Multiscale Simulation Method for Quantitative Prediction of Surface

Mar 20, 2018 - ... wetting phenomena at an atomistic level and can eventually be utilized to design a surface with a controlled hydrophobic(philic)ity...
0 downloads 5 Views 1MB Size
Subscriber access provided by Queen Mary, University of London

Surfaces, Interfaces, and Catalysis; Physical Properties of Nanomaterials and Materials

Multiscale Simulation Method for Quantitative Prediction of Surface Wettability at the Atomistic Level Suji Gim, Hyung-Kyu Lim, and Hyungjun Kim J. Phys. Chem. Lett., Just Accepted Manuscript • DOI: 10.1021/acs.jpclett.8b00466 • Publication Date (Web): 20 Mar 2018 Downloaded from http://pubs.acs.org on March 21, 2018

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry Letters

Multiscale Simulation Method for Quantitative Prediction of Surface Wettability at the Atomistic Level Suji Gim1, Hyung-Kyu Lim2,*, and Hyungjun Kim1,*

1

Department of Chemistry and Graduate School of EEWS, Korea Advanced Institute of

Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea 2

Department of Chemical Engineering, Kangwon National University, Chuncheon,

Gangwon-do 24341, Korea

*

Correspondence to H.-K. L. ([email protected]) and H.K. ([email protected]) 1

ACS Paragon Plus Environment

The Journal of Physical Chemistry Letters 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

2

ACS Paragon Plus Environment

Page 2 of 35

Page 3 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry Letters

TOC GRAPHICS

KEYWORDS wettability, work of adhesion, contact angle, QM/MM, graphene wetting

3

ACS Paragon Plus Environment

The Journal of Physical Chemistry Letters 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Abstract The solid-liquid interface is of great interest because of its highly heterogeneous character and its ubiquity in various applications. The most fundamental physical variable determining the strength of the solid-liquid interface is the solid-liquid interfacial tension, which is usually measured according to the contact angle. However, an accurate experimental measurement and a reliable theoretical prediction of the contact angle remain lacking because of many practical issues. Here, we propose a first principles-based simulation approach to quantitatively predict the contact angle of an ideally clean surface using our recently developed multiscale simulation method of density functional theory in classical explicit solvents (DFT-CES). Using this approach, we simulate the surface wettability of a graphene and graphite surface, resulting in a reliable contact angle value that is comparable to the experimental data. From our simulation results, we find that the surface wettability is dominantly affected by the strength of the solid-liquid van der Waal’s interaction. However, we further elucidate that there exists a secondary contribution from the change of water-water interaction, which is manifested by the change of liquid structure and dynamics of interfacial water layer. We expect that our proposed method can be used to quantitatively predict and understand the intriguing wetting phenomena at an atomistic level and can eventually be utilized to design a surface with a controlled hydrophobic(philic)ity.

4

ACS Paragon Plus Environment

Page 4 of 35

Page 5 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry Letters

Introduction The concept of wettability, i.e., the degree of spreading water over the solid surface, has been applied to regulate various chemo-physical reactions in the fields of water harvesting [1], self-cleaning [2], corrosion [3], filtration [4], heterogeneous catalytic reaction [5,6], etc. Despite its critical importance in a number of practical applications, fundamental characterizations and understanding on the wetting phenomena at the molecular level remain lacking. Moreover, an accurate measurement of the contact angle ( ) is often difficult to accomplish because of defects [7], airborne contaminants [8], and oxide layer formation [9] on the surface. In case of thin film systems, their intrinsic surface corrugation adds more complications because the surface geometry is another influential element on the surface energy. Even for a graphite surface that is chemically much more inert than other surfaces, e.g., metals, experimental measurement on the water contact angle substantially varies. In 1940, Fowkes et al. reported the  of 86° that is measured using the tilting plate method [10]. Using the rising meniscus method, Morcos reported the similar value of 86° in 1972 [11]. However, Tadros et al. measured a rather low value of 60-80° using the captive bubble method in 1974. [12]. An even lower value of 42±7° was estimated by Schrader in 1980 [7], and