Simulation of percolation threshold and electrical conductivity in composites filled with conductive particles: Effect of polydisperse particle size distribution

2014 ◽  
Vol 37 (1) ◽  
pp. 61-69 ◽  
Author(s):  
R.G. Arenhart ◽  
G.M.O. Barra ◽  
C.P. Fernandes
Keyword(s):  
Electrical Conductivity ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Percolation Threshold ◽  
Size Distribution ◽  
Polydisperse Particle ◽  
Conductive Particles

Simplified estimation of unsaturated soil hydraulic conductivity using bulk electrical conductivity and particle size distribution

Soil Research ◽  
2013 ◽  
Vol 51 (1) ◽  
pp. 23 ◽  
Author(s):  
Mohammad Reza Neyshabouri ◽  
Mehdi Rahmati ◽  
Claude Doussan ◽  
Boshra Behroozinezhad
Keyword(s):  
Electrical Conductivity ◽  
Particle Size ◽  
Hydraulic Conductivity ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Unsaturated Soil ◽  
Soil Core ◽  
Soil Hydraulic Conductivity ◽  
Core Samples ◽  
Soil Hydraulic

Unsaturated soil hydraulic conductivity K is a fundamental transfer property of soil but its measurement is costly, difficult, and time-consuming due to its large variations with water content (θ) or matric potential (h). Recently, C. Doussan and S. Ruy proposed a method/model using measurements of the electrical conductivity of soil core samples to predict K(h). This method requires the measurement or the setting of a range of matric potentials h in the core samples—a possible lengthy process requiring specialised devices. To avoid h estimation, we propose to simplify that method by introducing the particle-size distribution (PSD) of the soil as a proxy for soil pore diameters and matric potentials, with the Arya and Paris (AP) model. Tests of this simplified model (SM) with laboratory data on a broad range of soils and using the AP model with available, previously defined parameters showed that the accuracy was lower for the SM than for the original model (DR) in predicting K (RMSE of logK = 1.10 for SM v. 0.30 for DR; K in m s–1). However, accuracy was increased for SM when considering coarse- and medium-textured soils only (RMSE of logK = 0.61 for SM v. 0.26 for DR). Further tests with 51 soils from the UNSODA database and our own measurements, with estimated electrical properties, confirmed good agreement of the SM for coarse–medium-textured soils (<35–40% clay). For these textures, the SM also performed well compared with the van Genuchten–Mualem model. Error analysis of SM results and fitting of the AP parameter showed that most of the error for fine-textured soils came from poorer adequacy of the AP model’s previously defined parameters for defining the water retention curve, whereas this was much less so for coarse-textured soils. The SM, using readily accessible soil data, could be a relatively straightforward way to estimate, in situ or in the laboratory, K(h) for coarse–medium-textured soils. This requires, however, a prior check of the predictive efficacy of the AP model for the specific soil investigated, in particular for fine-textured/structured soils and when using previously defined AP parameters.

Effect of the Ball Milling on the Microstructure and Mechanical Properties of AlN/Cu Composite

2015 ◽  
Vol 816 ◽  
pp. 15-20
Author(s):  
Qian Yu ◽  
Mei Hui Song ◽  
Yan Li ◽  
Xiao Chen Zhang
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Ball Milling ◽  
Bending Strength ◽  
Rotation Speed ◽  
Mixing Time ◽  
Composite Powders

AlN/Cu composite powder was prepared by ball milling method. Laser particle size analyzer, X-ray diffraction and scanning electron microscopy analysis were performed to study AlN/Cu composite powders. The effects of rotation speed, mixing time, and ball to powder weight ratio (BPR) on the particle size distribution, composition, and morphology were investigated. Results showed that the best ball milling parameters were the rotation speed of 200r/min, mixing time of 6 hours and BPR 10:1. In this best condition, AlN/Cu composite powders would be obtained with optimum particle size distribution and morphology. Then composite powders were pressed at 500MPa and sintered at 1000°C in N2atmosphere. Finally, the composite with an AlN content of 33wt% showed the bending strength of 370MPa, Vikers hardness HV154, thermal conductivity of 182.7W/m°C and electrical conductivity of 3.08MS/m. However, the composite with an AlN content of 25wt% showed the bending strength of 329MPa, Vikers hardness HV122, thermal conductivity of 195W/m°C and electrical conductivity of 6.54MS/m.

