99%

Dear Husham N Noori many thanks for posting this interesting technical question on RG. The use of ethanol is well established for obtaining nanoparticles (especially metal oxide NPs) with low agglomeration. I'm certainly not a proven expert in this field, but I noticed that the purity of the ethanol used for the washing and purification process of nanoparticles is often not specified. In this context, please have a look at the following typical article:

Hydrogen response of palladium nanoparticles washed with different solvents

https://www.ias.ac.in/article/fulltext/boms/044/0045

This paper is freely accessible as public full text on the internet (please see attached pdf file). Thus I assume that you can use the commercially available 96% ethanol, but it certainly doesn't hurt employing higher grade ethanol (which can, however, be much more expensive).

In the previous literature it has frequently been suggested to make the ethanol washing step more effective by using ultrasound or microwave irradiation. This can be done in a normal ultrasound cleaning bath or a household microwave oven. For more information, please check e.g. the following Open Access article (also attached):

The Effect of Solvents, Acetone, Water, and Ethanol, on the Morphological and Optical Properties of ZnO Nanoparticles Prepared by Microwave

Article The Effect of Solvents, Acetone, Water, and Ethanol, on the ...

This paper is freely accessible as public full text on RG.

For more information about ethanol washing assisted by ultrasonication please also see this relevant literature reference:

Synergistic effects of ultrasonication and ethanol washing in controlling the stoichiometry, phase-purity and morphology of rare-earth doped ceria nanoparticles

Article Synergistic Effects of Ultrasonication and Ethanol Washing i...

Please check if you can access this paper through your institution. All three authors of this work have RG profiles. Thus you can also easily contact one of them directly via RG and request the full text of the article.

I hope this helps. Good luck with your work and please stay safe and healthy!

Dear Husham,

For the synthesis of nanoparticles, we normally use absolute ethanol (200 proof) from Sigma-Aldrich. This is the one that, so far, has been most useful to us. Any other ethanol, especially the less pure or those stabilized with different preservatives, can interact in some way, leading to less than optimal results.

Dear Husham,

For the synthesis of nanoparticles, we normally use absolute ethanol (200 proof) from Sigma-Aldrich. This is the one that, so far, has been most useful to us. Any other ethanol, especially the less pure or those stabilized with different preservatives, can interact in some way, leading to less than optimal results.

Dear Husham N Noori I think that Francisco Manuel Marquez is certainly right in that one should be ware of the fact that commercial laboratory grade ethanol can contain different preservatives / denaturing agents. I still remember times when 96% ethanol was denatured with a small amount of pyridine. This gave the ethanol a bad smell and taste and made it unsuitable for drinking. Chances are that pyridine could also interact with nanoparticles and coordinate to them. Nowadays, ethanol is mostly denatured with hexane / petroleum ether. This are absolutely inert hydrocarbons, so that this type of e.g. 96% ethanol can be used for washing nanoparticles without any risk.