Vol. 22, No. 4
Books and Publications
from the National Institute of Standards and Technology
Guide to the Nomenclature of Particle Dispersion Technology for
By Vincent A. Hackley. NIST Special Publication 945, U.S. Department
of Commerce, Technology Administration, National Institute of Standards
and Technology, 24 pp., 2000. Available from the Superintendent of Documents,
U.S. Government Printing Office, Washington, DC 20402-9325.
This little pamphlet is the work of a committee of academic, government,
and industry specialists and is designed to provide a collection of
standard definitions for the most common technical terms used in the
area of particle dispersion technology for ceramic systems. The aim
is certainly a worthy one, because the fields of particle technology
and colloid science cover a diverse range of applications and have given
rise to an equally diverse nomenclature.
The nomenclature problem stems partly from the wide range of areas
to which the subject has some relevancefrom food science through
pharmaceuticals and cosmetics all the way to agricultural and soil engineering.
But there is also the fact that many of these areas have a very long
history of prescientific technological development, and in none of them
is that more evident than in ceramics. The modern scientific understanding
of ceramic processing has been grafted onto the enormously rich legacy
of art and craft that underpinned the technology until relatively recently,
and which still strongly influences some areas even today.
Because I had an opportunity to look at the material and offer comments
prior to publication, I have not found any obvious deficiencies in the
final work. There are some odd statements, however, such as the separation
of the term fine from coarse, which is said to correspond
to a dimension less or more than roughly 37 mm
(my emphasis). It seems curious to make the separation so precisely
and call it roughly until one translates that dimension into a sieve
size and then recognizes it in terms of an aperture for a standard screen
measured in the old f.p.s. unit of inches. Such are the strange ways
in which we are reminded of the history of the subject.
There are well over a hundred definitions, covering the description
of disperse systems, states of subdivision, association and dissociation
processes, dispersion stability, and interfacial and electrokinetic
properties. Each is succinct and carefully presented together with a
bibliography and index.
I would not pretend that everyone will agree that every definition
is couched in the most effective way. There will even be arguments about
the exact meaning of some terms. When the phenomenon of particle association
is described by terms like aggregation, agglomeration, coagulation,
and flocculation (and there may be more), there is ample room for disagreement
on details, but the definitions offered here have the weight of common
usage behind them. The purpose of the exercise is to encourage a wider
and more consistent use of the terms. That can only be an aid to communication
and a contribution to clarity. The distinguished group of advisors on
this project and the recorder, Vince Hackley, are to be congratulated
on so ably performing such an important service.
Robert J. Hunter
School of Chemistry University of Sydney