DMAP-based flexible polymer networks formed via Heck coupling as efficient heterogeneous organocatalysts

2016 ◽  
Vol 104 ◽  
pp. 15-21 ◽  
Author(s):  
Wei Xu ◽  
Wu Xia ◽  
Yukun Guan ◽  
Yiming Wang ◽  
Cuifen Lu ◽  
...  
Keyword(s):  
Polymer Networks ◽  
Heck Coupling ◽  
Flexible Polymer

Equilibrium phase diagram of semi-flexible polymer networks with linkers

2013 ◽  
Vol 102 (3) ◽  
pp. 38003 ◽  
Author(s):  
C. J. Cyron ◽  
K. W. Müller ◽  
K. M. Schmoller ◽  
A. R. Bausch ◽  
W. A. Wall ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Polymer Networks ◽  
Equilibrium Phase ◽  
Equilibrium Phase Diagram ◽  
Flexible Polymer ◽  
Semi Flexible Polymer

scholarly journals Computational analysis of morphologies and phase transitions of cross-linked, semi-flexible polymer networks

2015 ◽  
Vol 471 (2182) ◽  
pp. 20150332 ◽  
Author(s):  
Kei W. Müller ◽  
Christian J. Cyron ◽  
Wolfgang A. Wall
Keyword(s):  
Phase Transitions ◽  
Computational Study ◽  
Polymer Networks ◽  
Constitutive Models ◽  
Structural Polymorphism ◽  
Flexible Polymers ◽  
Fibre Network ◽  
Flexible Polymer ◽  
Morphological Differences ◽  
Semi Flexible Polymer

The eukaryotic cytoskeleton is a protein fibre network mainly consisting of the semi-flexible biopolymer F-actin, microtubules and intermediate filaments. It is well known to exhibit a pronounced structural polymorphism, which enables intracellular processes such as cell adhesion, cell motility and cell division. We present a computational study on cross-linked networks of semi-flexible polymers, which offers a detailed analysis of the network structure and phase transitions from one morphology to another. We elaborate the morphological differences, their mechanical implications and the order of the observed phase transitions. Finally, we present a perspective on how the information gained in our simulations can be exploited in order to build both flexible and accurate, microstructurally informed, homogenized constitutive models of the cytoskeleton.

scholarly journals Theory of Flexible Polymer Networks: Elasticity and Heterogeneities

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 767 ◽  
Author(s):  
Sergey Panyukov
Keyword(s):  
Volume Fraction ◽  
Polymer Networks ◽  
Chain Model ◽  
Flexible Polymer ◽  
Classical Models ◽  
Polymer Volume

A review of the main elasticity models of flexible polymer networks is presented. Classical models of phantom networks suggest that the networks have a tree-like structure. The conformations of their strands are described by the model of a combined chain, which consists of the network strand and two virtual chains attached to its ends. The distribution of lengths of virtual chains in real polydisperse networks is calculated using the results of the presented replica model of polymer networks. This model describes actual networks having strongly overlapping and interconnected loops of finite sizes. The conformations of their strands are characterized by the generalized combined chain model. The model of a sliding tube is represented, which describes the general anisotropic deformations of an entangled network in the melt. I propose a generalization of this model to describe the crossover between the entangled and phantom regimes of a swollen network. The obtained dependence of the Mooney-Rivlin parameters C 1 and C 2 on the polymer volume fraction is in agreement with experiments. The main results of the theory of heterogeneities in polymer networks are also discussed.

scholarly journals Nonaffine Displacements in Flexible Polymer Networks

2011 ◽  
Vol 44 (6) ◽  
pp. 1671-1679 ◽  
Author(s):  
Anindita Basu ◽  
Qi Wen ◽  
Xiaoming Mao ◽  
T. C. Lubensky ◽  
Paul A. Janmey ◽  
...  
Keyword(s):  
Polymer Networks ◽  
Flexible Polymer

