Title: Nonlinear Architectures Can Alter the Dynamics of Polymer–Nanoparticle Composites

Abstract

Polymer nanocomposites exhibit remarkable physical properties that are attractive for many applications. These systems have been so far investigated by using linear polymer chains; the role of polymer matrix architecture on local dynamics, bulk rheology and nanoparticle motion remains unexplored. Here, using quasielastic neutron scattering, bulk rheology and x-ray photon correlation spectroscopy, we investigated nanocomposites with spherical silica nanoparticles well dispersed in poly (ethylene oxide) matrices having different architectures (specifically linear, stars and hyperbranched). The results reveal that the mechanical reinforcement of the nanocomposites with the nonlinear polymers can be altered by orders of magnitude with respect to the conventional nanocomposite with the linear polymer. Additionally, the polymer compactness and inter-penetrability are found to play crucial roles in determining their bulk rheology. At microscopic level, average segmental dynamics is remarkably slowed down by the attractive NPs in the matrices of high degree of branching whereas no significant effect is observed in linear polymer matrix at the same NP loading. In addition, the nanoscale dynamics of particles in the compact nonlinear matrices exhibit strong decoupling from the bulk viscoelasticity, allowing their fast relaxation even at ≈ 30% by volume. These results provide an experimental evidence that macromolecular architecture is a powerfulmore » new tool for tuning the bulk rheological properties as well as the nanoscale dynamics of PNCs without the need for changing polymer molecular weight, nanoparticle size, shape, loading or dispersion state.« less

Authors:

Darvishi, Saeid ^[1]; Nazeer, Muhammad Anwaar  ^[2];

• Search DOE PAGES for author "Nazeer, Muhammad Anwaar"
• Search DOE PAGES for ORCID "0000-0002-7906-8010"

Tyagi, Madhusudan ^[3]; Zhang, Qingteng  ^[4];

• Search DOE PAGES for author "Zhang, Qingteng"
• Search DOE PAGES for ORCID "0000-0002-1600-2161"

Narayanan, Suresh ^[4]; Kizilel, Seda  ^[1];

• Search DOE PAGES for author "Kizilel, Seda"
• Search DOE PAGES for ORCID "0000-0001-9092-2698"

Senses, Erkan  ^[1]

• Search DOE PAGES for author "Senses, Erkan"
• Search DOE PAGES for ORCID "0000-0003-2593-1146"

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+ Show Author Affiliations

1. Koc University, Istanbul (Turkey)
2. Koc University, Istanbul (Turkey); National Textile University, Faisalabad (Pakistan)
3. National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States). Center for Neutron Research; Univ. of Maryland, College Park, MD (United States)
4. Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)

Publication Date:

Mon Oct 25 00:00:00 EDT 2021

Research Org.:

Argonne National Lab. (ANL), Argonne, IL (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF)

OSTI Identifier:

1868561

Grant/Contract Number:  

AC02-06CH11357; DMR-1508249

Resource Type:

Accepted Manuscript

Journal Name:

Macromolecules

Additional Journal Information:

Journal Volume: 54; Journal Issue: 21; Journal ID: ISSN 0024-9297

Publisher:

American Chemical Society

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; chain architecture; rheology; Polymer nanocomposites; interfaces; segmental dynamics