The Hydro MV

Overview

Wet dispersion is the method used most widely when preparing samples for particle size analysis by laser diffraction. Essential for slurries and emulsions, wet dispersion is also important in the analysis of fine, friable and fragile powders, because the process is gentler than dry dispersion and  more easily separates agglomerates via the process of wetting.

The Hydro MV is a relatively small volume unit with a dispersant volume of 120 ml. Designed for applications that require small sample sizes, it is especially valuable when the supply of test material is limited: during product development, for example and/or when dispersant usage must be minimized, such as in the measurement of water soluble material. All wetted surfaces are chemically compatible with a wide choice of organic and inorganic dispersants.

The Hydro MV uses in-line sonication to achieve de-agglomeration. A powerful centrifugal pump prevents sedimentation and ensures bias-free measurement. The dispersant supply is fully automated for streamlined measurement.

The result is reliable and reproducible wet dispersion, closely controlled via the Mastersizer 3000 software.

• 120 ml dispersant volume
• 35 W in-line sonication probe, for rapid agglomerate dispersion
• Powerful centrifugal pump system ensures bias-free sampling
• Automated dispersant supply
• Chemically compatible with a wide choice of organic and inorganic dispersants
• Full software control of all measurement functions, including dispersant supply, sample dispersion and cleaning
• Integral sample tank light

Back

How it works

Dispersing a sample within a liquid involves wetting and separating each individual particle to ensure the complete breakdown of agglomerates. The aim is to produce a stable, completely dispersed suspension for measurement. It is vital to select an appropriate dispersant, although water is the one most commonly used and, when suitable, it clearly offers many benefits. Sonication promotes the wetting process, by helping to disrupt the structure of any agglomerates, and stabilizers may be used to prevent re-agglomeration.

With certain wet dispersion applications, such as those involving water soluble particles, aqueous measurement is not appropriate. Here, alternative dispersants are required and it can become important to minimize dispersant volumes within the constraint of producing a stable, representative suspension for measurement. For other applications sample volume is limited by the supply of material or by its cost.

The Hydro MV is designed for relatively small volume wet dispersion and is suitable for a very broad range of sample types. In-line sonication promotes the dispersion process while a powerful centrifugal pump prevents sedimentation, ensuring that all the sample is measured, in a bias-free way. Automated dispersant delivery of both organic and inorganic dispersants, allows close tailoring of the dispersion process and accelerates analysis.

Wet Dispersion unit schematic, showing the sample tank, stirrer, centrifugal pump and in-line sonication system.

Back

Specifications

Parameter

Specification

Pump speed range

0-3500 rpm ††

Pump speed resolution

+/- 10 rpm

Pump speed accuracy

+/- 50 rpm

Maximum flow rate

2.3 l/min ††

Sonication power & frequency

40W max, 40kHz (nominal) ††

Maximum volume

120ml

Materials in contact with sample

316 stainless
Borosilicate Glass
Tygon
Viton (cell seal only - upgrade available)
PTFE
PEEK
FEP

Maximum particle size

2100 µm (density 2200 kg/m³) †

Minimum time between measurements

less than 60 sec †

Dimensions

280mm x 180mm x 300mm (LxWxH)

Mass

5kg

† Sample dependent
†† Dispersant dependent