Insights into interphase thickness characterization for graphene/epoxy nanocomposites: a molecular dynamics simulation

Sahraei, Abolfazl Alizadeh; Mokarizadeh, Abdol Hadi; George, D.; Rodrigue, Denis; Baniassadi, Majid; Foroutan, Masumeh

doi:10.1039/c9cp04091a

Cited by 35 publications

(29 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One notable point is that the peak magnitudes of the density profiles increased with increasing the crosslinking ratio (from 1.25 g/cc to 1.44 g/cc). In terms of the interactions between polymer-heterogeneous material, these results are quite different from those of other studies using epoxy resins, which reported a decrease in the peak magnitude with increasing crosslinking density [12,14,32]. This difference can be attributed to the structure of the polymer network generated during the crosslinking reaction.…”

Section: Density Distributions In the Interfacial Regions Of Hap/bc Bcontrasting

confidence: 96%

Computational Study on Interfacial Interactions between Polymethyl Methacrylate-Based Bone Cement and Hydroxyapatite in Nanoscale

Kim

Goh

Lee³

et al. 2021

Applied Sciences

View full text Add to dashboard Cite

Polymethyl methacrylate (PMMA)-based bone cement (BC) is a key material in joint replacement surgery that transfers external forces from the implant to the bone while allowing their robust binding. To quantitatively evaluate the effect of polymerization on the thermomechanical properties of the BC and on the interaction characteristics with the bone ceramic hydroxyapatite (HAp), molecular dynamics simulations were performed. The mechanical stiffness of the BC material under external loading increased gradually with the crosslinking reaction occurrence, indicating increasing load transfer between the constituent molecules. In addition, as the individual Methyl Methacrylate (MMA) segments were interconnected in the system, the freedom of the molecular network was largely suppressed, resulting in more thermally stable structures. Furthermore, the pull-out tests using HAp/BC bilayer models under different constraints (BC at 40% and 85%) revealed the cohesive characteristics of the BC with the bone scaffold in molecular detail. The stiffness and the fracture energy increased by 32% and 98%, respectively, with the crosslink density increasing.

show abstract

Section: Density Distributions In the Interfacial Regions Of Hap/bc Bcontrasting

confidence: 96%

Computational Study on Interfacial Interactions between Polymethyl Methacrylate-Based Bone Cement and Hydroxyapatite in Nanoscale

Kim

Goh

Lee³

et al. 2021

Applied Sciences

View full text Add to dashboard Cite

show abstract

“…Figure shows the distribution of nanocomposite mass density of DGEBA:TETA and DGEBA:DAB. As we described in our previous study, [ 47 ] to plot the mass density curve, we need to divide the structures into bins with a thickness of 0.05 Å along the z‐direction and calculate the atom mass to the bin volume ratio. The local mass density profile was achieved by plotting these densities as the function of the distance in the z‐direction.…”

Section: Resultsmentioning

confidence: 99%

“…The first five peaks at the beginning of the density curves are created due to the five layers of graphene at the bottom of the simulation boxes. [ 47 ] After the last graphene peak, there is a zero‐density area called the “vdW gap”. This gap is an equilibrium space created by the van der Waals interactions between the epoxy molecules and graphene layers.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Influence of Curing Agents Molecular Structures on Interfacial Characteristics of Graphene/Epoxy Nanocomposites: A Molecular Dynamics Framework

Siahtiri

Sahraei

Mokarizadeh

et al. 2023

Macro Materials & Eng

Self Cite

View full text Add to dashboard Cite

This paper presents a comprehensive molecular dynamics study on the effects of the stoichiometric ratio of epoxy:hardener, hardener's linear and cyclic structure, and number of aromatic rings on the interfacial characteristics of graphene/epoxy nanocomposite. The van der Waals gap and polymer peak density as a function of the type of the hardener is calculated by analyzing the local mass density profile. Additionally, steered molecular dynamics are used to conduct normal pull‐out of graphene to study the effect of the mentioned features of hardeners on the interfacial mechanical properties of nanocomposites, including traction force, separation distance, and distribution quality of reacted epoxide rings in the epoxy. Influence of the hardeners on the damage mechanism and its initiation point are also studied by analyzing the evolution of local mass density profile during the normal pull‐out simulation. It is seen that stoichiometric ratio and geometrical structure of the hardeners affect the interfacial strength. It is also revealed that the hardener type can change the epoxy damage initiation point. The damage occurs in the interphase region for a higher stoichiometric ratio or cyclic structure of hardener. In comparison, for hardener's lower stoichiometric ratio and non‐cyclic structure, failure begins in the epoxy near graphene layers.

show abstract

“…This technique captures the chemical details and, thus, describes chemistry-specific polymer–solid interactions. Polymer/graphene or polymer/graphite hybrid materials can serve as a good example of hybrid materials containing flat surfaces [ 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ]. In these studies, the properties are analyzed as a function of the distance from the flat surface, quantifying in such a way the extension of the interphase region, i.e., extension of the region of the altered properties with respect to expected bulk-like behavior of the given polymer.…”

Section: Introductionmentioning

confidence: 99%

Coupling between Polymer Conformations and Dynamics Near Amorphous Silica Surfaces: A Direct Insight from Atomistic Simulations

Bačová

Behbahani

et al. 2021

Nanomaterials

View full text Add to dashboard Cite

The dynamics of polymer chains in the polymer/solid interphase region have been a point of debate in recent years. Its understanding is the first step towards the description and the prediction of the properties of a wide family of commercially used polymeric-based nanostructured materials. Here, we present a detailed investigation of the conformational and dynamical features of unentangled and mildly entangled cis-1,4-polybutadiene melts in the vicinity of amorphous silica surface via atomistic simulations. Accounting for the roughness of the surface, we analyze the properties of the polymer chains as a function of their distance from the silica slab, their conformations and the chain molecular weight. Unlike the case of perfectly flat and homogeneous surfaces, the monomeric translational motion parallel to the surface was affected by the presence of the silica slab up to distances comparable with the extension of the density fluctuations. In addition, the intramolecular dynamical heterogeneities in adsorbed chains were revealed by linking the conformations and the structure of the adsorbed chains with their dynamical properties. Strong dynamical heterogeneities within the adsorbed layer are found, with the chains possessing longer sequences of adsorbed segments (“trains”) exhibiting slower dynamics than the adsorbed chains with short ones. Our results suggest that, apart from the density-dynamics correlation, the configurational entropy plays an important role in the dynamical response of the polymers confined between the silica slabs.

show abstract

Insights into interphase thickness characterization for graphene/epoxy nanocomposites: a molecular dynamics simulation

Abstract: This paper presents a methodology to systematically quantify the interphase thickness in epoxy nanocomposites using local mass density profile.

Cited by 35 publications

References 52 publications

Computational Study on Interfacial Interactions between Polymethyl Methacrylate-Based Bone Cement and Hydroxyapatite in Nanoscale

Computational Study on Interfacial Interactions between Polymethyl Methacrylate-Based Bone Cement and Hydroxyapatite in Nanoscale

Influence of Curing Agents Molecular Structures on Interfacial Characteristics of Graphene/Epoxy Nanocomposites: A Molecular Dynamics Framework

Coupling between Polymer Conformations and Dynamics Near Amorphous Silica Surfaces: A Direct Insight from Atomistic Simulations

Contact Info

Product

Resources

About