When Light Scattering is Important

Light Scattering occurs when polarizable particles in a sample are bathed in the oscillating electric field of a beam of light. The varying field induces oscillating dipoles in the particles and these radiate light in all directions. This important and universal phenomena is the basis for explaining why the sky is blue, why fog and emulsions are opaque and other observations. It has been utilized in many areas of science to determine particle size, molecular weight, shape, diffusion coefficients etc.

Brookhaven Instruments uses light scattering in four, distinct ways:

• Static LS for determination of molecular and colloidal properties and structure functions for complex fluids (BI-MwA, BI-200SM/TurboCorr) 
• Dynamic LS for particle sizing and particle size distribution information as well as for protein characterization (90Plus, FOQELS, BI-200SM/TurboCorr) 
• Electrophoretic LS for zeta potential distribution (ZetaPlus) 
• Phase Analysis LS for zeta potential in low mobility suspensions (ZetaPALS) 

Of all these choices, if you are interested in multiangle, DLS and SLS, the BI-200SM goniometer and TurboCorr digital autocorrelator are the instruments of choice for basic research. Using primarily batch mode, the angular range is nominally 10 to 155 with 0.01 steps. Nothing comes close to this combination for the ability to study colloids and polymers.