Nanoparticle motion and segmental mobility in polymer nanocomposites subjected to large shear

The effect of large deformation on mobility of nanoparticles and chain dynamics in attractive polymer nanocomposites were investigated using x-ray and neutron scattering techniques. Polymer segmental mobility, measured by QENS, reduced in presence of attractive, well-dispersed nanoparticles. After application of large deformation, the Rouse dynamics was further slowed down at high particle loadings (in strongly confined state) while no noticeable change was detected for light confinement. On a larger scale, the reptation tube diameter, measured by neutron spin echo, remained unaltered after shear, suggesting that the level of chain–chain entanglements was not significantly affected. The results suggest a shear induced de-bridging of nanoparticles via stronger adsorption of polymer on NPs with deformation. The changes at the nanoparticle-polymer interface also cause speeding up nanoparticles after shearing.