There are many methods we can make to ensure that the compound becomes in the size of the nanoparticles, most based on devices such as transmission electron microscopy (TEM). Which are not available in developing countries. Are there any methods that do not depend on the devices to make sure of that?
If you are interested in metal nanoparticles like e.g. Au or Ag, you can use a simple UV/Vis Photometer. The absorption maximum is a good indicator for particle size.
There are certain colloidal nanoparticle we can easily preliminary confirm by our naked eyes without going for costly and most expensive instrumentation such as TEM, SEM or XPS.
The reason behind those colloidal nanoparticle is that during the synthesis process they changes the colors which are the proof of nanoparticles synthesis.
For example.
Let us talk about silver nanoparticles.
When we synthesis silver nanopartricles by using solution methods, chemical reduction methods etc. We can easily see the colourless solution containing silver precursor changes to light yellow to dark brown. Which confirms the synthesis of silver nanoparticles without going to UV vis spectrometer or through TEM.
Similar in case of gold nanoparticles we can see the colorless solution containing gold precursor change from gold to dark violet to red.
So these are the method for preliminary confirming the nanoparticles. But for deeper understanding and to know the shape, size and other characteristics of nanoparticles you have to go for sophisticated instruments mention above.
Hope you got your answer.
Best Wishes
Dr. S Pandey
Usually we synthesize NPs according to some references either exactly or with minor modification. Although visual test can give some clue for the synthesis of the NPs, it is not a reliable method and can be misleading. You need to use at least one scientific method to confirm the production of the expected NPs. I recommend DLS which is easy, fast and not costume.
Good luck!
A simple visual inspection is often enough. If the particles are < < 100 nm, then the liquid will be transparent. May be colored in the case of metals like Au. A laser pen shone through the colloidal suspension will pick up the scattering from the particles. If the particles are >> 100 nm then typically one will have a cloudy suspension and perhaps sedimentation. Obviously a technique such as DLS will provide a distribution.
- Badges
- Science topic
- Similar topics
- Chemistry
- Nanotechnology
- Nanostructured Materials
- Nanoparticles