Specialist : Dr. Bilge Gedik ULUOCAK

Phone : +90 212 359 72 30
Fax : +90 212 358 27 24
E-mail :


 Brookhaven Instruments 90Plus Particle Size /Zeta Analyzer


The 90Plus performs fast, routine submicron particle size measurements on a wide variety of samples and concentrations. It is an ideal instrument for measuring colloids, latexes, micelles, mi-croemulsions, proteins, and other nanoparticles. Based on the principles of dynamic light scattering (DLS), also known as QELS (quasi elastic light scattering), most measurements only take a minute or two.

Features :

• Particle sizing from 2 nm to 3 μm

• Multimodal and unimodal size distribution software: Average size & size distribution width, lognormal fit, and multimodal size distribution provided as standard

• Scattering angles 90°

• 35 mW laser with high sensitivity detector

Typical Applications


•Polymer Latexes

•Pharmaceutical Preparations

•Oil/Water and Water/Oil Emulsions

•Paints and Pigments

•Inks and Toners

•Cosmetic Formulations


Zeta potential is a measure of surface charge on a particle and is readily measured with the BI-Zeta option. Since zeta potential is a measure of the repulsive forces in electrostatically-stabilized systems, it is an excellent indicator of relative stability. The sign and magnitude of zeta potential, as a function of pH, salt, or dispersing agent concentration are indicators of stability against flocculation or coagulation.

Applications include waste water treatment and stability of pigments, latexes, ceramics, and other colloidal dispersions.

ZetaPALS mode is based on Phase Analysis Light Scattering (PALS), for the determination of zeta potential of colloidal suspensions. The ZetaPALS is used in all dilute suspensions including under high salt conditions and in solvents. In addition, every ZetaPALS can operate in the ELS (electrophoretic light scattering) mode, just like Brookhaven’s ZetaPlus. The ELS mode is useful in low to moderate salt conditions in aqueous samples.

ZETAPLUS mode measures complete electrophoretic mobility distributions in seconds, including multi modals, from which zeta potential distribution is calculated. The ZetaPlus utilizes electrophoretic laser light scattering in the reference beam mode with realtime, on-screen data acquisition and display. The measured frequency shift provides the highest resolution without the operator bias found in manual systems.