Core/Shell Structure of TiO₂-Coated MWCNTs for Thermal Protection for High-Temperature Processing of Metal Matrix Composites

Table 1

FTIR bands observed for pristine, acid-functionalized, and TiO₂-coated MWCNTs.

Band (cm^−1)	Interpretation	Pristine	Acid functionalized	TiO2 coated
3400	OH stretching vibrations of isolated surface –OH moieties and in sorbed water [31]	x	x	x
2924	Asymmetric stretching of CH bonds located on the MWCNT surface defects [32]	—	x	—
2849	Symmetric stretching of CH bonds located on the MWCNT surface defects [32]	—	x	—
1730	C=O bonds related to the carboxyl group COOH [33]	—	x	—
1630	OH stretch of adsorbed water and Ti-OH [34]	x	x	x
1560	C-O carboxylate anion stretch mode [33]	—	x	—
1430	O-H deformation vibrations [31]	—	x	—
1100	C-O stretch [31, 35]	—	x	—
930	O-H stretch [36]	—	x	—
500	Ti-O-Ti stretch [34]	—	—	x