PARTICLE CHARACTERISATION

Heuer, M. and Lesclioiiski, K., 1985. Results obtained with a new instrument for the measurement of particle size distributions from diffraction patterns. Particle Characterisation, 2, 7-15. 

U. Krauter and U. Riebel, Proceedings of the First International Particle Technology Forum, Part 1, Particle Characterisation, American Institute of Chemical Engineers, New York, 1994, p. 30. 

As previously established, particle characterisation has a big impact on downstream processability. Milling is carried out by passing the dried API through a simple pin or air jet mill. If the output from these mills can be monitored, the mill settings can be adjusted and particle characteristics of the mill output changed. 

Another more complicated approach to obtaining fnrther dates on SCP profiles is to use particles characterised to their fuel-type, and then nse docnmentary evidence for major changes in fuel-use to allocate dates to those changes. Particle characterisation and other methods of determining changes in fuel-use are described later. 

Particle characterisation can be applied to both core samples and surface sediments to obtain information on the impacts of changes through time at a site or the impacts of contemporary emissions across a region, respectively. Such information is useful for policy formulation and in terms of targeted emission reductions, whether to protect a sensitive environment or the health of a population, source identification for airborne pollutants is vital. Supporting evidence can also be provided for long-range transport models as particulate sources may be identified from external sources (e.g. Davies et al., 1984). 

In parts of the world where single fuels are used extensively, however, particle characterisation may remain useful in, for example, transboundary studies. An example of this is in eastern Asia where coal combustion from China may influence areas such as Japan where mainly oil is used. In such cases, identification of coal SCPs may still provide evidence of long-range transport from external sources (Nagafuchi pers. commun.). 

For the future, SCP dating may become important, especially for the 19 century, as the half-life of - Pb progressively precludes its use for this period. Coal consumption for electricity generation is currently predicted to double by 2020 and hence the use of fly-ash particles in paleolimnological studies is assured for at least the short term. However, interpretation of particle characterisation data may become more problematic as industrial sources move towards the use of multiple fuels. 

Xu R (2000) Particle Characterisation Light Scattering Methods. Amsterdam Kluwer Academic Publishers. 

Field-flow fractionation is closely related to chromatographic techniques, which are traditionally employed for the analysis of dissolved substances, yet can be used to a certain extent for particle characterisation as well. An example of this is the size-exclusion chromatography (SEC). 

The simation that the principal morphology of particles is completely unknown before characterisation may occur during the development of new routes for particle synthesis or when taking samples from the environment. However, when particle characterisation is part of quality assurance and process monitoring in industrial practice or for research applications, there is always prior knowledge on the particle shape or the state of aggregation. This also applies to pyrogenic materials, which... 

The stability of colloidal suspensions is frequently examined for a certain variety of suspension properties (e.g. solid content, liquid phase, concentration of ionic, or polymeric additives). That is, for instance, relevant for developing suspension formulas and preparation procedures for particle characterisation or for predicting the particle behaviour in environmental milieus. A typical problem of such parameter studies is that a variation in the concentration of the charge determining additive (e.g. a pH variation as in Fig. 5.10, p. 261) coincides with a significant variation of the total electrolyte content. This problem is most pronounced for dense suspensions (pv 1 vol%) of very small particles (or particles with a high specific surface area). 

Enll, W. E., Ehrlich, R. and Kennedy, S., Optimal definition of class intervals of histograms or frequency plots . In Morphological Analysis, Particle Characterisation in Technology (J. K Beddow, Ed.), Vol. II, Chap. II, CRC Press Inc., Boca Raton, EL (1984)... 

Monolayers of nanoparticles at liquid-fluid interfaces have attracted considerable attention over several decades [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17]. Among others, the examinations focused on thin-layer preparation [10, 18, 19, 20, 21, 22, 23], emulsion stabilisation [15, 24] and particle characterisations [25, 26, 27]. The Stober silica (synthesised by controlled hydrolysis of tetraethylorthosilicate in ethanol in the presence of ammonia and water) [28] has many advantageous properties for model investigations. The nearly spherical particles show a narrow size distribution and are compact above a certain particle size (around 20 nm diameter) [29]. The particles, on the one hand, show partial wettability and, on the other hand, form a weakly cohesive two-dimensional dispersion at the water-air interface [10, 14]. All that makes them suitable to determine the total repulsive interparticle energies in a film balance by measuring the effective surface tension of the monoparticulate layer [30, 31, 32, 33, 34, 35, 36]. 

Stanley-Wood NG. Particle characterisation by size, shape and surface for individual particles. Stanley-Wood NG, ed. Enlargement and Compaction of Particulate Solids. London Butterworths, 1983 18. 

Stanley-Wood, N.G. (2000) Particle size analysis introduction. In Encyclopaedia of Analytical Chemistry Applicatons, Theory and Instrumentation, Vol. 6 (ed R.A. Myers). Wiley, Chichester, UK, pp. 5301-5337. Stanley-Wood, N.G. (2005) Particle characterisation in bulk powders. In Characterisation of Bulk Powders (ed D. McGlinchey). Blackwell Publishing, UK. 

The interest in the measurement of size, size distribution, shape, shape distribution and surface area of powders and all forms of particulate matter has increased enorroously since those days, along with the technologies of measurement. The disciplines of Particle Characterisation and Powder technology, which initially emanated from the UK and continental Europe, have... 

This 25th PSA Conference gave authors not only the opportunity to review the development of particle characterisation over the past 25 years, but also provided the Keynote lecturers with the stimulus to speculate on the future. These Keynote lectures, highlighting the changes and advances in various fields of... 

Particle Characterisation, were presented by widely known experts in their specialised fields [Scarlett Sing Jimbo Azzopardi Vfeiner Rood Kaye Lines Leschonski Allen] before each scientific session. 

As in many previous PSA conferences, the metrology of particle characterisation by the electrical sensing zone method was again prominent [Berge, Feder and Jfefssang]. The emphasis these days is however on the mass calibration of the instrument, sometimes also using certified or standard reference materials... 

The extent that particle characterisation techniques can be used in other technological fields was illustrated by the inclusion at this Conference of two papers which have taken the principles of solid particle characterisation and applied them successfully to biological systems [Groves Dunnett et al.] and to the pharmaceutical industry [Atkinson and White Atkinson, Greenway, Holland, Merrifield and Scott Cararoella, Ferrari, Bonferoni and Bertoni]. 

Walter J, Thajudeen T, SiiB S, Segets D, Peukert W New possibilities of accurate particle characterisation by applying direct boundary models to analytical centrifugation, Nanoscale 7 6574-6587, 2015a. 

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