Coarse-Grained Molecular Simulation of Self-Assembly for Nonionic Surfactants on Graphene Nanostructures

Abstract

Self-assembly of amphiphilic molecules on the surfaces of nanoscale materials has an important application in a variety of nanotechnology. Here, we report a coarse-grained molecular dynamics simulation on the structure and morphology of the nonionic surfactant, n-alkyl poly(ethylene oxide) (PEO), adsorbed on planar graphene nanostructures. The effects of concentration, surfactant structure, and size of graphene sheet are explored. Because of the finite dimension effect, various morphological hemimicelles can be formed on nanoscale graphene surfaces, which is somewhat different from the self-assembly structures on infinite carbon surfaces. The aggregate morphology is highly dependent on the concentration, the chain lengths, and the size of graphene nanosheets. For the nonionic surfactant, the PEO headgroups show strong dispersion interaction with the carbon surface, leading to a side edge adsorption behavior. This simulation provides insight into the supramolecular self-assembly nanostructures and the adsorption mechanism for the nonionic surfactants aggregated on graphene nanostructures, which could be exploited to guide fabrication of graphene-based nanocomposites.

Interaction modes between nanosized graphene flakes and liposomes: Adsorption, insertion and membrane fusion

“…Graphene is modeled by means of a hexagonal lattice of apolar particles, each one representing four carbon atoms according to the 4-to-1 Martini rule. Although the Martini force field recommends a 3-to-1 mapping for the description of molecules with rings (such as cholesterol), here we choose the 4-to-1 coarse-graining in order to preserve the original hexagonal lattice symmetry of graphene as it has been used in [28] and in other simulations of this material with amphiphilic molecules [29]. Other carbon-based nanomaterials like nanotubes [30] and fullerenes [31] have been also successfully modeled following a 4-to-1 approach.…”

Self‐assembling study of sarcolipin and its mutants in multiple molecular dynamic simulations

“…The CG-MD and AT-MD simulations together have been successfully applied in inter-helical interactions in membrane with free energy calculation, such as WALP23 transmembrane proteins dimerization, 32 GxxxG motif interaction, 33-35 G protein-coupled receptors association in bilayers, 36 large membrane proteins interaction 28 and some nonionic surfactants and ion-channels. 37,38 The conformations of the pentameric SLN and PLB were obtained from homology modeling and NMR, 17,39,40 they both formed a left-hand complex. However, there are still many questions remained in the assembling process of SLN, such as how does SLN self-assemble to form pentamer, initiating from dimer or just monomer?…”

The microscopic deformation mechanism of 3D graphene foam materials under uniaxial compression

“…In the present paper, the technique of coarse-grained molecular dynamics simulation (CGMD) is adopted, which is advantageous in contrast to the time-consuming full-atom molecular dynamics method and the inconvenient in-site experimental observation. Furthermore, the CGMD method has been well verified to successfully study many graphene-related problems, such as the mechanical property of a single-or multi-layer graphene [29,30], adsorption of surfactants [31], self-assembly and penetration of graphene sheets in membranes [32,33], etc..…”