements is not significantly affected. The shear-induced changes in the interparticle bridging reflect the slow nanoparticle motion measured by X-ray photon correlation spectroscopy. These results provide a first step for understanding how large shear can significantly affect the segmental motion in nanocomposites and open up new opportunities for designing mechanically responsive soft materials.