For those familiar with dynamic light scattering (DLS), you’ll know it’s an excellent tool for characterizing the size of your proteins, polymers, colloids, or nanomaterials. But does it always give you the information you need? Perhaps you struggle to accurately size your polymer solutions or are unable to resolve different populations in your colloidal dispersion. Maybe you need another technique to help fill in the information gaps.
Good news, it doesn’t need to be this way. Multi-angle dynamic light scattering, or MADLS® for short, changes all this. A MADLS measurement can give you a clearer, more complete data picture in as little as three minutes and builds on the established benefits of DLS such as speed of measurement, ease of use, and low cost of ownership. With a simple MADLS measurement, you get:
- A more complete analysis that auto-compiles all the data into a single integrated picture
- An increase in resolution
- Less guesswork when interpreting your results.
Unique insight into your nanoparticle dispersions
Let’s explain. With traditional DLS experiments, the scattered light is detected at a single angle and auto-correlated to determine the correlation function. The correlation function is used to calculate the diffusion rate of the particles from which the particle size distribution is obtained.
What’s interesting, is that the direction and the number of photons scattered depends on the size of the particle. For example, if the particle is small, light is scattered quite uniformly in all directions. But if the particle is large, more light is scattered in the forward direction. So, if you’re looking at a mixture of particle sizes – some small and some large- they may be misrepresented in your result. Or you may not see them at all. This is because each particle size produces a unique scattering pattern. So, you’ll get a different perspective on the particles in your dispersion, dependent on which angle you look at. For example, if we measured at three different angles, we would get three different results, as show below.
MADLS resolves this issue by detecting the scattered light at multiple angles. But unlike other multi-angle DLS systems, MADLS also combines the autocorrelation function at each angle by using a new and innovative analysis. This gives a single high resolution and angle independent result. It allows you to resolve previously hidden size populations, generating a more complete size distribution, with less need for further characterization, or confusing manual interpretation.
MADLS is one of the many new features available on Malvern Panalytical’s flagship Zetasizer Ultra, which is part of the new Zetasizer Advance range.
If you’re interested in characterizing the particle size distribution of your dispersions or want to find out more about the benefits that MADLS can offer, we recommend that you register for our MADLS webinar on 6th May.
Also, why not check out our animated introduction to MADLS or download one of our many content pieces listed below.