scholarly journals Structural and Mechanical Properties of Ionic Di-block Copolymers via a Molecular Dynamics Approach

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1546
Author(s):  
Mengze Ma ◽  
Yao Fu
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Block Copolymers ◽  
Electrostatic Interactions ◽  
Glassy State ◽  
Limited Range ◽  
Dynamics Simulation ◽  
Charge Ratio ◽  
Coarse Grained ◽  
Coulombic Interaction

Polymerized ionic copolymers have recently evolved as a new class of materials to overcome the limited range of mechanical properties of ionic homopolymers. In this paper, we investigate the structural and mechanical properties of charged ionic homopolymers and di-block copolymers, while using coarse-grained molecular dynamics simulation. Tensile and compressive deformation are applied to the homopolymers and copolymers in the glassy state. The effect of charge ratio and loading direction on the stress-strain behavior are studied. It is found that the electrostatic interactions among charged pairs play major roles, as evidenced by increased Young’s modulus and yield strength with charge ratio. Increased charge ratio lead to enhanced stress contribution from both bonding and pairwise (Van der Waals + coulombic) interaction. The increase in the gyration of the radius is observed with increasing charge ratio in homopolymers, yet a reversed tendency is observed in copolymers. Introduced charge pairs leads to an increased randomness in the segmental orientation in copolymers.

Stress–strain behavior of block-copolymers and their nanocomposites filled with uniform or Janus nanoparticles under shear: a molecular dynamics simulation

2016 ◽  
Vol 18 (39) ◽  
pp. 27232-27244 ◽  
Author(s):  
Lu Wang ◽  
Hongji Liu ◽  
Fanzhu Li ◽  
Jianxiang Shen ◽  
Zijian Zheng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Block Copolymers ◽  
Dynamics Simulation ◽  
Stress Strain ◽  
Ordered Structures ◽  
Strain Behavior ◽  
Janus Nanoparticles

We adopted molecular dynamics simulation to study the relation between the ordered structures and the resulting mechanical properties of block copolymers filled with uniform or Janus nanoparticles.

Investigation of the Microscopic Viscoelastic Property for Cross-linked Polymer Network by Molecular Dynamics Simulation

2011 ◽  
Vol 39 (1) ◽  
pp. 44-58 ◽  
Author(s):  
Y. Masumoto ◽  
Y. Iida
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Analytical Method ◽  
Viscoelastic Properties ◽  
Polymer Network ◽  
Dynamics Simulation ◽  
Coarse Grained ◽  
The Cross ◽  
Microscopic Dynamic ◽  
Coarse Grained Molecular Dynamics

Abstract The purpose of this work is to develop a new analytical method for simulating the microscopic mechanical property of the cross-linked polymer system using the coarse-grained molecular dynamics simulation. This new analytical method will be utilized for the molecular designing of the tire rubber compound to improve the tire performances such as rolling resistance and wet traction. First, we evaluate the microscopic dynamic viscoelastic properties of the cross-linked polymer using coarse-grained molecular dynamics simulation. This simulation has been conducted by the coarse-grained molecular dynamics program in the OCTA) (http://octa.jp/). To simplify the problem, we employ the bead-spring model, in which a sequence of beads connected by springs denotes a polymer chain. The linear polymer chains that are cross-linked by the cross-linking agents express the three-dimensional cross-linked polymer network. In order to obtain the microscopic dynamic viscoelastic properties, oscillatory deformation is applied to the simulation cell. By applying the time-temperature reduction law to this simulation result, we can evaluate the dynamic viscoelastic properties in the wide deformational frequency range including the rubbery state. Then, the stress is separated into the nonbonding stress and the bonding stress. We confirm that the contribution of the nonbonding stress is larger at lower temperatures. On the other hand, the contribution of the bonding stress is larger at higher temperatures. Finally, analyzing a change of microscopic structure in dynamic oscillatory deformation, we determine that the temperature/frequency dependence of bond stress response to a dynamic oscillatory deformation depends on the temperature dependence of the average bond length in the equilibrium structure and the temperature/frequency dependence of bond orientation. We show that our simulation is a useful tool for studying the microscopic properties of a cross-linked polymer.

Coarse-grained simulation of the self-assembly of lipid vesicles concomitantly with novel block copolymers with multiple tails

Soft Matter ◽  
2021 ◽  
Author(s):  
Alexander Kantardjiev
Keyword(s):  
Molecular Dynamics ◽  
Block Copolymers ◽  
Self Assembly ◽  
Lipid Vesicles ◽  
The Self ◽  
Coarse Grained ◽  
Copolymer Concentration ◽  
Copolymer Structure ◽  
Coarse Grained Molecular Dynamics

We carried out a series of coarse-grained molecular dynamics liposome-copolymer simulations with varying extent of copolymer concentration in an attempt to understand the effect of copolymer structure and concentration on vesicle self-assembly and stability.

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