BeNano 180 Zeta Max

1. Size Measurement 

 

Dynamic Light Scattering (DLS), also known as Photon Correlation Spectroscopy (PCS) or Quasi-Elastic Light Scattering (QELS), is a technique used to determine particle size by analyzing the Brownian motion of particles in a dispersion.DLS is based on the principle of Brownian motion, which relates particle size to velocity—smaller particles diffuse more rapidly, while larger particles move more slowly. The scattering intensities of the particles are detected by an avalanche photodiode (APD) and then converted into a correlation function. From this correlation function, a mathematical algorithm can be applied to obtain the diffusion coefficient (D). The hydrodynamic diameter (D_H) and its distribution can be calculated using the Stokes-Einstein equation, which relates the diffusion coefficient to the particle size.

 

2. Zeta Potential Measurement 

 

In aqueous systems, charged particles are surrounded by counter-ions that form an inner Stern layer and an outer shear layer. Zeta potential is the electrical potential at the interface of the shear layer. A higher zeta potential indicates greater stability and less aggregation of the suspension system. Electrophoretic light scattering (ELS) measures electrophoretic mobility via Doppler shifts of scattered light, which can be used to determine the zeta potential of a sample by Henry's equation.

 

Colloidal Stability

Stable particle system	Unstable particle system
High repulsion force of particles High zeta potential	Flocculation, aggregation, sedimentation Low or zero zeta potential

 

 

3. Molecular Weight Measurement 

 

Static light scattering (SLS) is a technique that measures scattering intensities to calculate the weight-average molecular weight (Mw) and the second virial coefficient (A2) of a sample using the Rayleigh equation.

where c is the sample concentration, θ is the detection angle, R_θ is the Rayleigh ratio used to characterize the intensity ratio between the scattered light and the incident light at the angle of θ, M_w is the sample’s weight-average molecular weight, A₂ is the second virial coefficient, and K is a constant related to (dn/dc)².

 

Features & Benefits

• Non-invasive technique
• Suitable for particles dissolved in liquid
• Measures molecular weight of samples smaller than 30 nm
• Provides second virial coefficient A₂, indicating the intermolecular interactions

 

 

4. Microrheology Measurement 

 

Dynamic Light Scattering Microrheology (DLS Microrheology) is an economical and efficient technique that utilizes dynamic light scattering to determine rheological properties. By analyzing the Brownian motion of colloidal tracer particles, information about the viscoelastic properties of the system, such as viscoelastic modulus, complex viscosity and creep compliance, can be obtained with the generalized Stokes-Einstein equation.

 

Features & Benefits

• Investigates rheological behaviors by measuring the thermally-driven motion of tracer particles within a material being studied 
• Facilitates the measurement of a broad frequency range in a single measurement 
• Suitable for dilute, weakly structured solutions
• Delivers fast results in 1–2 minutes with easy operation
• Offers rheological insights across a wide temperature range from -15°C to 120°C
• Complements conventional mechanical rheology

 

5. Flow Mode Measurement 

 

DLS flow mode provides a high-resolution size result of a complex, polydisperse system. When combined with front-end separation equipment such as GPC/SEC or FFF, particles are separated into monodisperse fractions and flow through the BeNano in sequence by size. The size of each fraction is continuously measured and summed into a high-resolution size distribution. 

 

 

BeNano can acquire RI or UV signals, offering a more accurate volume and number distributions independent of algorithm compared to a batch-mode measurement.

 

Features & Benefits

• DLS analyzer connecting with GPC/SEC, FFF, etc.
• Receiving up to 3 signals from RI, UV, or other detectors 
• 27 μL low-volume flow cell to avoid band broadening
• Size resolution as high as 1.3:1
• Size distributions weighted by number and volume, in addition to intensity
• Suitable for complex, polydisperse systems such as proteins, polymers, etc.

 

6. Temperature Trend Measurement 

 

Features & Benefits

• Programmed temperature trend measurement from -15°C to 120°C 
• Important for analyzing particle size and zeta potential across varying temperatures
• Easy examination of protein formulation stability 
• Accelerates real-time aging through elevated temperature simulation

Size vs. Temperature trend measurement of the BSA protein

 

7. Transmittance Measurement 

 

Features & Benefits

• Measures transmittance rapidly by detecting the light intensity transmitted through the sample
• Requires a minimum sample volume of 3 μL
• Sensitive indicator for evaluating batch consistency in industrial products
• Quantitative tool for identifying sample instability

Transmittance measurement monitoring sample instability

 

8. Refractive Index Measurement 

 

The BeNano 180 Zeta Max can determine the refractive index (RI) measurement of liquids with outstanding precision. A patented wedge-shaped cuvette holds the liquid sample while the CMOS detector measures the deflection of the light path after it traverses the liquid to calculate the RI.

 

Measurement Parameters

• Positions of the light spot centers
• Refractive index of the liquid being measured

 

Features & Benefits

• Patented technique supports a broad refractive index range from 1.2 to 1.6
• Requires only two calibration references and utilizes linear calibration suitable for extrapolation
• No tracer particles or prior knowledge of viscosity are required
• Enables DLS and ELS measurement for dispersants with unknown refractive indices
• Suitable for both organic and aqueous solvents

A calibration curve is established by measuring the light spot position for two references with known refractive indices, then used to determine the refractive index of unknown samples.

 

9. Concentration Measurement 

 

The BeNano measures particle volume fraction and number concentrations in particles per milliliter (particles/mL) for each population through the patented LEDLS technique. 

 

The incident light passes through the sample and reaches a photodiode detector, which records the transmitted intensity. By comparing it with that of a blank solution and combining the data with the particle size distribution from dynamic light scattering, the particle concentration is determined.

 

Measurement Parameters

• Volume fraction (%) of each particle population
• Number concentration (particles/mL) of each particle population

 

Features & Benefits

• Enables fast measurement with single-angle Detection
• Simplifies sample preparation with no need for calibration
• Ideal for screening-type measurements
• Suitable for both aqueous and organic samples

By analyzing individual population concentrations, users can make informed decisions on sample preparation, formulation adjustments, or further analysis.

 

10. Sedimentation Size Measurement 

 

The BeNano 180 Zeta Max provides particle size results based on the sedimentation method. The sedimentation rate of particles is directly related to their size, with larger particles settling faster. The PD detector monitors the changes in transmitted intensity over time, enabling the determination of particle size and distribution for particles up to 50 microns.

Schematic of sedimentation method

 

Measurement Parameters

• D10, D50, D90
• Span
• Volume-weighted Mean Diameter D[4,3]
• Size Distributions Weighted by Volume

 

Features & Benefits

• Expands size measurement range up to 50 μm 
• Suitable for samples containing both nanoparticles and microparticles, meeting the needs of broad distribution samples
• Provides volume-based size distributions for micron-sized particles, consistent with laser diffraction results
• Achieves up to 1.5x size resolution for multiple peaks

5 μm + 10 μm polystyrene mixture

 

11. pH Autotitration Measurement 

 

The BAT-1 + Degasser units integrate seamlessly with the BeNano 180 Zeta Max for automatic acid-base titration and isoelectric point (IEP) determination. The system automatically enables sample flow during measurement, ensuring high efficiency, consistent, operator-independent results as well as precise titration.

An optional degasser is available to remove dissolved gases from titrants. Preventing bubbles improves the accuracy of zeta potential measurements.

 

Measurement Parameters

• Zeta potential vs. pH 
• Size vs. pH 
• Size and Zeta Potential vs. pH 
• Conductivity vs. pH
• Isoelectric point

 

Features & Benefits

• Accurate size and zeta potential analysis from pH 1 to 13 
• Enhanced safety with minimal exposure to corrosive liquids 
• Automated workflow reduces training needs and researcher workload 
• Fewer manual steps minimize human error
• Completes each measurement cycle in as little as 30 minutes
• Smart Titration: Based on the initial pH and the target pH, the required titrants can be chosen automatically via the software

 

The software can automatically generate the size and zeta potential vs. pH curve and identify the isoelectric point (IEP).

 

 

Measurement Modes

 

 

1. Backscattering Dynamic Light Scattering 

 

Collects more scattered light than 90° optics, improving sensitivity to small particles. The auto-adjusting measurement position ensures accurate size results even at concentrations up to 40% w/v.

 

2. Phase Analysis Light Scattering 

 

Precisely distinguishes weak to strong electrophoretic signals, enabling superior zeta potential measurements, especially near isoelectric points or in high-salinity conditions.

 

3. Autotitrator & Degasser 

 

The BAT-1 autotitrator enables automated pH titration from 1 to 13. It can be integrated with a triple-channel degasser to eliminate air bubbles during titration.

 

4. Novel 0° Detector Module 

 

Positioned at 0°, this module employs a photodiode and a CMOS camera to measure refractive index, concentration and microparticle size via sedimentation.

 

5. Ultra-Low Sample Volume 

 

Ideal for early-stage research, the capillary sizing cell requires only 3 to 5 μL, enabling precise size measurements with minimal sample consumption.

 

6. Adjustable Correlator Mode 

 

Offers short, medium, and long-time correlator modes that can be configured based on sample type, ensuring powerful and adaptable correlation function calculation.

 

7. Work in Combination with GPC/SEC or FFF 

 

Flow mode enables high-resolution size analysis. The BFC-1 signal collector auto-triggers and captures RI or UV signals from GPC/SEC or FFF, delivering accurate volume-weighted results.

 

8. Regulatory Compliance 

 

Compliant with ISO 22412 and ISO 13099, featuring IQ/OQ tools and FDA 21 CFR Part 11 support for use in regulated environments.

 

 

 

 

 

Dynamic Light Scattering (DLS) -Applications	Electrophoretic Light Scattering(ELS) -Applications	Static Light Scattering(SLS) -Applications	DLS Microrheology -Applications
1) Particle size and distribution of polymers, colloids, biomacromolecules, etc. 2) Research on thermal-sensitive systems, such as PNIPAm polymer. 3) Studies on polymerization process and reaction mechanisms.  4) Kinetics  analysis of self-assembly, polymerization and depolymerization, etc.	1) Particle suspensions, includingcolloids, proteins, nanometals, etc. 2) Industries such as chemicals, biology, water treatment, paints, etc. 3) Product stability control and monitoring 4) Stability research and control of suspension system 5) Surface property and modification study	1) Chemical engineering:  characterization of polymers, micelles and macromolecules 2) Life science: characterization of proteins, polypeptides, and polysaccharides. 3) Pharmaceuticals:  research on aggregation and stability of drugs and biomacromolecules.	1) Polymer solution 2) Protein solution 3) Gel system

1. Cells 

 

Standard
	Folded Capillary Cell BT-C1 Compatibility: Aqueous samples for zeta potential measurement Material: PC, Gold-plated Phosphor Bronze Min. Sample Volume: 0.75 mL Temp. Upper Limit: 70 °C		PS Cuvette Compatibility: Aqueous samples for size measurement Material: Polystyrene Min. Sample Volume: 1 mL Temp. Upper Limit: 70 °C
	Glass Cuvette  Compatibility: Aqueous/organic samples for size measurement, good sealing performance   Material: Glass Min. Sample Volume: 1 mL Temp. Upper Limit: 120 °C		Capillary Sizing Cell Compatibility: Aqueous/organic samples with ultra-micro volume for size measurement Material: Quartz Min. Sample Volume: 3 μL Temp. Upper Limit: 70 °C
Optional
	Folded Capillary Cell BT-C1-Pt Compatibility: Aqueous samples with moderate to high salinity (conductivity up to 260 mS/cm) for zeta potential measurement Material: PC, Platinum Min. Sample Volume: 0.75 mL Temp. Upper Limit: 70 °C		Micro-volume PMMA Cuvette Compatibility: Aqueous samples with  micro volume for size measurement Material: PMMA Min. Sample Volume: 40 μL Temp. Upper Limit: 70 °C
	Dip Cell Compatibility: Aqueous/organic samples for zeta potential measurement Material: PEEK, Platinum Min. Sample Volume: 1 mL Temp. Upper Limit: 70 °C		Micro-volume Glass Cuvette Compatibility: Aqueous/organic samples with micro volume for size measurement Material: Quartz Min. Sample Volume: 25 μL Temp. Upper Limit: 120 °C
	Flow Cell Compatibility: Aqueous/organic samples for DLS flow mode measurement Material: Quartz Min. Sample Volume: 27 uL Temp. Upper Limit: 70 °C		Micro-volume Fluorescence-filtered Cell Compatibility: Aqueous samples for size measurement, equipped with a narrow band filter Material: Quartz Min. Sample Volume: 16 uL  Temp. Upper Limit: 90 °C
	Micro-volume VH Cell Compatibility: Aqueous samples, eliminates the vertical element of scattered light Material: Quartz  Min. Sample Volume: 16 uL Temp. Upper Limit: 90 °C		Micro-volume VV Cell Compatibility: Aqueous samples, eliminates the horizontal element of scattered light Material: Quartz Min. Sample Volume: 16 uL Temp. Upper Limit: 90 °C
	High Concentration Zeta Cell Compatibility: Aqueous samples with moderate to high concentrations (up to 80% w/v) for zeta potential measurement Material: Quartz  Min. Sample Volume: 64 uL Temp. Upper Limit: 70 °C		RI Cuvette Compatibility: Aqueous/organic samples for refractive index (RI) measurement with a quartz wedge design Material: Quartz  Min. Sample Volume: 380 uL Temp. Upper Limit: 120 °C

 

 

2. BAT-1 Autotitrator 

1) Introduction  

The BAT-1 autotitrator, a highly recommended accessory for the BeNano series, is an ideal option for analyzing the zeta potential as a function of pH and determining the isoelectric point (IEP) of a colloidal system. It is equipped with three high-precision titration pumps with a precision of 0.28 μL, and the system can select the optimal titrant and adjust the addition volume intelligently to optimize titration efficiency and accuracy.

2) Features 

• • Combination electrode with high precision and high feedback speed
  • High precision ternary titration pumps
  • Controllable peristaltic pump with high flow capacity and high flow rate
  • Internal magnetic stirrer system
  • SOP operation
  • Replaceable tubes
  • Corrosion-resistant design
  • General-purpose electrode
  • Intelligentization
  • Determination of the isoelectric point

 

3) How it works 

The BAT-1 Autotitrator is designed to be used with the BeNano series for the measurement of zeta potential over a wide pH range, providing information on zeta potentials and the stability of samples in different conditions. The operation flow is as follows:

 

a) Preparing the samples to be detected and the titrants in the containers, respectively;

 

b) Creating or editing a titration SOP in BeNano software by setting the volume of the sample to be measured, the concentrations of the titrants, the initial pH, the target pH, the pH interval, and the target pH tolerance, etc..

 

c) To start the determination, the sample is titrated to approach the first pH value through automatic calculation, and is injected into the folded capillary cell by the peristaltic pump for zeta potential measurement;

 

d). Repeating the above procedures until approaching the final target pH automatically;

 

e) Saving and outputting complete data and the trend plot of zeta potential vs. pH;

 

f). Giving the isoelectric point if it is included in the setting pH range.

 

4) Download BAT-1 Autotitrator Flyer