Exact Scaling Laws for Electrical Conductivity Properties of Nematic Polymer Nanocomposite Monodomains

2005 ◽  
Vol 15 (4) ◽  
pp. 627-638 ◽  
Author(s):  
X. Zheng ◽  
M. G. Forest ◽  
R. Lipton ◽  
R. Zhou ◽  
Q. Wang
Keyword(s):  
Electrical Conductivity ◽  
Scaling Laws ◽  
Polymer Nanocomposite ◽  
Nematic Polymer ◽  
Exact Scaling

scholarly journals Propagation Analysis of the Coronavirus Pandemic on the Light of the Percolation Theory

2021 ◽  
Author(s):  
Moez Guettari ◽  
Ahmed El Aferni
Keyword(s):  
Electrical Conductivity ◽  
Percolation Theory ◽  
Scaling Laws ◽  
High Accuracy ◽  
The Novel ◽  
Infected People ◽  
Boltzman Equation ◽  
Novel Approach ◽  
Propagation Analysis ◽  
Speed Of Propagation

Efforts to combat the Covid-19 pandemic have not been limited to the processes of vaccine production, but they first began to analyze the dynamics of the epidemic’s spread so that they could adopt barrier measures to bypass the spread. To do this, the works of modeling, predicting and analyzing the spread of the virus continue to increase day after day. In this context, the aim of this chapter is to analyze the propagation of the Coronavirus pandemic by using the percolation theory. In fact, an analogy was established between the electrical conductivity of reverse micelles under temperature variation and the spread of the Coronavirus pandemic. So, the percolation theory was used to describe the cumulate infected people versus time by using a modified Sigmoid Boltzman equation (MSBE) and several quantities are introduced such as: the pandemic percolation time, the maximum infected people, the time constant and the characteristic contamination frequency deduced from Arrhenius equation. Scaling laws and critical exponents are introduced to describe the spread nature near the percolation time. The speed of propagation is also proposed and expressed. The novel approach based on the percolation theory was used to study the Coronavirus (Covid-19) spread in five countries: France, Italy, Germany, China and Tunisia, during 6 months of the pandemic spread (the first wave). So, an explicit expression connecting the number of people infected versus time is proposed to analyze the pandemic percolation. The reported MSBE fit results for the studied countries showed high accuracy.

Scaling of Transport Properties of Reservoir Material at Low Saturations of a Wetting Phase

1994 ◽  
Vol 367 ◽  
Author(s):  
Y. Carolina Araujo ◽  
Pedro G. Toledo ◽  
Hada Y. Gonzalez
Keyword(s):  
Electrical Conductivity ◽  
Porous Media ◽  
Transport Properties ◽  
Capillary Pressure ◽  
Power Law ◽  
Scaling Laws ◽  
Pore Space ◽  
Conductivity Data ◽  
Phase Saturation ◽  
Electrical Conductivity Data

AbstractTransport properties of natural porous media have been observed to obey scaling laws in the wetting phase saturation. Previous work relates power-law behavior at low wetting phase saturations, i.e., at high capillary pressures, to the thin-film physics of the wetting phase and the fractal character of the pore space of porous media. Here, we present recent combined porousplate capillary pressure and electrical conductivity data of Berea sandstone at low saturations that lend support to the scaling laws. Power law is interpreted in terms of the exponent m in the relation of surface forces and film thickness and the fractal dimension D of the interface between pore space and solid matrix. Simple determination of D from capillary pressure and m from electrical conductivity data can be used to rapidly determine wetting phase relative permeability and capillary dispersion coefficient at low wetting phase saturations.

scholarly journals Polymer-Single Wall Carbon Nanotube Composites for Potential Spacecraft Applications

2001 ◽  
Vol 706 ◽  
Author(s):  
Cheol Park ◽  
Zoubeida Ounaies ◽  
Kent A. Watson ◽  
Kristin Pawlowski ◽  
Sharon E. Lowther ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Composite Films ◽  
Polymeric Materials ◽  
Polymer Nanocomposite ◽  
Weight Percent ◽  
Nanocomposite Films ◽  
Mechanical And Thermal Properties ◽  
Single Wall Carbon Nanotube ◽  
Single Wall Carbon

AbstractPolymer-single wall carbon nanotube (SWNT) composite films were prepared and characterized as part of an effort to develop polymeric materials with improved combinations of properties for potential use on future spacecraft. Next generation spacecraft will require ultra-lightweight materials that possess specific and unique combinations of properties such as radiation and atomic oxygen resistance, low solar absorptivity, high thermal emissitivity, electrical conductivity, tear resistance, ability to be folded and seamed, and good mechanical properties. The objective of this work is to incorporate sufficient electrical conductivity into space durable polyimides to mitigate static charge build-up. The challenge is to obtain this level of conductivity (10-8 S/cm) without degrading other properties of importance, particularly optical transparency. Several different approaches were attempted to fully disperse the SWNTs into the polymer matrix. These included high shear mixing, sonication, and synthesizing the polymers in the presence of pre-dispersed SWNTs. Acceptable levels of conductivity were obtained at loading levels less than one tenth weight percent SWNT without significantly sacrificing optical properties. Characterization of the nanocomposite films and the effect of SWNT concentration and dispersion on the conductivity, solar absorptivity, thermal emissivity, mechanical and thermal properties were discussed. Fibers and non-woven porous mats of SWNT reinforced polymer nanocomposite were produced using electrospinning.

