Multiple relaxation modes in associative polymer networks with varying connectivity

Research output: Contribution to journalArticleAcademicpeer-review

6 Citations (Scopus)

Abstract

The dynamics and mechanics of networks depend sensitively on their spatial connectivity. To explore the effect of connectivity on local network dynamics, we prepare transient polymer networks in which we systematically cut connecting bonds. We do this by creating networks formed from hydrophobically modified difunctionalized polyethylene glycol chains. These form physical gels, consisting of flowerlike micelles that are transiently cross-linked by connecting bridges. By introducing monofunctionalized chains, we can systematically reduce the number of bonds between micelles and thus lower the network connectivity, which strongly reduces the network elasticity and relaxation time. Dynamic light scattering reveals a complex relaxation dynamics that are not apparent in bulk rheology. We observe three distinct relaxation modes. First we find a fast diffusive mode that does not depend on the number of bridges and is attributed to the diffusion of micelles within a cage formed by neighboring micelles. A second, intermediate mode depends strongly on network connectivity but surprisingly is independent of the scattering vector q. We attribute this viscoelastic mode to fluctuations in local connectivity of the network. The third, slowest mode is also diffusive and is attributed to the diffusion of micelle clusters through the viscoelastic matrix. These results shed light on the microscopic dynamics in weakly interconnected transient networks.

LanguageEnglish
Article number032507
JournalPhysical Review. E, Statistical nonlinear, and soft matter physics
Volume94
Issue number3
DOIs
Publication statusPublished - 2016

Fingerprint

Micelles
Connectivity
Polymers
polymers
micelles
Network Connectivity
Local Connectivity
Dynamic Light Scattering
Network Dynamics
Cage
Rheology
Relaxation Time
Mechanics
Elasticity
Attribute
Scattering
Fluctuations
Distinct
rheology
glycols

Cite this

@article{c52ed75ba62246e3917d0a10cd72b3f4,
title = "Multiple relaxation modes in associative polymer networks with varying connectivity",
abstract = "The dynamics and mechanics of networks depend sensitively on their spatial connectivity. To explore the effect of connectivity on local network dynamics, we prepare transient polymer networks in which we systematically cut connecting bonds. We do this by creating networks formed from hydrophobically modified difunctionalized polyethylene glycol chains. These form physical gels, consisting of flowerlike micelles that are transiently cross-linked by connecting bridges. By introducing monofunctionalized chains, we can systematically reduce the number of bonds between micelles and thus lower the network connectivity, which strongly reduces the network elasticity and relaxation time. Dynamic light scattering reveals a complex relaxation dynamics that are not apparent in bulk rheology. We observe three distinct relaxation modes. First we find a fast diffusive mode that does not depend on the number of bridges and is attributed to the diffusion of micelles within a cage formed by neighboring micelles. A second, intermediate mode depends strongly on network connectivity but surprisingly is independent of the scattering vector q. We attribute this viscoelastic mode to fluctuations in local connectivity of the network. The third, slowest mode is also diffusive and is attributed to the diffusion of micelle clusters through the viscoelastic matrix. These results shed light on the microscopic dynamics in weakly interconnected transient networks.",
author = "M. Bohdan and J. Sprakel and {van der Gucht}, J.",
year = "2016",
doi = "10.1103/PhysRevE.94.032507",
language = "English",
volume = "94",
journal = "Physical Review. E, Statistical nonlinear, and soft matter physics",
issn = "1539-3755",
publisher = "American Physical Society",
number = "3",

}

Multiple relaxation modes in associative polymer networks with varying connectivity. / Bohdan, M.; Sprakel, J.; van der Gucht, J.

In: Physical Review. E, Statistical nonlinear, and soft matter physics, Vol. 94, No. 3, 032507, 2016.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Multiple relaxation modes in associative polymer networks with varying connectivity

AU - Bohdan, M.

AU - Sprakel, J.

AU - van der Gucht, J.

PY - 2016

Y1 - 2016

N2 - The dynamics and mechanics of networks depend sensitively on their spatial connectivity. To explore the effect of connectivity on local network dynamics, we prepare transient polymer networks in which we systematically cut connecting bonds. We do this by creating networks formed from hydrophobically modified difunctionalized polyethylene glycol chains. These form physical gels, consisting of flowerlike micelles that are transiently cross-linked by connecting bridges. By introducing monofunctionalized chains, we can systematically reduce the number of bonds between micelles and thus lower the network connectivity, which strongly reduces the network elasticity and relaxation time. Dynamic light scattering reveals a complex relaxation dynamics that are not apparent in bulk rheology. We observe three distinct relaxation modes. First we find a fast diffusive mode that does not depend on the number of bridges and is attributed to the diffusion of micelles within a cage formed by neighboring micelles. A second, intermediate mode depends strongly on network connectivity but surprisingly is independent of the scattering vector q. We attribute this viscoelastic mode to fluctuations in local connectivity of the network. The third, slowest mode is also diffusive and is attributed to the diffusion of micelle clusters through the viscoelastic matrix. These results shed light on the microscopic dynamics in weakly interconnected transient networks.

AB - The dynamics and mechanics of networks depend sensitively on their spatial connectivity. To explore the effect of connectivity on local network dynamics, we prepare transient polymer networks in which we systematically cut connecting bonds. We do this by creating networks formed from hydrophobically modified difunctionalized polyethylene glycol chains. These form physical gels, consisting of flowerlike micelles that are transiently cross-linked by connecting bridges. By introducing monofunctionalized chains, we can systematically reduce the number of bonds between micelles and thus lower the network connectivity, which strongly reduces the network elasticity and relaxation time. Dynamic light scattering reveals a complex relaxation dynamics that are not apparent in bulk rheology. We observe three distinct relaxation modes. First we find a fast diffusive mode that does not depend on the number of bridges and is attributed to the diffusion of micelles within a cage formed by neighboring micelles. A second, intermediate mode depends strongly on network connectivity but surprisingly is independent of the scattering vector q. We attribute this viscoelastic mode to fluctuations in local connectivity of the network. The third, slowest mode is also diffusive and is attributed to the diffusion of micelle clusters through the viscoelastic matrix. These results shed light on the microscopic dynamics in weakly interconnected transient networks.

U2 - 10.1103/PhysRevE.94.032507

DO - 10.1103/PhysRevE.94.032507

M3 - Article

VL - 94

JO - Physical Review. E, Statistical nonlinear, and soft matter physics

T2 - Physical Review. E, Statistical nonlinear, and soft matter physics

JF - Physical Review. E, Statistical nonlinear, and soft matter physics

SN - 1539-3755

IS - 3

M1 - 032507

ER -