ISO/TC 229/JWG 2 - Measurement and characterization

This document specifies a mild oxidation method to determine the content of carbon impurities (carbon material content not in the form of CNT, including amorphous carbon and trace amountd of other types of structured carbon) less stable than multiwall carbon nanotubes (MWCNTs) by thermogravimetric analysis (TGA) under carbon dioxide atmosphere. This document is applicable to the characterization of carbon impurities content in MWCNT samples prepared by chemical vapour deposition (CVD). Measurement of carbon impurities in MWCNT samples prepared by other methods can refer to this document. This method is not applicable to functionalized MWCNT samples or MWCNT samples with encapsulant species. NOTE This method is applicable for the case of TG curves with a single-stage.

This document provides guidance and requirements for the determination of the mean (spherical) equivalent diameter of nano-objects (i.e. particles, droplets or bubbles) dispersed in liquids using the static multiple light scattering (SMLS) technique. The technique is applicable to a wide range of materials and does not require dilution of concentrated samples.

This document specifies requirements and recommendations for the identification of measurands to characterize nano-objects and their agglomerates and aggregates, and to assess specific properties relevant to the performance of materials that contain them. It provides recommendations for relevant measurement.

This document describes methods for the measurement of particle size distributions for cellulose nanocrystals using atomic force microscopy and transmission electron microscopy. The document provides a protocol for the reproducible dispersion of the material using ultrasonication, as assessed using dynamic light scattering. Sample preparation for microscopy, image acquisition and data analysis are included.

This document specifies methods of determining nanoparticle size and shape distributions by acquiring and evaluating scanning electron microscope images and by obtaining and reporting accurate results. NOTE 1 This document applies to particles with a lower size limit that depends on the required uncertainty and on the suitable performance of the SEM, which is to be proven first -according to the requirements described in this document. NOTE 2 This document applies also to SEM-based size and shape measurements of larger than nanoscale particles.

This document provides guidance for sample preparation, data acquisition by transmission electron microscopy, data processing, and three-dimensional image reconstruction to measure size and shape parameters of nano-objects on rod-shaped supports. The method is applicable to samples dispersed on or within an electron-transparent rod-shaped support.

This document describes methods for the quantification of nano-object release from powders as a result of treatment, ranging from handling to high energy dispersion, by measuring aerosols liberated after a defined aerosolization procedure. Particle number concentration and size distribution of the aerosol are measured and the mass concentration is derived. This document provides information on factors to be considered when selecting among the available methods for powder sampling and treatment procedures and specifies minimum requirements for test sample preparation, test protocol development, measuring particle release and reporting data. In order to characterize the full size range of particles generated, the measurement of nano-objects as well as agglomerates and aggregates is adressed in this document. This document does not include the characterization of particle sizes within the powder. Tribological methods are excluded where direct mechanical friction is applied to grind or abrade the material.

IEC TR 63258:2021 is a Technical Report focused on the practical protocol of ellipsometry to evaluate the thickness of nanoscale films. This document does not include any specification of the ellipsometers, but suggests how to minimize the data variation to improve data reproducibility.

This document specifies characteristics to be measured of individualized cellulose nanofibril (iCNF) samples in suspension and powder forms and their measurement methods. In addition, it provides sample preparation, measurement and data analysis procedures. This document does not apply to the characterization of iCNFs that have been modified after they are manufactured.

This document specifies the sequence of methods for characterizing the structural properties of graphene, bilayer graphene and graphene nanoplatelets from powders and liquid dispersions using a range of measurement techniques typically after the isolation of individual flakes on a substrate. The properties covered are the number of layers/thickness, the lateral flake size, the level of disorder, layer alignment and the specific surface area. Suggested measurement protocols, sample preparation routines and data analysis for the characterization of graphene from powders and dispersions are given.

This document specifies how to capture, measure and analyse transmission electron microscopy images to obtain particle size and shape distributions in the nanoscale. This document broadly is applicable to nano-objects as well as to particles with sizes larger than 100 nm. The exact working range of the method depends on the required uncertainty and on the performance of the transmission electron microscope. These elements can be evaluated according to the requirements described in this document.

