Surface confinement induces the formation of solid-like insulating ionic liquid nanostructures

2017 ◽  
Author(s):  
Massimiliano Galluzzi ◽  
Simone Bovio ◽  
Paolo Milani ◽  
Alessandro Podestà
Keyword(s):  
Ionic Liquid ◽  
Electrical Properties ◽  
Electric Fields ◽  
Relative Dielectric Constant ◽  
Ionic Mobility ◽  
Electric Properties ◽  
Bulk Liquid ◽  
Structural Reorganization ◽  
Surface Confinement ◽  
Insulator Layers

We report on the modification of the electric properties of the imidazolium-based [BMIM][NTf2] ionic liquid upon surface confinement in the sub-monolayer regime. Solid-like insulating nanostructures of [BMIM][NTf2] spontaneously form on a variety of insulating substrates, at odd with the liquid and conductive nature of the same substances in the bulk phase. A systematic spatially resolved investigation by atomic force microscopy of the morphological, mechanical and electrical properties of [BMIM][NTf2] nanostructures showed that this liquid substance rearranges into lamellar nanostructures with a high degree of vertical order and enhanced resistance to mechanical compressive stresses and very intense electric fields, denoting a solid-like character. The morphological and structural reorganization has a profound impact on the electric properties of supported [BMIM][NTf2] islands, which behave like insulator layers with a relative dielectric constant between 3 and 5, comparable to those of conventional ionic solids, and significantly smaller than those measured in the bulk ionic liquid. These results suggest that in the solid-like ordered domains confined either at surfaces or inside the pores of the nanoporous electrodes of photo-electrochemical devices, the ionic mobility and the overall electrical properties can be significantly perturbed with respect to the bulk liquid phase, which would likely influence the<br>performance of the devices.<br>

Surface confinement induces the formation of solid - like insulating ionic liquid nanostructures

2018 ◽  
Author(s):  
Massimiliano Galluzzi ◽  
Simone Bovio ◽  
Paolo Milani ◽  
Alessandro Podestà
Keyword(s):  
Ionic Liquid ◽  
Electrical Properties ◽  
Electric Fields ◽  
Relative Dielectric Constant ◽  
Ionic Mobility ◽  
Electric Properties ◽  
Bulk Liquid ◽  
Structural Reorganization ◽  
Surface Confinement ◽  
Insulator Layers

We report on the modification of the electric properties of the imidazolium-based [BMIM][NTf2] ionic liquid upon surface confinement in the sub-monolayer regime. Solid-like insulating nanostructures of [BMIM][NTf2] spontaneously form on a variety of insulating substrates, at odd with the liquid and conductive nature of the same substances in the bulk phase. A systematic spatially-resolved investigation by atomic force microscopy of the morphological, mechanical and electrical properties of [BMIM][NTf2] nanostructures showed that this liquid substance rearranges into lamellar nanostructures with a high degree of vertical order and enhanced resistance to mechanical compressive stresses and very intense electric fields, denoting a solid-like character. The morphological and structural reorganization has a profound impact on the electric properties of supported [BMIM][NTf2] islands, which behave like insulator layers with a relative dielectric constant between 3 and 5, comparable to those of conventional ionic solids, and significantly smaller than those measured in the bulk ionic liquid. These results suggest that in the solid-like ordered domains confined either at surfaces or inside the pores of the nanoporous electrodes of photo-electrochemical devices, the ionic mobility and the overall electrical properties can be significantly perturbed with respect to the bulk liquid phase, which would likely influence the performance of the devices. <br><br>Published on J. Phys. Chem. C, 2018, 122 (14), pp 7934–7944. DOI: 10.1021/acs.jpcc.7b12600. <br>

scholarly journals Surface confinement induces the formation of solid - like insulating ionic liquid nanostructures

2018 ◽  
Author(s):  
Massimiliano Galluzzi ◽  
Simone Bovio ◽  
Paolo Milani ◽  
Alessandro Podestà
Keyword(s):  
Ionic Liquid ◽  
Electrical Properties ◽  
Electric Fields ◽  
Relative Dielectric Constant ◽  
Ionic Mobility ◽  
Electric Properties ◽  
Bulk Liquid ◽  
Structural Reorganization ◽  
Surface Confinement ◽  
Insulator Layers

