scholarly journals Microporous MOF as nanogen facilitating diffusion-coupled charge transfer near the percolation threshold in a polyaniline pseudo-supercapacitor

2021 ◽  
Author(s):  
Worood A. El-Mehalmey ◽  
Rana R. Haikal ◽  
Aya Mohamed Ali ◽  
Ahmed B. Soliman ◽  
Mady ElBahri ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Percolation Threshold ◽  
Specific Capacitance ◽  
Ion Diffusion ◽  
The Matrix ◽  
Pani Matrix

A facile and potentially transferrable approach to enhance the PANI specific capacitance through the incorporation of MOF nanocrystals, as a microporous filler (nanogens), into the PANI matrix to provide ion-diffusion channels within the matrix.

scholarly journals Characterization of percolation behavior in conductor–dielectric 0-3 composites

2014 ◽  
Vol 04 (04) ◽  
pp. 1450035 ◽  
Author(s):  
Lin Zhang ◽  
Patrick Bass ◽  
Zhi-Min Dang ◽  
Z.-Y. Cheng
Keyword(s):  
Dielectric Constant ◽  
Percolation Threshold ◽  
Frequency Dependence ◽  
Experimental Results ◽  
Effective Dielectric Constant ◽  
Filler Concentration ◽  
Percolation Behavior ◽  
The Matrix ◽  
The Relationship

The equation ε eff ∝ (ϕc - ϕ)-s which shows the relationship between effective dielectric constant (εeff) and the filler concentration (φ), is widely used to determine the percolation behavior and obtain parameters, such as percolation threshold φc and the power constant s in conductor–dielectric composites (CDCs). Six different systems of CDCs were used to check the expression by fitting experimental results. It is found that the equation can fit the experimental results at any frequency. However, it is found that the fitting constants do not reflect the real percolation behavior of the composites. It is found that the dielectric constant is strongly dependent on the frequency, which is mainly due to the fact that the frequency dependence of the dielectric constant for the composites close to φc is almost independent of the matrix.

A 2D donor–acceptor covalent organic framework with charge transfer for supercapacitors

2020 ◽  
Vol 56 (91) ◽  
pp. 14187-14190
Author(s):  
Tao Li ◽  
Xiaodong Yan ◽  
Wen-Da Zhang ◽  
Wang-Kang Han ◽  
Yong Liu ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Charge Transfer ◽  
Energy Density ◽  
Specific Capacitance ◽  
Intramolecular Charge Transfer ◽  
High Electrical Conductivity ◽  
Covalent Organic Framework ◽  
Redox Active ◽  
Donor Acceptor ◽  
Organic Framework

A 2D covalent organic framework with intramolecular charge transfer, numerous redox-active groups and high electrical conductivity possesses a specific capacitance of 752 F g−1 and an energy density of 57 W h kg−1.

Optical Absorption Processes in CdSe Nanocrystals Embedded in Silicate Glass and Organic Polymer Matrices Under 7-MeV Electron Irradiation

2008 ◽  
Vol 8 (2) ◽  
pp. 806-811 ◽  
Author(s):  
Yu. M. Azhniuk ◽  
A. V. Gomonnai ◽  
V. V. Lopushansky ◽  
I. G. Megela ◽  
A. E. Raevskaya ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Optical Absorption ◽  
Silicate Glass ◽  
Electron Irradiation ◽  
Polymer Matrices ◽  
Organic Polymer ◽  
Color Centers ◽  
Cdse Nanocrystals ◽  
Deep Traps ◽  
The Matrix

Irradiation-induced bleaching occurs in the spectra of glass-embedded CdSe nanocrystals due to their ionization resulting from charge transfer between them and color centers formed in glass by electron irradiation. No bleaching in the spectra of CdSe nanocrystals encapsulated in gelatine is observed because no deep traps are formed in the matrix under electron irradiation.

