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

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.

Soil Research ◽  
2013 ◽  
Vol 51 (1) ◽  
pp. 23 ◽  
Author(s):  
Mohammad Reza Neyshabouri ◽  
Mehdi Rahmati ◽  
Claude Doussan ◽  
Boshra Behroozinezhad

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.


Author(s):  
Евгений Попов ◽  
Evgeniy Popov

This work is aimed at confirming the adequacy of the probabilistic and statistical approach to determining the aerodynamic resistance coefficient of particles in a flow of the free falling polyfractional material, suggested by the author. The aerodynamic resistance coefficient of particles in a flow of falling material is defined by calculating the probability of finding particles out of air shadows of the neighboring particles. The laboratory experiment was performed on the offered experimental samples of bulk materials having different particle size distribution, but the identical average diameter of particles. The design of a laboratory experimental installation which allows determining the consumption of air, ejected by a polyfractional material flow, was described. The amount of the air, ejected with experimental samples, depends on their particle size distribution that confirms the insufficiency of describing the properties of bulk material only with the average diameter value. The given comparison of results of the analytical calculations with experimental data shows the reliability and adequacy of the calculated values.


1996 ◽  
Vol 69 (4) ◽  
pp. 696-712 ◽  
Author(s):  
Mario A. Llosent ◽  
Luis M. Gugliotta ◽  
Gregorio R. Meira

Abstract This paper deals with data treatment problems that arise when turbidimetry is employed to estimate the particle size distribution (PSD) of soft polymer latexes with low diameter limits around 40 nm. Scanning electron microscopy and dynamic light scattering were used as comparison techniques. Industrial latexes of styrene-butadiene rubber (SBR) and of acrylonitrile-butadiene rubber (NBR) were investigated. The data treatment involved the use of Mie's Model to obtain an average diameter and/or the complete PSD. For estimating the complete PSD, a least squares optimization (with an imposed distribution shape) and a numerical deconvolution procedure (without assumptions on the distribution shape) were attempted. A synthetic example was solved to investigate the limits of the applied numerical methods. For the polymer refractive index functions, Cauchy's Law was used — and its adequate adjustment proved essential for good turbidimetric estimations. A reasonable agreement between the turbidity measurements and the other independent estimations was verified. For the SEM observations, the soft latexes were hardened by irradiation before observation, but negligible diameter variations were detected.


2009 ◽  
Vol 87-88 ◽  
pp. 200-205 ◽  
Author(s):  
Yan He ◽  
Zhong Yin ◽  
Lian Xiang Ma ◽  
Jun Ping Song

Through measuring the thermal conductivities and tensile strength of nature rubbers filled with carbon black and comparing with each other, it is shown that the difference of carbon black particle size and the structure affects on the thermal conductivity and tensile strength of nature rubber. Thermal conductivities of carbon black-filled nature rubber are enhanced with the increase of volume fraction of filler; tensile strength of composite increases first and then decreases with the increase of carbon black volume fraction.


2015 ◽  
Vol 88 (2) ◽  
pp. 276-288 ◽  
Author(s):  
Chang Liu ◽  
Bin Dong ◽  
Li-Qun Zhang ◽  
Qiang Zheng ◽  
You-Ping Wu

ABSTRACT Singularity of strain field at the crack tip of elastomeric material has recently attracted considerable attention. For SBR filled with four different types of carbon black, the strain distribution at the crack tip of the single-edge notched tension specimens are investigated using digital image correlation (DIC) and finite element analysis (FEA). Both DIC and FEA results demonstrate that the larger the carbon black particle size, the less strain amplification at the crack tip of SBR. However, the strain amplification region obtained from FEA simulation is much smaller than the strain amplification observed from DIC, and the reasons are discussed. Critical J-integral (JIC) and tearing modulus (TR) are calculated via J-integral method and are connected to crack initiation and propagation resistance of the SBR, respectively. With increasing carbon black particle size, both JIC and TR decrease. Similar trends also occur for tearing energy deduced from the dynamic mechanical thermal analysis. These results are in agreement with the prediction based on strain amplification at the crack tip.


2011 ◽  
Vol 399-401 ◽  
pp. 828-833
Author(s):  
Xiao Su Cheng ◽  
Meng Qi Peng ◽  
Yu Fa Zhong

The centrifugal spray drying process of bauxite slurry was studied to investigate the influence of slurry solid content on the particle size distribution and the sphericity of the microspheres, and so was operation technology on average diameter and the sphericity of the microspheres. The optimal operation parameters are obtained to prepare high spherical microspheres bauxite with the diameter distribution of 100 μm and whose particle size distribution is narrow: the slurry solid content is 70 wt%, the dry air temperature is 250 °C, the rotation rate of spray head is 6000 rpm and the feed flow rate is 1 L/h in the experiments.


1967 ◽  
Vol 40 (5) ◽  
pp. 1319-1322 ◽  
Author(s):  
Merton L. Studebaker ◽  
Lester G. Nabors

Abstract A simple technique of sample preparation using dry carbon black samples has been developed which gives a carbon black surface of reasonably reproducible reflectance, using a commercially available and reasonably priced reflectance meter. The reflectance values were calibrated against particle size determined by Kraus and Rollmann using the calorimetric procedure of Harkins and Jura.


KIMIKA ◽  
2018 ◽  
Vol 29 (2) ◽  
pp. 30-35
Author(s):  
Erick Christofer I. Gonzales ◽  
Karl Gabriel M. Lloren ◽  
Jihan S. Al-shdifat ◽  
Lica B. Valdez ◽  
Krizzia Rae Gines ◽  
...  

Studies regarding particle size distribution, particularly in espressos are surprisingly few. Particle size distribution (PSD) is a plot that displays the average diameter versus percentage volume of the particles present in a sample. With increased awareness amongst coffee drinkers, a study aiming to report the effects of different pressure on particle size distribution of espresso from four different coffee blends was conducted. The method involved pulling of espresso shots at 7, 9, and 11 bar (or atm) from different coffee blends labeled as MA, CO, AL, and MO. Laser diffraction analysis showed different particle size groupings for each set of extraction pressure. Fine particles are within 1.20 to 28.70 µm. The most abundant particle size is centered at 185.4 µm. The particle size distribution of coffee blends composed of 100% Arabica coffee (AL and MO) but sourced from different locations, showed four similar modes or size ranges centered at 3.523, 13.005, 28.70, and 185.4 µm regardless of the extraction pressure or the coffee source. On the other hand, the coffee blends composed of different ratios of Arabica and Robusta (MA and CO) showed different modes depending on the pressure. This indicates the potential of PSD for characterizing the purity of a coffee blend. The particle size distribution can also give insights as to the sensory attributes of the espresso coffee.


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