Molecular dynamics simulation of polymers adsorbed onto an alumina surface

Cheng, Chang-Yuan; Lee, Kuei-Jen; Li, Yong; Wang, Bo-Cheng

doi:10.1163/156856198x00245

Cited by 7 publications

(4 citation statements)

References 28 publications

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“…An initial distance of 10 nm was used in this study. The thickness of the surfaces was selected to be 1.3 nm 17 . A single PAA chain consisting of 50–70 acrylic acid monomers with a specified M w of 5000 in the atactic configuration was constructed and packed into a cubic simulation cell at a density of 0.9 g/cm 3 .…”

Section: Computational Methodologymentioning

confidence: 99%

Adsorption of PAA on the α‐Al₂O₃ Surface

Chen

Wang

Hsu

et al. 2007

Journal of the American Ceramic Society

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The specific system of interest is the polyacrylic acid (PAA) and (0001) a-Al 2 O 3 surface, which was modeled and simulated by Cerius 2 4.9 software with empirical potentials. The simulation predicted that the adsorbed conformations of PAA with a molecular weight (M w ) of 5000 were train and tail at pH o4 and >10, respectively. After gradually inserting additional PAA molecular chains, the adsorption reached a saturated amount. Gel permeation chromatography experimental results showed that the adsorption amount at pH 3.6 was three times greater than that at pH 11. Based on the results from simulations and experiments, a successively increasing pH environment was modeled to illustrate the possibility of optimizing electro-steric effects by combining the higher adsorption density at a lower pH and strong steric repulsion of tail-adsorbed configuration at a higher pH.

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Section: Computational Methodologymentioning

confidence: 99%

Adsorption of PAA on the α‐Al₂O₃ Surface

Chen

Wang

Hsu

et al. 2007

Journal of the American Ceramic Society

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“…The structure and dynamics of polymer chains at interfaces have been extensively studied using both molecular dynamics (MD) − and Monte Carlo simulations. − The results gathered from these theoretical studies provide limited insight into, for example, the factors that control the intercalation of the polymer chains in the gallery, the role played by the surfactant molecules, or the factors that contribute to the complete dispersion of the sheets. A mean field lattice approach developed by Vaia et al , for a system consisting of polymer chains and surfactant chains tethered to silica surfaces has provided a qualitative overview of the conditions that promote intercalation and exfoliation.…”

Section: Introductionmentioning

confidence: 99%

“…The structure and dynamics of polymer chains at interfaces have been extensively studied using both molecular dynamics (MD) [2][3][4][5][6][7][8][9][10][11][12] and Monte Carlo simulations. [13][14][15][16][17][18] The results gathered from these theoretical studies provide limited insight into, for example, the factors that control the intercalation of the polymer chains in the gallery, the role played by the surfactant molecules, or the factors that contribute to the complete dispersion of the sheets.…”

Section: Introductionmentioning

confidence: 99%

Molecular Dynamics Simulations of Nanocomposites Based on Poly(ε-caprolactone) Grafted on Montmorillonite Clay

2005

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Intercalated and exfoliated models of polymer nanocomposites based on poly(epsilon-caprolactone) and functionalized montmorillonite clay are studied by means of molecular dynamics simulations. Intercalated and exfoliated models are considered for probing the structural characteristics of the corresponding nanocomposites prepared by melt intercalation and in situ polymerization, respectively. In the exfoliated system, the organization of the polymer chains onto the clay surface is examined in terms of the density profiles and the order parameter function. A layered structure can clearly be seen to form near the surface with density maxima higher than in amorphous poly(epsilon-caprolactone). This can be viewed as an increase in effective particle thickness, which can contribute to the outstanding gas barrier properties of the exfoliated nanocomposites. The comparison of the structures and energetics of the intercalated model with those of a nanocomposite model based on a nonfunctionalized clay indicates nearly similar characteristics. Nevertheless, the slight differences observed for the interfacial polymer density and clay- and surfactant-polymer binding energies can account for the differences in rheological measurements. The results also suggest that the difference in morphology obtained for the nanocomposites prepared by the two synthetic approaches can be ascribed to both a difference in interfacial polymer density and the formation of bridging polymer chain structures that hinder the exfoliation process.

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“…Molecular dynamics (MD) simulation is a method to obtain the interfacial behavior and properties of materials at the atomic or molecular scale level, which can provide detailed insights into molecular diffusion and interactions across the interface caused by chemical bonding. It has been used to determine the properties of metal/metal [ 9 , 10 ], polymer/metal [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ], polymer/ceramics [ 18 , 19 ], polymer/fiber [ 20 , 21 , 22 , 23 , 24 ], polymer/polymer [ 25 , 26 , 27 , 28 ] and even polymer/nanoparticle [ 29 ] interfaces. In particular, Wang et al [ 25 ] investigated the interfacial energy of hybrid composites through MD methods.…”

Section: Introductionmentioning

confidence: 99%

Molecular Dynamics Simulation on the Interfacial Behavior of Over-Molded Hybrid Fiber Reinforced Thermoplastic Composites

et al. 2020

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Hybrid fiber reinforced thermoplastic composites are receiving important attention in lightweight applications. The fabrication process of hybrid thermoplastic composites is that discontinuous fiber reinforced thermoplastics are injected onto the continuous fiber reinforced thermoplastics by over-molding techniques. The key issue during this process is to get a reliable interfacial bonding strength. To understand the bonding mechanism at the heterogeneous interface of hybrid thermoplastic composites which is difficult to obtain through experimental investigations, a series of molecular dynamic (MD) simulations were conducted in this paper. The influence of processing parameters on the interfacial characteristics, i.e., the distribution of interfacial high-density enrichment areas, radius of gyration, diffusion coefficient and interfacial energy, were investigated during the forming process of a heterogeneous interface. Simulation results reveal that some of molecule chains get across the interface and tangle with the molecules from the other layer, resulting in the penetration phenomenon near the interface zone. In addition, the melting temperature and injection pressure exhibit positive effects on the interfacial properties of hybrid composites. To further investigate the interfacial bonding strength and fracture mechanism of the heterogeneous interface, the uniaxial tensile and sliding simulations were performed. Results show that the non-bonded interaction energy plays a crucial role during the fracture process of heterogeneous interface. Meanwhile, the failure mode of the heterogeneous interface was demonstrated to evolve with the processing parameters.

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Molecular dynamics simulation of polymers adsorbed onto an alumina surface

Cited by 7 publications

References 28 publications

Adsorption of PAA on the α‐Al₂O₃ Surface

Adsorption of PAA on the α‐Al₂O₃ Surface

Molecular Dynamics Simulations of Nanocomposites Based on Poly(ε-caprolactone) Grafted on Montmorillonite Clay

Molecular Dynamics Simulation on the Interfacial Behavior of Over-Molded Hybrid Fiber Reinforced Thermoplastic Composites

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Molecular dynamics simulation of polymers adsorbed onto an alumina surface

Cited by 7 publications

References 28 publications

Adsorption of PAA on the α‐Al2O3 Surface

Adsorption of PAA on the α‐Al2O3 Surface

Molecular Dynamics Simulations of Nanocomposites Based on Poly(ε-caprolactone) Grafted on Montmorillonite Clay

Molecular Dynamics Simulation on the Interfacial Behavior of Over-Molded Hybrid Fiber Reinforced Thermoplastic Composites

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Adsorption of PAA on the α‐Al₂O₃ Surface

Adsorption of PAA on the α‐Al₂O₃ Surface