Colloid characterization laboratory

Nanoparticle size analyzer and zeta potential

The determination is based on the non-invasive technology of dynamic light scattering (DLS) emitted by a laser. The particle is assimilated with a sphere shape in constant Brownian motion due to statistical collisions with liquid molecules. In this motion, the small particles will move faster than the large particles. 

The particle size distribution obtained by DLS depends on the relative intensity of the light scattered by particles of different dimensional classes. The time dependence of the intensity fluctuations is measured to determine the translational diffusion coefficient (D), respectively the hydrodynamic diameter (DH). The result is an intensity distribution that can be converted to a volume or mass distribution if the optical properties of the particles are known (Mie Theory). 

Mie theory allows a rigorous calculation of the particle size distribution from laser diffraction data, but this prediction of the size of all particles, small or large, transparent or opaque, is conditioned by the following approximations:

- The particles to be measured are spherical.

- The particle suspension is diluted.

- The optical properties of particles and the environment are known.

- The particles are homogeneous.

Surface analysis equipment - BET

The gas porosimeter system (Horiba SA 9600) offers a cheap alternative for determining the specific surface area. It uses the flue gas method, which determines the amount of gas (for example, nitrogen and helium mixture) that is adsorbed on a sample as a single layer of molecules, the so-called monomolecular layer.

Using this approach, total surface measurements can be made quickly, every six minutes, depending on the surface size.

The system is recommended for quick and easy surface area determination for a wide range of powder samples including:

  • active pharmaceutical ingredients, especially those with small areas
  • a variated range of nanostructured catalysts.

Technical specifications:

  • analysis method:
  1. BET surface index - single point analysis
  2. BET surface index – 3-point analysis
  3. pore volume (min. 0.005 cc/g)
  • measuring range: 0.10 - 2000 m2/g
  • analysis time: 3 - 6 minutes for a sample (analysis point)
  • productivity: 15 analyzes / hour (single point analysis) or 3 analyses / hour (3-point analysis) 
  • measurement accuracy: 0.01 m2/g
  • repeatability: 0.15%;
  • Relative Standard Deviation (RDS)

Particle and cell counter

The analyzer provides information on the behavior of the sample during measurement (agglomeration, dissolution, sedimentation), and can be used in various fields such as: food safety, biomedical, biotechnology, cell biology, bacteriology, air pollution, ceramics, cosmetics, pharmaceutical industry, food industry, metals, seaweed, lubricants, hydraulic fluids, the oil industry and environmental protection.

Measuring principle used: electrical sensing zone, according to ISO 13319. 

A particular advantage of this tool is that the results are NOT influenced by the color, shape of the particles or the composition and refractive index.