Overview
The dip cell uses a pair of electrodes that dip into a sample in a disposable plastic or a glass or quartz cuvette.
The dip cell electrodes are designed to be cleaned and reused, and the PEEK electrode holder and electrodes can be immersed in an ultrasonic bath for thorough cleaning.
- Reusable cell for zeta potential measurement
- Compatible with aqueous and non-aqueous dispersants and solvents, e.g. hydrocarbons
- Robust solid palladium electrodes
- East to clean and compatible with cleaning in an ultrasonic bath
- Uses standard glass or disposable polystyrene cuvettes
How it works
The dip cell uses the standard ‘Uzgiris’ configuration. This employs two parallel plate shaped electrodes dipped into the sample, with the optical measurement zone between them. An alternating electric field is applied to these electrodes that drives particles with a non-zero zeta potential between them to migrate to the oppositely charged electrode. The patented M3-PALS measurement procedure is used to optimize the measurement of the velocity of the particles.
The electrodes of the dip cell are spaced only 2mm apart. This means that high field strengths can be achieved with the application of a modest voltage. Applying 50 volts gives a field strength of 250 V/cm which is ideal for non-aqueous applications where particle mobility is very low. Applying a high field strength gives a higher particle velocity, and hence results in a more accurate measurement. Even though PALS is good for measurements of low velocities, accuracy will still improve at higher particle velocities. As non-aqueous dispersants generally have a very low conductivity, the application of a high voltage will not generate a high current that would result in Joule heating, and cause inaccuracies in the measurement.
For aqueous applications a much lower voltage is used, usually 3V. This low voltage still gives a reasonable field of 15V/cm sufficient for accurate measurements.
As the presence of water is so important in non-aqueous zeta potential chemistry, ideally separate cells should be used for aqueous and non-aqueous applications.
Specification
Specifications
| System compatibility | Zetasizer Nano ZSP, ZS, Z, ZS90. |
|---|---|
| Sample compatibility | All aqueous and non-aqueous dispersants. |
| Sample volume | Minimum 0.75mL. |
| Operating temperature (°C) | 0°C - 70°C. |
| Includes | Electrode assembly, Glass cuvette, labels for aqueous, non-aqueous or universal use, storage box. |
| Materials | Electrode - PEEK, Palladium, cuvette - polystyrene, glass or quartz. |