Effect of Carbon Black Particle Size Distribution on Electrical Conductivity

1978 ◽  
Vol 51 (1) ◽  
pp. 126-132 ◽  
Author(s):  
A. K. Sircar ◽  
T. G. Lamond
Keyword(s):  
Electrical Conductivity ◽  
Particle Size ◽  
Carbon Black ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Carbon Black Particle ◽  
Average Diameter ◽  
Industrial Practice ◽  
Black Particle ◽  
Gap Width

Abstract Wide particle size distribution (PSD) of carbon black increases electrical conductivity, consistent with the industrial practice of manufacturing conductive grades. An explanation has been offered based on the lower linear average diameter of wider-distribution blacks. Consequently, for the same weight, there is a larger number of particles in the broad-PSD black. The resulting agglomerates are therefore more numerous, although somewhat reduced in dimension because of higher packing density. The larger number of agglomerates results in lower average gap width, which accounts for the increased electrical conductivity.

Printing of Ultrathin Nanoparticulate Indium Tin Oxide Structures

2015 ◽  
Vol 2015 (CICMT) ◽  
pp. 000092-000102
Author(s):  
Moritz Wegener ◽  
Dieter Spiehl ◽  
Florian Mikschl ◽  
Xinxin Liu ◽  
Andreas Roosen
Keyword(s):  
Electrical Conductivity ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Inkjet Printing ◽  
Indium Tin Oxide ◽  
High Speed ◽  
Organic Additives ◽  
Glass Substrates ◽  
Printing Processes

This contribution focusses on three printing techniques: inkjet printing, flexographic printing and gravure printing for the manufacture of ITO structures based on nanoparticular ITO inks. The quality and stability of nanoparticular inks depends mainly on the dispersing step and is reflected by the achieved particle size distribution. The particle size distribution of the ITO inks has a distinct influence on the optical and electrical properties of the deposited ITO structures. The optimization of nanoparticular ITO inks concerning rheological behavior, wetting behavior and resulting material performance is presented. Inkjet printing was used as a low speed method to manufacture structures in the range of 30 μm. It is shown how coffee-staining, a frequently arising problem in inkjet printing, can be prevented by different strategies. Nanoparticular ITO structures with layer thicknesses clearly below 1 μm were printed. Gravure and flexography printing are well-established industrial printing processes with printing speeds above 100 m/min. These high-speed printing processes were used to print structures on PET film and glass substrates. Different solvents, e.g., water and ethanol, solvent compositions and binder types were varied to optimize the resulting ITO structures. The printed structures in the range of 10 to 2000 μm with thicknesses down to 1 μm were evaluated concerning surface topography and electrical conductivity. The high inter-grain porosity and the used organic additives limit the electrical conductivity of nanoparticulate ITO structures. To further improve their electrical conductivity laser post-treatment of printed ITO structures was performed.

Some Properties of Polyconjugated Polymers Obtained by Oxidative Polymerization of Benzylidene-m-Phenylenediamines

2021 ◽  
Vol 899 ◽  
pp. 563-569
Author(s):  
Timur A. Borukaev ◽  
A.Kh. Salamov ◽  
Andrei V. Orlov
Keyword(s):  
Thermal Stability ◽  
Electrical Conductivity ◽  
Particle Size ◽  
Electrical Properties ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Chemical Structure ◽  
Oxidative Polymerization ◽  
Thermal And Electrical Properties

New polyconjugated polymers have been synthesized by oxidative polymerization of benzylidene-m-phenylenediamines. The morphology, particle size distribution, thermal and electrical properties of the obtained polybenzylidene-m-phenylenediamines have been investigated. The morphology of the particles of the obtained polymers was determined. It was shown that the synthesized polybenzylidene-m-phenylenediamines exhibit noticeable thermal stability and electrical conductivity. In this case, the thermal stability and the process of decomposition of polybenzylidene-m-phenylenediamines substantially depend on the chemical structure of the side fragments of macromolecules.

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