skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Size-Dependent Particle Dynamics in Entangled Polymer Nanocomposites

Abstract

Polymer-grafted nanoparticles with diameter d homogeneously dispersed in entangled polymer melts with varying random coil radius R0, but fixed entanglement mesh size ae, are used to study particle motions in entangled polymers. We focus on materials in the transition region between the continuum regime (d > R0), where the classical Stokes-Einstein (S-E) equation is known to describe polymer drag on particles, and the non-continuum regime (d < ae), in which several recent studies report faster diffusion of particles than expected from continuum S-E analysis, based on the bulk polymer viscosity. Specifically, we consider dynamics of particles with sizes d ≥ ae in entangled polymers with varying molecular weight Mw in order to investigate how the transition from non-continuum to continuum dynamics occur. We take advantage of favorable enthalpic interactions between SiO2 nanoparticles tethered with PEO molecules and entangled PMMA host polymers to create model nanoparticle-polymer composites, in which spherical nanoparticles are uniformly dispersed in entangled polymers. Investigation of the particle dynamics via X-ray photon correlation spectroscopy measurements reveal a transition from fast to slow particle motion as the PMMA molecular weight is increased beyond the entanglement threshold, with a much weaker Mw dependence for Mw>Me than expected from S-E analysismore » based on bulk viscosity of entangled PMMA melts. We rationalize these observations using a simple force balance analysis around particles and find that nanoparticle motion in entangled melts can be described using a variant of the S-E analysis in which motion of particles is assumed to only disturb sub-chain entangled host segments with sizes comparable to the particle diameter.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1391685
DOE Contract Number:  
AC02-06CH11357
Resource Type:
Journal Article
Journal Name:
Langmuir
Additional Journal Information:
Journal Volume: 32; Journal Issue: 2; Journal ID: ISSN 0743-7463
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English

Citation Formats

Mangal, Rahul, Srivastava, Samanvaya, Narayanan, Suresh, and Archer, Lynden A. Size-Dependent Particle Dynamics in Entangled Polymer Nanocomposites. United States: N. p., 2016. Web. doi:10.1021/acs.langmuir.5b03311.
Mangal, Rahul, Srivastava, Samanvaya, Narayanan, Suresh, & Archer, Lynden A. Size-Dependent Particle Dynamics in Entangled Polymer Nanocomposites. United States. doi:10.1021/acs.langmuir.5b03311.
Mangal, Rahul, Srivastava, Samanvaya, Narayanan, Suresh, and Archer, Lynden A. Tue . "Size-Dependent Particle Dynamics in Entangled Polymer Nanocomposites". United States. doi:10.1021/acs.langmuir.5b03311.
@article{osti_1391685,
title = {Size-Dependent Particle Dynamics in Entangled Polymer Nanocomposites},
author = {Mangal, Rahul and Srivastava, Samanvaya and Narayanan, Suresh and Archer, Lynden A.},
abstractNote = {Polymer-grafted nanoparticles with diameter d homogeneously dispersed in entangled polymer melts with varying random coil radius R0, but fixed entanglement mesh size ae, are used to study particle motions in entangled polymers. We focus on materials in the transition region between the continuum regime (d > R0), where the classical Stokes-Einstein (S-E) equation is known to describe polymer drag on particles, and the non-continuum regime (d < ae), in which several recent studies report faster diffusion of particles than expected from continuum S-E analysis, based on the bulk polymer viscosity. Specifically, we consider dynamics of particles with sizes d ≥ ae in entangled polymers with varying molecular weight Mw in order to investigate how the transition from non-continuum to continuum dynamics occur. We take advantage of favorable enthalpic interactions between SiO2 nanoparticles tethered with PEO molecules and entangled PMMA host polymers to create model nanoparticle-polymer composites, in which spherical nanoparticles are uniformly dispersed in entangled polymers. Investigation of the particle dynamics via X-ray photon correlation spectroscopy measurements reveal a transition from fast to slow particle motion as the PMMA molecular weight is increased beyond the entanglement threshold, with a much weaker Mw dependence for Mw>Me than expected from S-E analysis based on bulk viscosity of entangled PMMA melts. We rationalize these observations using a simple force balance analysis around particles and find that nanoparticle motion in entangled melts can be described using a variant of the S-E analysis in which motion of particles is assumed to only disturb sub-chain entangled host segments with sizes comparable to the particle diameter.},
doi = {10.1021/acs.langmuir.5b03311},
journal = {Langmuir},
issn = {0743-7463},
number = 2,
volume = 32,
place = {United States},
year = {2016},
month = {1}
}