scholarly journals Interface and Interphase in Polymer Nanocomposites with Bare and Core-Shell Gold Nanoparticles

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 541 ◽  
Author(s):  
Albert J. Power ◽  
Ioannis N. Remediakis ◽  
Vagelis Harmandaris
Keyword(s):  
Polymer Nanocomposites ◽  
Polymer Matrix ◽  
Md Simulations ◽  
Polymer Chains ◽  
Core Shell ◽  
Wulff Construction ◽  
Density Profiles ◽  
Au Nps ◽  
Polymeric Chains ◽  
Terminal Dynamics

Metal nanoparticles are used to modify/enhance the properties of a polymer matrix for a broad range of applications in bio-nanotechnology. Here, we study the properties of polymer/gold nanoparticle (NP) nanocomposites through atomistic molecular dynamics, MD, simulations. We probe the structural, conformational and dynamical properties of polymer chains at the vicinity of a gold (Au) NP and a functionalized (core/shell) Au NP, and compare them against the behavior of bulk polyethylene (PE). The bare Au NPs were constructed via a systematic methodology starting from ab-initio calculations and an atomistic Wulff construction algorithm resulting in the crystal shape with the minimum surface energy. For the functionalized NPs the interactions between gold atoms and chemically adsorbed functional groups change their shape. As a model polymer matrix we consider polyethylene of different molecular lengths, from the oligomer to unentangled Rouse like systems. The PE/Au interaction is parametrized via DFT calculations. By computing the different properties the concept of the interface, and the interphase as well, in polymer nanocomposites with metal NPs are critically examined. Results concerning polymer density profiles, bond order parameter, segmental and terminal dynamics show clearly that the size of the interface/interphase, depends on the actual property under study. In addition, the anchored polymeric chains change the behavior/properties, and especially the chain density profile and the dynamics, of the polymer chain at the vicinity of the Au NP.

Structure, dynamics and primitive path network of polymer nanocomposites containing spherical nanoparticles

2014 ◽  
Vol 1619 ◽  
Author(s):  
Argyrios Karatrantos ◽  
Nigel Clarke ◽  
Russel J. Composto ◽  
Karen I. Winey
Keyword(s):  
Polymer Nanocomposites ◽  
Volume Fraction ◽  
Md Simulations ◽  
Polymer Structure ◽  
Polymer Chains ◽  
Radius Of Gyration ◽  
Spherical Nanoparticles ◽  
Topological Constraints ◽  
Nanoparticle Radius ◽  
Entangled Polymer

ABSTRACTWe investigate the effect of nanoparticles on polymer structure, polymer dimensions and topological constraints (entanglements) in polymer melts for nanoparticle loading above percolation threshold as high as 40.9% using stochastic molecular dynamics (MD) simulations. We show unambiguously that short polymer chains are not disturbed by the presence of repulsive nanoparticles. In contrast entangled polymer chains can be perturbed by the presence of attractive nanoparticles when the polymer radius of gyration is larger than the nanoparticle radius. They can expand under the presence of attractive nanoparticles even at low nanoparticle loadings of very small nanoparticle size. We observe an increase in the number of entanglements (decrease of Ne with 40.9% volume fraction of nanoparticles dispersed in the polymer matrix) in the nanocomposites as evidenced by larger contour lengths of the primitive paths. Attraction between polymers and nanoparticles affects the entanglements in the nanocomposites and alters the primitive path.

scholarly journals Recent Advances in the Synthesis of Polymer-Grafted Low-K and High-K Nanoparticles for Dielectric and Electronic Applications

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2942
Author(s):  
Bhausaheb V. Tawade ◽  
Ikeoluwa E. Apata ◽  
Nihar Pradhan ◽  
Alamgir Karim ◽  
Dharmaraj Raghavan
Keyword(s):  
Energy Density ◽  
Polymer Nanocomposites ◽  
High Performance ◽  
Breakdown Strength ◽  
Polymer Nanocomposite ◽  
High Energy ◽  
Polymer Chains ◽  
High Energy Density ◽  
Grafted Nanoparticles ◽  
Grafting From

