Powerful Analyses at your Fingertips
Brookhaven’s NanoBrook 90Plus Zeta employs Dynamic Light Scattering (DLS) for particles/molecules size and Electrophoretic Light Scattering (ELS) for zeta potential determination. This package not only allows rapid measurements of the effective size and zeta potential of samples, but also provides further information on multi-modal distribution in size and zeta potential in polydisperse samples. Based on the proven technologies of Brookhaven, the NanoBrook 90Plus Zeta guarantees excellent mobility measurement performance in aqueous suspensions and low salt environments.
Features at a glance
- Rapid and accurate particle size distributions
- Multimodal & unimodal size distribution software
- ISO 13321 and ISO 22412 compliant results
- Range > 0.3 nm to 10 µm
- Customizable reports
- Ideal for fast, routine sizing applications in research or quality control
- High power 40 mW diode laser
- Dynamic light scattering at 90°
- Temperature control, -5 °C to 110 °C
- Compact bench top unit, USB connection
- Zeta potential in low salt aqueous solutions/suspensions
- Accurate, rapid, easy to make zeta potential determination
- One piece, easy-fill disposable sample cells
- No cell alignment or calibration
- Zeta potential at 15°
- Temperature control, -5 °C to 110 °C
- Customizable reports, two parameter plots, graphical overlays
- Can resolve multi-modals
- Built in automatic procedures and parameters SOP
Simple fluids like water (low viscosity), glycerin (high viscosity) are Newtonian and exhibit viscosity effects, the dissipation of energy when particles move in such fluids. But dissolve macromolecules in these liquids –synthetic or biopolymers—and networks can form. In addition to viscosity effects, there are now elasticity effects, the storage of energy when embedded particle move. By following the mean square displacement (MSD) of tracer (probe) particles in such fluid and microrheological properties such as η*, the complex viscosity, G″, the viscous loss modulus, and G′, the elastic storage modulus, can be determined as a function of frequency.
Measurement of the autocorrelation function (ACF) using DLS techniques yields the MSD of tracer particles, which, under the right conditions, can be used to determine η*, G″, and G′ over a range of frequencies much higher than mechanical rheometers can attain. Much smaller sample volumes, in the microliters, are possible compared to mechanical instruments. Finally, since strains result from the thermally driven motion of tracer particles, these much smaller strains allow the study of fragile samples. The study of viscoelasticity in aggregating dilute protein solutions is a prime example of the benefits of DLS microrheology.
Reliable and Accurate Analysis
The new NanoBrook 90Plus Zeta particle analyzer incorporates all you need for fast, routine, sub-micron measurements of size and zeta potential. Based on the principles of Dynamic Light Scattering (DLS) for particle sizing and distribution, and based on electrophoretic light scattering (ELS) for zeta potential measurements, most measurements only take a minute or two. Please see the 90Plus PALS for instruments combining sizing and PALS zeta potential.
Two Scattering Angles:
Size measurements will be made at the 90° scattering angle. Zeta potential measurements are always done using the 15° detection angle to minimize diffusion broadening.
Principles of Operation – Particle Sizing using DLS
Dilute suspensions, on the order of 2 ppm to 50 mg/mL are prepared, using suitable wetting and/or dispersing agents. A small ultrasonicator is sometimes useful in breaking up loosely-held agglomerates. Two or three mL of suspension is required to make the measurements. Disposable, polystyrene square cells are used for aqueous and simple alcohol suspensions. Disposable, glass round cells with reusable Teflon stoppers are used for aggressive solvent suspensions. Just a few minutes are required for the sample and cell to equilibrate with the actively controlled temperature environment inside the NanoBrook 90Plus Zeta.A square glass cell is available if desired and special small-volume cells may be used to reduce the volume of material needed to just 50 µL or 10 µL. For aqueous samples the 50 µL is a disposable cuvette. In all cases the sample is recoverable. For very small particles the high-sensitivity BI-APD detector is invaluable.
Perhaps the most important benefit for users is the reproducibility from sample-to-sample, operator-to-operator, and instrument-to-instrument. The figure above shows the repeatability of the results obtained by one instrument for a silica (LUDOX) sample. Notice the Std. Error of the Effective Diameter is less than ½% of the mean of the six repeated runs. Such excellent repeatability is typical of the NanoBrook 90Plus Zeta for even routine QC analysis and ensures product quality time-after-time.
|Test Results from Brookhaven Instruments Particle Size Analyzers (diameter in nm)
The table to the right shows several aspects of the inter-instrument reproducibility found with routine Brookhaven dynamic light scattering equipment. To test the reliability of the information obtained with Brookhaven Instruments a customer subjected five instruments in five locations with different operators and using four different samples to examination. This table shows excellent reproducibility with recognized standard materials and superb internal agreement. You can be confident of the results you get with your NanoBrook 90Plus Zeta!
