Title: Atomistic understanding of surface wear process of sodium silicate glass in dry versus humid environments

Abstract

Understanding surface reactions of silicate glass under interfacial shear is vital as it can provide physical insights needed for rational design of more durable glasses. In this work, we performed reactive molecular dynamics (MD) simulations with ReaxFF potentials to study the mechanochemical wear of sodium silicate glass rubbed with amorphous silica in the absence and presence of interfacial water molecules. The effect of water molecules on the shear-induced chemical reaction at the sliding interface was investigated. The dependence of wear on the number of interfacial water molecules in ReaxFF-MD simulations was in reasonable agreement with the experimental data. Confirming this, the ReaxFF-MD simulation was used to find further details of atomistic reaction dynamics that cannot be obtained from experimental investigations only. The simulation demonstrated that the severe wear in the dry condition is due to the formation of interfacial Sisubstrate–O–Sicounter_surface bond that convey the interfacial shear stress to the subsurface and the presence of interfacial water reduces the interfacial bridging bond formation. The leachable sodium ions facilitate surface reactions with water-producing hydroxyl groups and their key role in the hydrolysis reaction is discussed.

Authors:

Hahn, Seung Ho  ^[1];

• Search DOE PAGES for author "Hahn, Seung Ho"
• Search DOE PAGES for ORCID "0000-0002-1722-5631"

Liu, Hongshen  ^[1];

• Search DOE PAGES for author "Liu, Hongshen"
• Search DOE PAGES for ORCID "0000-0002-2936-1841"

Kim, Seong H.  ^[1];

• Search DOE PAGES for author "Kim, Seong H."
• Search DOE PAGES for ORCID "0000-0002-8575-7269"

Duin, Adri C. T.  ^[1]

• Search DOE PAGES for author "Duin, Adri C. T."
• Search DOE PAGES for ORCID "0000-0002-3478-4945"

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+ Show Author Affiliations

1. Pennsylvania State Univ., University Park, PA (United States)

Publication Date:

Tue Jan 14 00:00:00 EST 2020

Research Org.:

Energy Frontier Research Centers (EFRC) (United States). Multi-Scale Fluid-Solid Interactions in Architected and Natural Materials (MUSE); Univ. of Utah, Salt Lake City, UT (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF)

Contributing Org.:

Energy Frontier Research Center. Multi‐Scale Fluid‐Solid Interactions in Architected and Natural Materials (MUSE) Center

OSTI Identifier:

1597300

Alternate Identifier(s):

OSTI ID: 1594188

Grant/Contract Number:  

SC0019285; DMR‐1609107

Resource Type:

Accepted Manuscript

Journal Name:

Journal of the American Ceramic Society

Additional Journal Information:

Journal Volume: 103; Journal Issue: 5; Journal ID: ISSN 0002-7820

Publisher:

American Ceramic Society

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; MD simulation; mechanochemistry; ReaxFF; shear‐induced hydrolysis; silicate glass; surface wear