This document gives guidelines for the characterization of carbon nanotube (CNT)-containing samples by thermogravimetric analysis (TGA), performed in either an inert or oxidizing environment. Guidance is provided on the purity assessment of the CNT samples through a quantitative measure of the types of carbon species present as well as the non-carbon impurities (e.g. metal catalyst particles) within the material. In addition, this technique provides a qualitative assessment of the thermal stability and homogeneity of the CNT-containing sample. Additional characterization techniques are required to confirm the presence of specific types of CNT and to verify the composition of the metallic impurities present.

This document gives guidelines for the characterization of single-wall carbon nanotubes (SWCNTs) using near infrared (NIR) photoluminescence (PL) spectroscopy. It provides a measurement method for the determination of the chiral indices of the semi-conducting SWCNTs in a sample and their relative integrated PL intensities. The method can be expanded to estimate the relative mass concentrations of semi-conducting SWCNTs in a sample from their measured integrated PL intensities and knowledge of their PL cross-sections.

This document specifies a method for the characterization of evolved gas components in single-wall carbon nanotube (SWCNT) samples using evolved gas analysis/gas chromatograph mass spectrometry (EGA/GCMS). NOTE Some difference could appear between qualitative and quantitative results of emitted gas and gas content in the sample due to the heating and the possible presence of catalysts.

This document provides guidelines to quantify and identify air concentration (number of particles/cm3) of particles of carbon black and/or amorphous silica by size in air samples collected in a mixed dust industrial manufacturing environment. The method is defined for air samples collected with an electrical low pressure cascade impactor (ELPCI). on a 25 mm polycarbonate substrate. The method is suitable for sampling in manufacturing environments where there are a variety of particle types contributing to the overall atmosphere. This method is applicable only to environments with chemically and physically distinct particles contributing to aerosols or when confounders can be controlled (e.g. diesel sources). Other sampling methods can also be suitable, though this document is limited to describing methods associated with the electrical low pressure cascade impactor. Samples collected with the electrical low pressure cascade impactor are analyzed via TEM and EDS to for particle morphology and elemental composition, respectively, to permit identification of particles by type. This information is then used, in conjunction with particle concentration by size range, as determined by the electrical low pressure cascade impactor, to determine concentration of the materials of interest by size.

This document specifies development of representative test materials consisting of nano-objects in dry powder form, to enable test method development and improve comparability of data for nanotechnology applications. It includes the physico-chemical properties (specifically, size and shape, specific surface area, crystal structure, and bulk chemical composition) that are required to be measured and reported with the representative test material.

This document identifies parameters and conditions, as part of an integrated measurement system, necessary to develop and validate methods for the application of asymmetrical-flow and centrifugal field-flow fractionation to the analysis of nano-objects and their aggregates and agglomerates dispersed in aqueous media. In addition to constituent fractionation, analysis can include size, size distribution, concentration and material identification using one or more suitable detectors. General guidelines and procedures are provided for application, and minimal reporting requirements necessary to reproduce a method and to convey critical aspects are specified.

ISO/TS 11888:2017 describes methods for the characterization of mesoscopic shape factors of multiwall carbon nanotubes (MWCNTs). Techniques employed include scanning electron microscopy (SEM), transmission electron microscopy (TEM), viscometry, and light scattering analysis. ISO/TS 11888:2017 also includes additional terms needed to define the characterization of static bending persistence length (SBPL). Measurement methods are given for the evaluation of SBPL, which generally varies from several tens of nanometres to several hundred micrometres. Well-established concepts and mathematical expressions, analogous to polymer physics, are utilized for the definition of mesoscopic shape factors of MWCNTs.

ISO/TS 10868:2017 provides guidelines for the characterization of compounds containing single-wall carbon nanotubes (SWCNTs) by using optical absorption spectroscopy. The aim of this document is to describe a measurement method to characterize the diameter, the purity, and the ratio of metallic SWCNTs to the total SWCNT content in the sample. The analysis of the nanotube diameter is applicable for the diameter range from 1 nm to 2 nm.

IEC/TS 62622:2012(E), which is a technical specification, specifies the generic terminology for the global and local quality parameters of artificial gratings, interpreted in terms of deviations from nominal positions of grating features, and provides guidance on the categorization of measurement and evaluation methods for their determination. This specification is intended to facilitate communication among manufacturers, users and calibration laboratories dealing with the characterization of the dimensional quality parameters of artificial gratings used in nanotechnology. This specification supports quality assurance in the production and use of artificial gratings in different areas of application in nanotechnology. Whilst the definitions and described methods are universal to a large variety of different gratings, the focus is on one-dimensional (1D) and two-dimensional (2D) gratings.

