Document Type

Journal Article

Publication Title

Langmuir

ISSN

1520-5827

Volume

35

Issue

17

First Page

5746

Last Page

5752

PubMed ID

30942583

Publisher

American Chemical Society

School

School of Engineering

Comments

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Langmuir, copyright © 2019 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see: Abramov, A., & Iglauer, S. (2019). Application of the CLAYFF and the DREIDING force fields for modeling of alkylated quartz surfaces. Langmuir, 35(17), 5746-5752. Original publication available here

Abstract

To extend applicability and to overcome limitations of combining rules for nonbond potential parameters, in this study, CLAYFF and DREIDING force fields are coupled at the level of atomic site charges to model quartz surfaces with chemisorpt hydrocarbons. Density functional theory and Bader charge analysis are applied to calculate charges of atoms of the OC bond connecting a quartz crystal and an alkyl group. The study demonstrates that the hydrogen atom of the quartz surface hydroxyl group can be removed and its charge can be redistributed among the oxygen and carbon atoms of the OC bond in a manner consistent with the results calculated at the density functional level of theory. Augmented with modified charges of the OC bond, force fields can then be applied to a practical problem of evaluation of the contact angle of a water droplet on alkylated quartz surfaces in a carbon dioxide environment, which is relevant for carbon geo-sequestration and in a broader context of oil and gas recovery. Alkylated quartz surfaces have been shown to be extremely hydrophobic even when the surface density of hydroxyl groups is close to the highest naturally observed density of 6.2 OH groups per square nanometer.

DOI

10.1021/acs.langmuir.9b00527

Available for download on Friday, April 03, 2020

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