Analysis of two-dimensional energy and relaxation-time distributions from temperature-dependent broadband dielectric spectroscopy

1998 ◽  
Vol 57 (15) ◽  
pp. 8763-8766 ◽  
Author(s):  
R. Pelster ◽  
T. Kruse ◽  
H. G. Krauthäuser ◽  
G. Nimtz ◽  
P. Pissis
Keyword(s):  
Relaxation Time ◽  
Dielectric Spectroscopy ◽  
Two Dimensional ◽  
Temperature Dependent ◽  
Broadband Dielectric Spectroscopy

scholarly journals Evaluation of water structures in cotton cloth by fractal analysis with broadband dielectric spectroscopy

2021 ◽  
Vol 56 (31) ◽  
pp. 17844-17859
Author(s):  
Shin Yagihara ◽  
Hironobu Saito ◽  
Hironori Sugimoto ◽  
Tsubasa Kawaguchi ◽  
Minoru Fukuzaki ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Fractal Analysis ◽  
Dielectric Spectroscopy ◽  
Water Structure ◽  
Cellulose Microfibrils ◽  
Cotton Cloth ◽  
Water Molecules ◽  
Relaxation Processes ◽  
Analytical Technique ◽  
Broadband Dielectric Spectroscopy

AbstractBroadband dielectric spectroscopy measurements were performed on naturally dried cotton cloth, and a recently developed analytical technique for fractal analysis of water structures was applied to obtain existential states and locations of water molecules in the material. Three relaxation processes observed in GHz, MHz, and kHz frequency regions were attributed to dynamic behaviors of hydrogen bonding networks (HBNs) of water and interacting molecules, polymer chains with interacting ion and water molecules, and ions restricted on the interfaces of larger structures, respectively. Water molecules were heterogeneously distributed in the cotton cloth, and the HBNs remained as a broad GHz frequency process. Fractal analysis suggested that water molecules distributed in the material were characterized by a small value (0.55) of the Cole–Cole relaxation time distribution parameter, indicating spatial distribution of HBN fragments with various sizes in cotton cloth. This result was also supported by the T2 relaxation time obtained from nuclear magnetic resonance for naturally dried cotton yarn. Comparing previous results of dielectric relaxation measurements and fractal analysis with the τ–β diagram for various aqueous systems, the results determined that water molecules cannot exist inside cellulose microfibrils. The fractal analysis employed in this work can be applied to dynamic water structures in any material. The presented analytical technique with a universal τ–β diagram is expected to be an effective tool to clarify water structure detail even for heterogeneous hydrations of the low water content substances. Graphical abstract

scholarly journals Dynamics of Confined Short-Chain alkanol in MCM-41 by Dielectric Spectroscopy: Effects of matrix and system Treatments and Filling Factor

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 610
Author(s):  
Josef Bartoš ◽  
Silvia Arrese-Igor ◽  
Helena Švajdlenková ◽  
Angela Kleinová ◽  
Angel Alegría
Keyword(s):  
Relaxation Time ◽  
Pore Size ◽  
Dielectric Spectroscopy ◽  
Filling Factor ◽  
Short Chain ◽  
Main Process ◽  
Broadband Dielectric Spectroscopy ◽  
Drying Procedures ◽  
Matrix Conditioning ◽  
Mcm 41

The dynamics of n-propanol confined in regular MCM-41 matrix with the pore size Dpore = 40 Å, under various matrix conditioning and sample confining conditions, using broadband dielectric spectroscopy (BDS), is reported. First, various drying procedures with the capacitor filling under air or N2 influence the BDS spectra of the empty MCM-41 and the confined n-PrOH/MCM-41 systems, but have a little effect on the maximum relaxation time of the main process. Finally, various filling factors of n-PrOH medium in the optimally treated MCM-41 system lead to unimodal or bimodal spectra interpreted in terms of the two distinct dynamic phases in the confined states.

scholarly journals Broadband dielectric spectroscopy for monitoring temperature-dependent chloride ion motion in BiOCl plates

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Adrian Radoń ◽  
Dariusz Łukowiec ◽  
Patryk Włodarczyk
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Spectroscopy ◽  
Low Frequency ◽  
Chloride Ion ◽  
Ion Source ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Broadband Dielectric Spectroscopy ◽  
Free Chloride ◽  
Structure Rebuilding

AbstractThe dielectric properties and electrical conduction mechanism of bismuth oxychloride (BiOCl) plates synthesized using chloramine-T as the chloride ion source were investigated. Thermally-activated structure rebuilding was monitored using broadband dielectric spectroscopy, which showed that the onset temperature of this process was 283 K. This rebuilding was related to the introduction of free chloride ions into [Bi2O2]2+ layers and their growth, which increased the intensity of the (101) diffraction peak. The electrical conductivity and dielectric permittivity were related to the movement of chloride ions between plates (in the low-frequency region), the interplanar motion of Cl− ions at higher frequencies, vibrations of these ions, and charge carrier hopping at frequencies above 10 kHz. The influence of the free chloride ion concentration on the electrical conductivity was also described. Structure rebuilding was associated with a lower concentration of free chloride ions, which significantly decreased the conductivity. According to the analysis, the BiOCl plate conductivity was related to the movement of Cl− ions, not electrons.

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