Raman spectroscopy and XPS are very effective tools to prove whether the removal of surfactant residuals within the SWCNTs films are done. To quantitatively know how much the surfactants remain within the film, you have to employ a known quantity of the surfactant as a refenerce to calibrate a spectrum, so you can compare the unknown samples' spectra against the spectrum of your calibrated reference to obtain how much the residuals of the surfactant left over within the film. Hope it helps.

Respected Dr.Xuhua Wang,

I prepared the flexible electrode from the suspension of SWCNTs with sodium deoxycholate surfactant and tested them in LIBs. Yes, the approach you suggested is quite reasonable. I personally performed Moldi-TOF technique to determine the surfactant presence presence before and after its addition to the SWCNTs film. the molecular weight is not high enough so it could be easily determined. however, it is a kind of qualitative characterization. the reviewer asked me to determine it quantitatively.

thank you.

Aziz

Dear Aziz Ahmad , If you have access to some electron microscopy. There can be installed also EDX or EDS. This is fast and can be used for relative comparison of components. The quality is question but you could have also another technique at least.

Dear Roman,

Thank for your interest. I think these characterization well suited to determined the amount of various fractions/elements of the target material. In my situation, the reviewer asked me to determine the exact amount of the whole compound. May be you are correct too but i dont, know how to calculate the exact amount of the whole compound from its after through EDS. Certainly, we have this facility but pretend to use it because of no concept. I personally proceeded through Raman as suggested by Dr.Xuhua Wang and Maldi-Toff techniques myself. It would be nice if you could share your valuable knowledge. thanks

Dear Aziz Ahmad, I understood that XPS or Raman can help so EDX could be another fast method. However, yes EDX is for determination of fraction of element only ... the same as in the case of XPS and Raman I think (I do not have experience with Raman). For determination of absolute amount may be possible add some exact amount of any other elements and then determine the fractions between elements by some methods mentioned above. However, I have never heard, never seen. It is instant idea. As I know for determination of absolute amount of substance the Gravimetric analysis is used. In this case perhaps using sulfuric acid with formation of Na2SO4 but it needs to be check.

Dear Roman Fiala,

Yes, i will agreed with the statement you added here. From % fraction of the elements, through, EDX, and XPS, at least we could guess or estimate the content of the precursor materials. I hope, we could keep continuing and will share the new ideas for the better science.

Aziz Ahmad