Static Light Scattering

 
 

Static Light Scattering (SLS) is an optical technique that measures the intensity of the scattered light in dependence of the scattering angle to obtain information on the scattering source.
A typical application is the determination of the weight average molecular weight Mw of a macromolecule such as a polymer or a protein. Other popular applications are the measurement of the radius of gyration Rg or the form and structure factor. By measuring the scattering intensity for one macromolecule at various concentrations, the second virial coefficient A2, can be calculated. Special analysis techniques such as the Zimm or Guinier Plot can be used to obtain the optimum result from the measured data.

 

Related products:

 

Performs advanced DLS & SLS to obtain hydrodynamic radius, radius of gyration, molecular weight, form and structure factor as well as second virial coefficient. Offers unmatched range and precision of scattering angles.

LS Spectrometer

 

Image presents LS Spectrometer which is an advanced instrument for DLS and SLS measurements. It enables measurement of hydrodynamic radius, radius of gyration, 2nd viral coefficient, molecular weight, form factor and structure factor.

3D LS Spectrometer

 
 

The angular scattering pattern is measured. The resulting form factor allows to determine the size and shape of the dispersed particles in the sample.

 
 

For static light scattering experiments a laser is used to illuminate a cuvette containing the sample to be analyzed. One or many detectors are used to measure the scattering intensity in dependence of the scattering angle θ. This so-called scattering curve Is(θ) contains information about the scattering particle's size, its shape and molar mass. In order to measure the average molecular weight SLS instruments are calibrated using a well know reference such as toluene. The Rayleigh Ratio of toluene can be checked in existing tables.


Static light scattering is an in-situ technique where, as opposed to direct imaging techniques such as SEM or TEM, the sample can be measured in its natural state as long as the particle concentration is small enough to avoid multiple scattering effects. False measurements due to multiple scattering result in significant errors in both SLS and DLS measurements, often without ever being noticed. They can only be avoided if special techniques such as cross-correlation are used to suppress the multiple scattering.

 
 


 
 

Learn more about static light scattering by following our online technology section step by step.

It is advisable to read the different sections in the suggested order if you want to understand all the details. For a quick reference you can also jump to each section individually.

 

 

A very detailed source of information is the slide show "Light Scattering Fundamentals".