How can you be sure that your CNT is functionalized?

[cubicboy]

Hi everyone;

 

I know you can try to dissolve CNTs in ethanol or some solvent then wait. After a while if you can't see sediment in the bottle then there is no problem, your CNTs are succesfully functionalized.

 

So my first question is how long does it take to decide that it is functionalized.

 

And second one what is the reliability of this method? (I know there are other methods which are used to support the result such as FTIR spectra. But can we trust just this method without using another one?)

 

The last and important one is that Do I have to use specific solvent which is related to my functional groups on CNTs?

[AbeMichelson]

How are you functionalizing? It doesn't seem like simply adding ethanol will do it. As far as techniques go, what functional groups are you adding will determine best methods.

 

Hydrogen, COOH, CO, NH2 will be best served with FTIR. Honestly, I like using a second technique, but it is not strictly necessary. However:

1) Raman can show you the disappearance of C=C bond structure (not a great primary method, but it shows the bonds have been broken)

2) XPS will show the presence of O, N, and other elements (but not Hydrogen). It can give some chemical bonding information (usually in relation to C, but not as good as FTIR). It is an expensive technique. An inexpensive alternative is EDX, but it doesn't have the resolution for bonding information.

3) You may get some info from UV-Vis. pi-pi* transitions for C=C bonds will decrease. n-pi* transitions will show for O or N.

These will give you another leg for your proof. Really, though, FTIR gives you the best proof positive of functionalization. For small amounts, I'd recommend a MCT detector and ATR or grazing angle reflectance on a gold-coated slide.

[John Cuthber]

It might be quicker to list the analytical techniques that can't be used for this.

[AbeMichelson]

The last and important one is that Do I have to use specific solvent which is related to my functional groups on CNTs?

If you are trying to put the functionalized CNTs into solution, yes. Like dissolves like should work.