ASTM E3220-20

Standard Guide for Characterization of Graphene Flakes

SIGNIFICANCE AND USE
4.1 The remarkable structural, physical and chemical properties of graphene — particularly its mechanical strength, high electronic mobility, lightness, and transparency (single layer or a few layers) — have generated worldwide research and industrial production efforts aimed at developing practical applications. Various industrially scalable production methods have been developed, including bottom-up approaches that grow graphene from small molecules (with or without a substrate), and top-down methods that start with graphite and exfoliate it by mechanical, chemical or electrochemical methods to produce nanoscale product such as graphene flakes. Two common exfoliation methods are: (1) oxidation of graphite to graphene oxide (GO) followed by additional processing to form reduced graphene oxide (r-GO) (2) and, (2) liquid phase exfoliation of graphite (3). The exfoliation methods, as well as substrate-less bottom-up approaches, produce materials in the form of flakes that can be dispersed in various solvents, making them suitable for applications requiring solution processing. Although there are many commercial “graphene” materials available on the market, the quality of these products is highly variable (4). There are many challenges in assessing the physical properties of the materials. In this guide we discuss how Raman spectroscopy (Raman) and X-ray photoelectron spectroscopy (XPS), as well as atomic force microscopy (AFM) can be used to characterize materials consisting of flakes of graphene and related materials (that is, few layer graphene (FLG), GO, r-GO). Illustrative examples are provided showing how these methods can be used to identify the type of material present and to extract important parameters including lateral flake size, average flake thickness, ratio of intensities of the D and G modes (ID/IG) in the Raman spectrum and carbon to oxygen ratio. Specifically, when encountering an “unknown” material or product purporting to be “graphene,” it is essent...
SCOPE
1.1 This standard will provide guidance on the measurement approaches for assessment of lateral flake size, average flake thickness, Raman intensity ratio of the D to G bands, and carbon/oxygen ratio for graphene and related products. The techniques included here are atomic force microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. Examples will be given for each type of measurement.  
1.2 This guide is intended to serve as an example for manufacturers, producers, analysts, and others with an interest in graphene and related products such as graphene oxide and reduced graphene oxide. This Standard Guide is not intended to be a comprehensive overview of all possible characterization methods.  
1.3 This guide does not include all sample preparation procedures for all possible materials and applications. The user must validate the appropriateness for their particular application.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Mar-2020
• ICS: 59.100.20 - Carbon materials
• Technical Committee: E56 - Nanotechnology
• Drafting Committee: E56.02 - Physical and Chemical Characterization

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E3220 − 20
Standard Guide for
1
Characterization of Graphene Flakes
This standard is issued under the fixed designation E3220; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
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1.1 Thisstandardwillprovideguidanceonthemeasurement 2.1 ASTM Standards:
approaches for assessment of lateral flake size, average flake E2530Practice for Calibrating the Z-Magnification of an
thickness, Raman intensity ratio of the D to G bands, and AtomicForceMicroscopeatSubnanometerDisplacement
carbon/oxygen ratio for graphene and related products. The Levels Using Si(111) Monatomic Steps (Withdrawn
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techniques included here are atomic force microscopy, Raman 2015)
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spectroscopy and X-ray photoelectron spectroscopy. Examples 2.2 ISO Standards:
will be given for each type of measurement. ISO13067:2011MicrobeamAnalysis—ElectronBackscat-
ter Diffraction — Measurement of Average Grain Size
1.2 This guide is intended to serve as an example for
ISO 13322-1:2014Particle SizeAnalysis — ImageAnalysis
manufacturers, producers, analysts, and others with an interest
Methods — Part 1: Static Image Analysis Methods
in graphene and related products such as graphene oxide and
ISO 18115-2:2013Surface Chemical Analysis — Vocabu-
reduced graphene oxide. This Standard Guide is not intended
lary—Part2:TermsUsedinScanning-ProbeMicroscopy
tobeacomprehensiveoverviewofallpossiblecharacterization
ISO 18116:2005Surface Chemical Analysis — Guidelines
methods.
for Preparation and Mounting of Specimens for Analysis
1.3 This guide does not include all sample preparation
ISO/TR 18196:2016 Nanotechnologies — Measurement
proceduresforallpossiblematerialsandapplications.Theuser
Technique Matrix for the Characterization of Nano-
must validate the appropriateness for their particular applica-
Objects
tion.
ISO 18554:2016Surface Chemical Analysis — Electron
Spectroscopies — Procedures for Identifying, Estimating,
1.4 The values stated in SI units are to be regarded as
and Correcting for Unintended Degradation by X-Rays in
standard. No other units of measurement are included in this
standard. a Material Undergoing Analysis by X-Ray Photoelectron
Spectroscopy
1.5 This standard does not purport to address all of the
ISO 80004-1:2015Nanotechnologies — Vocabulary — Part
safety concerns, if any, associated with its use. It is the
1: Core Terms
responsibility of the user of this standard to establish appro-
ISO 80004-13:2017Nanotechnologies — Vocabulary —
priate safety, health, and environmental practices and deter-
Part 13: Graphene and Related Two-Dimensional (2D)
mine the applicability of regulatory limitations prior to use.
Materials
1.6 This international standard was developed in accor-
ISO/IEC Guide 9:2010International Vocabulary of Metrol-
dance with internationally recognized principles on standard-
ogy—BasicandGeneralConceptsandAssociatedTerms
ization established in the Decision on Principles for the
(VIM)
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
2
Barriers to Trade (TBT) Committee. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
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This guide is under the jurisdiction of ASTM Committee E56 on Nanotech- The last approved version of this historical standard is referenced on
nology and is the direct responsibility of Subcommittee E56.02 on Physical and www.astm.org.
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Chemical Characterization. Available from International Organization for Standardization (ISO), ISO
Current edition approved April 1, 2020. Published May 2020. DOI: 10.1520/ Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier,
E3220-20. Geneva, Switzerland, http://www.iso.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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E3220 − 20
3. Terminology 4. Significance and Use
3.1 Definitions: 4.1 The remarkable structural, physical and chemical prop-
3.1.1 Feret diameter, n—perpendicular distance between erties of graphene — particularly its mechanical strength, high
two parallel lines drawn in a given direction tangential to the electronicmobility,lightness,andtransparency(singlelayeror
p
...