Anomalous dielectric relaxation of water confined in graphite oxide

Journal Article · Mon Sep 28 00:00:00 EDT 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4931664· OSTI ID:22492721

Yu, Ji; Tian, Yuchen; Gu, Min ^[1]; Tang, Tong B. ^[2]

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1. National Laboratory of Solid State Microstructures and Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)
2. Department of Physics, Hong Kong Baptist University, Kowloon, Hong Kong (China)

Nonmonotonic thermal dependence of dielectric relaxation of water has been observed in hydrated graphite oxide (GO). Graphite oxide prepared via Hummers method then imbued with specific water contents were characterized, with {sup 13}C and {sup 1}H nuclear magnetic resonance spectroscopies, X-ray photoelectron spectroscopy, ambient- and variable-temperature X-ray diffractometries, as well as thermogravimetric analysis. Pressed pellets provided with either conducting or blocking electrodes yielded dielectric loss, which was shown to originate from dielectric relaxation of the confined water. Three relaxation processes were observed in impedance spectroscopy. Our previous work has identified two different types of water in GO, namely, intercalated water and water in inter-grain voids. P{sub 1} expresses the reorientation of water confined inside inter-grain voids, and P{sub 2}, the rotation of intercalated water molecules confined in interlayers. The present work reveals a new process P{sub 3}, which also relates to intercalated water. It slows down with temperature, and this apparent anomaly is explained by the decrease in water content and consequent narrowing of interlayer spacing in graphite oxide, as confirmed by characterization techniques. The present study should contribute to our understanding of surface water dynamics.

• OSTI ID: 22492721
• Journal Information: Journal of Applied Physics, Vol. 118, Issue 12; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CARBON 13
CLATHRATES
DIELECTRIC MATERIALS
ELECTRODES
GRAPHITE
HUMIDITY
IMPEDANCE
LOSSES
MOLECULES
NUCLEAR MAGNETIC RESONANCE
OXIDES
PELLETS
RELAXATION
THERMAL GRAVIMETRIC ANALYSIS
WATER
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY