scholarly journals Dielectric relaxation of nonaqueous ionic liquid microemulsions: polarization, microstructure, and phase transition

RSC Advances ◽  
2017 ◽  
Vol 7 (23) ◽  
pp. 13733-13741 ◽  
Author(s):  
Cancan Zhang ◽  
Zhen Zhen ◽  
Liyan Ma ◽  
Kongshuang Zhao
Keyword(s):  
Phase Transition ◽  
Ionic Liquid ◽  
Dielectric Relaxation ◽  
Dielectric Spectroscopy ◽  
Wide Frequency Range ◽  
Frequency Range ◽  
40 Hz

Two nonaqueous ionic liquid (IL) microemulsions (toluene/TX-100/[bmim][PF6] and [bmim][BF4]/TX-100/benzene) were studied by dielectric spectroscopy covering a wide frequency range (40 Hz to 110 MHz).

Temperature dependent dielectric relaxation of ionic liquid ([bmim][BF4])/alcohol binary mixtures

2017 ◽  
Vol 41 (17) ◽  
pp. 9330-9337 ◽  
Author(s):  
Man Yang ◽  
Liyan Ma ◽  
Kongshuang Zhao
Keyword(s):  
Ionic Liquid ◽  
Dielectric Relaxation ◽  
Binary Mixtures ◽  
Dielectric Spectroscopy ◽  
Spectroscopy Study ◽  
Frequency Range ◽  
Temperature Dependent

A dielectric spectroscopy study on the binary mixtures of the ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) and four kinds of alcohols as a function of temperature was carried out over a frequency range of 100 MHz to 20 GHz.

High Frequency Dielectric Response of the Ionic Liquid N-Methyl-N-ethylpyrrolidinium Dicyanamide

2007 ◽  
Vol 60 (1) ◽  
pp. 6 ◽  
Author(s):  
Simon Schrödle ◽  
Gary Annat ◽  
Douglas R. MacFarlane ◽  
Maria Forsyth ◽  
Richard Buchner ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Dielectric Loss ◽  
Dielectric Relaxation ◽  
High Frequency ◽  
Dielectric Response ◽  
Room Temperature ◽  
Room Temperature Ionic Liquid ◽  
Dielectric Relaxation Spectroscopy ◽  
Frequency Range ◽  
Fast Rotation

A study of the room-temperature ionic liquid N-methyl-N-ethylpyrrolidinium dicyanamide by dielectric relaxation spectroscopy over the frequency range 0.2 GHz ≤ ν ≤ 89 GHz has revealed that, in addition to the already known lower frequency processes, there is a broad featureless dielectric loss at higher frequencies. The latter is probably due to the translational (oscillatory) motions of the dipolar ions of the IL relative to each other, with additional contributions from their fast rotation.

Dielectric spectroscopy of alumina ceramics over a wide frequency range

1998 ◽  
Vol 253 (1-3) ◽  
pp. 141-148 ◽  
Author(s):  
R Vila ◽  
M González ◽  
J Mollá ◽  
A Ibarra
Keyword(s):  
Dielectric Spectroscopy ◽  
Wide Frequency Range ◽  
Alumina Ceramics ◽  
Frequency Range

Dielectric Relaxation in Composite Systems

1995 ◽  
Vol 411 ◽  
Author(s):  
Frederick I. Mopsik
Keyword(s):  
Composite Material ◽  
Dielectric Relaxation ◽  
Polymeric Materials ◽  
Wide Frequency Range ◽  
Relaxation Phenomena ◽  
Large Role ◽  
Frequency Range ◽  
Phase Boundaries ◽  
Composite Systems ◽  
Liquid Solutions

ABSTRACTDielectric relaxation phenomena have contributions from both the internal reorientation modes of the molecules comprising a material as well as the details of how those modes couple together to form the material. This behavior can change quite sensitively with changes in the composition of material. For a composite material that has more than one phase, the presence of phase boundaries and even shape can play an additional and large role in the observed relaxation behavior. Analysis of the relaxation spectra can be used to study these effects. Examples are shown, primarily of polymeric materials, ranging from liquid solutions to phase separated mixtures to show how dielectric relaxation over a wide frequency range can be used to characterize and study composite materials.

