Dear Professor,

In the analyses performed with FTIR, firstly the nanoparticles are prepared as a thin film or KBr pellet by providing a homogeneous distribution. Then, infrared light is passed through the sample and the frequencies absorbed by the molecular bonds are recorded. The obtained spectrum shows the characteristic peaks belonging to the functional groups on the surface of the nanoparticles. For example, bonds such as O-H, C=O and C-H create distinct absorption peaks at different wavelengths. In this way, it is determined which functional groups are present on the surface of the nanoparticles and what their chemical structure is. As far as I know the FTIR technique is preferred especially for examining surface modifications and obtaining detailed information about the chemical structure, but it does not directly determine the size of the nanoparticles.

Kind Regards.

Dear Mohsin O. Mohammed ,

FTIR is a technique that gives you a signal based on the chemical group involved in the structures you are analysing. In this sense, if you know the chemical groups involves in your nanoparticles (i.e.: for silica nanoparticles, normally Si-O groups are present, so FTIR shows signals relative to these groups), then you can infer the structure of your nanoparticles. Nevertheless, if you would like to see that you have nanoparticles and not polymer chains for example, some microscopy (such as TEM) might be the best technique to explore, or DLS.

Hope this helps!

With the term structure do you mean the crystallographic structure, so the atomic coordinates and lattice parameters? FT-IR is useful to verify the functional groups present in your molecule and is particularly useful for organic molecules. Your nanoparticles are organic or inorganic?

Fourier Transform Infrared Spectroscopy (FTIR) is a powerful analytical technique used to obtain information about the molecular structure of materials, including nanoparticles.