Ionic Species-Modulated Interfacial Polarization and Frequency Selectivity in Polymer Electrolyte/Semiconductor Heterojunctions

2017 ◽  
Vol 121 (30) ◽  
pp. 16629-16636 ◽  
Author(s):  
Yuandong Hu ◽  
Fei Zeng ◽  
Qin Wan ◽  
Jun Yin ◽  
Jialu Liu
Keyword(s):  
Polymer Electrolyte ◽  
Interfacial Polarization ◽  
Ionic Species ◽  
Frequency Selectivity ◽  
Semiconductor Heterojunctions

Effect of Nano-Porous Alumina Filler on Thermal and Electrical Transport Properties of Solid Polymer Electrolyte (PEO)12LiBF4

2008 ◽  
Vol 55-57 ◽  
pp. 745-748 ◽  
Author(s):  
H.M.J.C. Pitawala ◽  
M.A.K.L. Dissanayake ◽  
V.A. Seneviratne ◽  
B.E. Mellander ◽  
I. Albinsson
Keyword(s):  
Polymer Electrolyte ◽  
Electrical Transport ◽  
Solid Polymer Electrolyte ◽  
Porous Alumina ◽  
Weight Ratio ◽  
Ionic Species ◽  
Solid Polymer ◽  
Electrical Transport Properties ◽  
Composite Electrolyte ◽  
Conductivity Enhancement

onic conductivity, dielectric and thermal properties of (PEO)12LiBF4 solid polymer electrolyte, dispersed with nanoporous Al2O3 have been studied. Out of seven different compositions studied, the (PEO)12LiBF4 polymer-salt complex showed the highest conductivity with σ25 oC = 8.27 × 10-6 S cm-1. Dispersion of different weight ratio of nano-porous alumina fillers to this electrolyte showed that the composite electrolyte composition with 15 wt. % Al2O3 gave the highest conductivity with σ25 oC = 6.05 × 10-5 S cm-1. The glass transition temperature, Tg decreased from -35.3 oC to -43.2 oC and the PEO crystallite melting temperature, Tm decreased from 64.5 oC to 58.8 oC due to the incorporation of 15 wt. % Al2O3 filler, suggesting that the interaction between the PEO backbone and the Al2O3 filler have affected the main chain dynamics of the host polymer. As the presence of the filler results in an increased conductivity mainly due to an increased amount of amorphous phase in the electrolyte above Tm, another mechanism, directly associated with the filler particles, appears to contribute to the observed conductivity enhancement. A possible mechanism for this could be the creation of additional hopping sites and favorable conducting pathways for migrating ionic species though Lewis acid-base type interactions between ionic species and O/OH sites on the filler grain surface. Results of the dielectric relaxation spectroscopy agree with the suggestion that the increased mobility is largely responsible for the obtained conductivity enhancement caused by the nano- porous filler.

Effect of heavy-ion on frequency selectivity of semiconducting polymer/electrolyte heterojunction

RSC Advances ◽  
2015 ◽  
Vol 5 (119) ◽  
pp. 98110-98117 ◽  
Author(s):  
W. S. Dong ◽  
F. Zeng ◽  
S. H. Lu ◽  
X. J. Li ◽  
C. T. Chang ◽  
...  
Keyword(s):  
Polymer Electrolyte ◽  
Pulse Shape ◽  
Heavy Ion ◽  
Spike Rate ◽  
Frequency Selectivity ◽  
Semiconducting Polymer ◽  
Dependent Plasticity ◽  
Rate Dependent

Long-term bidirectional frequency selectivity has been achieved in MEH-PPV/PEO–Nd3+cells, which suggests spike-rate-dependent plasticity learning protocol. It depends on pulse shape due to variation of ionic type.

