Understanding the Roles of Mesh Size, Tg, and Segmental Dynamics on Probe Diffusion in Dense Polymer Networks

2021 ◽  
Author(s):  
Grant S. Sheridan ◽  
Christopher M. Evans
Keyword(s):  
Polymer Networks ◽  
Mesh Size ◽  
Segmental Dynamics

The effect of blob size in polymer networks on nanoparticle-mediated adhesion of hydrogels

Soft Matter ◽  
2019 ◽  
Vol 15 (48) ◽  
pp. 9942-9948
Author(s):  
Sohyun Kim ◽  
Tae Hui Kang ◽  
Gi-Ra Yi
Keyword(s):  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Pore Diameter ◽  
Physical Adsorption ◽  
Mesoporous Silica Nanoparticles ◽  
Polymer Networks ◽  
Mesh Size ◽  
Adhesion Energy ◽  
Polymer Chains

Mesoporous silica nanoparticles can be used as an adhesive for hydrogels due to their physical adsorption to polymer chains, in which adhesion energy can be affected by the ratio of mesh size and pore diameter.

scholarly journals High-Performance Polymer Dispersed Liquid Crystal Enabled by Uniquely Designed Acrylate Monomer

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1625 ◽  
Author(s):  
Rijeesh Kizhakidathazhath ◽  
Hiroya Nishikawa ◽  
Yasushi Okumura ◽  
Hiroki Higuchi ◽  
Hirotsugu Kikuchi
Keyword(s):  
Optical Properties ◽  
Liquid Crystal ◽  
Low Voltage ◽  
Polymer Networks ◽  
Mesh Size ◽  
Laser Scanning Microscopy ◽  
Present System ◽  
Driving Voltage ◽  
Acrylate Monomer ◽  
Polymer Dispersed

The widespread electro–optical applications of polymer dispersed liquid crystals (PDLCs) are hampered by their high-driving voltage. Attempts to fabricate PDLC devices with low driving voltage sacrifice other desirable features of PDLCs. There is thus a clear need to develop a method to reduce the driving voltage without diminishing other revolutionary features of PDLCs. Herein, we report a low-voltage driven PDLC system achieved through an elegantly simple and uniquely designed acrylate monomer (A3DA) featuring a benzene moiety with a dodecyl terminal chain. The PDLC films were fabricated by the photopolymerization of mono- and di-functional acrylate monomers (19.2 wt%) mixed in a nematic liquid crystal E7 (80 wt%). The PDLC film with A3DA exhibited an abrupt decline of driving voltage by 75% (0.55 V/μm) with a high contrast ratio (16.82) while maintaining other electro–optical properties almost the same as the reference cell. The response time was adjusted to satisfactory by tuning the monomer concentration while maintaining the voltage significantly low (3 ms for a voltage of 0.98 V/μm). Confocal laser scanning microscopy confirmed the polyhedral foam texture morphology with an average mesh size of approximately 2.6 μm, which is less in comparison with the mesh size of reference PDLC (3.4 μm), yet the A3DA-PDLC showed low switching voltage. Thus, the promoted electro–optical properties are believed to be originated from the unique polymer networks formed by A3DA and its weak anchoring behavior on LCs. The present system with such a huge reduction in driving voltage and enhanced electro–optical performance opens up an excellent way for abundant perspective applications of PDLCs.

Tuning the Elasticity of Biopolymer Gels for Optimal Wound Healing

2005 ◽  
Vol 897 ◽  
Author(s):  
Penelope Georges ◽  
Margaret McCormick ◽  
Lisa Flanagan ◽  
Yo-El Ju ◽  
Evelyn Sawyer ◽  
...  
Keyword(s):  
Cell Structure ◽  
Polymer Networks ◽  
Neuronal Cell ◽  
Mesh Size ◽  
Cell Types ◽  
Animal Cells ◽  
Normal Environment ◽  
Biopolymer Gels ◽  
Soft Polymer ◽  
And Function

