Processing route to disentangle multi-walled carbon nanotube towards ceramic composite

Area of Science:

• Materials Science
• Nanotechnology
• Composite Materials

Background:

• Multi-walled carbon nanotubes (MWNTs) synthesized via chemical vapor deposition often form aggregated ropes.
• Effective dispersion of MWNTs is crucial for their application in advanced materials.

Purpose of the Study:

• To investigate methods for disentangling aggregated MWNTs.
• To develop a process for manufacturing dense silicon nitride composites with well-dispersed MWNTs.

Main Methods:

• Comparison of mechanical treatments (mild and vigorous sonication in ethanol) and dispersant-assisted exfoliation in aqueous media.
• Evaluation of sodium dodecyl sulfate and gum arabic as dispersants for MWNTs.
• Spark plasma sintering (SPS) was used to fabricate silicon nitride composites.

Main Results:

• Mechanical sonication alone was insufficient to disentangle MWNT ropes.
• A combination of mild sonication and gum arabic in aqueous suspension significantly improved MWNT exfoliation.
• Stable MWNT suspensions were achieved with a low gum arabic concentration (0.05 wt%).
• Dense, homogenous silicon nitride composites with 1.8 vol% MWNTs were successfully fabricated using SPS without MWNT degradation or aggregation.

Conclusions:

• Gum arabic offers a highly efficient and low-concentration dispersant for MWNTs.
• The developed method allows for the production of high-performance MWNT-reinforced silicon nitride composites.
• This approach minimizes organic content and prevents MWNT aggregation during composite manufacturing.