Effect of the degree of polymerization, crystallinity and sulfonation on the thermal behaviour of PEEK: a molecular dynamics-based study.

The safe and efficient working of fuel cells depends on the thermal management of the heat generated during the electrochemical process. The aim of the article is to study the thermal transport phenomenon in polyether ether ketone (PEEK) using molecular dynamics (MD) based simulations. MD simulations were performed in conjunction with hybrid force fields.

Thermal Transport Phenomena in PEGDA-Based Nanocomposite Hydrogels Using Atomistic and Experimental Techniques.

Poly(ethylene glycol) diacrylate (PEGDA) hydrogel is a very peculiar, fascinating material with good chemical stability and biocompatibility. However, the poor thermal transport phenomenon in PEGDA, limits its performance in cartilage replacement and developing therapies for treating burns. In this article, a combined experimental and atomistic approach was adopted to investigate the thermal transport phenomena in PEGDA hydrogel with different weight concentrations of boron nitride nanoplatelets as a function of water content.

Covalently bonded interface in polymer/boron nitride nanosheet composite toward enhanced mechanical and thermal behaviour.

This experimental study aimed to enhance the mechanical and thermal properties of BN (hexagonal boron nitride) nanosheet-reinforced high-density polyethylene by functionalizing its interface. The challenges associated with this nanocomposites are its poor dispersion and weak interface. Accordingly, to improve the load transfer at the interface, BN nanosheets were chemically modified with silane functional groups ((3-aminopropyl)tri-ethoxy silane), making it possible to form covalent bonds between the maleic anhydride-grafted polyethylene and nanosheet.

Effect of the degree of polymerization and water content on the thermal transport phenomena in PEGDA hydrogel: a molecular-dynamics-based study.

A hydrogel is a 3D cross-linked polymer network that can absorb copious amounts of water or biological fluid. Due to their biocompatibility and non-toxicity, hydrogels have a wide range of applications in biomedical engineering. To develop hydrogels with superior thermal dissipation properties, atomistic-level studies are required to quantify the effect of the water content and the degree of polymerization.

Mechanical strength of a nanoporous bicrystalline h-BN nanomembrane in a water submerged state.

Due to superior water permeability, structural stability, and adsorption capability, h-BN nanosheets are emerging as an efficient membrane for water desalination. In order to cater to the demand for potable water, large size membranes are required to maintain a high desalination rate from water purification systems. These large size membranes usually contain polycrystals with an offset in their mechanical properties from pristine h-BN nanosheets.

Atomistic simulations to study the effect of grain boundaries and hydrogen functionalization on the fracture toughness of bi-crystalline h-BN nanosheets.

The aim of this research article was to investigate the effect of grain boundaries (GBs), and hydrogen functionalisation on the fracture toughness of bi-crystalline hexagonal boron nitride (h-BN) nanosheets. Molecular dynamics based simulations were performed in conjunction with the reactive force field to study the crack tip behaviour in single and bi-crystalline h-BN nanosheets. Atomistic simulations help in predicting a positive effect of the GB plane in the near vicinity of the crack tip.

Enhanced thermal transport across a bi-crystalline graphene-polymer interface: an atomistic approach.

The objective of this investigation was to elaborate on the influence of grain boundaries on the interfacial thermal conductance between bi-crystalline graphene and polyethylene in a nanocomposite. Reverse non-equilibrium molecular dynamics simulations were implemented in combination with Lennard-Jones and reactive force field interatomic potential parameters. According to the simulation results, high-energy grain boundary atoms in bi-crystalline graphene played a substantial role in enhancing the interfacial thermal conductance values.

Molecular dynamics based simulations to study the fracture strength of monolayer graphene oxide.

The aim of this article is to study the effects of functional groups such as hydroxyl, epoxide and carboxyl on the fracture toughness of graphene. These functional groups form the backbone of the intrinsic atomic structure of graphene oxide (GO). Molecular dynamics based simulations were performed in conjunction with reactive force field parameters to capture the Mode-I fracture toughness of functionalised graphene.

Dislocation assisted crack healing in h-BN nanosheets.

Large size h-BN nanosheets are usually polycrystalline in nature and contain different types of grain boundaries. The low angle grain boundaries are usually referred as dislocations. The interaction of dislocations with the defects present in materials may affect the properties of materials.

The effect of STW defects on the mechanical properties and fracture toughness of pristine and hydrogenated graphene.

Graphene is emerging as a versatile material with a diverse field of applications. Synthesis techniques for graphene introduce several topological defects such as vacancies, dislocations and Stone-Thrower-Wales (STW) defects. Among them STW defects are generated without deleting any atom from the lattice position, but are introduced by rotating single C-C bonds.

Fracture toughness enhancement of h-BN monolayers via hydrogen passivation of a crack edge.

Molecular dynamics-based simulations were performed in conjunction with reactive force-field potential parameters to investigate the effect of crack-edge passivation via hydrogenation on the fracture properties of h-BN nanosheets. In semi-hydrogenated (H is attached to either B or N) and fully hydrogenated (H is attached to both B and N) crack-edge atoms, three hybridisation states-sp, sp and sp + sp-were considered in the simulations. Significant improvement in the fracture toughness of h-BN nanosheets was predicted with semi- and fully hydrogenated crack-edge atoms.

Optimised cut-off function for Tersoff-like potentials for a BN nanosheet: a molecular dynamics study.

In this article, molecular dynamics based simulations were carried out to study the tensile behaviour of boron nitride nanosheets (BNNSs). Four different sets of Tersoff potential parameters were used in the simulations for estimating the interatomic interactions between boron and nitrogen atoms. Modifications were incorporated in the Tersoff cut-off function to improve the accuracy of results with respect to fracture stress, fracture strain and Young's modulus.

Atomistic modeling of BN nanofillers for mechanical and thermal properties: a review.

Due to their exceptional mechanical properties, thermal conductivity and a wide band gap (5-6 eV), boron nitride nanotubes and nanosheets have promising applications in the field of engineering and biomedical science. Accurate modeling of failure or fracture in a nanomaterial inherently involves coupling of atomic domains of cracks and voids as well as a deformation mechanism originating from grain boundaries. This review highlights the recent progress made in the atomistic modeling of boron nitride nanofillers.

Multiscale model to investigate the effect of graphene on the fracture characteristics of graphene/polymer nanocomposites.

In this theoretical research work, the fracture characteristics of graphene-modified polymer nanocomposites were studied. A three-dimensional representative volume element-based multiscale model was developed in a finite element environment. Graphene sheets were modeled in an atomistic state, whereas the polymer matrix was modeled as a continuum.

Representative volume element to estimate buckling behavior of graphene/polymer nanocomposite.

The aim of the research article is to develop a representative volume element using finite elements to study the buckling stability of graphene/polymer nanocomposites. Research work exploring the full potential of graphene as filler for nanocomposites is limited in part due to the complex processes associated with the mixing of graphene in polymer. To overcome some of these issues, a multiscale modeling technique has been proposed in this numerical work.

Three Cavity Tunable MEMS Fabry Perot Interferometer.

In this paper a four-mirror tunable micro electro-mechanical systems (MEMS)Fabry Perot Interferometer (FPI) concept is proposed with the mathematical model. Thespectral range of the proposed FPI lies in the infrared spectrum ranging from 2400 to 4018(nm). FPI can be finely tuned by deflecting the two middle mirrors (or by changing the threecavity lengths).