AbstractSoft polymer networks with large mesh size, not flat rigid surfaces, are the normal environment for most animal cells. Cell structure and function depend on the stiffness of the surfaces on which cells adhere as well as on the type of adhesion complex by which the cell binds its extracellular ligand. Many cell types, including fibroblasts and endothelial cells, switch from a round to spread morphology as stiffness is increased between 1000 and 10,000 Pa. Coincident with the change in morphology are a host of differences in protein phosphorylation levels, expression of integrins, and changes in cytoskeletal protein expression and assembly. In contrast, other cells types such as neutrophils and platelets do not require rigid substrates in order to spread, and neurons extend processes better on soft (50 Pa) materials than on stiffer gels. We compare the stiffness sensing of four cell types: platelets, neurons and astrocytes, a glial cell type derived from embryonic rat brain, and melanoma cells. Astrocytes switch from a round to spread morphology as substrate stiffness increases, but do so over a stiffness range 10 times softer than that over which fibroblasts alter morphology. Stiffness-dependent morphologic changes observed from studies of cells grown on surfaces of protein-laminated polyacrylamide gels that have linear elasticity are also seen when cells are on matrices of natural biopolymers such as fibrin. Biopolymer gels like fibrin can be formed with appropriate stiffness to optimize for neuronal cell survival and patterning, and may have utility for repair of damaged neural tissues. The complex non-linear rheology of fibrin and other gels formed by semi-flexible biopolymers that exhibit strain-stiffening provide additional mechanisms by which cells can respond to and actively remodel the mechanical features of their environment.

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.

Main chain and segmental dynamics of semi interpenetrating polymer networks based on polyisoprene and poly(methyl methacrylate)

Polymer ◽  
2010 ◽  
Vol 51 (11) ◽  
pp. 2390-2402 ◽  
Author(s):  
Jacob John ◽  
Damir Klepac ◽  
Mirna Didović ◽  
C.J. Sandesh ◽  
Yong Liu ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Main Chain ◽  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Segmental Dynamics ◽  
Poly Methyl Methacrylate

scholarly journals Tracer Diffusion in Tightly-Meshed Homogeneous Polymer Networks: A Brownian Dynamics Simulation Study

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2067
Author(s):  
Hyun Woo Cho ◽  
Haein Kim ◽  
Bong June Sung ◽  
Jun Soo Kim
Keyword(s):  
Brownian Dynamics ◽  
Structural Changes ◽  
Tracer Particle ◽  
Polymer Networks ◽  
Mesh Size ◽  
Tracer Diffusion ◽  
Dynamics Simulation ◽  
Brownian Dynamics Simulation ◽  
Volume Fractions ◽  
Polymer Volume

We report Brownian dynamics simulations of tracer diffusion in regularly crosslinked polymer networks in order to elucidate the transport of a tracer particle in polymer networks. The average mesh size of homogeneous polymer networks is varied by assuming different degrees of crosslinking or swelling, and the size of a tracer particle is comparable to the average mesh size. Simulation results show subdiffusion of a tracer particle at intermediate time scales and normal diffusion at long times. In particular, the duration of subdiffusion is significantly prolonged as the average mesh size decreases with increasing degree of crosslinking, for which long-time diffusion occurs via the hopping processes of a tracer particle after undergoing rattling motions within a cage of the network mesh for an extended period of time. On the other hand, the cage dynamics and hopping process are less pronounced as the mesh size decreases with increasing polymer volume fractions. The interpretation is provided in terms of fluctuations in network mesh size: at higher polymer volume fractions, the network fluctuations are large enough to allow for collective, structural changes of network meshes, so that a tracer particle can escape from the cage, whereas, at lower volume fractions, the fluctuations are so small that a tracer particle remains trapped within the cage for a significant period of time before making infrequent jumps out of the cage. This work suggests that fluctuation in mesh size, as well as average mesh size itself, plays an important role in determining the dynamics of molecules and nanoparticles that are embedded in tightly meshed polymer networks.

scholarly journals Influence of cross-linking on the segmental dynamics in model polymer networks

2000 ◽  
Vol 113 (1) ◽  
pp. 447-452 ◽  
Author(s):  
V. Yu Kramarenko ◽  
T. A. Ezquerra ◽  
I. Šics ◽  
F. J. Baltá-Calleja ◽  
V. P. Privalko
Keyword(s):  
Polymer Networks ◽  
Cross Linking ◽  
Segmental Dynamics
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