We report on the modification of the electric properties of the imidazolium-based [BMIM][NTf2] ionic liquid upon surface confinement in the sub-monolayer regime. Solid-like insulating nanostructures of [BMIM][NTf2] spontaneously form on a variety of insulating substrates, at odd with the liquid and conductive nature of the same substances in the bulk phase. A systematic spatially-resolved investigation by atomic force microscopy of the morphological, mechanical and electrical properties of [BMIM][NTf2] nanostructures showed that this liquid substance rearranges into lamellar nanostructures with a high degree of vertical order and enhanced resistance to mechanical compressive stresses and very intense electric fields, denoting a solid-like character. The morphological and structural reorganization has a profound impact on the electric properties of supported [BMIM][NTf2] islands, which behave like insulator layers with a relative dielectric constant between 3 and 5, comparable to those of conventional ionic solids, and significantly smaller than those measured in the bulk ionic liquid. These results suggest that in the solid-like ordered domains confined either at surfaces or inside the pores of the nanoporous electrodes of photo-electrochemical devices, the ionic mobility and the overall electrical properties can be significantly perturbed with respect to the bulk liquid phase, which would likely influence the performance of the devices.<br>

Effect Of Moisture On The Physical Properties Of Polyimide Films

1991 ◽  
Vol 227 ◽  
Author(s):  
Rajeevi Subramanian ◽  
Michael T. Pottiger ◽  
Jacqueline H. Morris ◽  
Joseph P. Curilla
Keyword(s):  
Dielectric Constant ◽  
Steady State ◽  
Electrical Properties ◽  
Relative Humidity ◽  
Quartz Crystal ◽  
Moisture Absorption ◽  
Relative Dielectric Constant ◽  
Moisture Uptake ◽  
Polyimide Films ◽  
Effect Of Moisture

ABSTRACTMoisture absorption and its effect on electrical properties were measured for several polyimides. A Quartz Crystal Microbalance (QCM) was used to investigate the moisture absorption in BPDA/PPD, PMDA/ODA, and BTDA//ODA/MPD polyimides. The steady-state moisture uptake in polyimides as a function of relative humidity (RH) was determined by exposing film samples to successively higher RH values ranging from 10 to 85% at 25°C. The isothermal moisture absorption as a function of percent RH was found to be nearly linear for all of the polyimides studied. The effect of moisture on the electrical properties of a BPDA/PPD polyimide was also investigated. The relative dielectric constant at 25 °C was found to be a linear function of the moisture absorbed.

Electrical Properties of Flames. BurnerFlames in Longitudinal Electric Fields.

1951 ◽  
Vol 43 (12) ◽  
pp. 2726-2731 ◽  
Author(s):  
Hartwell F. Calcote ◽  
Robert N. Pease
Keyword(s):  
Electrical Properties ◽  
Electric Fields

Reactive Ion Etching Damage to Ferroelectric Thin Films Capacitors

1994 ◽  
Vol 361 ◽  
Author(s):  
W. Pan ◽  
C.L. Thio ◽  
S.B. Desu ◽  
Cheewon Chung
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Leakage Current ◽  
Reactive Ion Etching ◽  
Ferroelectric Thin Films ◽  
Electric Properties ◽  
Etching Time ◽  
Ion Etching ◽  
Before And After ◽  
Ferroelectric Capacitors

ABSTRACTReactive ion etching damage to sputtered Pt/PZT/Pt ferroelectric capacitors was studied using Ar and CHCIFCF3 etch gases. Electrical properties, hysteresis, fatigue, and leakage current of PZT capacitors, before and after etching, were compared to examine the etching damage. It is found that the damage effects depend on etching time and are mainly due to the physical bombardment effect. The PZT capacitors etched with CHCIFCF3 plasma showed less damage than those etched in Ar plasma. The electric properties of etched Pt/PZT/Pt capacitors are recovered by annealing at 400 °C for 30min.