The synthesis of polymer-grafted nanoparticles (PGNPs) or hairy nanoparticles (HNPs) by tethering of polymer chains to the surface of nanoparticles is an important technique to obtain nanostructured hybrid materials that have been widely used in the formulation of advanced polymer nanocomposites. Ceramic-based polymer nanocomposites integrate key attributes of polymer and ceramic nanomaterial to improve the dielectric properties such as breakdown strength, energy density and dielectric loss. This review describes the ”grafting from” and ”grafting to” approaches commonly adopted to graft polymer chains on NPs pertaining to nano-dielectrics. The article also covers various surface initiated controlled radical polymerization techniques, along with templated approaches for grafting of polymer chains onto SiO2, TiO2, BaTiO3, and Al2O3 nanomaterials. As a look towards applications, an outlook on high-performance polymer nanocomposite capacitors for the design of high energy density pulsed power thin-film capacitors is also presented.

scholarly journals Investigation of Ring and Star Polymers in Confined Geometries: Theory and Simulations

Entropy ◽  
2021 ◽  
Vol 23 (2) ◽  
pp. 242
Author(s):  
Joanna Halun ◽  
Pawel Karbowniczek ◽  
Piotr Kuterba ◽  
Zoriana Danel
Keyword(s):  
Star Polymers ◽  
Polymer Chains ◽  
The Other ◽  
Nano Particles ◽  
Dilute Solution ◽  
Confined Geometries ◽  
Density Profiles ◽  
Ideal Ring ◽  
Ring Polymer ◽  
Monomer Density

The calculations of the dimensionless layer monomer density profiles for a dilute solution of phantom ideal ring polymer chains and star polymers with f=4 arms in a Θ-solvent confined in a slit geometry of two parallel walls with repulsive surfaces and for the mixed case of one repulsive and the other inert surface were performed. Furthermore, taking into account the Derjaguin approximation, the dimensionless layer monomer density profiles for phantom ideal ring polymer chains and star polymers immersed in a solution of big colloidal particles with different adsorbing or repelling properties with respect to polymers were calculated. The density-force relation for the above-mentioned cases was analyzed, and the universal amplitude ratio B was obtained. Taking into account the small sphere expansion allowed obtaining the monomer density profiles for a dilute solution of phantom ideal ring polymers immersed in a solution of small spherical particles, or nano-particles of finite size, which are much smaller than the polymer size and the other characteristic mesoscopic length of the system. We performed molecular dynamics simulations of a dilute solution of linear, ring, and star-shaped polymers with N=300, 300 (360), and 1201 (4 × 300 + 1-star polymer with four arms) beads accordingly. The obtained analytical and numerical results for phantom ring and star polymers are compared with the results for linear polymer chains in confined geometries.

Graft Polymers Derived from Natural Rubber

1956 ◽  
Vol 29 (1) ◽  
pp. 99-105 ◽  
Author(s):  
G. F. Bloomfield ◽  
F. M. Merrett ◽  
F. J. Popham ◽  
P. Mc L. Swift
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Methyl Methacrylate ◽  
Transfer Reaction ◽  
Polymer Chains ◽  
Vinyl Monomers ◽  
Grafted Polymer ◽  
Polymeric Chains ◽  
Graft Polymers ◽  
Direct Growth

Abstract Graft polymers result when vinyl monomers are polymerized in the presence of natural rubber, either in solution or as latex, and some of the polymeric chains become attached to the rubber molecules. The properties of the natural rubber can be widely modified according to the nature and the amount of the grafted polymer. The polymer-modified natural rubber appears to be produced by direct growth of polymer chains on to rubber molecules rather than by a transfer reaction involving the rubber. Graft polymers of styrene and methyl methacrylate with natural rubber can be compounded and cured to give light-colored articles of good tensile strength, and rubber-methyl methacrylate graft polymers have outstanding flex-cracking and fatigue resistance.

Molecular Dynamics Simulation of a Pullout Test on a Carbon Nanotube in a Polymer Matrix

2014 ◽  
Vol 1700 ◽  
pp. 61-66
Author(s):  
Guttormur Arnar Ingvason ◽  
Virginie Rollin
Keyword(s):  
Molecular Dynamics ◽  
Polymer Matrix ◽  
Large Scale ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Atomistic Simulations ◽  
Polymer Molecules ◽  
Molecular Potential ◽  
Pull Out ◽  
Walled Carbon Nanotubes

ABSTRACTAdding single walled carbon nanotubes (SWCNT) to a polymer matrix can improve the delamination properties of the composite. Due to the complexity of polymer molecules and the curing process, few 3-D Molecular Dynamics (MD) simulations of a polymer-SWCNT composite have been run. Our model runs on the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS), with a COMPASS (Condensed phase Optimized Molecular Potential for Atomistic Simulations Studies) potential. This potential includes non-bonded interactions, as well as bonds, angles and dihedrals to create a MD model for a SWCNT and EPON 862/DETDA (Diethyltoluenediamine) polymer matrix. Two simulations were performed in order to test the implementation of the COMPASS parameters. The first one was a tensile test on a SWCNT, leading to a Young’s modulus of 1.4 TPa at 300K. The second one was a pull-out test of a SWCNT from an originally uncured EPON 862/DETDA matrix.

