More reliable zeta potential measurements without dilution Agilent Particle Analysis Solutions Agilent 7020 ZetaProbe Zeta Potential Analyzer
Sample dilution changes the concentration of the background electrolyte making it impossible for us to accurately measure zeta potential. Using the trial-and-error method to find the right combination of ph and dispersant is a waste of our time and resources. We can never be sure whether variations in the measured zeta indicate a physical change in the colloid, or are the result of an instrument artifact. The Agilent 7020 ZetaProbeeliminates the problems and the uncertainties of sample dilution. Traditional devices for measuring zeta potential rely on optical methods for determining the particle motion in an applied electric field. Unfortunately, such methods require sample dilution a time-consuming process that can alter the characteristics of the sample you are trying to measure. But now, Agilent s 7020 ZetaProbe lets you measure samples at concentrations up to 60% volume without sample dilution or preparation. This multi-frequency electroacoustic zeta potential analyzer measures sound, rather than light, which eliminates the need to see through the sample. So you can make direct, continuous measurements of concentrated colloids and emulsions at your true process conditions. Even better, you no longer have to worry about sample dilution changing the particle zeta potential. Multi-frequency electroacoustic technology that automatically compensates for particle size effects. Unlike other electroacoustic devices, the 7020 ZetaProbe automatically corrects for the particle size effect, which eliminates the need for you to enter a particle size. And because our ZetaProbe averages the effects of billions of particles, you can count on consistent zeta potential results from sample to sample batch to batch and day to day. 2
Rapid cycle times for results in seconds. One of the greatest strengths of the 7020 ZetaProbe is that it can give a reliable, reproducible zeta potential reading just seconds after being inserted into a colloidal suspension. Unlike optical methods, the sample is continuously stirred during the measurement cycle to prevent particle sedimentation. The ZetaProbe can also measure large particles of up to 50 microns or more that are impossible to measure with optical methods. As an optional accessory, Agilent also offers flow-through sensors that can be used to measure process slip streams. Simple to use. Simple to maintain. The versatile, compact 7020 ZetaProbe eliminates many routine measurement hassles with these time-saving tools: Software wizards that automate many tedious, time-consuming tasks. Built-in potentiometric and volumetric titration that permits unattended rapid isoelectric point determination, and lets you control dispersant or flocculant levels with the click of a button. Automatic correction of particle size and double-layer distortion. Rugged, low-maintenance design including chemicalresistant metal electrodes that makes the ZetaProbe ideal for use in research and plant optimization. No dilution required, which eliminates the need to maintain rigorous cleanliness, and transforms clean-up into a simple flush-out/wipe-down activity. And because undiluted samples have a large particle surface area, your zeta potential measurements won t be sensitive to low levels of surface active contaminants. 40 years of Agilent expertise behind every measurement. When you buy instruments and supplies from Agilent, you get more than just reliability. You also get unmatched technical support on the Web, by phone, or email plus a one-year warranty. And of course, the 7020 ZetaProbe is covered by Agilent s Service Guarantee. If your Agilent instrument requires service while covered by an Agilent service agreement, we guarantee repair or we will replace it free. Zeta Potential (mv) 14 12 10 8 6 4 2 0 Calcium carbonate -2 6 7 8 9 10 11pH Because calcium carbonate particles dissolve at low ph, even the most careful dilution will alter its ion concentration and zeta potential. This is not a problem with the 7020 ZetaProbe, which can measure zeta potential at working concentrations. To learn how you can confidently measure zeta potential at significant concentrations, go to www.agilent.com/chem/particles 3
The proof is in the performance. 60 40 Agilent s 7020 ZetaProbe overcomes the most daunting challenges of zeta potential measurement including sample dilution and particle aggregation. Zeta Potential (mv) 20 0-20 4 5 6 7 8 9 10 11 But don t take our word for it. Review these results drawn from real-life sample matrices under actual laboratory conditions. -40-60 ph Agilent s 7020 ZetaProbe delivers very reproducible results for the zeta potential of this titania sample. Here, the isoelectric point is close to ph 9, suggesting that the titania has an alumina coating. It s important to note that, because the 7020 ZetaProbe requires no sample dilution, you can finish entire titrations in less time than it takes to obtain one or two points by traditional light-scattering or microelectrophoresis methods. Zeta Potential (mv) 50.00 40.00 30.00 20.00 10.00 0.00-10.00-20.00-30.00 correct result manual, ph-independent manual, ph-dependent ZetaProbe with automatic software correction large errors -40.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 ph Here you can see that the 7020 ZetaProbe software automatically subtracts the salt background to deliver an accurate IEP for this 0.1M zirconia dispersion. No other electroacoustic instrument can do this automatic correction for salt. Note, too, that the two manual background subtraction methods take more time, and show errors at the IEP. 4