Electrical properties of aluminum oxide ceramics film on a metal

2021 ◽  
Vol 2 ◽  
pp. 59-65
Author(s):  
I. Yu. Bakeev ◽  
◽  
Yu. A. Burachevsky ◽  
E. S. Dvilis ◽  
D. B. Zolotukhin ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electrical Properties ◽  
Aluminum Oxide ◽  
Relative Dielectric Constant ◽  
Plasma Electron ◽  
Electron Beam Evaporation ◽  
Original Method ◽  
Alumina Powder ◽  
Oxide Ceramic ◽  
Temperature Dependences

The work is devoted to the study of electrical properties (temperature dependences of conductivity, relative dielectric constant, dielectric loss tangent for various frequencies) of an aluminum oxide ceramic film deposited on a metal substrate. The film was created by the original method of electron beam evaporation of a non-conductive target, consisting of a compressed alumina powder, using a plasma electron source, which is able to reliably operate in the fore-vacuum pressure range (5 – 100 Pa). Such increased working gas pressures ensures the generation of a dense beam plasma near the target, which neutralizes the charging of a non-conducting target and thereby provides its effective melting and electron beam evaporation.

scholarly journals The Effect of Dielectric Polarization Rate Difference of Filler and Matrix on the Electrorheological Responses of Poly(ionic liquid)/Polyaniline Composite Particles

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 703 ◽  
Author(s):  
Chen Zheng ◽  
Qi Lei ◽  
Jia Zhao ◽  
Xiaopeng Zhao ◽  
Jianbo Yin
Keyword(s):  
Ionic Liquid ◽  
Electric Fields ◽  
Flow Behavior ◽  
Composite Particles ◽  
Dielectric Polarization ◽  
Rate Difference ◽  
Polarization Rate ◽  
Carrier Liquid ◽  
Poly Ionic Liquid ◽  
Stable Flow

By using different conductivity of polyaniline as filler, a kind of poly(ionic liquid)/polyaniline composite particles was synthesized to investigate the influence of dielectric polarization rate difference between filler and matrix on the electrorheological response and flow stability of composite-based electrorheological fluids under simultaneous effect of shear and electric fields. The composite particles were prepared by a post ion-exchange procedure and then treated by ammonia or hydrazine to obtain different conductivity of polyaniline. Their electrorheological response was measured by dispersing these composite particles in insulating carrier liquid under electric fields. It showed that the composite particles treated by ammonia had the strongest electrorheological response and most stable flow behavior in a broad shear rate region from 0.5 s−1 to 1000 s−1. By using dielectric spectroscopy, it found that the enhanced electrorheological response with stable flow depended on the matching degree of the dielectric polarization rates between poly(ionic liquid) matrix and polyaniline filler. The closer their polarization rates are, the more stable the flow curves are. These results are helpful to design optimal composite-based electrorheological materials with enhanced and stable ER performance.

Nonlinear Dynamics of Electrokinetic Instabilities

2005 ◽  
Author(s):  
Jonathan D. Posner ◽  
Juan G. Santiago
Keyword(s):  
Electric Fields ◽  
High Speed ◽  
Power Spectra ◽  
Epifluorescence Microscopy ◽  
Bulk Liquid ◽  
Sample Stacking ◽  
Electrokinetic Instability ◽  
Absolute Flow ◽  
Electrokinetic Flows ◽  
Continuous Power

Electrokinetic instabilities are generated by a coupling of electric fields and ionic conductivity gradients. This coupling results in an electric body force in the bulk liquid that can generate temporal, convective, and absolute flow instabilities. In this work, we perform a parametric experimental study of convective instabilities in cross-shaped microchannels using epifluorescence microscopy and high speed digital imaging. We report temporal power spectra and spatiotemporal maps as a function of the applied field. The spectral analyses reveal that disturbances induced by electrokinetic instability are purely sinuous at the onset of instability and exhibit higher-order harmonics, frequency bifurcations, and continuous power spectra with increasing electric Rayleigh number. Electrokinetic instabilities (EKI) in cross-shaped channels are relevant to injections for field amplified sample stacking, electrokinetic flows at the intersections in multi-dimensional assay devices, and systems with indeterminate sample chemistry.

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