scholarly journals Energy transfer speed of polymer network and its scaling-law of elastic modulus—New insights

2019 ◽  
Vol 126 (21) ◽  
pp. 215101 ◽  
Author(s):  
Ziqian Li ◽  
Zishun Liu
Keyword(s):  
Energy Transfer ◽  
Elastic Modulus ◽  
Scaling Law ◽  
Polymer Network

Interaction Model for “Shelled Particles” and Small-Strain Modulus of Granular Materials

2018 ◽  
Vol 85 (10) ◽  
Author(s):  
Shun-hua Zhou ◽  
Peijun Guo ◽  
Dieter F. E. Stolle
Keyword(s):  
Elastic Modulus ◽  
Contact Stiffness ◽  
Scaling Law ◽  
Interaction Model ◽  
Contact Problems ◽  
Hertzian Contact ◽  
Spherical Particles ◽  
Thin Coating ◽  
Normal Contact ◽  
Laboratory Test Results

The elastic modulus of a granular assembly composed of spherical particles in Hertzian contact usually has a scaling law with the mean effective pressure p as K∼G∼p1/3. Laboratory test results, however, reveal that the value of the exponent is generally around 1/2 for most sands and gravels, but it is much higher for reclaimed asphalt concrete composed of particles coated by a thin layer of asphalt binder and even approaching unity for aggregates consisting of crushed stone. By assuming that a particle is coated with a thin soft deteriorated layer, an energy-based simple approach is proposed for thin-coating contact problems. Based on the features of the surface layer, the normal contact stiffness between two spheres varies with the contact force following kn∼Fnm and m∈[1/3,  1], with m=1/3 for Hertzian contact, m=1/2 soft thin-coating contact, m=2/3 for incompressible soft thin-coating, and m=1 for spheres with rough surfaces. Correspondingly, the elastic modulus of a random granular packing is proportional to pm with m∈[1/3,  1].

scholarly journals Sensitization of ultra-long-range excited-state electron transfer by energy transfer in a polymerized film

2012 ◽  
Vol 109 (38) ◽  
pp. 15132-15135 ◽  
Author(s):  
Akitaka Ito ◽  
David J. Stewart ◽  
Zhen Fang ◽  
M. Kyle Brennaman ◽  
Thomas J. Meyer
Keyword(s):  
Electron Transfer ◽  
Energy Transfer ◽  
Excited State ◽  
Charge Transfer ◽  
Long Range ◽  
Methyl Viologen ◽  
Polymer Network ◽  
Triplet Energy ◽  
Ligand Charge Transfer ◽  
Triplet Energy Transfer

Distance-dependent energy transfer occurs from the Metal-to-Ligand Charge Transfer (MLCT) excited state to an anthracene-acrylate derivative (Acr-An) incorporated into the polymer network of a semirigid poly(ethyleneglycol)dimethacrylate monolith. Following excitation, to Acr-An triplet energy transfer occurs followed by long-range, Acr-3An—Acr-An → Acr-An—Acr-3An, energy migration. With methyl viologen dication (MV2+) added as a trap, Acr-3An + MV2+ → Acr-An+ + MV+ electron transfer results in sensitized electron transfer quenching over a distance of approximately 90 Å.

Simple Scaling Law for Rotational-Energy Transfer inNa2*-Xe Collisions

1978 ◽  
Vol 41 (13) ◽  
pp. 856-859 ◽  
Author(s):  
Timothy A. Brunner ◽  
Richard D. Driver ◽  
Neil Smith ◽  
David E. Pritchard
Keyword(s):  
Energy Transfer ◽  
Scaling Law ◽  
Rotational Energy ◽  
Rotational Energy Transfer ◽  
Simple Scaling

scholarly journals Effect of different monomer precursors with identical functionality on the properties of the polymer network

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Ariana Torres-Knoop ◽  
Verena Schamboeck ◽  
Nitish Govindarajan ◽  
Pieter D. Iedema ◽  
Ivan Kryven
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Elastic Modulus ◽  
Transition Temperature ◽  
Materials Science ◽  
Polymer Network ◽  
Network Density ◽  
Sudden Increase ◽  
Spatial Networks ◽  
Vitrification Temperature

AbstractThe association between thermo-mechanical properties in polymers and functionality of monomer precursors is frequently exploited in the materials science. However, it is not known if there are more variables beyond monomer functionality that have a similar link. Here, by using simulations to generate spatial networks from chemically different monomers with identical functionality we show that such networks have universal graph-theoretical properties as well as a near-universal elastic modulus. The vitrification temperature was found to be universal only up to a certain network density, as measured by the bond conversion. The latter observation is explained by the fact that monomer’s tendency to coil enhances formation of topological holes, which, when accumulated, amount to a percolating cell complex restricting network’s mobility. This higher-order percolation occurs late after gelation and is shown to coincide with the onset of brittleness, as indicated by a sudden increase in the glass transition temperature.

