ISO/TS 23302:2021

TECHNICAL ISO/TS
SPECIFICATION 23302
First edition
2021-11
Nanotechnologies — Requirements
and recommendations for the
identification of measurands that
characterise nano-objects and
materials that contain them
Nanotechnologies – Exigences et recommandations pour
l’identification des mesurandes qui caractérisent les nano-objets et les
matériaux les contenant
Reference number
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .vii
Introduction .viii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 General core terms . 1
3.2 Measurand related terms. 3
4 Abbreviated terms . 6
5 Approaches to identify measurands to characterize nano-objects and their
agglomerates and aggregates, and materials containing nano-objects .9
5.1 Procedure . 9
5.2 Types of measurands . 10
5.3 State of nano-objects . 10
6 Measurands related to size and shape measurement of nano-objects and their
agglomerates and aggregates .11
6.1 General . 11
6.2 Measurands related to size and shape measurement. 11
6.2.1 Overview . 11
6.2.2 General relevant standards .12
6.3 Measurands related to size and shape measurement in aerosols .12
6.3.1 Overview . 12
6.3.2 General relevant standards . 13
6.3.3 Electrical low-pressure impaction . 13
6.3.4 Cascade impactors . 14
6.3.5 Differential mobility analysing system . 14
6.3.6 Relevant standards . 15
6.3.7 Optical particle counter .15
6.3.8 Relevant standards .15
6.3.9 Aerodynamic particle sizing . 15
6.3.10 TEM combined with TEM grid samplers . 15
6.3.11 Relevant standards . 16
6.3.12 Scanning electron microscopy . 16
6.3.13 Relevant standards . 17
6.4 Measurands related to size and shape measurement in powders . 17
6.4.1 Overview . 17
6.4.2 Relevant standards . 17
6.4.3 Scanning electron microscopy . 18
6.4.4 Relevant standards . 18
6.4.5 Gas adsorption, the BET method. 18
6.4.6 Relevant standard . 18
6.4.7 Laser diffraction . 18
6.4.8 Relevant standard . 19
6.4.9 X-ray diffraction . 19
6.4.10 Relevant standards . 19
6.4.11 Raman spectroscopy . 19
6.5 Measurands related to size and shape measurements of nano-objects in liquid
dispersions . 20
6.5.1 Overview . 20
6.5.2 Centrifugal liquid sedimentation . 21
6.5.3 Relevant standards . 21
6.5.4 Dynamic light scattering . 21
6.5.5 Relevant standards . 22
iii
6.5.6 Laser diffraction . 22
6.5.7 Relevant standard . 22
6.5.8 Small angle X-ray scattering . 22
6.5.9 Relevant standard .22
6.5.10 Particle tracking analysis . 22
6.5.11 Relevant standards .23
6.5.12 Electron microscopy .23
6.5.13 Field flow fractionation .23
6.5.14 Relevant standard . 24
6.5.15 Single particle ICP-MS . 24
6.5.16 Relevant standard .25
6.6 Measurands related to size and shape measurement on surfaces (microscopy
techniques) . 25
6.6.1 Overview . 25
6.6.2 Scanning electron microscopy . 25
6.6.3 Atomic force microscopy . 25
6.6.4 Relevant standards . 26
7 Measurands related to chemical analysis of nano-objects and their agglomerates
and aggregates .26
7.1 General . 26
7.2 Measurands related to surface chemical analysis of nano-objects and their
agglomerates and aggregates. 27
7.2.1 Measurands . 27
7.2.2 Auger electron spectroscopy .28
7.2.3 Relevant standards .28
7.2.4 Electron energy loss spectroscopy .28
7.2.5 Relevant standard .28
7.2.6 Secondary ion mass spectroscopy .28
7.2.7 Relevant standards .29
7.2.8 X-ray fluorescence spectroscopy .29
7.2.9 Relevant standards .30
7.2.10 X-ray diffraction . 30
7.2.11 Relevant standard .30
7.2.12 X-ray photoelectron spectroscopy .30
7.2.13 Relevant standards . 31
7.2.14 Energy dispersive X-ray spectroscopy . 31
7.2.15 Low energy ion scattering . 31
7.3 Measurands related to the chemical analysis of nano-objects as bulk samples . 31
7.3.1 Measurands . 31
7.3.2 Fourier transform infrared spectroscopy . 32
7.3.3 Relevant standards . 33
7.3.4 Thermal analysis with evolved gas analyser plus FTIR or QMS .33
7.3.5 Relevant standards .34
7.3.6 Ultraviolet–visible spectroscopy .34
