A review on data and predictions of water dielectric spectra for calculations of van der Waals surface forces

Wang, Jianlong

doi:10.1016/j.cis.2017.10.004

Cited by 21 publications

(21 citation statements)

References 42 publications

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“…5 in Ref. [31]. The differences between these models can be partly understood from their chronological order.…”

Section: Available Data and Models For Dielectric Function Of Watermentioning

confidence: 99%

“…The Parsegian-Weiss parameters [28] were used to provide an initial guess. IR and UV oscillator parameters were frozen in order to fit the parameters for the initial single Debye oscillator using the real and imaginary data ε 1 (ω) and ε 2 (ω) in the real microwave regime simultaneously (for the purposes of fitting oscillator parameters we Here "This work" is the parameterised dielectric functions at 298.15 K and at 273.55 K. For comparision we show the room temperature models from Parsegian and Weiss [28], Roth and Lenhoff [29], Dagastine et al [30], Wang and Nguyen [31] (and a corrected version of this parameterisation). We also show the ice cold water from Elbaum and Schick [19].…”

Section: Fitted Oscillatorsmentioning

confidence: 99%

“…Figure 2: Dielectric function of water for imaginary frequencies.Here "This work" is the parameterised dielectric functions at 298.15 K and at 273.55 K. For comparision we show the room temperature models from Parsegian and Weiss[28], Roth and Lenhoff[29], Dagastine et al[30], Wang and Nguyen[31] (and a corrected version of this parameterisation). We also show the ice cold water from Elbaum and Schick[19].…”

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confidence: 99%

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Full-Spectrum High-Resolution Modeling of the Dielectric Function of Water

et al. 2020

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In view of the vital role of water in chemical and physical processes, an exact knowledge of its dielectric function over a large frequency range is important. In this article we report on currently available measurements of the dielectric function of water at room temperature (25 • C) across the full electromagnetic spectrum: microwave, IR, UV and X-ray (up to 100 eV). We provide parameterisations of the complex dielectric function of water with two Debye (microwave) oscillators and high resolution of IR and UV/X-ray oscillators. We also report dielectric parameters for ice-cold water with a microwave/IR spectrum measured at 0.4 • C, while taking the UV spectrum from 25 • C (assuming negligible temperature dependence in UV). We illustrate the consequences of the model via calculations of van der Waals interactions of gas molecules near water surfaces, and an assessment of the thickness of water films on ice and ice films on water. In contrast to earlier models of ice-cold water, we predict that a micron-scale layer of ice is stabilised on a bulk water surface. Similarly, the van der Waals interaction promotes complete freezing rather than supporting a thin premelting layer of water on a bulk ice surface. Density-based extrapolation from warm to cold water of the dielectric function at imaginary frequencies is found to be satisfactory in the microwave but poor (40% error) at IR frequencies.

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“…5 in Ref. [31]. The differences between these models can be partly understood from their chronological order.…”

Section: Available Data and Models For Dielectric Function Of Watermentioning

confidence: 99%

Section: Fitted Oscillatorsmentioning

confidence: 99%

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confidence: 99%

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Full-Spectrum High-Resolution Modeling of the Dielectric Function of Water

et al. 2020

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“…This is explained by the attendant absorption arising from the high imaginary component of the complex dielectric constant of water. At 2.45 GHz and 20 °C, ϵ~=ϵ1+iϵ2≈normal79+inormal10, with ϵ1 most directly contributing to the index of refraction, and ϵ2 most directly contributing to the absorption coefficient* (17). When simulating a reduced absorption coefficient, the Q factor of the dimers is boosted, and a menagerie of complicated electromagnetic field modes are found inside the simulated beads, consistent with other reports for dielectric spheres (12).…”

Section: The Effects Of Absorptionmentioning

confidence: 99%

“…The functional dependence of the complex dielectric constant on temperature, frequency, and salinity provides an important avenue for future research. For example, at 2.5 GHz, the absorptive properties of water change more rapidly than does the index of refraction between the temperatures of 0 °C and 60 °C ( 17 ). Thus, details of resonant mode structure, including localized hotspots, may result in dynamic runaway or self-tuning processes arising from local absorptive heating.…”

Section: The Effects Of Absorptionmentioning

confidence: 99%

Linking plasma formation in grapes to microwave resonances of aqueous dimers

Khattak

Bianucci

Slepkov

2019

Proc. Natl. Acad. Sci. U.S.A.

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The sparking of cut grape hemispheres in a household microwave oven has been a poorly explained Internet parlor trick for over two decades. By expanding this phenomenon to whole spherical dimers of various grape-sized fruit and hydrogel water beads, we demonstrate that the formation of plasma is due to electromagnetic hotspots arising from the cooperative interaction of Mie resonances in the individual spheres. The large dielectric constant of water at the relevant gigahertz frequencies can be used to form systems that mimic surface plasmon resonances that are typically reserved for nanoscale metallic objects. The absorptive properties of water furthermore act to homogenize higher-mode profiles and to preferentially select evanescent field concentrations such as the axial hotspot. Thus, beyond providing an explanation for a popular-science phenomenon, we outline a method to experimentally model subwavelength field patterns using thermal imaging in macroscopic dielectric systems.

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