Swelling of Thin Graphene Oxide Film in Water Vapor Studied by In Situ Spectroscopic Ellipsometry

Graphene oxide (GO) is obtained by the chemical treatment of graphene sheets, resulting in decoration with oxygen-containing functional groups. In the work presented here, we examined marked changes that occur in a thin film of parallel aligned GO sheets when exposed to water vapor at various pressu...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1999. - 40(2024), 24 vom: 18. Juni, Seite 12497-12503
1. Verfasser: Zhou, Yi (VerfasserIn)
Weitere Verfasser: Bauer, Ralph A, Zhang, Xin, Hong, Nina, Verweij, Hendrik
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2024
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article
Beschreibung
Zusammenfassung:Graphene oxide (GO) is obtained by the chemical treatment of graphene sheets, resulting in decoration with oxygen-containing functional groups. In the work presented here, we examined marked changes that occur in a thin film of parallel aligned GO sheets when exposed to water vapor at various pressures. It was found that exceptionally fast and substantial water uptake and release occur that is accompanied by major changes in GO interlayer spacing. These characteristics were obtained in situ with spectroscopic ellipsometry. At 99% relative humidity (RH) and 25 °C, the interlayer spacing became 1.41 nm, which recovers to ∼0.8 nm within 30 s when exposed to 10% RH. Besides layer thickness values, uniaxial optical constants for the GO vs RH were derived from the ellipsometry data. Molar refraction theory was applied that indicated monolayer water formation at ∼91% RH at 25 °C upon water adsorption. Our findings contribute to the understanding of the interaction between GO and its environment. The very outspoken effect of external water vapor pressure on GO water content, interlayer spacing, and optical properties can be utilized in sensing and separation devices, subnanometer positioning, chemical switches, and environmentally aware materials
Beschreibung:Date Revised 18.06.2024
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1520-5827
DOI:10.1021/acs.langmuir.4c00897