scholarly journals The Mechanical Mechanism and Influencing Factors of Ice Adhesion Strength on Ice-Phobic Coating

2021 ◽  
Vol 9 (3) ◽  
pp. 315
Author(s):  
Qiang Xie ◽  
Tianhui Hao ◽  
Chao Wang ◽  
Zhenhang Kang ◽  
Zhonghua Shi ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Polymer Network ◽  
Three Dimensional ◽  
Interpenetrating Polymer Network ◽  
Interface Debonding ◽  
Zone Model ◽  
Ice Accretion ◽  
Elastic Film

Ice accretion can cause problems on polar ships, ocean platforms, and in other marine industries. It is important to understand the interface debonding behavior between ice and the surface of equipment. In this work, we created a mechanical model to analyze the interface debonding behavior between a square-based ice cuboid and an elastic coating base, using contact mechanics and fracture mechanics. Three-dimensional (3D) finite element (FE) simulation was used to simulate the interface debonding for normal and shear separation. A bilinear cohesive zone model (CZM) was used to simulate the interface between the ice cuboid and the elastic coating. We investigated the effect of the elastic modulus E of an elastic film on the critical detachment force Fc for normal and shear separation. The results showed that Fc increases with an increase of the elastic modulus of the elastic film. When E exceeds a certain level, Fc achieves a constant value and then remains stable. Finally, a series of epoxy/polydimethylsiloxane (PDMS) interpenetrating polymer-network (IPN) gel coatings with different elastic moduli were prepared. The ice tensile and shear adhesion strengths (σice and τice) of the coatings were measured. The results were roughly consistent with the results of the numerical simulation when E < 1 MPa.

Modeling of CH4 Adsorption-Induced Curvature of a Nanocantilever

2013 ◽  
Vol 364 ◽  
pp. 233-237
Author(s):  
Bing Li ◽  
Qing An Huang
Keyword(s):  
Energy Transfer ◽  
Elastic Modulus ◽  
Potential Energy ◽  
Simulation Model ◽  
Elastic Energy ◽  
Metal Layer ◽  
Single Layer ◽  
Basic Structure ◽  
Native Oxide ◽  
Cantilever Sensors

In this paper, a simulation model is proposed to describe CH4 adsorption-induced curvature of a nanocantilever, based on the energy transfer between potential energy of adsorbates and elastic energy of the bending cantilever. For most cantilever sensors, the basic structure is a silicon beam coated with a metal layer on the top, and aluminum is chosen here. Because the native oxide is usually formed during the fabrication of silicon beams, we have to describe the effect of native oxide on the elastic modulus of the silicon nanobeam in this model based on the semi-continuum method. This model gives a way to predict the curvature of the composite cantilever with native oxide when adsorbing a single layer of CH4 molecules.

scholarly journals Stretchable materials of high toughness and low hysteresis

2019 ◽  
Vol 116 (13) ◽  
pp. 5967-5972 ◽  
Author(s):  
Zhengjin Wang ◽  
Chunping Xiang ◽  
Xi Yao ◽  
Paul Le Floch ◽  
Julien Mendez ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Stress Concentration ◽  
Polymer Network ◽  
High Toughness ◽  
Human Machine Interfaces ◽  
Low Dissipation ◽  
Low Elastic Modulus ◽  
The Matrix ◽  
Strong Adhesion ◽  
Highly Stretchable

In materials of all types, hysteresis and toughness are usually correlated. For example, a highly stretchable elastomer or hydrogel of a single polymer network has low hysteresis and low toughness. The single network is commonly toughened by introducing sacrificial bonds, but breaking and possibly reforming the sacrificial bonds causes pronounced hysteresis. In this paper, we describe a principle of stretchable materials that disrupt the toughness–hysteresis correlation, achieving both high toughness and low hysteresis. We demonstrate the principle by fabricating a composite of two constituents: a matrix of low elastic modulus, and fibers of high elastic modulus, with strong adhesion between the matrix and the fibers, but with no sacrificial bonds. Both constituents have low hysteresis (5%) and low toughness (300 J/m2), whereas the composite retains the low hysteresis but achieves high toughness (10,000 J/m2). Both constituents are prone to fatigue fracture, whereas the composite is highly fatigue resistant. We conduct experiment and computation to ascertain that the large modulus contrast alleviates stress concentration at the crack front, and that strong adhesion binds the fibers and the matrix and suppresses sliding between them. Stretchable materials of high toughness and low hysteresis provide opportunities to the creation of high-cycle and low-dissipation soft robots and soft human–machine interfaces.

scholarly journals Dynamics of a Complex Multilayer Polymer Network: Mechanical Relaxation and Energy Transfer

Polymers ◽  
2018 ◽  
Vol 10 (2) ◽  
pp. 164 ◽  
Author(s):  
Aurel Jurjiu ◽  
Flaviu Turcu ◽  
Mircea Galiceanu
Keyword(s):  
Energy Transfer ◽  
Polymer Network ◽  
Mechanical Relaxation
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