Hydrogen network fluctuations and dielectric spectrometry of liquids

Kaatze, U.; Behrends, R.; Pottel, R.

doi:10.1016/s0022-3093(02)01084-0

Cited by 171 publications

(175 citation statements)

References 33 publications

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“…These theoretical results are in accordance with other investigations showing that the presence of foreign molecules in water mainly result in the reduction of the potential barrier of the dipole reorientation process or an enhanced formation of hydrogen bonds (Kaatze et al, 2002). Both effects directly influence the dipole relaxation time and therefore the parameter τ .…”

Section: Dispersion Of Layered Plasticssupporting

confidence: 92%

Investigation of dielectric properties of multilayer structures consisting of homogeneous plastics and liquid solutions at 75–110 GHz

Klenner

Abels

Zech

et al. 2015

J. Sens. Sens. Syst.

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Abstract. In this paper, we demonstrate an active 3-D millimeter wave (mmW) imaging system used for characterization of the dielectric function of different plastic materials and liquid solutions. The method is based on reflection spectroscopy at frequencies between 75 and 110 GHz, denoted as W-band, and can be used to investigate homogeneous dielectric materials such as plastics or layered structures and liquid solutions. Precise measurement of their dielectric properties not only allows for characterization and classification of different fluids, but also for reliable detection and localization of small defects such as voids or delamination within multilayer structures built from plastic materials. The radio frequency (RF) signal generation is based on circuits that have been designed and fabricated at the Fraunhofer Institute for Applied Solid State Physics (IAF) using a 100 nm InGaAs mHEMT process (Tessmann et al., 2006; Weber et al., 2011).

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Section: Dispersion Of Layered Plasticssupporting

confidence: 92%

Investigation of dielectric properties of multilayer structures consisting of homogeneous plastics and liquid solutions at 75–110 GHz

Klenner

Abels

Zech

et al. 2015

J. Sens. Sens. Syst.

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“…Water is undoubtedly the most widely studied chemical system, with thousands of experimental and theoretical characterizations reported to date [1][2][3][4][5][6][7][8][9][10][11][12] . Detailed understanding of its collective molecular dynamics nevertheless remains an important outstanding problem in the physical and biological sciences [13][14][15][16] .…”

Section: Introductionmentioning

confidence: 99%

High-precision gigahertz-to-terahertz spectroscopy of aqueous salt solutions as a probe of the femtosecond-to-picosecond dynamics of liquid water

Vinh

Sherwin

Allen

et al. 2015

The Journal of Chemical Physics

100

110

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Abstract. Because it is sensitive to fluctuations occurring over femtoseconds to picoseconds, gigahertz-to-terahertz dielectric relaxation spectroscopy can provide a valuable window into water's most rapid intermolecular motions. In response, we have built a vector network analyzer dielectric spectrometer capable of measuring absorbance and index of refraction in this frequency regime with unprecedented precision. Using this to determine the complex dielectric response of water and aqueous salt solutions from 5.9GHz to 1.12 THz (which we provide in the SI), we have obtained strong new constraints on theories of water's collective dynamics. For example, while the salt-dependencies we observe for water's two slower relaxations (8 and 1 ps) are easily reconciled with suggestions that they arise due to rotations of fully and partially hydrogen bonded molecules, respectively, the salt-dependence of the fastest relaxation (180 fs) appears difficult to reconcile with its prior assignment to liberations of single hydrogen bonds.

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“…26 This is the opposite of the change in observed for 1-propanol-isoamylbromide mixture. 17,24 In view of the interpretation of the Debye-type spectra in terms of the relaxation by hydrogen bond breaking and reforming, [1][2][3][11][12][13][14]27,28 and our findings for the 5-methyl-2-hexanol mixture, 26 we have restudied the dielectric behavior of 1-propanol-isoamylbromide mixture in detail and have examined its crystallization behavior in real time by using broad band spectroscopy. Studies on their pure liquid states have been reported in earlier papers, 16,22 and are used for comparison.…”

Section: Introductionmentioning

confidence: 93%

“…Water, [1][2][3] and solid crystalline ices 3,4 at high temperatures also show a similar Debye-type relaxation spectra. Most liquids, whether hydrogen bonded or not, have shown a distribution of relaxation times 5 for the ␣-relaxation process that represents structural fluctuations observed in viscous flow and whose kinetic freezing causes a liquid to vitrify and which have been related to the time scale of the JohariGoldstein ͑JG͒ relaxation.…”

Section: Introductionmentioning

confidence: 94%

Dielectric relaxation and crystallization of nanophase separated 1-propanol-isoamylbromide mixture

Power

Vij

Johari

2007

The Journal of Chemical Physics

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The effects of liquid-liquid phase separation on molecular relaxation of an apparently homogeneous mixture of 1-propanol and isoamylbromide has been studied by dielectric spectroscopy over a broad frequency and temperature range, and its crystallization kinetics investigated in real time. The mixture shows two widely separated relaxation processes, as before, with the faster relaxation due to the orientational diffusion of isoamylbromide and the slower due to that of 1-propanol. In the mixture, the scaled contribution to permittivity from orientation polarization, ⌬ , of isoamylbromide is about the same as in the pure state, but that of 1-propanol decreases by a factor of ϳ3 at 120 K. As the temperature is decreased, this difference remains constant. The relaxation time, , of isoamylbromide and its distribution parameter remains the same as for the pure liquid, but that of 1-propanol is longer and increases with decrease in T, becoming ϳ130 times the pure liquid's value at 119 K. This is in contrast to the finding for an isomeric heptanol, whose had decreased. Extrapolation suggests that at T Ͼ 151 K, of 1-propanol in the mixture may become less than that in the pure liquid ͑the isoamylbromide component crystallizes before this temperature could be reached͒. This indicates that T g corresponding to of 10 3 s for 1-propanol in the mixture would be higher than in the pure liquid. Crystallization of the two components in the mixture occurs at different rates and 1-propanol remains partially uncrystallized while isoamylbromide completely crystallizes.of any remaining liquid isoamylbromide does not change in the presence of crystallized states while of residual liquid 1-propanol in the mixture is reduced. The mixture phase separates in submicron or nanosize aggregates of the alcohol in isoamylbromide, without affecting the latter's relaxation kinetics, while its own s decreases and increases. Consequences of the finding for various relaxation mechanisms are briefly described.

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Hydrogen network fluctuations and dielectric spectrometry of liquids

Cited by 171 publications

References 33 publications

Investigation of dielectric properties of multilayer structures consisting of homogeneous plastics and liquid solutions at 75–110 GHz

Investigation of dielectric properties of multilayer structures consisting of homogeneous plastics and liquid solutions at 75–110 GHz

High-precision gigahertz-to-terahertz spectroscopy of aqueous salt solutions as a probe of the femtosecond-to-picosecond dynamics of liquid water

Dielectric relaxation and crystallization of nanophase separated 1-propanol-isoamylbromide mixture

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