scholarly journals Colloidal Shear-Thickening Fluids Using Variable Functional Star-Shaped Particles: A Molecular Dynamics Study

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6867
Author(s):  
Rofiques Salehin ◽  
Rong-Guang Xu ◽  
Stefanos Papanikolaou

Complex colloidal fluids, depending on constituent shapes and packing fractions, may have a wide range of shear-thinning and/or shear-thickening behaviors. An interesting way to transition between different types of such behavior is by infusing complex functional particles that can be manufactured using modern techniques such as 3D printing. In this paper, we perform 2D molecular dynamics simulations of such fluids with infused star-shaped functional particles, with a variable leg length and number of legs, as they are infused in a non-interacting fluid. We vary the packing fraction (ϕ) of the system, and for each different system, we apply shear at various strain rates, turning the fluid into a shear-thickened fluid and then, in jammed state, rising the apparent viscosity of the fluid and incipient stresses. We demonstrate the dependence of viscosity on the functional particles’ packing fraction and we show the role of shape and design dependence of the functional particles towards the transition to a shear-thickening fluid.

Author(s):  
Rofiques Salehin ◽  
Rongguang Xu ◽  
Stefanos Papanikolaou

Complex colloidal fluids, depending on particulates’ shapes and packing fractions, may have a wide range of shear thinning and thickening behaviors. A particular interesting way to transition between different types of such behavior is by infusing functional complex particles that can be manufactured using modern techicques such as 3D printing. In this paper, we display 2D molecular dynamics simulations of such fluids with infused star-shaped functional particles, with variable leg length and number of legs, as they are infused in a non-interacting, coarse-grained fluid. We vary the packing fraction (ϕ) of the system, and for each different system we apply shear with various strain rate that turns the fluid into a jammed state and rise the apparent viscosity of fluid. We demonstrate the dependence of viscosity with the particles’ packing fraction. We show the role of shape and design dependence of the functional particles towards the transition to a shear thickening fluid .


Soft Matter ◽  
2021 ◽  
Vol 17 (10) ◽  
pp. 2942-2956
Author(s):  
Rishabh D. Guha ◽  
Ogheneovo Idolor ◽  
Katherine Berkowitz ◽  
Melissa Pasquinelli ◽  
Landon R. Grace

We investigated the effect of temperature variation on the secondary bonding interactions between absorbed moisture and epoxies with different morphologies using molecular dynamics simulations.


Soft Matter ◽  
2021 ◽  
Author(s):  
Garima Rani ◽  
Kenichi Kuroda ◽  
Satyavani Vemparala

Using atomistic molecular dynamics simulations, we study the interaction of ternary methacrylate polymers, composed of charged cationic, hydrophobic and neutral polar groups, with model bacterial membrane. Our simulation data shows...


2021 ◽  
Vol 23 (10) ◽  
pp. 5984-5991
Author(s):  
Letizia Tavagnacco ◽  
Ester Chiessi ◽  
Emanuela Zaccarelli

By using extensive all-atom molecular dynamics simulations of an atactic linear polymer chain, we unveil the role of pressure in the coil-to-globule transition of poly(N-isopropylacrylamide) (PNIPAM).


Langmuir ◽  
2017 ◽  
Vol 33 (42) ◽  
pp. 11543-11553 ◽  
Author(s):  
Li Li ◽  
Deshuai Yang ◽  
Trevor R. Fisher ◽  
Qi Qiao ◽  
Zhen Yang ◽  
...  

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 294
Author(s):  
Jiaqing Li ◽  
Cheng Lu ◽  
Long Wang ◽  
Linqing Pei ◽  
Ajit Godbole ◽  
...  

Hydrogen embrittlement (HE) has been extensively studied in bulk materials. However, little is known about the role of H on the plastic deformation and fracture mechanisms of nanoscale materials such as nanowires. In this study, molecular dynamics simulations are employed to study the influence of H segregation on the behavior of intergranular cracks in bicrystalline α-Fe nanowires. The results demonstrate that segregated H atoms have weak embrittling effects on the predicted ductile cracks along the GBs, but favor the cleavage process of intergranular cracks in the theoretically brittle directions. Furthermore, it is revealed that cyclic loading can promote the H accumulation into the GB region ahead of the crack tip and overcome crack trapping, thus inducing a ductile-to-brittle transformation. This information will deepen our understanding on the experimentally-observed H-assisted brittle cleavage failure and have implications for designing new nanocrystalline materials with high resistance to HE.


2006 ◽  
Vol 110 (7) ◽  
pp. 3323-3329 ◽  
Author(s):  
Said Hamad ◽  
Changman Moon ◽  
C. Richard A. Catlow ◽  
Ashley T. Hulme ◽  
Sarah L. Price

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