100.00 Zeta Potential (mv) 80.00 60.00 40.00 20.00 0.00 correct IEP 0.1M, uncorrected 0.01M 0.001M 0.1M, ZetaProbe with autocorrection -20.00-40.00 3.50 5.50 7.50 9.50 11.50 13.50 ph With software autocorrection for the high (0.1M) salt background, the 7020 ZetaProbe produces an accurate IEP for these alumina dispersions. This difficult determination is nearly impossible with other techniques. The 7020 ZetaProbe opens the door to sophisticated QA/QC, plant optimization, and research applications such as: Abrasives/polishing compounds Catalysts and zeolites Cement Ceramics Clay materials CMP slurries Coal slurries Dispersant optimization Emulsions Filtration Food colloids Homogenization control Light phosphors Minerals processing Natural latexes Paints and inks Paper coatings Pharmaceuticals Pigments Surface coating control Wet milling/grinding Focus more on your analysis and less on the accuracy of your zeta potential measurements. Go to www.agilent.com/chem/particles 5
Making impossible measurements possible. The Problem: We manufacture several grades of TiO 2, each with a different surface coating. This coating strongly influences product performance, so it is critical that we are able to check the coating from one batch to the next. The Solution: The 7020 ZetaProbe can be used in QC labs to check the coating type and consistency by measuring the sample s isoelectric point (IEP). No other instrument provides such accurate and rapid IEP measurement. The Problem: We sell pigments to many diverse industries, and we need to advise our customers which dispersant they should use to optimize the dispersion and deagglomeration of our pigments into their custom formulations. The Solution: The 7020 ZetaProbe allows you to rapidly screen a wide range of dispersants and get the answers you need in hours instead of wasting days or even weeks on tedious dilution and sample preparation. The Problem: The stability of our oil-in-water emulsion hinges on its droplet zeta potential. But our measurements are based on laser scattering, which requires us to dilute and alter our sample conditions. The Solution: With Agilent s 7020 ZetaProbe, you can pour emulsions directly into the sample vessel for accurate, repeatable results in seconds as well as reliable correlations between zeta potential and stability. 6
Technology Electroacoustic spectral analysis Instrument Specifications Particle concentration 0.5 to 60 volume percent Sample volume 20 ml* to 250 ml Maximum viscosity 20,000 centipoise stirred (higher viscosities unstirred) Conductivity range 0 S/m to 5 S/m ph range 0.5 to 13.5 Temperature range 5 C to 50 C Zeta Potential no restrictions Analysis time Less than 30 seconds, with selectable time delays between analysis Sample Characteristics Particle size range for zeta measurements Titration capabilities Titration module Wetted sensor materials Sample options Power requirements Dimensions (H x W x D) Shipping weight 1 nm to 50 microns (varies by application and particle density) Potentiometric and volumetric 1 microliter resolution, dual syringe pump Kalrez, Niobium, Teflon, 316 Stainless Steel Bottom-stirred sample container, or user-supplied container 100-240 VAC 50/60 Hz 5 Amps @ 120 VAC 3 Amps @ 240 VAC 17" x 20" x 14" (440 mm x 505 mm x 410 mm) 50 lbs (23 Kg) Performance Other Characteristics * with optional flow-through sensor Minimum Computer System Requirements: Pentium III class or better 512 Mb RAM, 1 Gb hard disk space available, one serial or USB port available High-resolution color monitor with at least 1024 X 768 resolution Microsoft Excel 2000 or later installed Windows 2000/XP/Vista All trademarks are the property of their respective companies. For additional specifications, proof statements, and application examples, go to www.agilent.com/chem/particles 7
Start achieving ultimate confidence in your results with our complete family of 7000 Series Particle Analyzers. Designed and manufactured to uncompromising standards, Agilent s 7000 Series Particle Analyzers deliver reliable, repeatable particle size and zeta potential measurements on nanometer to micrometer-sized particles. In addition to Agilent s 7020 ZetaProbe, this groundbreaking family of instruments includes Agilent s 7010 Particle Size Spectrophotometer, which quickly and accurately measures particle size distribution and concentration in complex mixtures. An atomic force microscope system is also available for sizing and imaging individual nanometer particles under in situ conditions. Whether you want to discover new ways to prevent food spoilage or ensure that particle agglomeration will not compromise a material s integrity, Agilent s 7000 Series Particle Analyzers can help ensure your best results and your best product. To put Agilent s 7000 Series Particle Analyzers to work in your lab, go to www.agilent.com/chem/particles Or call 1-800-227-9770 (in the US and Canada). In other countries, please call your local Agilent Representative or Agilent Authorized Distributor. Information, descriptions, and specifications in this publication are subject to change without notice. Agilent Technologies, Inc. 2008 Printed in the U.S.A. March 3, 2008 5989-8054EN