Effect of clay modification on the dynamic mechanical and dielectric properties of PMMA nanocomposites via melt blending

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Yeh Wang ◽  
Wei-C. Chen
Keyword(s):  
Dielectric Properties ◽  
Ionic Conduction ◽  
Interfacial Polarization ◽  
Ionic Species ◽  
Space Charge Polarization ◽  
Melt Blending ◽  
Dynamic Mechanical ◽  
Clay Modification ◽  
Β Relaxation ◽  
Clay Layers

AbstractThe dynamic mechanical and dielectric properties of poly(methyl methacrylate)/ clay nanocomposites (PCNs) prepared with melt blending was studied in terms of clay modification and nanoscale dispersion. The pristine clay was modified via various routes, including PMMA concentrates from in situ polymerization and POP-diamine intercalation. Partially exfoliated clay layers were uniformly dispersed in the nanocomposites as evidenced from x-ray diffraction study. The subglass β relaxation, the segmental α relaxation, and the α β-merging process above Tg were observed in the nanocomposites from the dielectric analysis. Compared to neat PMMA, with only 5 wt% clay loading, the modified PCN materials exhibit higher glass-transition temperatures and higher dynamic storage moduli, which was attributed to the polymer chain tethering and confinement effect. Significant increase in dielectric permittivity’s and losses due to interfacial polarization and ionic conduction were observed for the PCNs. The intensity of the interfacial polarization process increases with the dispersion degree of clay layers and hence the relaxation process can be assigned to the space charge polarization of the ionic species in the clay intergalleries.

Ultraviolet Absorption of Refractory Elements by a Dual Laser Plasma Method

1988 ◽  
Vol 102 ◽  
pp. 243-246
Author(s):  
J.T. Costello ◽  
W.G. Lynam ◽  
P.K. Carroll
Keyword(s):  
Absorption Spectra ◽  
Laser Plasma ◽  
Optical Pulse ◽  
Ionic Species ◽  
Neutral Species ◽  
Plasma Method ◽  
Plasma Technique ◽  
Refractory Elements ◽  
Delay Times ◽  
Dual Laser

AbstractThe dual laser-produced plasma technique for the study of ionic absorption spectra has been developed by the use of two Q-switched ruby lasers to enable independent generation of the absorbing and back-lighting plasmas. Optical pulse handling is used in the coupling cicuits to enable reproducible pulse delays from 250 nsec. to 10 msec, to be achieved. At delay times > 700 nsec. spectra of essentially pure neutral species are observed. The technique is valuable, not only for obtaining the neutral spectra of highly refractory and/or corrosive materials but also for studying behaviour of ionic species as a function of time. Typical spectra are shown in Fig. 1.

Effects of Electrical Discharges in Low Pressure Gases on the Morphology of Polyethylene Crystals

1974 ◽  
Vol 32 ◽  
pp. 544-545
Author(s):  
L.H. Bolz ◽  
D.H. Reneker
Keyword(s):  
Power Distribution ◽  
Electrical Discharge ◽  
Dielectric Breakdown ◽  
Ionic Species ◽  
Low Pressure ◽  
Polymer Surfaces ◽  
Electrical Discharges ◽  
Adhesive Bonds ◽  
Power Distribution Lines ◽  
Modification Of The Surface

The attack, on the surface of a polymer, by the atomic, molecular and ionic species that are created in a low pressure electrical discharge in a gas is interesting because: 1) significant interior morphological features may be revealed, 2) dielectric breakdown of polymeric insulation on high voltage power distribution lines involves the attack on the polymer of such species created in a corona discharge, 3) adhesive bonds formed between polymer surfaces subjected to such SDecies are much stronger than bonds between untreated surfaces, 4) the chemical modification of the surface creates a reactive surface to which a thin layer of another polymer may be bonded by glow discharge polymerization.