7.3.7 Relevant standards .34
7.3.8 Raman spectroscopy .34
7.3.9 Inductively coupled plasma techniques .34
7.3.10 Relevant standards .34
7.3.11 Contact angle . 35
8 Measurands related to mass and density .35
8.1 General . 35
8.2 Aerosols . 35
8.2.1 Measurands . 35
8.2.2 Relevant standards . 35
8.2.3 Aerosol particle mass analyser . 36
8.2.4 Time of flight mass spectrometry .36
8.3 Powders . 36
iv
8.3.1 Measurands .36
8.3.2 Pycnometry .36
8.3.3 Relevant standards .36
8.4 Liquid dispersions . 37
8.4.1 Measurands . 37
8.4.2 Relevant standards . 37
8.4.3 Centrifugal liquid sedimentation (isopycnic method). 37
8.4.4 Static light scattering . 37
8.4.5 Resonant mass measurement .38
9 Measurands related to charge — Liquid dispersions .38
9.1 Measurands .38
9.2 Relevant standards .38
9.3 Electrophoretic light scattering .38
9.4 Electroacoustic phenomena measurements . 39
10 Measurands related to crystallinity .39
10.1 Measurands . 39
10.2 Small-angle/wide-angle X-ray scattering .40
10.3 X-ray diffraction .40
10.4 High-resolution transmission electron microscopy . 41
10.5 Electron backscattered diffraction . 41
10.6 Neutron diffraction . 41
10.7 Reflection high-energy electron diffraction and low-energy electron diffraction . 41
10.8 Differential scanning calorimetry. 41
10.9 Relevant standards . 42
10.10 Solid state nuclear magnetic resonance crystallography . 42
10.11 Raman crystallography . 42
10.12 Relevant standards . 42
11 Optical properties measurands .42
11.1 General . 42
11.2 Measurands . 43
11.3 Spectroscopy techniques . 43
11.4 Relevant standards .44
12 Electrical and electronic measurands . 44
12.1 Measurands .44
12.2 Techniques . 45
12.2.1 2- or 4-point conductance measurements . 45
12.2.2 Angle-resolved ultraviolet photoemission spectroscopy . 45
12.2.3 Scanning tunnelling microscopy . 45
12.2.4 Conductive atomic force microscopy . 45
12.2.5 Piezoforce microscopy .46
13 Magnetic measurands .46
13.1 General .46
13.2 Measurands .46
13.3 Techniques . 47
13.3.1 Superconducting quantum interference device . 47
13.3.2 Vibrating sample magnetometer .48
13.3.3 Mössbauer spectroscopy .48
13.3.4 Electron paramagnetic resonance spectroscopy .48
13.3.5 Magneto-optical Kerr-effect .48
13.3.6 Magnetic force microscopy .48
13.3.7 Scanning Hall effect microscopy .48
13.3.8 Spin-polarized scanning tunnelling microscopy .49
13.3.9 Relevant standards .49
14 Thermal measurands .49
14.1 Measurands .49
v
14.2 Techniques .49
14.2.1 Measurement of specific heat capacity .49
14.2.2 Scanning thermal microscopy .49
14.3 Relevant standard .50
15 Other performance related measurands .50
15.1 General .50
15.2 Powders — Dustiness . 50
15.2.1 Measurands .50
15.2.2 Relevant standards .50
15.3 Liquid dispersions . 51
15.3.1 Measurands . 51
15.3.2 Viscosity . 51
15.3.3 Dispersibility . 53
15.3.4 Relevant standard .53
15.3.5 Solubility and rate of dissolution . 53
15.3.6 Relevant standards .54
15.4 Mechanical properties .54
15.4.1 General .54
15.4.2 Measurement of elastic constants by static methods . 55
15.4.3 Relevant standards .55
15.4.4 Measurement of elastic constants by dynamic methods . 55
15.4.5 Relevant standards .56
15.4.6 Measurement of elastic and plastic properties by instrumented indentation
methods .56
15.4.7 Relevant standards .56
15.4.8 Measurement of surface properties and wear .56
15.4.9 Relevant standard . 57
Bibliography .58
vi
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 229, Nanotechnologies, and IEC/TC 113,
Nanotechnology for electrotechnical products and systems.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
vii
Introduction
The term “nano-object” applies to materials having one, two or three external dimensions in the
nanoscale (therefore in the range of approximately 1 nm to 100 nm). Specific size dependent properties
are usually exhibited in this size range, even if they do not disappear abruptly beyond these limits.