scholarly journals Conduction mechanism in (ZnO/PVC) polymer nanocomposite

2021 ◽  
Vol 2070 (1) ◽  
pp. 012007
Author(s):  
A Joy Singh
Keyword(s):  
Electrical Conductivity ◽  
Electric Field ◽  
Space Charge ◽  
Applied Electric Field ◽  
High Field ◽  
Conduction Mechanism ◽  
Polymer Nanocomposite ◽  
Zno Nanoparticle ◽  
Pure Sample ◽  
Transition Field

Abstract The electrical conductivity of ZnO nanoparticle doped PVC polymer of different concentrations and thickness has been investigated as a function if applied electric field and temperature. The LnJ versus E1/2 plot for the pure sample shows transition field but for highly doped sample, the plot shows curvature for both low and high field, i.e., there is no transition field. This nonlinearity of the plot is due to space charge built up in the sample. The value of β is calculated from the slope of LnJ versus E1/2 plot and compared with the theoretical value. The result shows the Poole-Frenkel mechanism of conduction is operative.

Synthesis and Characterization of Nanocomposite of Copolymer of N-Methyl Pyrrole (NMPy) and N, N-Dimethyl Aniline (NDMA)

2019 ◽  
pp. 124-129
Author(s):  
R. Rathore ◽  
Soni Sharma
Keyword(s):  
Electrical Conductivity ◽  
Surface Morphology ◽  
Oxidative Polymerization ◽  
Polymer Nanocomposite ◽  
Xrd Analysis ◽  
Probe Method ◽  
Synthesis And Characterization ◽  
Chemical Oxidative Polymerization ◽  
Amorphous Nature

Nanocomposite of copolymer of N-Methyl pyrrole (NMPy) and N, N-Dimethyl aniline (NDMA) doped with HCl was synthesized by chemical oxidative polymerization. APS was used as oxidant. The sample was characterized by FTIR, TGA, XRD and four probe method. FTIR confirms the formation of copolymer and its structure. XRD analysis shows the amorphous nature of polymer nanocomposite. The electrical conductivity of sample was measured by using four probe method. Size and surface morphology were demonstrated by SEM.

PVP a binder for the manufacture of ultrathin ITO/polymer nanocomposite films with improved electrical conductivity

2015 ◽  
Vol 50 (18) ◽  
pp. 6124-6133 ◽  
Author(s):  
Moritz Wegener ◽  
Minato Kato ◽  
Ken-ichi Kakimoto ◽  
Stefanie Spallek ◽  
Erdmann Spiecker ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Polymer Nanocomposite ◽  
Nanocomposite Films

scholarly journals 3D Monte Carlo simulation modeling for the electrical conductivity of carbon nanotube-incorporated polymer nanocomposite using resistance network formation

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Nanzhu Zhao 1 ◽  
Yongha Kim 1 ◽  
Joseph H. Koo 1
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Carbon Nanotube ◽  
Network Formation ◽  
Polymer Nanocomposite ◽  
Electrical Percolation ◽  
Resistance Network ◽  
3D Monte Carlo

High electrical and thermal conductivity associated with high stiffness and strength offer tremendous opportunities to the development of a series of carbon nanotube incorporated composite materials for a variety of applications. In particular, a small amount of carbon fibers or carbon nanotubes in a non-conductive polymer will transform a composite into a conductive material, which reveals superb potential of their future application in electronic devices. The relation between the amount of carbon nanotubes in a polymer and the electrical conductivity of it can be studied experimentally as well as theoretically with various simulation models. A three-dimensional (3D) Monte Carlo simulation model using resistance network formation was developed to study the relation between the electrical conductivity of the polymer nanocomposite and the amount of carbon nanotubes dispersed in it. In this model, carbon nanotubes were modeled as curvy cylindrical nanotubes with various lengths and fixed tube diameter, all of which were randomly distributed in a non-conductive constrained volume, which represents polymer. The model can be used to find the volumetric electrical resistance of a constrained cubic structure by forming a comprehensive resistance network among all of the nanotubes in contact. As more and more nanotubes were added into the volume, the electrical conductivity of the volume increases exponentially. However, once the amount of carbon nanotubes reached about 0.1 % vt (volume percentage), electrical percolation was detected, which was consistent with the experimental results. This model can be used to estimate the electrical conductivity of the composite matrix as well as to acquire the electrical percolation threshold.

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