Dynamic Light Scattering (DLS) Tests

Particle size analysis is a technique used to characterize the size distribution of particles in a given sample. Particle size analysis can be applied to solid materials, suspensions, emulsions and even aerosols. There are many different methods used to measure particle size.

Some particle sizing methods are used for a wide variety of samples, but some are used only for certain applications. Since different methods can produce quite different results for the same material, it is very important to choose the most appropriate method for different samples.

Particle size analysis is a very important test and is used for quality control purposes in many different industries. In almost every industry where grinding or grinding is used, particle size is a critical factor in determining the efficiency of production processes and the performance of the final product. Some industries and product types where particle sizing is used include: pharmaceuticals, building materials, paints and coatings, food and beverages, and aerosols.

Laser diffraction is one of the most widely used particle sizing methods, especially for particles in the 0,5-1000 micron range. It works on the principle that when a light ray is scattered by a group of particles, the angle of scattering of the light is inversely proportional to the particle size (the smaller the particle size, the larger the angle of scattering of the light).

There are many other methods other than laser diffraction to analyze particle size. When measuring very small particles (e.g. less than 0,5um), dynamic light scattering (DLS) is by far the easiest method to use.

Dynamic light scattering (DLS) is a well-established non-invasive technique used to measure the size and size distribution of molecules and particles typically located in the submicron region, providing measurements below 1 nm with the latest technologies.

Typical applications of dynamic light scattering are the characterization of particles, emulsions or molecules dispersed or dissolved in a liquid. The Brownian motion of the particles or molecules in suspension causes the laser light to be scattered at different intensities. Analysis of these density fluctuations gives the speed of Brownian motion and hence the particle size. Small particles move faster than large particles.

When a laser light source is applied to an aqueous particle sample in solution during testing, it scatters around as it passes. The scattered light is detected and recorded at some predefined angle, and the time dependence of the changes in the scattered intensity profiles is related to the speed of the particles and hence to their average size and distribution in the system.

Briefly, dynamic light scattering analysis is an indirect and high-throughput method to measure the sizes of particles in a solution relative to the hydrodynamic diameter. The strengths of this technique can be listed as follows: it is a fast and automatic method, provides rapid results, accepts low sample concentrations, provides general particle size distribution, works well with a wide range of particle sizes, and is a non-destructive analysis method.

However, this method has some limitations. For example, this technique does not provide particle shape information for irregular geometries. Additionally, heavy particles can sometimes precipitate and cause erroneous information. Larger particles have a higher weight in the raw density distribution.

Dynamic light scattering tests are used to determine the size of a variety of particles, including proteins, polymers, micelles, protein cages and virus-like particles, vesicles, carbohydrates, nanoparticles, biological cells and gels. If the size of the system is not dispersed, the average effective diameter of the particles can be determined by this method. Measurements depend on the size of the particle or particle nucleus, surface structures, particle concentration, and the type of ions in the environment.

Dynamic light scattering (DLS) testing services are among the numerous testing, measurement, analysis and evaluation studies provided to businesses by our organization.