System for characterization of colloids by dynamic light scattering within a size range of 0.3 nm to 10 µm. Suitable for material systems with concentrations from ppm up to 40% vol., depending on substance type. Minimum is 1 droplet.

Particle Size Distributions

The NANO-flex® 180° DLS System measures size distributions in the range of 0.3 nm to 10 µm.

The applied heterodyne 180° back scattering principle of the Nanotrac® is characterised by its high selectivity in the nano-range and is therefore also suitable for samples with broad size distribution. Furthermore, the resolution is impressing. Highly concentrated samples are measured without interfering multiple scattering.

The applied Nanotrac® back scattering in the NANO-flex® is designed as a flexible measuring probe with 8 mm ø. Thus, it can be used in many ways, even in-situ  and in the measuring cylinder of the Stabino®!

The 180° DLS–Method

The laser is focused to the sample via an optical fiber and a sapphire window. The window reflects a part of the incoming laser light. Both, laser reflection and scattered light interfere at the detector diode. Due to the excellent signal/noise ratio, there is no need for an expensive detection system.

Benefits of 180° DLS:

  • Shortest light path in the sample (<0.3 µm) implying
    o no multiple light scattering
    o samples from transparent to opaque
  • up to 40% v/v from 0.8 (LOQ) to 10,000  nm
  • size result does not change over decades of sample concentration
  • high dynamic range and high resolution in ONE measurement

In-situ Applications

Inserted in a reactor or in the sample circuit of a milling system the probe delivers in-situ size information. When the probe is kept by a roboter arm, multiple sampling is possible. Customized solutions may be offered on demand.

Applications

DLS applications with the NANO-flex® module are almost unlimited, provided the viscosity of the sample is in the Newtonian range, a condition for the free Brownian movement in the fluid and for the accurate calculation of the size. The liquid medium of the particles can be of organic or aqueous nature. The critical coagulation point of a dispersion can be determined by measurement of size and potential with the Stabino®. For this purpose, the NANO-flex® size sensor is dipped into the Stabino® measuring cylinder.