Andrew Pollard | National Physical Laboratory: Is your "graphene" actually graphene? Without a common language and set of standards, the industry is flying blind.
00:04:30 - 00:06:53
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Is your "graphene" actually graphene? Without a common language and set of standards, the industry is flying blind.
The foundation for industrial adoption of graphene relies on a robust framework of international standards, led by ISO Technical Committee 229 for nanomaterials. This holistic suite of joint ISO/IEC standards begins with "enabling standards" that create a common language. These include critical documents on terminology, which precisely define terms like "few-layer graphene" versus "nanographite," and a classification framework that specifies how to report on a material, including its production method (e.g., CVD, exfoliation) to avoid market confusion.
At the core of the framework are specific measurement standards for both structural and chemical characterization. Structurally, the standards are divided to address the unique challenges of different material forms. One set of protocols is designed for graphene flakes, such as nanoplatelets and graphene oxide, which are typically handled as bulk powders or liquid dispersions. A separate standard addresses the characterization of single-layer CVD graphene on a substrate, recognizing that the measurement requirements for a continuous film are fundamentally different.
Chemical characterization standards are equally vital, providing the methods needed to distinguish between pristine graphene, graphene oxide, and other functionalized forms. The ultimate goal of this comprehensive toolkit is to empower producers and end-users to reliably determine a material's properties. By using these standardized methods, the industry can build confidence in technical data sheets, compare materials from different suppliers, and accurately match a material's properties to the performance requirements of a specific application.
In this short video, you can learn:
* The structure of the ISO/IEC international standards for graphene characterization.
* Key differences in measurement approaches for graphene flakes vs. CVD graphene.
* How standards for terminology, classification, and chemical analysis build a reliable supply chain.
š **Clip Abstract** Andrew Pollard outlines the comprehensive landscape of ISO/IEC standards developed to characterize graphene and related 2D materials. This framework provides a common language and a suite of measurement protocols to ensure producers and end-users can reliably define and compare materials.
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#GrapheneStandards, #GrapheneCharacterization, #CVDGraphene, #GrapheneOxide, #AdvancedMaterials, #2DMaterials
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00:09:16 - 00:11:24
What if the "gold standard" technique for graphene analysis has a 300% error rate?
What if the "gold standard" technique for graphene analysis has a 300% error rate?
Raman spectroscopy is widely considered a "gold standard" technique for characterizing nanocarbons like graphene, using laser light to analyze material properties through characteristic spectral peaks. Ratios of these peak intensities are commonly used as a key determinant of material quality. However, despite its widespread use in academia and industry, a formal interlaboratory study to quantify the measurement uncertainty had never been performed, leaving a critical gap in understanding the technique's true reliability.
An extensive interlaboratory comparison, essential for developing any robust ISO standard, revealed a shocking source of variability. When different labs measured the exact same CVD graphene sample using the same protocol, the results for peak intensity ratios varied wildly, in some cases by as much as 300%. The study pinpointed the primary cause: the measurement instrumentation itself, not the sample preparation or data analysis. This demonstrated that without a key calibration step, comparing Raman data between different instruments was fundamentally unreliable.
The critical factor, previously overlooked by many users, was the need for an intensity calibration of the Raman spectrometer. Without this calibration, the average measurement uncertainty was a staggering 20-30%. By simply implementing a proper intensity calibration protocol, the uncertainty plummeted to just 2%. This crucial finding is now embedded in the ISO standard for CVD graphene, highlighting how rigorous metrology uncovers hidden variables and establishes true best practices for reliable material characterization.
In this short video, you can learn:
* Why interlaboratory studies are essential for creating robust measurement standards.
* The massive impact of intensity calibration on the accuracy of Raman spectroscopy for graphene.
* How measurement uncertainty was reduced from over 20% down to just 2% by identifying a single critical step.
š **Clip Abstract** Andrew Pollard reveals the surprising results of the first-ever interlaboratory study on Raman spectroscopy for graphene. The study uncovered that a lack of intensity calibration was causing measurement errors of up to 300%, a critical finding that has now informed new ISO standards.
š Link in comments š
#RamanSpectroscopy, #GrapheneCharacterization, #IntensityCalibration, #MetrologyStandards, #AdvancedMaterials, #Nanomaterials
00:13:37 - 00:15:45
How can you measure graphene quality in seconds, not weeks, right on the production line?
How can you measure graphene quality in seconds, not weeks, right on the production line?
As graphene production scales to hundreds of tons per year, traditional lab-based characterization methods become a major bottleneck. Sending samples to a lab and waiting two weeks for results is unfeasible for real-time quality control (QC). This delay can lead to immense waste if a production batch is found to be out-of-spec, highlighting the urgent need for low-cost, rapid, in-line techniques that can provide immediate feedback on material quality directly on the factory floor.
A promising solution for this challenge is NMR (Nuclear Magnetic Resonance) proton relaxation. Unlike complex and expensive research-grade NMR, this benchtop technique is relatively low-cost and provides a single numerical output in seconds rather than a full spectrum. The method is ideal for analyzing liquid dispersions of graphene flakes, a common industrial product format, by monitoring the exfoliation process in real-time and ensuring batch-to-batch consistency.
The technique works by measuring the specific surface area (SSA) of the flakes in the liquid, which is a direct indicator of the degree of exfoliation. This provides a rapid, quantitative measure of a critical material property. Crucially, the results from this NMR method show a direct correlation with the SSA values obtained from the traditional, time-consuming BET (gas physisorption) method, which can only be performed on dry powders. This validates NMR proton relaxation as a powerful tool for industrial QC, enabling producers to move beyond the lab and implement effective process control.
In this short video, you can learn:
* The critical need for rapid, in-line quality control in large-scale graphene manufacturing.
* How low-cost NMR proton relaxation can measure specific surface area in seconds.
* The direct correlation between this rapid liquid-phase measurement and traditional dry-powder BET analysis.
š **Clip Abstract** Andrew Pollard discusses the shift from high-precision standards to practical, in-line quality control for industrial-scale graphene production. He introduces NMR proton relaxation as a low-cost, rapid technique to measure the specific surface area of graphene flakes in liquid, enabling real-time process monitoring.
š Link in comments š
#NMRProtonRelaxation, #GrapheneQualityControl, #SpecificSurfaceArea, #InLineQC, #AdvancedMaterialsManufacturing, #CarbonNanomaterials