MORPHOLOGICAL PROPERTIES OF PYRROLE AND PHENYLENE ROD–COIL DIBLOCK COPOLYMERS BY DISSIPATIVE PARTICLE DYNAMICS

2013 ◽  
Vol 12 (01) ◽  
pp. 1250100 ◽  
Author(s):  
EROL YILDIRIM ◽  
MINE YURTSEVER

Poly (para-phenylene)s (PPP) and polypyrroles (PPy) are important members of the conducting polymers. Rod–coil type diblock copolymers formed by coupling of PPP and PPy rigid blocks with polycaprolactone (PCL), polystyrene (PS) and polymethylmethacrylate (PMMA) coil blocks were modeled and morphological properties have been studied by a coarse grained simulation method at the mesoscale. Geometry optimizations and the atomic charge calculations were done quantum mechanically to obtain the input parameters for the mesoscale dynamics simulations. The accurate mixing energies and the Flory–Huggins interaction parameters between the monomers of polymers were calculated and used to study the phase behaviors and the morphologies of the copolymers as a function of type and weight percentages of the blocks by Dissipative Particle Dynamics (DPD) simulations. We showed that the methodology employed took into account not only the interaction parameter and chain length of the blocks but also the chemical structure of the polymers and it could be used to produce the phase diagram of the copolymers which has importance for the industrial applications of such materials. Among the studied copolymers, the most suitable one for thin layer applications was predicted to be PPP–b–PCL in which PPP forms lamellar and cylindrical phases in the PCL matrix if amount of PPP rod block is below 50 wt%.

Soft Matter ◽  
2021 ◽  
Author(s):  
Rakesh K Vaiwala ◽  
Ganapathy Ayappa

A coarse-grained force field for molecular dynamics simulations of native structures of proteins in a dissipative particle dynamics (DPD) framework is developed. The parameters for bonded interactions are derived by...


e-Polymers ◽  
2016 ◽  
Vol 16 (4) ◽  
pp. 343-349 ◽  
Author(s):  
Ya-Juan Su ◽  
Ze-Xin Ma ◽  
Jian-Hua Huang

AbstractDissipative particle dynamics simulations are performed to study the self-assembly of rod-coil (RC) diblock copolymers confined in a slit with two coil-selective surfaces. The effect of rod length and slit thickness on the assembly structure is investigated. A morphological phase diagram as a function of slit thickness and rod length is presented. We observe several ordered structures, such as perpendicular cylinders, parallel cylinders, and puck-shaped structure. In the assembly structures, long-range rod-rod orientational order is observed when the rod length exceeds a critical rod length. Our results show that the coil-selective slit influences the assembly structure as well as the rod orientation of RC diblock copolymers.


Author(s):  
M. Lemaalem ◽  
A. Derouiche ◽  
S. EL Fassi ◽  
H. Ridouane

Long polymer chains that mainly exhibit thermoplastic properties are recognized to demonstrate excellent thermal and mechanical features at the molecular level. For the purpose of facilitating its study, we present the results of a coarse-grained Molecular Dynamics (MD) and Dissipative Particle Dynamics (DPD) simulations under the Canonical ensemble (NVT) conditions. For each simulation method, the structure, static and dynamic properties were analyzed, with particular emphasis on the influence of density and temperature on the equilibrium of the polymer. We find, after correcting the Soft Repulsive Potential (SRP) parameters used in DPD method, that both simulation methods describe the polymer physics with the same accuracy. This proves that the DPD method can simplify the polymer simulation and can reproduce with the same precision the equilibrium obtained in the MD simulation.


1998 ◽  
Vol 09 (08) ◽  
pp. 1307-1318 ◽  
Author(s):  
Edo S. Boek ◽  
Paul Van Der Schoot

Dissipative Particle Dynamics (DPD) simulations were performed to investigate resolution or "coarse graining" effects on the simulation results. Fluid flow through a periodic array of spheres has been studied as a model for fluid filtration into a porous medium. In our model system, it appears that quantitatively correct results for the dimensionless drag can be obtained for relatively small system sizes. For higher solid volume fractions, it is necessary to increase the system size to avoid finite size and resolution effects. Simulations of colloidal spheres suspended in a DPD fluid show effective attraction between the large colloid particles, causing depletion aggregation. This effect may be expected as a consequence of the coarse-grained nature of the DPD fluid. By imposing a steady shear rate the aggregation can be suppressed. The results show that for dilute suspensions, the Brownian noise in the particle interactions causes an effective colloid polydispersity, which suppresses aggregation effects.


2016 ◽  
Vol 18 (38) ◽  
pp. 26519-26529 ◽  
Author(s):  
Xiaofang Zhang ◽  
Wenjing Lin ◽  
Liyang Wen ◽  
Na Yao ◽  
Shuyu Nie ◽  
...  

We provide a mesoscopic insight into the micellar behavior of unimolecular polymeric micelles via dissipative particle dynamics simulations.


2019 ◽  
Author(s):  
James McDonagh ◽  
Ardita Shkurti ◽  
David J. Bray ◽  
Richard L. Anderson ◽  
Edward O. Pyzer-Knapp

This work demonstrates the use of open literature data to force field paramterization via a novel approach applying Bayesian optimization. We have selected Dissipative Particle Dynamics (DPD) as the simulation method in this proof-of-concept work.


2017 ◽  
Vol 1 (4) ◽  
pp. 697-708 ◽  
Author(s):  
Zhou Guan ◽  
Liquan Wang ◽  
Xingyu Zhu ◽  
Jiaping Lin

In this work, the structures and topological defects of striped patterns self-assembled from rod–coil diblock copolymers confined on spherical substrates were examined using dissipative particle dynamics simulations.


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