Dispersion Analysis

Dispersion Analysis


in chemistry, the aggregate of methods for the determination of dispersity (the particle size characteristics in disperse systems). Dispersion analysis includes various methods of determining the sizes of free particles in liquid and gaseous mediums, the channel or pore sizes in finely porous bodies (in this case the concept of porosity is used instead of the concept of dispersity), and the specific surface. Some methods of dispersion analysis make possible the development of a complete particle (pore) distribution pattern according to the size (volume); others provide only the average characteristics of the dispersity (porosity).

The first group of methods includes, for example, those for determining the size of individual particles by direct measurements (sieve analysis; optical and electron microscopy) or by using indirect measurements, such as the sedimentation rates in viscous mediums (sedimentation analysis in a gravitational field and in centrifuges), or the magnitude of the electrical current pulses generated during the passage of particles through an opening in a nonconducting membrane (the conduction-measurement method).

The second group of methods combines an estimate of the mean diameters of free particles with the determination of the specific surface of powders and porous bodies. The mean diameter of particles is determined from the intensity of scattered light (nephelometry), by using an ultramicroscope, and by diffusion methods. The specific surface is determined by the adsorption of gases (vapors) or dissolved materials, from the gas permeability, or from the solution rates. The limits of applicability of the various methods of dispersion analysis are given in Table 1 (particle sizes in m).

Table 1. Limits of applicability of methods of dispersion analysis
Type of analysisParticle size (m)
Sieve ...............10−2-10−4
Sedimentation (in a gravitational field) ...............10−4-10−6
Conduction-measurement ...............10−4-10−6
Microscopy ...............10−4-10−7
Filtration method ...............10−5-10−7
Centrifuging ...............10−6-10−8
Ultracentrifuging ...............10−7-10−9
Ultramicroscopy ...............10−7-10−8
Nephelometry ...............10−7-10−8
Electron microscopy ...............10−7-10−8
Diffusion method ...............10−7-10−10

Dispersion analysis is being widely used in various areas of science and industry for estimating the dispersity of systems (suspensions, emulsions, sols, powders, adsorbents, and other materials) having particle sizes from several millimeters (10−3 m) to several nanometers (10−9 m).


Figurovskii, N. A. Sedimentometricheskii analiz. Moscow-Leningrad, 1948.
Khodakov, G. S. Osnovye metody dispersionnogo analiza poroshkov. Moscow, 1968.
Kouzov, P. A. Osnovy analiza dispersnogo sostava pylei i izmel’chennykh materialov. Leningrad, 1971.
Rabinovich, F. M. Konduktometricheskii metod dispersionnogo analiza. Leningrad, 1970.
Irani, R. R., and C. F. Callis. Particle Size, Measurement, Interpretation, and Application. New York-London, 1963.
References in periodicals archive ?
The new GAME GOLF platform features complement the recently released Shot Dispersion Analysis and Challenges features.
Bharti, Dispersion analysis of a Hybrid Photonic Crystal Fiber.
This support enables them to purchase equipment for gel permeation chromatography, high performance liquid chromatography, dynamic light scattering and photometric dispersion analysis.
It is clear that besides the dispersion analysis, attention must be paid to specifying the main parameters.
To highlight the degree of influence of different factors may apply multifactorial regression model, respectively dispersion analysis method Analysis of Variance--ANOVA.
This can harm marine life, so the National Institute of Ocean Technology, Central Marine Fisheries Research Institute, the IIT and a host of other bodies come into the picture to ensure our dispersion analysis is acceptable.
In this study, viscoelasticity was evaluated by a cone rheometer from the elastic modulus obtained by giving a shear under a temperature at which resin flows, and used for dispersion analysis of a compound with high wood content.
Reflected light microscopy has become the prominent tool for dispersion analysis because of its ability to rapidly quantify dispersion.
Once collected, these data are incorporated into a dispersion analysis to quantify downwind concentrations, which can be compared to establish exposure thresholds and assess community exposure.
There are three basic types of diagrams for relating causes and effects in a process: dispersion analysis, production process classification and cause enumeration.