The NanoBrook 90Plus Zeta particle size and zeta potential analyzer offers three choices. For routine determinations an average diameter (Eff. Dia.) and a measure of the distribution width (Polydispersity) are sufficient for many applications. The second choice is to fit these values to a lognormal distribution, allowing the user to visualize the size distribution and to interpolate cumulative and differential results at 5% intervals.
Results from Test Bimodal Sample on NanoBrook 90Plus Zeta (diameters, in nm)
The figure above shows an example of the third choice, suitable for more complicated, multimodal size distributions. Here, a numerical algorithm, including Mie theory, is used. These results are for a mixture of known latex particles. Positions of the measured particle sizes on the accompanying graph are in excellent agreement with the known sizes of 92 and 269 nm.
During a measurement, the display can be switched interactively between any one of these — correlation function, lognormal, or multimodal — each shown “live” as data are accumulated. The live display is particularly useful in determining the end-point of a measurement where multimodal distribution shape may be important.
Reliable, Accurate, Easy to Use
The NanoBrook 90Plus Zeta is the simplest and most accurate particle electrophoresis system available. This revolutionary instrument has been designed to eliminate the shortcoming inherent in other zeta potential instruments. The 90Plus Zeta software is simple and intuitive to operate but yet offers flexibility and a full range of means for those that wish to tune their experiments to specific circumstances.
The screen image shown below indicates the clear and concise presentation. Information obtained from the sample is updated in real time and the user can select from several display formats. A literature of physical constants for many usual suspending fluids is provided but the user may provide their own values if desired. Printed reports are fully customizable.
The NanoBrook 90Plus Zeta measures complete electrophoretic mobility distributions in seconds including multimodals (an example of bimodal zeta potential sample can be seen on the result screen from analyzing a created mixture of charged particles.)
In the example below the results of analyzing a mixture of alpha and gamma Aluminas in 1 mMolar KCI at pH10 is displayed. The left peak is identified with the green curosr and shown to have a zeta potential of -75 mV. If the other peak is chosen the value given is -5.00 mV. The ability of the NanoBrook 90Plus Zeta to provide this informatino distinguishes it from other methods which provide only an ensemble average.
Derive Extended Information
The user can tabulate or graph any appropriate pair of parameters allowing, for example, the determination of the iso-electric point (IEP) as in the example below. The NanoBrook 90Plus Zeta is provided with a pH probe that can be used to measure this value.
Unique Cell Design
The unique cell configuration eliminates the electroosmotic effect: No stationary levels, no alignment, and no calibration are required; as evidenced by the excellent agreement with NIST1980, a standard reference material. The NanoBrook 90Plus Zeta uses low cost, disposable sample cells. There is no assembly or maintenance required: Cross contamination is eliminated. Glass and quartz cells are available optionally. The same basic cell design is used with the NanoBrook 90Plus Zeta, ZetaPALS, 90Plus PALS, and Omni.
||Sizing: nanoparticle and colloidal-sized materials, in any non-absorbing liquid.
Zeta potential: nanoparticle, polymer and colloidal-sized materials, suspended in any non-absorbing liquid, with relative mermittivity (dielectric constant) > 20 and viscosity < 5 cP.
||Sizing: > 0.3 nm to 10 µm, dependinjg on refractive index and concentration.
Zeta potential: 1 nm to 100 µm, sample dependent.
||10-9 to 10-7 m2 / V * s
|Zeta potential range
||-220 mV to 220 mV, sample dependent
|Maximum sample conductivity
Zeta potential: 7.5 mS/cm
||Sizing:1 to 3 mL disposable plastic, 50 µL disposable, 40 µL quartz flow cell, 10 µL quartz minimum
Zeta potential: 180 µL, 600 µL, 1250 µL
||Sizing: 2 ppm to 50 mg/mL, depending on refractive index and concentration
Zeta potential: 40% v/v, sample dependent
||Sizing: Dynamic Light Scattering, DLS
Zeta potential: Electrophoretic Light Scattering, ELS
||Brookhaven’s TurboCorr, multitau, research grade with 510 hardware channels, covering the equivalent of the 1010 linearly-spaced channels, 100% efficiency, real-time oepration over the entire delay-time range.
||Sizing: ± 1% typical
Zeta potential: ± 3% typical
|Temperature control range
||-5 °C to 110 °C ± 0.2 °C
||Purge facility using dry air, nitrogen preferred
||40 mW red diode laser, nominal 640 nm wavelength
||15° & 90°
||Average & wdith, lognormal fit, and multimodal size distribution for sizing.
Doppler Frequency Shift, electrophoretic mobility, zeta potential using Smoluchowski, Hückel, or Henry.
||ISO 13321 and ISO 22412 compliant results for sizing
||100/115/220/240 VAC, 50/60 Hz, 150 Watts
||23.3 x 42.7 x 48.1 cm (HWD)
||Temperature 10 °C to 75 °C
Humidity 0% to 95%, non-condensing
||Class I laser product, EN 60825-1:2001, CDRH
Notes: (*) Sample type dependant
A policy of continual improvement may lead to specification changes.