Characterization of functionalized multi-walled carbon nanotubes

Abstract

Multi-walled carbon nanotubes (MWCNTs) are functionalized to determine structural and chemical changes occurred due to oxidation at room temperature in presence of an aqueous solution of concentrated HNO3. The raw and processed (functionalized) MWCNTs were investigated with FTIR and FESEM spectroscopy methods. The surface morphology was examined by FESEM and presence of carboxylic group were identified with Fourier Transform Infrared Spectroscopy (FTIR). The multi walled carbon nanotube of 8 nm, 10–30 nm & 50 nm were taken for experimentation. The FTIR spectra revealed that the broad peak @3450 cm-1 corresponds to O–H bond and peak at @ 1630 cm-1 corresponds to C = O bond. The intensity of both raw and functionalized MWCNTs peak signifies presence of COOH group. Likewise, FESEM images shows, agglomeration of MWCNTs due to Van der Waals forces in raw MWCNTs but after functionalization, unbundled CNTs with reduction in length due to breakage of C = C bond and presence of carboxyl group at end of CNTs.