Reversible nonlinear electrical conductive behavior of high-density polyethylene composites

2018 ◽  
Vol 32 (8) ◽  
pp. 1123-1136 ◽  
Author(s):  
Ji-Zhao Liang
Keyword(s):  
Coordinate System ◽  
Percolation Threshold ◽  
Current Density ◽  
High Density Polyethylene ◽  
Specific Area ◽  
Ethylene Vinyl Acetate ◽  
High Density ◽  
Experimental Conditions ◽  
The Matrix ◽  
Polyethylene Composites

The reversible nonlinear electrical conductive properties of high-density polyethylene composites filled separately with carbon black (CB), ethylene-vinyl acetate copolymer, and carbon fiber (CF) were measured using a four-electrode method. It was found that these composites presented significant reversible nonlinear electrical conductive behavior under these experimental conditions; the correlation between the current density and the electrical field intensity was linear in a bi-logarithmic coordinate system; both the crossover current density and the conductivity were approximately a linear function of the conductivity in a bi-logarithmic coordinate system; there was a synergic effect in the electrical conductivity percolation threshold between the CB and CF in the matrix, and the percolation threshold decreased with increasing the Brunauer–Emmett–Teller specific area of the CB.

scholarly journals Electrical Conductivity of PA6/Graphite and Graphite Nanoplatelets Composites using Two Processing Streams

2021 ◽  
Vol 5 (1) ◽  
pp. 19-31
Author(s):  
M. Umar ◽  
M. I. Ofem ◽  
A. S. Anwar ◽  
M. M. Usman
Keyword(s):  
Electrical Conductivity ◽  
Percolation Threshold ◽  
Carbon Composite ◽  
Graphite Nanoplatelets ◽  
Particulate Carbon ◽  
The Matrix ◽  
Sonication Technique ◽  
Carbon Fillers ◽  
Made In

The percolation threshold (PT) of any polymer/particulate carbon composite depends on the processing, the dispersed state of the filler, the matrix used and the morphology attained. Sonication technique was used to make PA6/G and PA6/GNP composites employing in situ polymerisation, after which their electrical conductivity behaviours were investigated. While overhead stirring and horn sonication were used to distribute and disperse the carbon fillers, the composites were made in 2 streams 40/10 and 20/20. The 40/10 stream implies that while dispersing the carbon fillers in PA6 monomer, 40% amplitude of sonication was applied for 10 minutes whereas the 20/20 stream implies 20% amplitude of sonication for 20 minutes. In both streams, the dispersing strain imparted on the monomer/carbon mixture was 400 in magnitude. Purely ohmic electrical conductivity behaviour was attained at 9.75 G wt. % for IG 40/10 system. For composites in the IG 20/20 system, same was attained at 10.00 G wt. %. Electrical conductivity sufficient for electrostatic discharge applications was achieved above 15 G wt. % in the IG 40/10 system. Using the power law percolation theory, percolation threshold was attained at 9.7 G wt. % loading in IG 40/10 system, while same was attained at 7.6 G wt. % loading in IG 20/20 system. For the GNP based systems, percolation threshold occurred at 5.2 GNP wt. % in the INP 40/10 system whereas same occurred at 7.4 GNP wt. % in the IG 20/20 system.

scholarly journals Структурная трактовка изменения свойств нанокомпозитов полимер/углеродные нанотрубки у порога перколяции нанонаполнителя

2019 ◽  
Vol 89 (10) ◽  
pp. 1585
Author(s):  
Г.В. Козлов ◽  
И.В. Долбин
Keyword(s):  
Carbon Nanotube ◽  
Percolation Threshold ◽  
Polymer Matrix ◽  
Fractal Analysis ◽  
Formation Process ◽  
Structural State ◽  
The Matrix ◽  
Carbon Nanotube Network ◽  
Degree Of Reinforcement ◽  
Aggregation Level

AbstractThe structure of the nanofiller in the polymer matrix of polymer/carbon nanotube nanocomposites can be characterized by the dimension of the nanofiller network, which is a direct indicator of its aggregation level. The formation process of such a network is considered as a result of interaction of the matrix polymer and a carbon nanotube; which allows us to determine its dimension with the help of fractal analysis. It is found that the dimension of the carbon nanotube network changes both qualitatively and quantitatively at their percolation threshold, reflecting different aggregation levels. This dimension uniquely determines the degree of reinforcement of such nanocomposites and their structural state as a system.

