Acid functionalization of large-diameter multi-walled carbon nanotubes: improved dispersion with preserved graphitic structure

Le résumé fourni par la source

The use of multi-walled carbon nanotubes (MWCNTs) as reinforcing fillers in polymer composites is often limited by poor dispersion and weak interfacial compatibility. In this study, large-diameter MWCNTs (120–130 nm), previously synthesized via aerosol-assisted chemical vapor deposition, were subjected to mixed nitric–sulfuric acid functionalization to improve their surface characteristics. Structural and dispersion-related modifications were evaluated using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy, and UV–Vis spectroscopy. XRD results indicated reduced amorphous carbon contributions while preserving the graphitic framework. FTIR analysis confirmed the incorporation of oxygen-containing functional groups. Raman spectroscopy revealed a decrease in the ID/IG ratio from 1.19 to 0.83, corresponding to an increase in the in-plane crystallite size (La) from 3.7 nm to 5.3 nm, suggesting improved graphitic ordering following acid treatment. UV–Vis measurements demonstrated smoother and more stable absorbance profiles for functionalized samples across multiple dilution ratios, indicating enhanced dispersion and reduced aggregation. These findings demonstrate that acid functionalization improves dispersion while maintaining structural integrity, emphasizing the importance of controlled surface modification for large-diameter MWCNT-based composite applications.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.