scholarly journals A Soft-Particle Model for Simulations of Diblock Copolymers in Bulk and in Confinement

2012 ◽  
Vol 34 ◽  
pp. 105-113 ◽  
Author(s):  
C. Groβ ◽  
W. Paul
Keyword(s):  
Diblock Copolymers ◽  
Particle Model ◽  
Soft Particle

scholarly journals Soft particle model for block copolymers

2007 ◽  
Vol 127 (13) ◽  
pp. 134905 ◽  
Author(s):  
F. Eurich ◽  
A. Karatchentsev ◽  
J. Baschnagel ◽  
W. Dieterich ◽  
P. Maass
Keyword(s):  
Block Copolymers ◽  
Particle Model ◽  
Soft Particle

Effect of LPS Removal on Electrophoretic Softness of Acidithiobacillus ferrooxidans Cells

2007 ◽  
Vol 20-21 ◽  
pp. 341-344
Author(s):  
M.N. Chandraprabha ◽  
Jayant M. Modak ◽  
K.A. Natarajan
Keyword(s):  
Cell Surface ◽  
Acidithiobacillus Ferrooxidans ◽  
Ionic Concentration ◽  
Particle Model ◽  
Soft Particle ◽  
Bacterial Cells ◽  
Particle Theory ◽  
Particle Characteristics ◽  
Smoluchowski Theory ◽  
I Cells

Applicability of Ohshima’s soft-particle model to evaluate the surface potential of Acidithiobacillus ferrooxidans cells is discussed here. The electrokinetic properties were examined by electrophoretic mobility measurements and analyzed using the soft particle electrophoresis theory. As the ionic concentration increased, the mobility of the bacterial cells converged to nonzero values suggesting that the particles exhibited typical soft-particle characteristics. Also, cell surface potentials based on soft-particle theory were lower than those estimated using the conventional Smoluchowski theory. Effect of removal of LPS from the cell surface on surface softness and charge density are investigated and discussed.

Mesoscopic Simulations of Flow in Microchannel and Comparison With Continuum Model

2008 ◽  
Author(s):  
Anurag Kumar ◽  
Yutaka Asako ◽  
Mohammad Faghri
Keyword(s):  
Fundamental Problem ◽  
Molecular Model ◽  
Dissipative Particle Dynamics ◽  
Continuum Theory ◽  
Coarse Graining ◽  
Simulation Method ◽  
Particle Model ◽  
Soft Particle ◽  
Good Agreement ◽  
The Continuum

Dissipative particle dynamics (DPD) is a mesoscopic particle-based simulation method, where each particle represents a group or packet of actual molecules of the flow field. Despite its usefulness, a fundamental problem of the DPD is that there is no straightforward procedure to relate the soft-particle model to a realistic continuum or molecular model. In the present work, we studied the dynamics of a simple fluid flow in a microchannel based on the coarse-graining of the molecules and expressed DPD units in terms of real units. To compare DPD methodology with continuum theory, a relation between the viscosity of the fluid and dissipative coefficient of DPD was established. DPD equations and parameters were expressed in non-dimensional forms and related to the known hydrodynamic parameters such as Reynolds number and Peclet number. Poiseuille flow of water in microchannel of height 35 μm was modeled for different parameters. Coarse-graining for water was ranged from 5×109 to 5×1010 for each DPD particle. Re and Pe of the flow were varied from 0.7 to 60 and 5 to 140, respectively. Simulated results were compared to the continuum results with a good agreement.

scholarly journals Origin of nonlinear force distributions in a composite system

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Yuto Tamura ◽  
Marie Tani ◽  
Rei Kurita
Keyword(s):  
Composite Materials ◽  
Composite System ◽  
Density Difference ◽  
High Yield ◽  
Particle Model ◽  
Force Distribution ◽  
Soft Particle ◽  
Mechanical Responses ◽  
Load Response ◽  
Nonlinear Force

AbstractComposite materials have been actively developed in recent years because they are highly functional such as lightweight, high yield strength, and superior load response. In spite of importance of the composite materials, mechanisms of the mechanical responses of composites have been unrevealed. Here, in order to understand the mechanical responses of composites, we investigated the origin and nature of the force distribution in heterogeneous materials using a soft particle model. We arranged particles with different softness in a lamellar structure and then we applied homogeneous pressure to the top surface of the system. It is found that the density in each region differently changes and then the density difference induces a nonlinear force distribution. In addition, it is found that the attractive interaction suppresses the density difference and then the force distribution is close to the theoretical prediction. Those findings may lead material designs for functional composite materials.

Soft-particle model of compact macromolecules at interfaces

1982 ◽  
Vol 90 (1) ◽  
pp. 289-292 ◽  
Author(s):  
J.A de Feijter ◽  
J Benjamins
Keyword(s):  
Particle Model ◽  
Soft Particle

Morphological behavior of compatibilized ternary blends prepared by mechanical mixing

1993 ◽  
Vol 51 ◽  
pp. 1200-1201
Author(s):  
S.D. Smith ◽  
R.J. Spontak ◽  
D.H. Melik ◽  
S.M. Buehler ◽  
K.M. Kerr ◽  
...  
Keyword(s):  
Interfacial Adhesion ◽  
Diblock Copolymers ◽  
Ternary Blends ◽  
Mechanical Mixing ◽  
Design Considerations ◽  
Covalently Bonded ◽  
Homopolymer Blends ◽  
Emulsifying Agent ◽  
Surface Active ◽  
Low Entropy

When blended together, homopolymers A and B will normally macrophase-separate into relatively large (≫1 μm) A-rich and B-rich phases, between which exists poor interfacial adhesion, due to a low entropy of mixing. The size scale of phase separation in such a blend can be reduced, and the extent of interfacial A-B contact and entanglement enhanced, via addition of an emulsifying agent such as an AB diblock copolymer. Diblock copolymers consist of a long sequence of A monomers covalently bonded to a long sequence of B monomers. These materials are surface-active and decrease interfacial tension between immiscible phases much in the same way as do small-molecule surfactants. Previous studies have clearly demonstrated the utility of block copolymers in compatibilizing homopolymer blends and enhancing blend properties such as fracture toughness. It is now recognized that optimization of emulsified ternary blends relies upon design considerations such as sufficient block penetration into a macrophase (to avoid block slip) and prevention of a copolymer multilayer at the A-B interface (to avoid intralayer failure).

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