Sodium-ion diffusion and charge transfer kinetics of sodium-ion hybrid capacitors using bio-derived hierarchical porous carbon

2018 ◽  
Vol 286 ◽  
pp. 55-64 ◽  
Author(s):  
Nutthaphon Phattharasupakun ◽  
Juthaporn Wutthiprom ◽  
Nattapol Ma ◽  
Narong Chanlek ◽  
Montree Sawangphruk
Keyword(s):  
Charge Transfer ◽  
Porous Carbon ◽  
Sodium Ion ◽  
Ion Diffusion ◽  
Hierarchical Porous Carbon ◽  
Hierarchical Porous ◽  
Kinetics Of ◽  
Hybrid Capacitors

scholarly journals Collaboration between HPMC and NaCMC in order to Reach the Polymer Critical Point in Theophylline Hydrophilic Matrices

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
L. Contreras ◽  
L. M. Melgoza ◽  
A. Aguilar-de-Leyva ◽  
I. Caraballo
Keyword(s):  
Percolation Threshold ◽  
Critical Point ◽  
Critical Points ◽  
Percolation Theory ◽  
Minimum Concentration ◽  
Hydrophilic Matrices ◽  
Gel Layer ◽  
The Matrix ◽  
Effective Collaboration ◽  
First Time

Percolation theory has been applied in order to study the existence of critical points as well as the possibility to find a “combined percolation threshold” for ternary hydrophilic matrices prepared with HPMC, NaCMC, and theophylline. For this purpose, different batches of ternary as well as binary hydrophilic matrices have been prepared. Critical points have been found for binary hydrophilic matrices between 21.5 and 31.3% (v/v) of HPMC and between 39 and 54% (v/v) of NaCMC, respectively. In a previous work carried out with the same polymers but a much more soluble drug (KCl), it was demonstrated the existence of a partial collaboration between the polymers in order to establish the gel layer. In this work, it has been observed for the first time the need of a minimum concentration of one of the matrix-forming polymer (between 10 and 20% v/v, approximately) for establishing an effective collaboration.

Lowering The Percolation Threshold In Carbon Blackfilled Polymer Composites

1999 ◽  
Vol 576 ◽  
Author(s):  
J. C. Grujnlan ◽  
W. W. Gerberich ◽  
L. F. Francis
Keyword(s):  
Carbon Black ◽  
Polyvinyl Alcohol ◽  
Percolation Threshold ◽  
Polymer Composites ◽  
Polyvinyl Acetate ◽  
Water Dispersible ◽  
Polymeric Particles ◽  
The Matrix ◽  
Polymer Microstructures ◽  
Prepared Composite

ABSTRACTIn an effort to lower the percolation threshold of carbon black-filled polymer composites, various polymer microstructures were examined. Composites prepared with a polyvinyl acetate (PVAc) latex and a poly(vinyl acetate – ethylene) water-dispersible powder showed a significantly lowered percolation threshold relative to an equivalently prepared composite that used a polyvinyl alcohol (PVA) solution to form the matrix phase. The percolation threshold of the dispersion-based composites occurred at 5 vol.% carbon black, while the equivalent solutionbased composite produced a threshold at 14 vol.%. By excluding the carbon black from regions occupied by polymeric particles, the dispersion-based composites lead to preferential aggregation of carbon black, as evidenced by SEM, and a lowered percolation threshold.

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