High-Resolution X-ray Spectromicroscopy Reveals Process-Structure Correlations in sub-5-μm Diameter Carbon
Eric R Meshot1, Alexander Baker2, Daniel Malone2
1Materials Engineering Division, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States.
ACS Nano
|May 15, 2023
Summary
Quantitative analysis of carbon nanotube (CNT) yarns reveals how processing affects structure. This understanding is key to improving CNTs for macroscale applications.
Area of Science:
- Materials Science
- Nanotechnology
- Polymer Science
Background:
- Detailed structural analysis of carbon nanotube (CNT) ensembles is lacking.
- This gap hinders establishing processing-structure-property relationships for macroscale applications.
Purpose of the Study:
- To quantitatively analyze the hierarchical structure of dry-spun CNT yarns and their composites.
- To establish structure-property relationships for enhanced macroscale performance.
Main Methods:
- Scanning transmission X-ray microscopy (STXM) was used to analyze CNT yarn morphology.
- Key structural characteristics like density, porosity, alignment, and polymer loading were quantified.
- Spectromicroscopy with 30 nm resolution assessed polymer distribution.
Main Results:
- Yarn diameter decreased and density increased with higher twist density (15,000 to 150,000 turns/meter).
- Yarn density universally scaled with diameter as ρ ∼ d-2.
- Vapor-phase polymer coating nearly perfectly filled CNT voids, confirmed by elemental analysis.
Conclusions:
- Quantitative correlations between processing, structure, and polymer loading were established.
- These findings are crucial for translating nanoscale CNT properties to macroscale performance.
- The study provides insights for optimizing CNT yarn fabrication for diverse applications.
