scholarly journals A Dissipative Particle Dynamics Study of Flow Behaviors in Ultra High Molecular Weight Polyethylene/Polyamide 6 Blends Based on Souza-Martins Method

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1275 ◽  
Author(s):  
Wang ◽  
Li ◽  
Cao ◽  
ShijieRen ◽  
Yu
Keyword(s):  
Molecular Weight ◽  
Shear Flow ◽  
High Molecular Weight ◽  
Flow Behavior ◽  
Dissipative Particle Dynamics ◽  
Polyamide 6 ◽  
Particle Dynamics ◽  
Simple Shear Flow ◽  
Coupled Flow ◽  
Ultra High Molecular Weight

This paper presents our study on the use of dissipative particle dynamics (DPD) simulations to discover the flow behavior in ultra high molecular weight polyethylene/polyamide 6 (UHMWPE/PA6) blends associated with extensional-shear coupled flow, based on the Souza-Martins method, for the first time. By way of simulations, we aimed at investigating the mesoscopic morphology and alignment behavior in response to extensional-shear coupled flow, in comparison with simple shear flow and simple extensional flow. Our results reveal that the aggregation of polymers is noticeable under zero flow, as expected. Within the considered range of extensional-shear coupled rates, the morphology transforms from micelle-like clusters to a chain-like network structure by increasing coupled rates from 0.01 to 2.0. Furthermore, it shows a linear distribution along the flow direction at a high coupled rate. It can be concluded that the flow behaviors in UHMWPE/PA6 blends are significantly impacted by extensional-shear coupled rates. The orientation behavior induced by extensional-shear coupled flow is more obvious than shear flow, even though flow variations and mass fractions yield less effects on the distribution behaviors of UHMWPE/PA6 blends. The DPD results are verified by mean square displacement (MSD) as a function of simulation time and relative concentration distribution along Z direction.

scholarly journals Orientation and Dispersion Evolution of Carbon Nanotubes in Ultra High Molecular Weight Polyethylene Composites under Extensional-Shear Coupled Flow: A Dissipative Particle Dynamics Study

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 154 ◽  
Author(s):  
Junxia Wang ◽  
Changlin Cao ◽  
Xiaochuan Chen ◽  
Shijie Ren ◽  
Yu Chen ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Dissipative Particle Dynamics ◽  
Mean Square Displacement ◽  
Particle Dynamics ◽  
Distribution Functions ◽  
Coupled Flow ◽  
Uhmwpe Composites ◽  
Ultra High Molecular Weight

The property of carbon nanotubes (CNTs)-based composites are significantly dependent on the orientation and dispersion evolution of CNTs in the polymer matrix. In this work, the dissipative particle dynamics (DPD) simulations are employed to discover the orientation and dispersion evolution of CNTs in ultra–high molecular weight polyethylene (UHMWPE) under extensional–shear coupled flow conditions for the first time. In this paper, we investigate the roles of the increasing extensional-shear coupled rate in morphology of CNTs/UHMWPE composites by varying CNTs concentration and observe that the system under consideration lies in the same evolution morphologies. When comparing our results for various morphologies, we notice that the orientation is affected more significantly by changing the extensional-shear coupled rates. A good alignment appears with an increase of extensional-shear coupled rates, which transform it into ordered morphology. In addition, a higher extensional-shear coupled rate does not necessarily contribute to better dispersion even though CNTs concentration varies, as shown by the mean square displacement (MSD) and the relative concentration distribution functions of CNTs in CNTs/UHMWPE composites.

A new shear technique: Semi Continuous Shear Flow (SCSF) in medium and ultra high molecular weight Polyhydroxybutyrate blends

2006 ◽  
Vol 41 (17) ◽  
pp. 5687-5695 ◽  
Author(s):  
Lakshmi Sharma ◽  
Yoshino Ogino ◽  
Toshiji Kanaya ◽  
Tadahisa Iwata ◽  
Yoshiharu Doi
Keyword(s):  
Molecular Weight ◽  
Shear Flow ◽  
High Molecular Weight ◽  
Continuous Shear ◽  
Ultra High Molecular Weight

Fiber Formation in Medium and Ultra-High-Molecular-Weight Polyhydroxybutyrate Blends under Shear Flow

2004 ◽  
Vol 289 (12) ◽  
pp. 1068-1073 ◽  
Author(s):  
Lakshmi Sharma ◽  
Yoshino Ogino ◽  
Toshiji Kanaya ◽  
Tadahisa Iwata ◽  
Yoshiharu Doi
Keyword(s):  
Molecular Weight ◽  
Shear Flow ◽  
High Molecular Weight ◽  
Fiber Formation ◽  
Ultra High Molecular Weight

scholarly journals APPLICATION OF DISSIPATIVE PARTICLE DYNAMICS TO THE STUDY OF A RED BLOOD CELL IN SIMPLE SHEAR FLOW

2014 ◽  
Vol 34 ◽  
pp. 1460373
Author(s):  
TING YE ◽  
NHAN PHAN-THIEN ◽  
BOO CHEONG KHOO ◽  
CHWEE TECK LIM
Keyword(s):  
Shear Flow ◽  
Blood Cell ◽  
Simple Shear ◽  
Red Blood Cell ◽  
Dissipative Particle Dynamics ◽  
Particle Dynamics ◽  
Simple Shear Flow ◽  
Past Study ◽  
Computational Domain ◽  
Membrane Particles

The present work reports an attempt to apply the dissipative particle dynamics (DPD) method to study the dynamic behaviors of a red blood cell (RBC) in simple shear flow. The simulation system is discretized into four types of particles, namely wall particles, fluid particles, membrane particles and internal particles. The particle interaction is modeled by the DPD method, and the membrane particles are connected into a viscoelastic triangular network to represent the RBC membrane. As benchmarking tests, we simulate the deformation of a spherical capsule in shear flow and compare it with the past study, and also examine the effect of computational domain size. After that, we investigate the dynamics of a RBC in shear flow at different membrane shear and bending moduli. Our simulations reproduce the tank-treading, trembling and tumbling motions of the RBC at the shear modulus Es = 6, 60 and 600 μN/m, respectively. Moreover, we find that the RBC undergoes a trembling motion when its bending modulus is large enough, where the obvious stretching and smoothing of the RBC occur alternately in shape.

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