Highly Oriented Direct-Spun Carbon Nanotube Textiles Aligned by In Situ Radio-Frequency Fields

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Individual carbon nanotubes (CNTs) possess exceptional properties but are limited in macroscopic applications.
• Harnessing nanoscale CNT properties in bulk materials requires effective alignment strategies.
• Previous methods struggled to translate individual CNT advantages to macroscopic scales.

Purpose of the Study:

• To develop a direct spinning method for aligned carbon nanotube (CNT) textiles.
• To investigate the use of AC electric fields for in situ CNT alignment during synthesis.
• To enhance the macroscopic properties of CNT materials by controlling CNT alignment.

Main Methods:

• An altered direct CNT spinning method using floating catalyst chemical vapor deposition.
• Application of an AC electric field during CNT bundle and aerogel formation for in situ alignment.
• Mesoscale CNT modeling to understand the influence of electric fields (AC vs. DC) on alignment.
• Characterization of CNT alignment using small-angle X-ray scattering and scanning electron microscopy.

Main Results:

• Successful in situ alignment of CNTs using an AC electric field, controlling bundle diameters.
• Achieved a significant increase in specific electrical (up to 90%) and tensile (up to 460%) properties.
• Verified CNT quality and quantity remained unchanged, with clear alignment (orientational order parameter = 0.5) achieved.

Conclusions:

• The developed AC electric field-assisted method effectively aligns CNTs during direct spinning.
• This alignment significantly enhances the macroscopic electrical and mechanical properties of CNT textiles.
• The findings pave the way for utilizing CNTs in high-performance macroscopic applications.