Distinct Viscoelasticity of Nanoparticle-Tethering Polymers Revealed by Nonequilibrium Molecular Dynamics Simulations

We employed nonequilibrium molecular dynamics simulations to study viscoelastic properties of nanoparticle-tethering polymers. Effects of nanoparticle–polymer interaction and molecular architecture on the viscoelasticity are investigated. The results show that the nanoparticle-tethering polymers with attractive nanoparticle–polymer interaction exhibit enhanced storage and loss moduli relative to the homopolymers or bare nanoparticle/polymer blend. In addition, the storage and loss moduli of nanoparticle-tethering polymers can be further enhanced through tuning their molecular architectures, such as increasing the nanoparticle diameter or decreasing the polymer chain length. From the physical origin, the enhancement of dynamic moduli originates from the slowdown of polymer dynamics, which arises from the attractive nanoparticle–polymer interaction, the tethering covalent bond, and the obstacle of nanoparticles. The present work not only reveals the physical origin of distinct viscoelasticity of nanoparticle-tethering polymers, but also provides useful information for preparing advanced materials based on these organic/inorganic components