Coarse grained models of graphene and graphene oxide for usein aqueous solution.

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985858%3A_____%2F20%3A00522212" target="_blank" >RIV/67985858:_____/20:00522212 - isvavai.cz</a>

Výsledek na webu

<a href="https://iopscience.iop.org/article/10.1088/2053-1583/ab6f0c" target="_blank" >https://iopscience.iop.org/article/10.1088/2053-1583/ab6f0c</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/2053-1583/ab6f0c" target="_blank" >10.1088/2053-1583/ab6f0c</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Coarse grained models of graphene and graphene oxide for usein aqueous solution.

Popis výsledku v původním jazyce

Obtaining stable aqueous dispersions of graphene-based materials is a major obstacle in the development and widespread use of graphene in nanotechnology. The efficacy of atomisticnsimulations in obtaining a molecular-level insight into aggregation and exfoliation of graphene/ graphene oxide (GO) is hindered by length and time scale limitations. In this work, we developed coarse-grained (CG) models of graphene/GO sheets, compatible with the polarizable Martini water model, using molecular dynamics, iterative Boltzmann inversion and umbrella sampling simulations. The new CG models accurately reproduce graphene/GO–water radial distribution functions and sheet–sheet aggregation free energies for small graphene (−316 kJ mol−1) and GO (−108 kJ mol−1) reference sheets. Deprotonation of carboxylic acid functionalities stabilize the exfoliated state by electrostatic repulsion, providing they are present at sufficiently high surface concentration. The simulations also highlight the pivotal role played by entropy in controlling the propensity for aggregation or exfoliation. The CG models improve the computational efficiency of simulations by an order of magnitude and the framework presented is transferrable to sheets of different sizes and oxygen contents. They can now be used to provide fundamental physical insights into the stability of dispersions and controlled self-assembly, underpinning the computationalndesign of graphene-containing nanomaterials.

Název v anglickém jazyce

Coarse grained models of graphene and graphene oxide for usein aqueous solution.

Popis výsledku anglicky

Obtaining stable aqueous dispersions of graphene-based materials is a major obstacle in the development and widespread use of graphene in nanotechnology. The efficacy of atomisticnsimulations in obtaining a molecular-level insight into aggregation and exfoliation of graphene/ graphene oxide (GO) is hindered by length and time scale limitations. In this work, we developed coarse-grained (CG) models of graphene/GO sheets, compatible with the polarizable Martini water model, using molecular dynamics, iterative Boltzmann inversion and umbrella sampling simulations. The new CG models accurately reproduce graphene/GO–water radial distribution functions and sheet–sheet aggregation free energies for small graphene (−316 kJ mol−1) and GO (−108 kJ mol−1) reference sheets. Deprotonation of carboxylic acid functionalities stabilize the exfoliated state by electrostatic repulsion, providing they are present at sufficiently high surface concentration. The simulations also highlight the pivotal role played by entropy in controlling the propensity for aggregation or exfoliation. The CG models improve the computational efficiency of simulations by an order of magnitude and the framework presented is transferrable to sheets of different sizes and oxygen contents. They can now be used to provide fundamental physical insights into the stability of dispersions and controlled self-assembly, underpinning the computationalndesign of graphene-containing nanomaterials.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

2D Materials

ISSN

2053-1583

e-ISSN

—

Svazek periodika

7

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

16

Strana od-do

025025

Kód UT WoS článku

000537340300001

EID výsledku v databázi Scopus

2-s2.0-85082518239