The reinforcing and characteristics of interphase as the polymer chains adsorbed on the nanoparticles in polymer nanocomposites

2017 ◽  
Vol 295 (10) ◽  
pp. 2001-2010 ◽  
Author(s):  
Nafiseh Nikfar ◽  
Milad Esfandiar ◽  
Mohammad Reza Shahnazari ◽  
Navid Mojtahedi ◽  
Yasser Zare
Keyword(s):  
Polymer Nanocomposites ◽  
Polymer Chains

Syntheses and crystal structures of two magnesium–tetrazole compounds in salt and polymeric forms

2015 ◽  
Vol 71 (3) ◽  
pp. 222-228 ◽  
Author(s):  
Mohamed Abdellatif Bensegueni ◽  
Aouatef Cherouana ◽  
Slimane Dahaoui
Keyword(s):  
Alkaline Earth ◽  
Three Dimensional ◽  
Polymer Chains ◽  
Magnesium Ion ◽  
Water Molecules ◽  
Compound I ◽  
Hydrothermal Conditions ◽  
One Dimensional ◽  
Polymeric Chains ◽  
Hydrogen Bonded

Two alkaline earth–tetrazole compounds, namelycatena-poly[[[triaquamagnesium(II)]-μ-5,5′-(azanediyl)ditetrazolato-κ3N1,N1′:N5] hemi{bis[μ-5,5′-(azanediyl)ditetrazolato-κ3N1,N1′:N2]bis[triaquamagnesium(II)]} monohydrate], {[Mg(C2HN9)(H2O)3][Mg2(C2HN9)2(H2O)6]0.5·H2O}n, (I), and bis[5-(pyrazin-2-yl)tetrazolate] hexaaquamagnesium(II), (C5H3N6)[Mg(H2O)6], (II), have been prepared under hydrothermal conditions. Compound (I) is a mixed dimer–polymer based on magnesium ion centres and can be regarded as the first example of a magnesium–tetrazolate polymer in the crystalline form. The structure shows a complex three-dimensional hydrogen-bonded network that involves magnesium–tetrazolate dimers, solvent water molecules and one-dimensional magnesium–tetrazolate polymeric chains. The intrinsic cohesion in the polymer chains is ensured by N—H...N hydrogen bonds, which formR22(7) rings, thus reinforcing the propagation of the polymer chain along theaaxis. The crystal structure of magnesium tetrazole salt (II) reveals a mixed ribbon of hydrogen-bonded rings, of typesR22(7),R22(9) andR24(10), running along thecaxis, which are linked byR24(16) rings, generating a 4,8-cflunet.

Interlamellar Incorporation of Charged Polymer Nanobeads into Sodium Montmorillonite

2004 ◽  
Vol 847 ◽  
Author(s):  
Svetlana Khvan ◽  
Sang-Soo Lee ◽  
Junkyung Kim
Keyword(s):  
Polymer Matrix ◽  
Surface Characterization ◽  
Particle Surface ◽  
Polymer Particle ◽  
Polymer Chains ◽  
Sem Images ◽  
Tof Sims ◽  
Strong Adhesion ◽  
Density Surface ◽  
Cationic Exchange

ABSTRACTComplete delamination of clay in polymer matrix has been strongly prohibited due to strong adhesion of guest polymer chains between hydrophilic clay as well as degradation and desorption of organic materials in the gallery at high temperature. Incorporation of charged nanosized polystyrene beads directly into the gallery of pristine clay through exfoliation-exchange mechanism has been proposed to overcome the drawbacks.Synthesis of polymer nanobeads via emulsifier-free emulsion polymerization allowed to achieving formation of particles of appropriate particle size and surface charge density. Surface characterization, performed with XPS and ToF SIMS, has provided the results on the existence and the nature of the functional groups on the polymer particle surface, which have been found to be in a good compliance.Morphology of polymer-incorporated clay was observed from TEM, FE-SEM images. Study on mechanism of incorporation via XRD, XPS, ToF-SIMS suggested that adsorption of polymer nanobeads through cationic exchange of intergallery cation of clay for onium ion at the surface of polymer nanobead not only improves compatibility of clay with polymer matrix, but, what is essential, dramatically promotes expansion of clay gallery.

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