Particle characterization applications

Xu RL (2015) Light scattering a review of particle characterization applications. Particuology 18 11-21... 

Allen, T. Particle Size Measurement, Volumes 1 and 2. 5th edn. (Chapman and Hall, London, 1997) Beddow, J. K. Particle Characterization inTechnology, Vol I Application and. Micro-analysis, Vol 2 Morphological Analysis. (CRC Press, Boca Raton, FL, 1984)... 

This paper outlines the basic principles and theory of sedimentation field-flow fractionation (FFF) and shows how the method is used for various particle size measurements. For context, we compare sedimentation FFF with other fractionation methods using four criteria to judge effective particle characterization. The application of sedimentation FFF to monodisperse particle samples is then described, followed by a discussion of polydisperse populations and techniques for obtaining particle size distribution curves and particle densities. We then report on preliminary work with complex colloids which have particles of different chemical composition and density. It is shown, with the help of an example, that sedimentation FFF is sufficiently versatile to unscramble complex colloids, which should eventually provide not only particle size distributions, but simultaneous particle density distributions. 

In addition to the relatively straightforward particle removal applications described above, ultracentrifugation is also effective at separating, purifying, and fractionating biological materials and for the study and physical characterization of macromolecules. These applications are beyond the scope of this chapter. 

The particles were made by spray-drying of an ethanol-water cosolvent into the form of large porous particles, characterized by geometric sizes greater than 5 pm and mass densities around 0.1 g/cm3 or less, this physical structure having achieved recent popularity as carriers of drugs to the lungs for local and systemic applications [25]. 

Exposed to an unlimited supply of gas phase particles characterized by the applied pressures and temperature, the surface will adapt on time scales set by the kinetic limitations. Already these time scales could be sufficiently long to render corresponding metastable states interesting for applications. In fact, the classic example is a slow thickening of oxide films due to limitations in the diffusion of oxygen atoms from the surface to the oxide-metal interface or in the diffusion of metal atoms from the interface to the surface [37,38]. Directly at the surface a similar bottleneck can be the penetration of oxygen, which... 

Because of the diverse applications involving liquid atomizers, a large vocabulary of terms has evolved in the spray community. The American Society for Testing and Materials, ASTM Subcommittee E29.04 on Liquid Particle Characterization, has attempted to standardize the terminology relating to atomizing devices (1). The definitions adopted by ASTM are used herein. 

Particle characterization is important in many petroleum and chemical applications. Therefore, it is essential to identify the main factors that control the behavior of particles in suspension. These factors include particle shape, size, size distribution, concentration, density, surface characteristics, and the dynamics of the suspension medium (7) (Figure 2). 

To specify powders for particular applications and products we need to be able to determine their physical and chemical characteristics, often with a high degree of accuracy and with statistical significance. In this chapter we will describe the different analytical techniques used for particle characterization and also indicate which technique works best. In addition to powders there are other important dimensionally constrained forms of ceranucs. Whiskers and fibers are long in one dimension but restricted in the other two. Ceranucs in these forms are important reinforcement phases in composites, such as... 

D. M. Scott, A. Boxman and R. Davies, Industrial Applications of In-Line Particle Characterization. World Congress in Particle Technology. Abstract of Papers. (1998)... 

Analogous to electrophoresis, diffusiophoresis is of practical importance in some applications to particle characterization and separation. In the metal and rubber technologies concerning surface treatment, diffusiophoresis is a transport mechanism in certain latex-particle coating processes. Being an efficient means to drive particles in nonuniform solutions, diffusiophoresis finds important applications in the area of particle manipulation in microfluidic or lab-on-a-chip devices and autonomous motions of micro/ nanomotors [8]. On the other hand. 

Lloyd, P. J. and Ward, W. S., Filtration applications of particle characterization . Filtration and Separation, May/June, 246 (1975)... 

The dispersion of bulk powders is important for a number of applications including particle characterization, powder transformation from a dense phase to a lean phase, aeolian dust formation, and the delivery of therapeutic drugs via the lung using dry powder inhalers (DPIs). Calvert et al. [85] have studied the dispersion... 

This entry describes the technology of surface-modification of rubber particles, characterizes the properties of some rubber/polyurethane composites, discusses processing considerations, and reviews applications that have been developed to date. 

According to the physical phase of particles and the surrounding media, we can construct the following matrix (Table 1.1) to classify dispersion systems. In Table 1.1 the first line in each box contains the common terminology used for that system and some examples are included in the second line. In particle characterization, most attention and interest concern the dispersions of particles in liquid and in gas (the right two columns in the matrix). Especially, dry powders, colloidal suspensions, aerosols and emulsions are prevalent in many fields and have the most applications in industry or academia. 

The choice of a proper analytical method for particle characterization wholly depends on the requirement of the application and the accessibility to a suitable analytical technique. Users often have to make a compromise when choosing the best method for their particulate materials. 

In this section, we describe common particle characterization methods other than light scattering methods presently used in various industrial applications. Also included are a few not yet commercialized methods. There are several monographs in which the reader can find more detail regarding some of these technologies [2,3,4,5,6,7]. 

During the past twenty years, PCS instrumentation has gone through big changes mainly because of the advancements in both lasers and microelectronics. Single PC card or even software correlators have replaced the old furniture-sized correlators. Fiber optics is used more and more in later models of conunercial instruments. PCS measurements of concentrated suspensions have become viable. Through all that, PCS has now truly become a workhorse for daily and routine particle characterization in many applications. 

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