Liquid Particle Size and Concentration Standards for Sub-100 nm Applications
Gary Van Schooneveld – CT Associates, Inc.
David Blackford – Fluid Measurement Technologies, Inc.
Fluid Measurement Technologies (FMT) and CT Associates (CTA) have developed and patented a new Liquid Nano-particle Sizing (LNS) technology that allows for the precise measurement (both size and concentration) of colloidal suspensions in the size range from 10-500nm. Current alternative sizing techniques, such as Photon Correlation Spectroscopy (PCS), use an algorithm that assumes a log-normal size distribution. As shown in Figure 1, a log-normal size distribution is not always applicable, therefore PCS gives an inaccurate size distribution. And since the PCS technique provides only particle-sizing data, no concentration data is available.
Using the LNS technology FMT and CTA have developed a range of Polystyrene Latex (PSL) spheres (from 30 to 500nm) standards and colloidal silica (10 to 50nm) standards. This breakthrough allows customers to perform more accurate optical particle counter calibrations and filtration studies. FMT and CTA have also developed a Precision Dilution system for use with the new standards.
CTA publication #117: American Filtration & Separations Society Spring Conference May 6-9, 2013 Minneapolis, MN