If you wash with ethanol instead of distilled water there should be changes in the characterizations. Because Hummers method uses H2SO4 and KMnO4. They are easily washed away during washing with water as the products are soluble in water. But With ethanol the washing procedure should be more rigorous to make graphite oxide impurity free. So if Mn2+ and acids remaining will interfere in the characterization and properties.

If you require washing with ethanol, then you can do this in the final step of washing after performing regular washing process by water & dil HCl.

Better use DI water during washing procedure

When we synthesize graphene oxide, we use concentrated acids and for removing these acids and other salts formed in the reaction process, distilled water is the best medium.

Ethanol reacts violently with H2SO4/KMnO4 liberating large amounts of heat.. You may get graphene oxide with lots of defects or even holey graphene oxide with in-plane holes ..

Ethanol reacts violently with H2SO4/KMnO4 liberating large amounts of heat.. You may get graphene oxide with lots of defects or even holey graphene oxide with in-plane holes ..

It depends upon how you initially process the material (flake size is something to also consider).  Your primary concern will relate to whether or not you have successfully attacked and, thus, removed all remnant Mn carboxylate and/or alkoxide type sites.  

Of course, you could always disperse it in concentrated acid again after the primary recovery--but you will still have an issue with remnant manganese.  To answer your question regarding spectra, your graphite oxide will be closer to a true 'as-prepared' graphite-oxide, I.e., very few, if any, -OH sites exist; (G-O-S((=O)2)-O-G) must first undergo hydrolysis (G-OH + HO-S((=O)2)-O-G) and the pH is too low.  There is one caveat though--you may or may not detect bands associated with ethoxide functional groups; this would depend upon how rigidly you process your material and/or atypical bands resulting from small fragment molecules (processing dependancy, but more so as a result of flake size).

Take the literature with a grain of salt--I routinely prepared unmodifed solutions of GO in "incompatible' solvents, e.g., chloroform; it simply requires careful processing and purification.

Ist wash with Distilled water followed by Ethanol for better characterizations.

With regards'

Try to Wash with DW many times, because to maintain their PH in 4 to 5. DW is best for characterization of GO.