Home >> Science & Nature >> Science

How to Find the Particle Size by FTIR

Particles are small three-dimensional objects. The size of a particle is described by at least three numbers, indicating its length, height and breadth. Determining accurate particle sizes is complex, because particles tend to be irregularly shaped, unlike a sphere, the size of which can be represented by a diameter. When scientists need accurate particle sizes, they use light diffraction techniques to determine the dimensions of each particle. The results are then subjected to a series of mathematical equations known as a Fast Fourier Transform. This eventually yields the dimensions of the particle size, called Fourier Descriptors, in terms of elongation, triangularity, squareness and asymmetry.

Things You'll Need

Fourier Transform InfraRed (FTIR) spectroscope
Electron micrograph
Image processing application
Nanoparticle size analyzer
Computer
Sand

Instructions

- 1
  Take detailed photographs of the sand sample, using the electron micrograph.
- 2
  Count the number of grains of sand in the sample from the micrograph and make any necessary adjustments. A sample size of approximately 200 grains should be sufficient for analysis.
- 3
  Create digital images of the individual sand particles and their outlines, using commercial image processing software.
- 4
  Place the sample into the spectroscope or nanoparticle analyzer and use the equipment to perform a light diffraction analysis and produce a power spectrum. You'll need highly specialized training to operate these machines, so you might need a research scientist to perform this analysis on your behalf.
- 5
  Calculate the Fourier Descriptors of the particles using the Fast Fourier Transform equations. If you use a nanoparticle size analyzer, it will automatically perform the calculations and output the results. You can also use a computer to do the Fourier Transform calculations based on the power spectrum and the coordinates of the individual sand particles.

Science