An Analytic Toolbox for Simulated Filament Networks

2014 ◽  
Vol 1688 ◽  
Author(s):  
Ronald J. Pandolfi ◽  
Lauren Edwards ◽  
Linda S. Hirst
Keyword(s):  
Structural Characteristics ◽  
Polymer Networks ◽  
Network Connectivity ◽  
Mesh Size ◽  
Distribution Functions ◽  
Morphological Properties ◽  
Scaling Analysis ◽  
Flexible Polymer ◽  
Recent Developments ◽  
Filament Networks

ABSTRACTSemi-flexible polymer networks generate a diverse family of structures. The network generating behaviors of specific semi-flexible biological filaments are well known (i.e. F-actin, microtubules, DNA etc.), however recent developments in tunable synthetic filaments extend the range of accessible structures. A similarly tunable model was developed using the molecular dynamics platform NAMD to provide a guide for generating synthetic filament networks. Structural characteristics of simulated networks may be quantitatively examined using connectivity analysis, radial pair distribution functions and scaling analysis. These methods provide a basis to calculate morphological properties, including mesh size, packing order, network connectivity, avg. cluster size, filaments per bundle, and space-filling dimensionality. An analytic toolset for describing the structure of filament networks is thus provided by detailing these methods.

scholarly journals The role of vimentin-nuclear interactions in persistent cell motility through confined spaces

2021 ◽  
Author(s):  
Sarthak Gupta ◽  
Alison E. Patteson ◽  
J. M. Schwarz
Keyword(s):  
Cell Motility ◽  
Mammalian Cells ◽  
Epithelial Mesenchymal Transition ◽  
Center Of Mass ◽  
Polymer Networks ◽  
Mesenchymal Transition ◽  
Flexible Polymer ◽  
Polarization Mechanism ◽  
Cellular Cytoskeleton

The ability of cells to move through small spaces depends on the mechanical properties of the cellular cytoskeleton and on nuclear deformability. In mammalian cells, the cytoskeleton is comprised of three interacting, semi-flexible polymer networks: actin, microtubules, and intermediate filaments (IF). Recent experiments of mouse embryonic fibroblasts with and without vimentin have shown that the IF vimentin plays a role in confined cell motility. We, therefore, develop a minimal model of cells moving through confined geometries that effectively includes all three types of cytoskeletal filaments with a cell consisting of an actomyosin cortex and a deformable cell nucleus and mechanical connections between the two cortices—the outer actomyosin one and the inner nuclear one. By decreasing the amount of vimentin, we find that the cell speed is typically faster for vimentin-null cells as compared to cells with vimentin. Vimentin-null cells also contain more deformed nuclei in confinement. Finally, vimentin affects nucleus positioning within the cell. By positing that as the nucleus position deviates further from the center of mass of the cell, microtubules become more oriented in a particular direction to enhance cell persistence or polarity, we show that vimentin-nulls are more persistent than vimentin-full cells. The enhanced persistence indicates that the vimentin-null cells are more subjugated by the confinement since their internal polarization mechanism that depends on cross-talk of the centrosome with the nucleus and other cytoskeletal connections is diminished. In other words, the vimentin-null cells rely more heavily on external cues. Our modeling results present a quantitative interpretation for recent experiments and have implications for understanding the role of vimentin in the epithelial-mesenchymal transition.

Building biobased, degradable, flexible polymer networks from vanillin via thiol–ene “click” photopolymerization

2021 ◽  
Author(s):  
Meiying Ge ◽  
Jia-Tao Miao ◽  
Kai Zhang ◽  
Yadong Wu ◽  
Longhui Zheng ◽  
...  
Keyword(s):  
Polymer Networks ◽  
Allyl Ether ◽  
Flexible Polymer ◽  
Acidic Conditions

A new biobased allyl ether monomer with acetal groups is synthesized from renewable vanillin for building flexible transparent thiol–ene networks with good degradability under mild acidic conditions.

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