Graphene/Hyperbranched Polymer Nanocomposites: Insight from Molecular Dynamics Simulations

Abstract

We explore by means of molecular dynamics (MD) simulations mixtures of graphene with hyperbranched polyesters (Boltorn) of two different pseudogenerations in a wide range of temperatures. Static and dynamic features of the polymeric component are probed in order to assess the effects of the presence of graphene in the polymer's behavior, while we also examine the structural rearrangement of the graphene sheets in the presence of a noncrystallizable highly branched polymeric component. Our results show that graphene platelets are forming stacks comprised by a small number of flakes (typically 2−3) which are dispersed within the polymeric matrix. The characteristics of the spatial arrangement of the graphene planes and that of the formed clusters (including their relative orientation) depend sensitively on the temperature and on the size of the hyperbranched component. From the dynamic point of view, a significant slowing down is detected both in local and in global polymer dynamics in composite systems. The strong dynamic slowing down is accompanied by the occurrence of a glass-like transition at a considerably higher temperature compared to that characterizing the respective pristine polymer systems. We believe that the results reported in the present study capture also generic characteristics of the behavior of such materials and therefore could be exploited for a better control of the mechanical and thermal characteristics of hyperbranched polymer/graphene systems in a more general aspect.

Structural and Dynamical Properties of Polyethylene/Graphene Nanocomposites through Molecular Dynamics Simulations

“…Many simulation and experimental studies [1,[6][7][8][9][10][11][12][13][14][15][16][17][18][19] explore the influence of the chemical functionalization of graphene on the various properties of the nanocomposites. For example, Konatham et al [14] presented results based on atomistic Molecular Dynamics simulations combined with coarse grained Monte Carlo simulations, focused on graphene sheets dispersed in n-octane.…”

Recent Studies on the Multiscale Analysis of Polymer Nanocomposites

“…In addition, as in Alian et al [104], a methodology for analyzing polymer nanocomposites is also emerging through a multiscale model that combines density functional theory (DFT) and FE. Based on this multiscale analysis model, multiscale analysis of polymer nanocomposites with carbon filler is performed as in Karatasos et al [105], and the modeling and general characteristics of clay/polymer nanocomposties [106][107][108] are also being analyzed. Interpretation of the size effect when inserting organic materials, such as clay and montmorillonite, has also been conducted [4,[109][110][111][112][113][114][115][116][117][118][119].…”

Synthesis and application of hyperbranched poly(urethane‐urea) finishing agent with amino groups

“…The 1 H-NMR spectra were measured using a spectrometer (ADVANCEIII 400 MHz BRUKER Company, Germany) at 25 8C, D 2 O, DMSO-d 6 , and TMS were used as solvent and internal standard substance.…”

“…[1][2][3][4] Thus, hyperbranched polymers have been widely used in biomedical materials, nonlinear optical materials, tanning, surface modification, supramolecular chemistry, and nano materials. [5][6][7][8][9][10] With abrasion resistance, high strength, and chemical resistance, polyurethane (PU) has been widely used in synthetic leather and leather finishing agent. 11,12 However, PU film has poor moisture adsorption and vapor permeability, which directly influence the wearing comfort of product significantly.…”