Method of characterizing particles

US8395398B2 · kind B2 · utility

Assignee

• Beckman Coulter, Inc. · US

Inventors

• Renliang Xu · Pembroke Pines, US
• Yiming Yang · Taichung, TW

Key dates

• Filing date: Apr 23, 2010
• Grant date: Mar 12, 2013
• Expiry date: Sep 6, 2031

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2015/1029
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Mixtures containing homogeneously-sized particles with a minimum concentration of agglomerates or larger particles are desired in various manufacturing processes such as, for example, in the manufacture and use of chemical mechanical polishing slurries, food emulsions, pharmaceutical products, paints, and print toner. The method disclosed herein provides these industries with an accurate and efficient method of screening such mixtures for such agglomerates and large particles. The method generally includes preparing a suspension of the mixture in an electrolyte, wherein the suspension includes a specified concentration of small particles per unit of electrolyte. The method further includes passing the prepared suspension, and a plurality of the particles therein, through an aperture of a device capable of characterizing particles according to the Coulter principle to obtain data on the particles. Still further, the method includes deriving a particle size distribution of the large particles from the obtained data. The suspension includes at least one small particle per aperture volume. The large particles have an average diameter that is at least five times greater than the average…