Molecular Modeling Combined with Advanced Chemistry for the Rational Design of Efficient Graphene Dispersing Agents

Abstract

Pyrene-functional PMMAs were prepared via ATRP-controlled polymerization and click reaction, as efficient dispersing agents for the exfoliation of few-layered graphene sheets (GS) in easily processable low boiling point chloroform. In parallel, detailed atomistic simulations showed fine dispersion of the GS/polymer hybrids in good agreement with the experiment. Moreover, the molecular dynamics simulations revealed interesting conformations (bridges, loops, dangling ends, free chains) of GS/polymer hybrids and allowed us to monitor their time evolution both in solution and in the polymer nanocomposite where the solvent molecules were replaced with PMMA chains. Microscopic information about these structures is very important for optimizing mechanical performance. It seems that the combination of atomistic simulation with advanced chemistry constitutes a powerful tool for the design of effective graphene dispersing agents that could be used for the production of graphene-based nanocomposites with tailor-made mechanical properties.

Ultrafast rotational motions of supported nanoclusters probed by electron diffraction

“…Au 923 NCs are modeled as a set of Lennard-Jones (12-6 LJ) Au atoms according to Heinz et al 28 Graphene is modeled through the all-atom DREIDING force-field, 29 already employed for the study of carbon nanotube-and graphene-based polymer nanocomposites. [30][31][32] The interactions of Au and graphene atoms are modelled with a 12-6 LJ potential according to Lewis et al 17 All MD simulations are executed with the LAMMPS software 33 (see also S3, ESI †).…”

Atomistic modeling of graphene/hexagonal boron nitride polymer nanocomposites: a review

“…Papadimitriou et al employed MD in conjunction with advance chemistry to study the conformations like bridges, loops, free chains, and dangling ends in GS‐pyrene functional PMMA nanocomposite. The main advantage of using the pyrene as modifier for functionalization purpose is their good compatibility with various polymer hosts that also renders graphene an adaptable nanofiller in nanocomposites.…”

“…Despite all these advantages, polymers are less dense and their structural strength is comparatively very low. In order to improve the strength of polymers, the properties of reinforcement/nanofiller play a decisive role . Polymers‐based nanocomposites exhibit high heat distortion temperature, curtailed scratch and mar resistance, noise damping, and tailored mechanical strength .…”

Effects of Reorientation of Graphene Platelets (GPLs) on Young’s Modulus of Polymer Composites under Bi-Axial Stretching

“…Kim et al [ 14 ] found that different processing routes to prepare graphene/polymer composites could have difference effects on the electrical conductivity of the composites due to the different dispersion level of graphene in the polymer matrix. In addition to experiments, extensive theoretical investigations, including molecular dynamics (MD) simulation [ 15 , 16 , 17 , 18 ], micromechanics modelling [ 19 , 20 ] and finite element method (FEM) [ 21 , 22 , 23 , 24 , 25 ], also observed the significant reinforcing effects of graphene and its derivatives. The mechanisms that underpin the prominent reinforcing effects can be attributed to graphene and its derivatives’ 2D structure features and their extremely high surface area, which result in excellent load transfer from the matrix to the reinforcements [ 1 , 8 , 11 , 20 , 26 , 27 ].…”