Paper Number
PM10
Session
Polymer Melts: From Molecular Rheology to Processing
Title
Mobility of polymer-tethered nanoparticles in unentangled polymer melts
Presentation Date and Time
October 16, 2018 (Tuesday) 3:45
Track / Room
Track 2 / Plaza I
Authors
- Ge, Ting (Duke University, Mechanical Engineering and Materials Science)
- Rubinstein, Michael (Duke University, Mechanical Engineering and Materials Science)
Author and Affiliation Lines
Ting Ge and Michael Rubinstein
Mechanical Engineering and Materials Science, Duke University, Durham, NC 27710
Speaker / Presenter
Ge, Ting
Text of Abstract
A scaling theory is developed for the motion of a polymer-tethered NP in an unentangled polymer melt. Both NPs tethered with a single polymer chain (tail) and with multiple chains (tails) are studied. For a single-tail NP in a polymer melt, we identify two types of scaling regimes, particle-dominated and tail-dominated regimes, depending on the NP diameter d and the size of the tail R_tail. In a particle-dominated regime, the single-tail NP motion is dominated by the bare NP, as the friction coefficient of the tail is lower than that of the less mobile particle. In a tail-dominated regime, the single-tail NP motion is dominated by the tail when the tail friction coefficient surpasses that of the particle at time scales above a crossover time. A multi-tail NP in an unentangled polymer melt is studied by considering a corresponding star polymer in the same melt. For loosely grafted tails, the boundary separating the tail-dominated and particle-dominated regions in the (d, R_tail) parameter space is similar to but shifted with respect to that for a single-tail NP. In each tail-dominated regime, the crossover time is smaller than its counterpart for a single-tail NP, resulting from enhanced effects of the multiple tails. For densely grafted tails, a multi-tail NP diffuses through the polymer melt with the hydrodynamic radius equal to the radius of the corresponding star polymer.