The observation of nano-voids in Au thin films

1987 ◽  
Vol 45 ◽  
pp. 366-367
Author(s):  
William Krakow
Keyword(s):  
Thin Films ◽  
Melting Point ◽  
Present Author ◽  
Stacking Faults ◽  
Damage Threshold ◽  
Ionic Species ◽  
Rare Gases ◽  
Chain Defects ◽  
Vacancy Chains ◽  
Au Thin Films

It has long been known that defects such as stacking faults and voids can be quenched from various alloyed metals heated to near their melting point. Today it is common practice to irradiate samples with various ionic species of rare gases which also form voids containing solidified phases of the same atomic species, e.g. ref. 3. Equivalently, electron irradiation has been used to produce damage events, e.g. ref. 4. Generally all of the above mentioned studies have relied on diffraction contrast to observe the defects produced down to a dimension of perhaps 10 to 20Å. Also all these studies have used ions or electrons which exceeded the damage threshold for knockon events. In the case of higher resolution studies the present author has identified vacancy and interstitial type chain defects in ion irradiated Si and was able to identify both di-interstitial and di-vacancy chains running through the foil.

Effect of High Salt Concentration on Ion Clustering and Transport in Polymer Solid Electrolytes: a Molecular Dynamics Study of PEO-LiTFSI

2018 ◽  
Author(s):  
Nicola Molinari ◽  
Jonathan P. Mailoa ◽  
Boris Kozinsky
Keyword(s):  
Polymer Electrolyte ◽  
Salt Concentration ◽  
Rational Design ◽  
Material System ◽  
Ion Dynamics ◽  
High Concentration ◽  
Anion Clusters ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

<div> <div> <div> <p>The model and analysis methods developed in this work are generally applicable to any polymer electrolyte/cation-anion combination, but we focus on the currently most prominent polymer electrolyte material system: poly(ethylene) oxide/Li- bis(trifluoromethane) sulfonamide (PEO + LiTFSI). The obtained results are surprising and challenge the conventional understanding of ionic transport in polymer electrolytes: the investigation of a technologically relevant salt concentration range (1 - 4 M) revealed the central role of the anion in coordinating and hindering Li ion movement. Our results provide insights into correlated ion dynamics, at the same time enabling rational design of better PEO-based electrolytes. In particular, we report the following novel observations. 1. Strong binding of the Li cation with the polymer competes with significant correlation of the cation with the salt anion. 2. The appearance of cation-anion clusters, especially at high concentration. 3. The asymmetry in the composition (and therefore charge) of such clusters; specifically, we find the tendency for clusters to have a higher number of anions than cations.</p> </div> </div> </div>

Effect of High Salt Concentration on Ion Clustering and Transport in Polymer Solid Electrolytes: a Molecular Dynamics Study of PEO-LiTFSI

2018 ◽  
Author(s):  
Nicola Molinari ◽  
Jonathan P. Mailoa ◽  
Boris Kozinsky
Keyword(s):  
Polymer Electrolyte ◽  
Salt Concentration ◽  
Rational Design ◽  
Material System ◽  
Ion Dynamics ◽  
High Concentration ◽  
Anion Clusters ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

<div> <div> <div> <p>The model and analysis methods developed in this work are generally applicable to any polymer electrolyte/cation-anion combination, but we focus on the currently most prominent polymer electrolyte material system: poly(ethylene) oxide/Li- bis(trifluoromethane) sulfonamide (PEO + LiTFSI). The obtained results are surprising and challenge the conventional understanding of ionic transport in polymer electrolytes: the investigation of a technologically relevant salt concentration range (1 - 4 M) revealed the central role of the anion in coordinating and hindering Li ion movement. Our results provide insights into correlated ion dynamics, at the same time enabling rational design of better PEO-based electrolytes. In particular, we report the following novel observations. 1. Strong binding of the Li cation with the polymer competes with significant correlation of the cation with the salt anion. 2. The appearance of cation-anion clusters, especially at high concentration. 3. The asymmetry in the composition (and therefore charge) of such clusters; specifically, we find the tendency for clusters to have a higher number of anions than cations.</p> </div> </div> </div>

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