Soft Materials by Design: Unconventional Polymer Networks Give Extreme Properties

2021 ◽  
Author(s):  
Xuanhe Zhao ◽  
Xiaoyu Chen ◽  
Hyunwoo Yuk ◽  
Shaoting Lin ◽  
Xinyue Liu ◽  
...  
Keyword(s):  
Polymer Networks ◽  
Soft Materials ◽  
Materials By Design

Modeling fracture in rate-dependent polymer networks: A quasicontinuum approach

2021 ◽  
pp. 1-22
Author(s):  
Ahmed Ghareeb ◽  
Ahmed Elbanna
Keyword(s):  
Adaptive Mesh Refinement ◽  
Polymer Networks ◽  
Viscoelastic Behavior ◽  
Adaptive Mesh ◽  
Soft Materials ◽  
Polymer Chains ◽  
Loading Rates ◽  
Viscous Forces ◽  
Rate Dependent ◽  
Bond Breakage

Abstract Soft materials, such as rubber and gels, exhibit rate-dependent response where the stiffness, strength and fracture patterns depend largely on loading rates. Thus, accurate modeling of the mechanical behavior requires accounting for different sources of rate-dependence such as the intrinsic viscoelastic behavior of the polymer chains and the dynamic bond breakage and formation mechanism. In this chapter, we extend the QC approach presented in Ghareeb and Elbanna [Journal of the Mechanics and Physics of Solids, 137, 103819 (2020)] to include ratedependent behavior of polymer networks. We propose a homogenization rule for the viscous forces in the polymer chains and update the adaptive mesh refinement algorithm to account for dynamic bond breakage. Then, we use nonlinear finite element framework with predictorcorrector scheme to solve for the nodal displacements and velocities. We demonstrate the accuracy of the method by verifying it against fully discrete simulations for different examples of network structures and loading conditions. We further use the method to investigate the effects of the loading rates on the fracture characteristics of networks with different ratedependent parameters. Finally, We discuss the implications of the extended method for multiscale analysis of fracture in rate-dependent polymer networks.

Microengineering of Supramolecular Soft Materials by Design of the Crystalline Fiber Networks

2010 ◽  
Vol 10 (6) ◽  
pp. 2699-2706 ◽  
Author(s):  
Jing-Liang Li ◽  
Bing Yuan ◽  
Xiang-Yang Liu ◽  
Hong-Yao Xu
Keyword(s):  
Soft Materials ◽  
Fiber Networks ◽  
Materials By Design

scholarly journals Dynamic Bottlebrush Polymer Networks: Self-Healing in Super-Soft Materials

2020 ◽  
Vol 142 (16) ◽  
pp. 7567-7573 ◽  
Author(s):  
Jeffrey L. Self ◽  
Caitlin S. Sample ◽  
Adam E. Levi ◽  
Kexin Li ◽  
Renxuan Xie ◽  
...  
Keyword(s):  
Polymer Networks ◽  
Soft Materials ◽  
Self Healing

scholarly journals Mechanical Response of Two-Dimensional Polymer Networks: Role of Topology, Rate Dependence, and Damage Accumulation

2018 ◽  
Vol 85 (3) ◽  
Author(s):  
Konik Kothari ◽  
Yuhang Hu ◽  
Sahil Gupta ◽  
Ahmed Elbanna
Keyword(s):  
Mechanical Response ◽  
Polymer Networks ◽  
Soft Materials ◽  
Crosslinking Density ◽  
State Theory ◽  
Polymer Chains ◽  
Local Network ◽  
Network Characteristics ◽  
Rate Dependent

The skeleton of many natural and artificial soft materials can be abstracted as networks of fibers/polymers interacting in a nonlinear fashion. Here, we present a numerical model for networks of nonlinear, elastic polymer chains with rate-dependent crosslinkers similar to what is found in gels. The model combines the worm-like chain (WLC) at the polymer level with the transition state theory for crosslinker bond dynamics. We study the damage evolution and the force—displacement response of these networks under uniaxial stretching for different loading rates, network topology, and crosslinking density. Our results suggest a complex nonmonotonic response as the loading rate or the crosslinking density increases. We discuss this in terms of the microscopic deformation mechanisms and suggest a novel framework for increasing toughness and ductility of polymer networks using a bio-inspired sacrificial bonds and hidden length (SBHL) mechanism. This work highlights the role of local network characteristics on macroscopic mechanical observables and opens new pathways for designing tough polymer networks.

Hierarchical Structures in Soft Materials

2018 ◽  
Vol 91 (10) ◽  
pp. 365-369
Author(s):  
Mikihito TAKENAKA
Keyword(s):  
Hierarchical Structures ◽  
Soft Materials

Crosslinker Chemistry Determines the Uptake Potential of Perfluorinated Alkyl Substances by β-Cyclodextrin Polymers

2018 ◽  
Author(s):  
Leilei Xiao ◽  
Casey Ching ◽  
Yuhan Ling ◽  
Mohammadreza Nasiri ◽  
Max Justin Klemes ◽  
...  
Keyword(s):  
Binding Affinity ◽  
Polymer Networks ◽  
Cyclodextrin Polymer ◽  
Perfluorinated Alkyl Substances ◽  
Cyclodextrin Polymers

This work describes several crosslinked β-cyclodextrin polymer networks and correlates the crosslinker chemistry with binding affinity for per- and polyfluorinated alkyl substances (PFASs), including PFOA and PFOS.

Design and Synthesis of Two-Dimensional Covalent Organic Frameworks with Four-Arm Cores: Prediction of Remarkable Ambipolar Charge-Transport Properties

2019 ◽  
Author(s):  
Simil Thomas ◽  
Hong Li ◽  
Raghunath R. Dasari ◽  
Austin Evans ◽  
William Dichtel ◽  
...  
Keyword(s):  
Charge Transport ◽  
Organic Semiconductors ◽  
Density Functional ◽  
Polymer Networks ◽  
Two Dimensional ◽  
Covalent Organic Frameworks ◽  
X Ray Diffraction ◽  
Zinc Porphyrin ◽  
Design And Synthesis ◽  
Predicted Values

<p>We have considered three two-dimensional (2D) π-conjugated polymer networks (i.e., covalent organic frameworks, COFs) materials based on pyrene, porphyrin, and zinc-porphyrin cores connected <i>via</i> diacetylenic linkers. Their electronic structures, investigated at the density functional theory global-hybrid level, are indicative of valence and conduction bands that have large widths, ranging between 1 and 2 eV. Using a molecular approach to derive the electronic couplings between adjacent core units and the electron-vibration couplings, the three π-conjugated 2D COFs are predicted to have ambipolar charge-transport characteristics with electron and hole mobilities in the range of 65-95 cm<sup>2</sup>V<sup>-1</sup>s<sup>-1</sup>. Such predicted values rank these 2D COFs among the highest-mobility organic semiconductors. In addition, we have synthesized the zinc-porphyrin based 2D COF and carried out structural characterization via powder X-ray diffraction and surface area analysis, which demonstrates the feasability of these electroactive networks.</p>

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