Computer simulations of two dimensional gold nanoparticle arrays: the influence of core geometry

Tay, Kafui A.; Bresme, Fernando

doi:10.1080/08927020500035879

Cited by 37 publications

(73 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Hamaker interaction between the gold cores is negligible compared to the total interaction as found earlier. 7,11,12,23 As the vdW interactions decay fast, the PMF is dominated by interactions between the entities that are in closest proximity, which are in our case the capping molecules. We summarize the computed PMFs for different NC cores and ligands in Fig.…”

Section: Pair Interactionsmentioning

confidence: 99%

“…10 It is well known that this attraction is at least one order of magnitude larger than the van der Waals ͑vdW͒ attractions between Au NC cores. [10][11][12] For the understanding of thermodynamic and kinetic properties of NCs, knowledge of the free energy or, equivalently, the potential of mean force ͑PMF͒ as a function of an appropriate order parameter is of vital importance. 13,14 This would allow fabrication of novel materials and devices with tailor-made structural, mechanical, and thermodynamic properties.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Understanding interactions between capped nanocrystals: Three-body and chain packing effects

Schapotschnikow

Vlugt

2009

The Journal of Chemical Physics

154

View full text Add to dashboard Cite

Self-assembly of capped nanocrystals ͑NC͒ attracted a lot of attention over the past decade. Despite progress in manufacturing of NC superstructures, the current understanding of their mechanical and thermodynamic stability is still limited. For further applications, it is crucial to find the origin and the magnitude of the interactions that keep self-assembled NCs together, and it is desirable to find a way to rationally manipulate these interactions. We report on molecular simulations of interacting gold NCs protected by capping molecules. We computed the potential of mean force for pairs and triplets of NCs of different size ͑1.8-3.7 nm͒ with varying ligand length ͑ethanethiol-dodecanethiol͒ in vacuum. Pair interactions are strongly attractive due to attractive van der Waals interactions between ligand molecules. Three-body interaction results in an energy penalty when the capping layers overlap pairwise. This effect contributes up to 20% to the total energy for short ligands. For longer ligands, the three-body effects are so large that formation of NC chains becomes energetically more favorable than close packing of capped NCs at low concentrations, in line with experimental observations. To explain the equilibrium distance for two or more NCs, the overlap cone model is introduced. This model is based on relatively simple ligand packing arguments. In particular, it can correctly explain why the equilibrium distance for a pair of capped NCs is always Ϸ1.25 times the core diameter independently on the ligand length, as found in our previous work ͓Schapotschnikow, R. Pool, and T. J. H. Vlugt, Nano Lett. 8, 2930 ͑2008͔͒. We make predictions for which ligands capped NCs self-assemble into highly stable three-dimensional structures, and for which they form high-quality monolayers.

show abstract

Section: Pair Interactionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Understanding interactions between capped nanocrystals: Three-body and chain packing effects

Schapotschnikow

Vlugt

2009

The Journal of Chemical Physics

154

View full text Add to dashboard Cite

show abstract

“…(4) has the same asymptotic behavior as the coarse-grained model of Ref., 20 where Au-CH x interaction is modeled via 12 − 4 potential. However, it is important to note that in that work the coarse-grained potential has a spherical symmetry (i.e.…”

Section: Force Field Developmentmentioning

confidence: 91%

“…[15][16][17][18][19] Due to high computational cost, only few studies investigated properties of systems with several NCs. 16,20,21 The NCs in those studies were relatively small (up to 140 atoms) compared to the ones typically used in assembly experiments. 12 Recent simulation studies 19,21 show, in addition, that the presence of solvent strongly influences the structure of capping layers.…”

Section: 13mentioning

confidence: 99%

Coarse-grained model for gold nanocrystals with an organic capping layer

Schapotschnikow¹,

Pool²,

Vlugt³

2007

Molecular Physics

View full text Add to dashboard Cite

“…The cluster construction was automatised using a Python script. Once all the clusters were constructed we quantified their shape by computing the radius of gyration tensor S. 38,39 We consider a cluster on the x, y plane, consisting of n s atoms with the cluster center of mass defined such that ∑ n s i=1 s i = 0, where s i = col(x i , y i ) are the coordinates of atom i in the cluster. The radius of gyration can be obtained from,…”

Section: Discussionmentioning

confidence: 99%

Structural organization of sterol molecules in DPPC bilayers: a coarse-grained molecular dynamics investigation

et al. 2016

Self Cite

View full text Add to dashboard Cite

We investigate the structural organization of cholesterol (CHOL) analogues in 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) bilayers using coarse-grained molecular dynamics simulations and the MARTINI forcefield. Different sterol molecules are modelled by increasing (CHOLL) or decreasing (CHOLS) the diameter of the sterol beads employed in the MARTINI model of CHOL. At high sterol concentrations, (x sterol = 0.5), typical of liquid ordered phases, we find that the sterol arrangement and sterol-DPPC interactions strongly depend on the sterol size. Smaller sterols (CHOLS and CHOL) form linear clusters, while the larger sterols (CHOLL) arrange themselves into disc shaped clusters. By combining structural and dynamical properties we also investigate the S o → L d transition for the CHOLL and CHOLS sterols. We show that small changes in the sterol size significantly affect the stability of the gel phase with the gel phase stabilized by the small sterols, but destabilized by large sterols. The general dependence of the phase behaviour of the membrane with sterol content, is reminiscent of the one observed in naturally occurring membranes. The relevance of our results to understand current cholesterol-bilayer structural models is discussed.

show abstract

Computer simulations of two dimensional gold nanoparticle arrays: the influence of core geometry

Cited by 37 publications

References 32 publications

Understanding interactions between capped nanocrystals: Three-body and chain packing effects

Understanding interactions between capped nanocrystals: Three-body and chain packing effects

Coarse-grained model for gold nanocrystals with an organic capping layer

Structural organization of sterol molecules in DPPC bilayers: a coarse-grained molecular dynamics investigation

Contact Info

Product

Resources

About