Effect of grafting density on conformation of poly(acrylic acid) in solution by dielectric spectroscopy

Soft Matter ◽  
2018 ◽  
Vol 14 (35) ◽  
pp. 7190-7203 ◽  
Author(s):  
Xinlu Zhou ◽  
Kongshuang Zhao
Keyword(s):  
Acrylic Acid ◽  
Ethylene Oxide ◽  
Dielectric Relaxation ◽  
Dielectric Spectroscopy ◽  
Dielectric Relaxation Spectroscopy ◽  
Frequency Range ◽  
Grafting Density ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Poly Acrylic Acid

The effect of grafting density of poly(ethylene oxide) and dodecyl groups on the conformation of poly(acrylic acid) in solution was clarified by dielectric relaxation spectroscopy over a frequency range from 40 Hz to 110 MHz.

Insight into the effect mechanism of urea-induced protein denaturation by dielectric spectroscopy

2017 ◽  
Vol 19 (47) ◽  
pp. 32007-32015 ◽  
Author(s):  
Cancan Zhang ◽  
Man Yang ◽  
Kongshuang Zhao
Keyword(s):  
Phase Transition ◽  
Dielectric Relaxation ◽  
Dielectric Spectroscopy ◽  
Protein Denaturation ◽  
Interaction Mechanism ◽  
Dielectric Relaxation Spectroscopy ◽  
Thermosensitive Polymer ◽  
Effect Mechanism ◽  
Protein Model ◽  
Insight Into

Dielectric relaxation spectroscopy was applied to study how urea affects the phase transition of a thermosensitive polymer, poly(N-isopropylacrylamide) (PNIPAM), which has been widely used as a protein model. The interaction mechanism of PNIPAM and urea in different concentration regions and the deduction of urea-induced protein denaturation mechanism was presented.

scholarly journals Crossover from Ferroelectric to Relaxor Behavior in Ba1−xCaxTiO3 (x = 0.17) System

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2854
Author(s):  
Edita Palaimiene ◽  
Jan Macutkevic ◽  
Juras Banys ◽  
Antoni Winiarski ◽  
Irena Gruszka ◽  
...  
Keyword(s):  
Phase Transition ◽  
Dielectric Properties ◽  
Ferroelectric Phase Transition ◽  
Ferroelectric Phase ◽  
Relaxation Times ◽  
Wide Frequency Range ◽  
Relaxor Behavior ◽  
Arrhenius Law ◽  
Frequency Range ◽  
Ferroelectric Phase Transition Temperature

The dielectric properties of Ba1−xCaxTiO3 (x = 0.17) ceramics were studied in a wide frequency range of 20 Hz–53 GHz. Diffused ferroelectric phase transition was revealed close to 339 K in the dielectric properties of ceramics. The behaviour of distributions of relaxation times in vicinity of the ferroelectric phase transition temperature is also typical for order-disorder ferroelectric phase transition. However, at lower temperatures (below 200 K), the most probable relaxation increased according to the Arrhenius law. At lower temperatures the maximum of the imaginary part of dielectric permittivity versus temperature strongly shifted to higher temperatures when the frequency increased (from 125 K at 1.21 kHz to 300 K at 33 GHz). This behaviour was attributed to the dynamics of Ti ions. The origin of the crossover from ferroelectric to relaxor behaviour of Ba1−xCaxTiO3 (x = 0.17) ceramics is discussed in the paper.

scholarly journals DIELECTRIC RELAXATION PHENOMENA IN PARAELECTRIC PHASE OF NANOCRYSTALLINE-TRIGLYCINE SULFATE COMPOSITE

2020 ◽  
Vol 38 (02) ◽  
Author(s):  
NGUYEN HOAI THUONG ◽  
MAI BICH DUNG ◽  
TRAN THANH NGOC ◽  
NGUYEN THI LAN HUONG ◽  
NGUYEN THI KIM ANH ◽  
...  
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Dielectric Properties ◽  
Dielectric Relaxation ◽  
Paraelectric Phase ◽  
Triglycine Sulfate ◽  
Weak Electric Field ◽  
Relaxation Phenomena ◽  
Frequency Range ◽  
Slowing Down

The aim of this work is to clarify dielectric relaxation phenomena in paraelectric phase of composites based on nanocrystalline cellulose and triglycine sulfate. Although the dielectric properties of this material were almost thoroughly investigated, but there has been no study devoted to relaxation anomalies in paraelectric phase. The results showed the presence of Debye-like relaxation at the entire studied frequency range 103 – 106 Hz under a weak electric field of 1 V.m-1 from phase transition temperature in the composite (54 ˚C) to 90 ˚C. In addition, the phenomena were observed at lower frequencies as compared to those of triglycine sulfate single crystals. The results were explained by the assumption based on critical slowing down occurred in the nanoparticles in the composite.

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