Issue 8, 2017, Issue in Progress

Dispersion of non-covalently modified graphene in aqueous medium: a molecular dynamics simulation approach

Abstract

Molecular dynamics were used to simulate the dispersion of graphene in aqueous medium in the presence of a novel organic modifier, sodium salt of 6-amino hexanoic acid (Na-AHA), which non-covalently modifies the graphene surfaces. The modifier molecule contains an ionizable carboxylate head group and an aliphatic tail. The extent of dispersion was estimated by calculating the potential of mean force (PMF) as a function of increasing concentration of the modifier using the thermodynamic perturbation method in conjunction with molecular dynamics simulations. With increasing concentration of the modifier, the PMF changed from a short-range strong attraction to a long-range repulsion at higher modifier concentrations. The simulation results clearly show the adsorption of modifier molecules at the graphene–water interface, which in turn causes the graphene surfaces to acquire a negative charge. Further, the development of a negative electric potential at the graphene surfaces induces a long-range electrostatic repulsion between the graphene sheets, clearly pointing to an electrostatic stabilization of Na-AHA modified-graphene in aqueous medium.

Graphical abstract: Dispersion of non-covalently modified graphene in aqueous medium: a molecular dynamics simulation approach

Supplementary files

Article information

Article type
Paper
Submitted
03 Nov 2016
Accepted
15 Dec 2016
First published
16 Jan 2017
This article is Open Access
Creative Commons BY license

RSC Adv., 2017,7, 4460-4467

Dispersion of non-covalently modified graphene in aqueous medium: a molecular dynamics simulation approach

A. Kulkarni, N. Mukhopadhyay, A. R. Bhattacharyya and A. S. Panwar, RSC Adv., 2017, 7, 4460 DOI: 10.1039/C6RA26263E

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements