Zeta/Nano Particle AnalyzerPLUS

Features

The NanoPlusZeta-Potential & Particle Size Analyzer

CELL LINE-UP

Zeta-potential Standard cell (Flow cell)Micro volume disposable cellHigh concentration cellLow conductivity cellSolid sample cell

Sizing Sizing cellDisposable cellMicro volume cellFlow cell

■Zeta-potential of ink for inkjet printer (Yellow)

-42.12mV

150 100 50 0 -50 -100 -150 -200 -250

Intensity

Zeta-potential（mV)

■Particle size distribution of thiamine

0

2

4

6

0.1 1 10 100diameter(nm)

prob

(%)

ave,diameter 0.6nm

■Ｃoncentration dependence of latex suspension

solid content（%）0.0001 0.001 0.01 0.1 1 10 1000 0

100

200

300

400

500

-20

-40

-60

-80

-100●Ze

ta-p

oten

tial（

mＶ）

◆di

amet

er（nm）

Zeta-potentialParticle size

ZETA-POTENTIAL & PARTICLE SIZE ANALYZER

FEATURES

Accurate measurement for dilute and concentrated suspensionEasy-to-use cells and user friendly softwareReliable measurement based on electroosmosis profile estimationEvaluation of surface charge on solid-plate, film and etc.Micro-volume disposable cell

Wide size range(0.6nm~10000nm), wide concentration range (0.00001%~40%) Combination of linear and log-scale correlator covers various sample characteristicsWell-established technique comform to ISO 13321 : Particle size analysis-photon correlation spectroscopyMicro-volume cell

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Zeta-potential

Particle size

ELSZ-1000 series

Zeta-potential -200~200mV

Particle size 0.6~10000nm

Concentration range 0.00001~40％

Evaluation of dispersion stability by zeta-potential/particle size

Evaluation of surface charge of solid plate

(3)Surface charge of glass change to positive owing absorption of excess CTAB

surface charge = +48.4mV(solvent F1mM NaCl solution containing 1×10-5mol/l CTAB)

(1)Zeta potential of glass plate charged to negative (Blank)

surface charge = -58.4mV(solvent:1mM NaCl solution)

(2)Surface charge of glass is neutralized by positive charge of cethyl trimethyl ammonium bromide (CTAB)

Using the solid-plate sample cell, surface charge of solid sample can be estimated

(solvent:1mM NaCl solution containing 1 x 10-5mol/l CTAB)

surface charge = +1.3mV

Zeta potential of Polystyrene latex mixture

Resolution of zeta-potential measurement is so high as to enable multi-component analysis owing to calculation of correlation and FFT calculation with the software. Mixture of five polystyrene latex of different particle size is measured.

Five spectrum correspounding to each latex are appeared. Zeta-potential of five components are in the range of -45mV to -107mV, and they show good cosistent with that from individual measurement.

High-resolution analysis of zeta-potential

Typical NanoPlus Applications

Resarches for control of surface reforming, dispersion and aggregation of ceramics(silica, alumina, titanium oxide, etc.) and inorganic sol, control of dispersion and aggregation of pigments),and for adsorption of collector of floating ores

Ceramic and color material

Researches for clarification of deposition mechanism of foreign matters on silicon wafer surfaces, and interactions among abrasives, additives and wafer surface

Semiconductor

Researches for control of dispersion and aggregation of emulsions(paints and adhesives), control of surface reforming of latex(for medicines and industrial use), and for functionality of electrolytic polymers (polystyrene sulfonate, polycarboxyloic acid ,etc.)Control of paper and pulp manufacturing process, and researches for pulp additives

Researches for control of dispersion and aggregation of emulations (foods, perfumes, medicines and cosmetics), for functionality of protein, for cintrol of dispersion and aggregation of ribosome, and for functionality of protein, for control of dispersion and aggregation of ribosome, and for functionality of surface active agents (micelle)

Polymer and chemical

Researches for fuel cells (carbon nanotube, fullerene, nano material, etc.) and for nano-bio (dendrimer, DDS, nano-capsule, etc.)

Nano Material / Nano Technology

Medicine and food

As the absolute value of zeta-potential is larger, general colloidal particles show good dispersibility, as the electrostatic repulsion

becomes stronger. As the zeta-potential is close to zero, they become so unstable as to

be likely to aggregate.

As the pH value of the solution changes from acidic to alkaline values, alumina particles show a large change of the zeta-potential from plus to minus values. It can be seen that they have the

isoelectric point to indicate the zero zeta-potential at around pH9.

In the pH range where the absolute value of zeta-potential is large, their average particle

size is small, and it can be seen that dispersion stability of the particles is good due to

electrostatic repulsion. On the other hand, it can be seen that particles aggregation to be large in the average particle size, resulting in instability,

in the area around the isoelectric point.

Evaluation of dispersion stability by zeta-potential/particle size

(Unstable・Aggregation)(Dispersion・Stable)

Neutralization of charge

Charge

Particle size

σ-Diameter

σ-Zeta potential

The NanoPlusZeta-Potential & Particle Size Analyzer

⊿vUζ

= 2Vn sin(θ/2)/λ= V/E= 4π ηU/… ... Smoluchowski equation

⊿v：Doppler shiftＶ ：Velocity of particle movementｎ ：Refractive indexη ：Viscosity

θ：Detect angleλ： Wavelength of incidence light Ｕ：Electrophoretic mobility

E：Electric fieldζ：Zeta-potentialε：Dielectric constant

In most cases, colloidal particles posses an either positively or negatively electrostatic charge. Having electrical fields applied to that particle dispersion, the particles migrate to oppositely charged direction. Upon particles being irradiated in migrating, scatter light causes Doppler shift depending upon electrophoresis mobility. ELSZ-1000 software calculates Doppler shift amount followed by electric mobility and zeta potential by combining heterodyne system and photon correlation method to perform Fourier transform (FFT) of obtained correlation function.

Slipping level Major part of medium

Ion diffuse layerFixed layer

Colloidalparticle

Electrophoresis

Principle of Zeta-Potential Measurement

When measurement of electrophoresis is actually taken, electroosmotic current is generated in the cell due to electric charge on the cell wall. The electroosmotic current means a phenomenon that, in the case of the cell wall charged to minus, ions and particles of plus electric charge gather together around the cell wall, so that the solution located around the wall faces migrates toward the minus electrode direction during electrophoresis and the solution located at the cell center follows in the opposite plus electrode direction to compensate the flow in the plus electrode direction. Accordingly, electroosmic current is added to the apparent electrophoreis of particles observed. The ELSZ-1000 series apparatuses are designed to measure the electrophoretic mobility at severall points in the cell to thereby obtain a position not influenced by the electroosmotic current, i.e.static surface,and then calulate the true mobility at the position. As a result, the moblity can be measured at high accuracy, even if the electroosmotic profile of the system is asymmetrical due to adsorption or sedimentation of the sample.

apparent mobility at position (Z)

True mobilityelectroosmosis flow at position (Z)

Stationary layercell wall

cell wall

Determination of true electrophoretic mobility

Incident beam

Incident beam

Electrode

Electrode

Electrode

Electrode

Cell

Transmission

Scattering

Scattering

High concentration cellStandard cell

By conventional method, scattered light from concentrated suspention can not be measured correctly due to multiple scattering (A). FST method developed recently detects the scattering light at forward direction through the transparent electrode. Optical path lengh of its detection is minimized to reduce the influence of multiple scattering. Thus, it can perform zeta-potential measurement of concentrated suspension with high accuracy (B).

FST*: Electrophoretic mobility measurement of concentrated suspension using Forward Scattering through Transparent electrode.

Concept of FST method

(A) (B)

* patent pending

G2(τ)

G1(τ)

d

= 1+α(G1(τ))2

= exp(-Dq2τ)= kT/3πηD ... Stokes-Einstein equation

Ｄ : Diffusion coefficentｑ : Scattering vectorτ : Correlation timeｄ : Hydrodynamic diameter

ｋ : Boltzmanns constantＴ : Absolute temperatureη : Viscosity of medium

G1(τ), G

2(τ): Secondary and primary

auto-correlation function(ACF)

Particulates dispersed in a solution are normally performing the Brownian motion. The motion is slower as the particles are larger and is faster as the particles are smaller. This principle is applicable namely when laser beams are irradiated to particles under the Brownian motion, scattered light from the particles shows fluctuation corresponding to individual particles.The fluctuation is observed according to the pinhole type photon detection method, so that particle size and particle size distributions are calculated.

(Colloid particle in Brown motion)

APD(Avalanche Photo Diode)

Pinhole 2

Pinhole 1

Incident beam

Measurement cell

Principle of particle sizingIn

tens

ityIn

tens

ity

Intensity and ACF of small particles

Intensity and ACF of large particles

ACF

ACF

Fluctuation of scattering light

Fluctuation of scattering light

T

T

Correlation time

Correlation time

Scattering light fluctuate fiercely

Scattering light fluctuate moderately

Difference of scattering intensity and autocorrelationfunction(ACF) between various sized particles

The smaller particle is,the quicker ACF is decaying

The larger particle is,the slower ACF is decaying

Component Particle Size Analyzer, Computer, Monitor, Size Cell

Zeta Potential Analyzer, Computer, Monitor, Flow Cell,Disposable Cell

NanoPlus-2NanoPlus-1 NanoPlus-3Particle Sizing & Zeta Potential Analyzer,Computer, Monitor, Size Cell, Flow Cell,Disposable Cell

Principle Photon Correlation Spectroscopy Laser Doppler MethodLaser Doppler Method & Photon CorrelationSpectroscopy

Light Source Semiconductor Laser Semiconductor Laser Semiconductor LaserDetector Avalanche Photodiode Avalanche Photodiode Avalanche Photodiode

Cell/Sample Volume [Size] Glass Cell(0.9mL~) [Zeta] Flow Cell(0.7mL~), High Concentration Cell(0.6mL~),Disposable Cell(130μL~)

[Size] Glass Cell(0.9mL~) [Zeta] Flow Cell(0.7mL~), High Concentration Cell(0.6mL~), Disposable Cell(130μL~)

Condensation Range [Size] :0.00001 to 40% [Zeta] 0.001 to 40% [Size] :0.00001 to 40% [Zeta] 0.001 to 40%

Measure Range [Size] :0.6nm to 10μm[Zeta] -200 to 200mV, [Mobility]-20x10-4 to 20x10-4cm2/Vs

Operation 15 to 35°C 15 to 35°C 15 to 35°CElectricity Requirement AC 100-240V, 50/60Hz

Dimention 380(W) x 600(D) x 210(H) mmWeight Approx. 22kg

Data Processing Desk Top PC, Windows 7

AC 100-240V, 50/60Hz AC 100-240V, 50/60Hz380(W) x 600(D) x 210(H) mm 380(W) x 600(D) x 210(H) mmApprox. 22kg Approx. 22kgDesk Top PC, Windows 7 Desk Top PC, Windows 7

Operation Temperature 15 to 35°C

Electricity Requirement AC 100-240V, 50/60Hz

Dimention 250(W) x 310(D) x 290(H) mm

Weight Approx. 7kg

Auto-Titrator

FunctionAutomatic perform liquid titration forzeta potential measurement

Principle Automatic pH control of liquidsuspension