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Modeling of polyethylene, poly(l-lactide), and CNT composites: a dissipative particle dynamics study.

Wang YC, Ju SP, Huang TJ, Wang HH - Nanoscale Res Lett (2011)

Bottom Line: Dissipative particle dynamics (DPD), a mesoscopic simulation approach, is used to investigate the effect of volume fraction of polyethylene (PE) and poly(l-lactide) (PLLA) on the structural property of the immiscible PE/PLLA/carbon nanotube in a system.In this work, the interaction parameter in DPD simulation, related to the Flory-Huggins interaction parameter χ, is estimated by the calculation of mixing energy for each pair of components in molecular dynamics simulation.Unlike the blend system, where no relationship exists between the micro-structure and the equilibrated structure, in the di-block copolymer system, the micro-structure and equilibrated structure have specific relationships.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mechanical and Electro-Mechanical Engineering, Center for Nanoscience and Nanotechnology, National Sun Yat-sen University, Kaohsiung, Taiwan 804. jushin-pon@mail.nsysu.edu.tw.

ABSTRACT
Dissipative particle dynamics (DPD), a mesoscopic simulation approach, is used to investigate the effect of volume fraction of polyethylene (PE) and poly(l-lactide) (PLLA) on the structural property of the immiscible PE/PLLA/carbon nanotube in a system. In this work, the interaction parameter in DPD simulation, related to the Flory-Huggins interaction parameter χ, is estimated by the calculation of mixing energy for each pair of components in molecular dynamics simulation. Volume fraction and mixing methods clearly affect the equilibrated structure. Even if the volume fraction is different, micro-structures are similar when the equilibrated structures are different. Unlike the blend system, where no relationship exists between the micro-structure and the equilibrated structure, in the di-block copolymer system, the micro-structure and equilibrated structure have specific relationships.

No MeSH data available.


The equilibrated structure at 6/14/1 volume fraction with blend method.
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Figure 3: The equilibrated structure at 6/14/1 volume fraction with blend method.

Mentions: Figure 2c,d shows the equilibrated structures, which are perforated lamellae and tube-like structures at 6/14/1 volume for blend and di-block copolymer methods, respectively. Figure 3a shows the CNT structure which forms three cylindrical structures. Compared to Figure 2a, the CNTs do not disperse at this volume fraction. The reason for this is that the repulsive interaction parameter between CNTs and PE polymers is larger than that between the same materials. As can be seen from Table 3, the repulsive interaction parameter between PLLA polymer and CNTs is the largest, and that between PLLA and PE polymer is just smaller than that between PLLA and CNTs. Therefore, there are two possible structural types for the CNTs in the polymer/CNT matrix. First, they form the cylindrical structure and are covered by PLLA polymers. Second, they are surrounded by PE polymers, and these PE polymers are surrounded by PLLA polymers. Figures 3b and 2d show the two structural types in the polymer/CNTs matrix. In Figure 2d, almost all of the CNTs are surrounded by PE polymers. This is due to the restrained movement and the relationship of repulsive interaction parameters. It is impossible for CNTs to exist in the middle of PE and PLLA polymers because of the connection between PE and PLLA polymers. In addition, the repulsive interaction parameter between PE and CNT is significantly smaller than that between PLLA and CNT. Therefore, CNTs can only be inside the PE polymers which are covered by the PLLA polymers.


Modeling of polyethylene, poly(l-lactide), and CNT composites: a dissipative particle dynamics study.

Wang YC, Ju SP, Huang TJ, Wang HH - Nanoscale Res Lett (2011)

The equilibrated structure at 6/14/1 volume fraction with blend method.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211851&req=5

Figure 3: The equilibrated structure at 6/14/1 volume fraction with blend method.
Mentions: Figure 2c,d shows the equilibrated structures, which are perforated lamellae and tube-like structures at 6/14/1 volume for blend and di-block copolymer methods, respectively. Figure 3a shows the CNT structure which forms three cylindrical structures. Compared to Figure 2a, the CNTs do not disperse at this volume fraction. The reason for this is that the repulsive interaction parameter between CNTs and PE polymers is larger than that between the same materials. As can be seen from Table 3, the repulsive interaction parameter between PLLA polymer and CNTs is the largest, and that between PLLA and PE polymer is just smaller than that between PLLA and CNTs. Therefore, there are two possible structural types for the CNTs in the polymer/CNT matrix. First, they form the cylindrical structure and are covered by PLLA polymers. Second, they are surrounded by PE polymers, and these PE polymers are surrounded by PLLA polymers. Figures 3b and 2d show the two structural types in the polymer/CNTs matrix. In Figure 2d, almost all of the CNTs are surrounded by PE polymers. This is due to the restrained movement and the relationship of repulsive interaction parameters. It is impossible for CNTs to exist in the middle of PE and PLLA polymers because of the connection between PE and PLLA polymers. In addition, the repulsive interaction parameter between PE and CNT is significantly smaller than that between PLLA and CNT. Therefore, CNTs can only be inside the PE polymers which are covered by the PLLA polymers.

Bottom Line: Dissipative particle dynamics (DPD), a mesoscopic simulation approach, is used to investigate the effect of volume fraction of polyethylene (PE) and poly(l-lactide) (PLLA) on the structural property of the immiscible PE/PLLA/carbon nanotube in a system.In this work, the interaction parameter in DPD simulation, related to the Flory-Huggins interaction parameter χ, is estimated by the calculation of mixing energy for each pair of components in molecular dynamics simulation.Unlike the blend system, where no relationship exists between the micro-structure and the equilibrated structure, in the di-block copolymer system, the micro-structure and equilibrated structure have specific relationships.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mechanical and Electro-Mechanical Engineering, Center for Nanoscience and Nanotechnology, National Sun Yat-sen University, Kaohsiung, Taiwan 804. jushin-pon@mail.nsysu.edu.tw.

ABSTRACT
Dissipative particle dynamics (DPD), a mesoscopic simulation approach, is used to investigate the effect of volume fraction of polyethylene (PE) and poly(l-lactide) (PLLA) on the structural property of the immiscible PE/PLLA/carbon nanotube in a system. In this work, the interaction parameter in DPD simulation, related to the Flory-Huggins interaction parameter χ, is estimated by the calculation of mixing energy for each pair of components in molecular dynamics simulation. Volume fraction and mixing methods clearly affect the equilibrated structure. Even if the volume fraction is different, micro-structures are similar when the equilibrated structures are different. Unlike the blend system, where no relationship exists between the micro-structure and the equilibrated structure, in the di-block copolymer system, the micro-structure and equilibrated structure have specific relationships.

No MeSH data available.