Heterogeneous liquid samples are most commonly subjected to dynamic light scattering as the technique relies on the effect of Brownian motion to characterize dispersed particles by their hydrodynamic radii. This principle enables dynamic light scattering tools to measure the thermodynamic stability of complex emulsions by monitoring particle migration phenomena as a function of time. It can also be used to study protein interactions.
What is Brownian Motion?
Brownian motion is the erratic and apparently random transportation of dispersed particles within a continuous or semi-continuous mobile phase. This phenomenon is determined by a number of complex mechanisms including gravitational settling and the zeta potential of the colloidal system. It can contribute to colloidal instability by causing particle collisions and separations from the mobile phase, but it can also be used to measure and quantify particles in solution.
How Does Dynamic Light Scattering Work?
Dynamic light scattering characterizes particle size by shining an incident light source, typically a monochromatic laser beam, into a sample. The sample may be an end-product formulation or a number of particles dispersed in a carrier fluid. The narrow laser beam scatters when it collides with nanoparticles within the solution, diffracting through the sample in multiple directions. An output beam is acquired by an optical detector and variations in the intensity of the laser beam are measured as a function of time.
This data is used to calculate the size (hydrodynamic radius) of the particles in solution. Chemists can use this information to research the behavior of colloidal systems, providing accurate insights into their thermodynamic stability in real-world storage, transportation, and usage conditions.
Dynamic Light Scattering with RQM+ Lab Services
RQM+ Lab Services is one of the leading suppliers of analytical chemistry solutions in the US. We are equipped with cutting edge dynamic light scattering tools to assist in the measurement of dispersed particles and emulsions below the 2.5-micron (um) level. Our dynamic light scattering services are suitable for characterizing proteins, polymers, micelles, carbohydrates, nanoparticles, and more with accurate identification of particles down to a single nanometer (nm).
If you would like any more information about our dynamic light scattering capabilities, please do not hesitate to contact us directly.