Over the Spring of 2004, the Particle Society presented several talks on a broad range of particle science topics during the noon hour. All members of the Particle Society were invited to join us for lunch and an interesting particle science presentation.

Luncheon Speaker Series, June 9th: Agglomeration: A Comparative Study.
By: Scott Halvorsen, of Bepex.

Abstract: This paper is presented as an introductory comparative study to the field of agglomeration of solid powder materials. Topics covered include several of the methods currently in practice in the field of agglomeration, including compression, agitation, thermal and liquid methods. The types of equipment used for each of the various methods and typical product characteristics relating to each will also be discussed. This should provide a preliminary technique for selection of a method of agglomeration to solve a particular problem or produce a predefined agglomerated product.

Click here to see a copy of the PowerPoint presentation given by this speaker. Note, you must have PowerPoint installed on your computer to read this file.

Luncheon Speaker Series, May 12th: Scattering metrology with size-monodisperse copper nanoparticles on silicon wafers.
By: Dr. Jung Hyeun Kim, of the University of Minnesota.

Abstract: Generation of size-monodisperse metal nanoparticles will be demonstrated using hydrogen free spray pyrolysis. Size classified copper spheres by a differential mobility analyzer are very monodisperse, for example, geometry standard deviation was 1.03 for 100nm copper particles. In the spray pyrolysis process, cosolvent approach is used to produce reducing atmosphere without direct use of reducing agents such as hydrogen and carbon monoxide. Particle deposition from monodisperse aerosol stream is conducted onto silicon wafers for light scattering metrology. Several different sizes of copper metal and PSL spheres are used to test light scattering theory, and the results show excellent agreement between measurements and complete scattering theory. Therefore, size-monodisperse metal spheres are successfully used in light scattering metrology besides dielectric PSL spheres.

Click here to see a copy of the PowerPoint presentation given by this speaker. Note, you must have PowerPoint installed on your computer to read this file.


Luncheon Speaker Series, April 22nd: Nano-Particle Technology and Sustainable Development.
By: Dr. Heinz Fissan.

Abstract:New technologies have to be developed according to the rules of sustainability with respect to economy, sociology and ecology. Especially negative effects on the environment and living beings have to be detected and avoided. The most interesting building blocks in nanotechnology are nanoparticles, because they provide the largest surface for interactions and they show the strongest size effects (the real nano-properties like quantum-effects).

Therefore new but also old process technologies for the production of nanoparticles have to be investigated with respect to their impact on the environment. Sampling, conditioning and measurement techniques have to developed or at least adjusted to nanoparticles, which show very different properties compared with super-micron particles.

Two examples of instrument designs will be shown, especially designed for nanoparticle characterization. The first one is a so called gas particle partitioner (GPP), which allows the adjustment of the zero point of aerosol instruments. The second is the idea of a personal sampler, which simulates the deposition process in the lung and allows the determination of the particle surface area deposited in the lung.

Two processes, the possible manufacturing of nanostructured gas sensors as well as existing carbon black manufacturing processes will be analyzed with respect to their potential or real nanoparticle emission into the ambient air.


Luncheon Speaker Series, March 30th: Case Studies in Morphological Powder Characterization.
By: Dr. David Leurkens, of Particle Measurements Inc.

Abstract: Several case studies in the application of morphological powder features will be presented and discussed. The first study illustrates the analysis of the spheronization of an extruded pharmaceutical powder highlighting the application of a new powder feature called the Grand Radial PlotTM developed by Dr. Luerkens. The Grand Radial PlotTM is an example of one of the new methods used to “visualize statistics”.

Another study to be presented includes the application of partial symmetry features in the analysis of apertures for some standard sieving screens. Partial symmetry elements are considered advanced morpohological features and illustrate the concept of a powder or particle “vector” feature. Finally a case study illustrating the use of morphological features to determine the optimum “cut” time required for a process involving irregular fibers will be presented. Characterization of irregular fibers will be discussed.


Luncheon Speaker Series, March 3rd: Filtration Technology: How does TWICE the filter life sound to you?
By: Ms. Lori Lehner, Donaldson Company.

Abstract: Ms. Lehner will discuss industrial air filtration, an area in which the Donaldson Company is an acknowledged leader and innovator. The presentation will begin with a review of filtration concepts, followed by a survey of filter and collector types. The talk will highlight recent developments in filtration technology, including an exciting new bag material technology that offers twice the life of standard 16 oz. polyester felt with a lower pressure drop, resulting in a savings in both labor and energy.

Ms. Lehner holds a degree in Chemical Engineering from the University of Minnesota, and has held the position of Applications Engineer supporting the Torit product line at Donaldson Company, Inc.