ISO/TS 10797:2012 establishes methods for characterizing the morphology of single-wall carbon nanotubes (SWCNTs) and identifying the elemental composition of other materials in SWCNT samples, using transmission electron microscopy and chemical analysis by energy dispersive X-ray spectrometry.

ISO/TR 10929:2012 identifies the basic properties of multiwall carbon nanotubes (MWCNTs) and the content of impurities, which characterize bulk samples of MWCNTs, and highlights the major measurement methods available to industry for the determination of these parameters. ISO/TR 10929:2012 provides a sound basis for the research, development and commercialization of these materials.

ISO/TS 10798:2011 establishes methods to characterize the morphology, and to identify the elemental composition of catalysts and other inorganic impurities in raw and purified single-wall carbon nanotube (SWCNT) powders and films, using scanning electron microscopy and energy dispersive X-ray spectrometry analysis. The methods described in ISO/TS 10798:2011 for SWCNTs can also be applied to the analysis of multiwall carbon nanotubes (MWCNTs).

This document provides an overview of the methods used to determine the nanoparticle number concentration in liquid dispersions and aerosols. The methods described are the ensemble measurement techniques of differential centrifugal sedimentation (DCS), multi-angle dynamic light scattering (MDLS), small-angle X-ray scattering (SAXS) and ultraviolet-visible spectroscopy (UV-vis) and the particle counting methods of particle tracking analysis (PTA), resistive pulse sensing (RPS), single particle inductively coupled plasma mass spectrometry (spICP-MS), condensation particle counter (CPC), and differential mobility analysing system (DMAS). This document provides information on the use of each technique, along with considerations on sample preparation, advantages and limitations.

ISO/TS 12025:2012 provides methodology for the quantification of nano-object release from powders as a result of treatment, ranging from handling to high energy dispersion, by measuring aerosols liberated after a defined aerosolization procedure. In addition to information in terms of mass, the aerosol is characterized for particle concentrations and size distributions. ISO/TS 12025:2012 provides information on factors to be considered when selecting from the available methods for powder sampling and treatment procedures and specifies minimum requirements for test sample preparation, test protocol development, measuring particle release and reporting data. In order to characterize the full size range of particles generated, the measurement of nano-objects as well as agglomerates and aggregates is recommended in ISO/TS 12025:2012.

ISO/TS 11888:2011 describes methods for the characterization of mesoscopic shape factors of multiwall carbon nanotubes (MWCNTs). Techniques employed include scanning electron microscopy, transmission electron microscopy, viscometry, and light scattering analysis. ISO/TS 11888:2011 also includes additional terms needed to define the characterization of scattered bending persistence length (SBPL). Two approximation methods are given for the evaluation of SBPL. Well-established concepts and mathematical expressions, analogous to polymer physics, are utilized for the definition of mesoscopic shape factors of MWCNTs.

ISO/TS 11308:2011 provides guidelines for the characterization of SWCNT-containing samples by the use of TGA, performed in an air environment. Guidance is provided on purity assessment of SWCNT samples through a quantitative measure of the non-carbon impurity (i.e. metal catalyst) level within the material.

ISO/TS 10868:2011 provides guidelines for the characterization of compounds containing single-wall carbon nanotubes (SWCNTs), using optical absorption spectroscopy. The purpose of ISO/TS 10868:2011 is to describe a measurement method for establishing the diameter, purity, and ratio of metallic SWCNTs to the total SWCNT content in the sample. The analysis of the diameter is applicable to a diameter range of 1 nm to 2 nm.

ISO/TS 11251:2010 specifies a method for the characterization of volatile components in single-wall carbon nanotubes (SWCNTs) samples using evolved gas analysis/gas chromatograph mass spectrometry (EGA/GCMS).

ISO/TS 10867:2010 provides guidelines for the characterization of single-wall carbon nanotubes (SWCNTs) using near infrared (NIR) photoluminescence (PL) spectroscopy. ISO/TS 10867:2010 provides a measurement method for the determination of the chiral indices of the semi-conducting SWCNT in a sample and their relative integrated PL intensities. The method can be expanded to estimate relative mass concentrations of semi-conducting SWCNTs in a sample from measured integrated PL intensities and knowledge of their PL cross-sections.