Graphene Raman Analyzer: Carbon Nanomaterials Characterization

Significance of the Topic

Carbon nanomaterials such as graphene, graphene oxide, carbon nanotubes and carbon nanofibers exhibit unique electrical, thermal and mechanical properties that drive applications in electronics, energy storage, catalysis and water treatment.

Objectives and Study Overview

This study evaluates a portable high‐throughput Raman analyzer as a rapid at‐line/on‐line tool to monitor and characterize graphene powders, carbon nanofibers and carbon black for quality control and process monitoring in industrial manufacturing.

Methodology

A 532 nm laser excitation was delivered via a fiber‐optic probe to powdered samples using the i‐Raman Pro HT spectrometer. Spectral acquisition and processing steps included airPLS background correction and Savitzky‐Golay smoothing. Measurements were performed with specific laser power and integration times for each sample type, and three replicates were collected per sample.

Instrumentation

• i‐Raman Pro HT portable Raman spectrometer with a back‐thinned CCD cooled to -25 °C
• Fiber‐optic sampling probe mounted on an XYZ adjustable holder
• BWSpec software for real‐time data acquisition, spectral correction and automated calculation of peak intensities and ratios

Main Results and Discussion

• Graphene powder sheets: ID/IG ratios for six samples ranged from 0.0635 to 0.4665, indicating varying degrees of disorder; sample 6 showed the highest defect density and weakened 2D‐band signal.
• 2D‐band profiles revealed sample 5 as having the most defined and symmetric shape, consistent with high crystallinity and few graphene layers.
• Carbon nanofibers and carbon black: ID/IG values identified one nanofiber sample with high order (0.4706) and another with pronounced disorder (1.3654); carbon black showed strong D‐bands and no 2D‐bands.
• Additional Raman peaks at ~213 and 280 cm−1 confirmed the presence of hematite (Fe2O3) residues in nanofiber samples from the manufacturing process.

Benefits and Practical Applications

The portable Raman analyzer enables rapid, non‐destructive characterization of carbon nanomaterials directly at production lines, supporting real‐time quality control, process optimization and product consistency without complex sample preparation.

Future Trends and Potential Applications

• Integration of portable Raman sensors into automated manufacturing workflows for continuous monitoring.
• Expansion to characterization of emerging two‐dimensional materials and hybrid nanocomposites.
• Development of chemometric models for predictive quality assessment and defect classification.
• Coupling with data analytics and digital twin platforms for process diagnostics and scalability.

Conclusion

The i‐Raman Pro HT system, combined with BWSpec software, provides a simple, cost‐effective and high‐throughput approach to assess crystallinity, layer number and defects in graphene and other carbon nanomaterials, facilitating at‐line and on‐line quality control in industrial settings.

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