Some disc centrifuge systems can analyse nanoparticles with a density lower than water by using an inverse sedimentation approach. In this case, the particles move upwards through the liquid rather than settling towards the bottom. This makes it possible to analyse a broader range of low-density nanoparticle materials.
DCS offers high resolution and can distinguish between particle populations with relatively small differences in size. The technique is particularly useful for analysing nanoparticle size distributions and detecting small changes or multiple particle populations in a sample.
DCS can cover a broad particle size range, depending on the instrument settings and analysis conditions. The technique can measure particles from approximately 2 nanometres up to around 80 micrometres, with its main strength being high-resolution analysis in the nanoparticle size range.
In DCS analysis, nanoparticles are subjected to high centrifugal forces in a rotating disc centrifuge. Larger or heavier particles sediment at a different rate than smaller or lighter particles. By measuring the sedimentation behaviour and accounting for particle density, an equivalent particle diameter can be calculated.
Differential centrifugal sedimentation, or DCS, is a particle size analysis technique that separates particles according to their sedimentation behaviour in a centrifugal field. The sedimentation time is related to particle size, density and the applied centrifugal force.