Nano-objects, either natural or manufactured, can be found in the form of nanoplates (one dimension
in the nanoscale), nanofibres (two dimensions, or the diameter, in the nanoscale), and nanoparticles
(three dimensions in the nanoscale). Nano-objects exhibit higher specific surface areas than larger
objects. They are particularly prone to aggregation and agglomeration phenomena due to attractive
interactions during their life cycle.
There is increasing use of nano-objects in research and development, industry and commercial
applications. Characterization of nano-objects, and their agglomerates and aggregates (NOAAs) plays
an essential role in basic and applied research, through process and product quality control and
commercialization to health and environmental protection. Characterization of nano-objects is key to
determine their physical and chemical properties, performance and lifetime. The methods available for
characterization of larger scale materials are often difficult to apply to nano-objects, sometimes due
to restrictions of the test systems (e.g. low sensitivity, inadequate resolution of equipment). This has
resulted in the development of new techniques and adaptation of existing ones.
The method selection is often strongly influenced by its initial cost and availability, time and sample
compatibility. However, an aspect that is easily forgotten is whether the selected method truly targets
the physical or chemical material property that is intended to be measured (“the measurand”). This can
sound trivial, but in practice, insufficient knowledge or consideration about the actual measurement
principle and/or the property measured can impede a correct assessment of the measurement results.
Measurement techniques and methods are typically classified according to the material properties
they can measure. One definition of “measurand” used in many ISO standards is the “quantity intended
to be measured”. In nanotechnologies popular material properties often considered as this “intended
measurand” can be size, shape, chemical composition, surface charge. However, in reality, due to their
different underlying physical measurement principles, results obtained by different techniques, for a
common material property, can differ significantly. The logical reason for this is that these different
techniques measure not the intended measurand but different measurands, which are specific to the
technique but are closely related to the intended measurand.
For intended use in biological systems and therapeutic purposes, additional characterization beyond
those mentioned in the document may be required.
This document describes measurands used to characterize nano-objects, and their agglomerates and
aggregates. This document is split into 10 main clauses covering:
— Clause 6: size and shape measurands;
— Clause 7: chemical analysis measurands;
— Clause 8: mass and density;
— Clause 9: charge measurands;
— Clause 10: crystallinity measurands;
— Clause 11: optical properties measurands;
— Clause 12: electrical and electronic measurands;
— Clause 13: magnetic measurands;
— Clause 14: thermal measurands;
— Clause 15: other performance related measurands.
viii
TECHNICAL SPECIFICATION ISO/TS 23302:2021(E)
Nanotechnologies — Requirements and recommendations
for the identification of measurands that characterise
nano-objects and materials that contain them
1 Scope
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.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 20579-4, Surface chemical analysis — Guidelines to sample handling, preparation and mounting —
Part 4: Reporting information related to the history, preparation, handling and mounting of nano-objects
prior to surface analysis
ISO/TS 80004-1:2015, Nanotechnologies — Vocabulary — Part 1: Core terms
ISO/TS 80004-2:2015, Nanotechnologies — Vocabulary — Part 2: Nano-objects
ISO/TS 80004-6:2021, Nanotechnologies — Vocabulary — Part 6: Nano-object characterization
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/TS 80004-1:2015,
ISO/TS 80004-2:2015 and ISO/TS 80004-6:2021 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at https:// www .electropedia .org/
— ISO Online browsing platform: available at https:// www .iso .org/ obp
3.1 General core terms
3.1.1
nanoscale
length range approximately from 1 nm to 100 nm
Note 1 to entry: Properties that are not extrapolations from a larger size are predominately exhibited in this
length range.
[SOURCE: ISO/TS 80004-1:2015, 2.1]
3.1.2
nano-object
discrete piece of material with one, two or three external dimensions in the nanoscale (3.1.1)
Note 1 to entry: The second and third external dimensions are orthogonal to the first dimension and to each
other.
[SOURCE: ISO/TS 80004-1:2015, 2.5]
3.1.3
agglomerate
collection of weakly bound particles (3.1.5) or aggregates (3.1.4) or mixtures of the two where the
resulting external surface area is similar to the sum of the surface areas of the individual components
Note 1 to entry: The forces holding an agglomerate together are weak forces, for example van der Waals forces, or
simple physical entanglement.
Note 2 to entry: Agglomerates are also termed secondary particles and the original source particles are termed
primary particles (3.1.6).
[SOURCE: ISO/TS 80004-6:2021, 3.10]
3.1.4
aggregate
particle (3.1.5) comprising strongly bonded or fused particles where the resulting external surface area
may be significantly smaller than the sum of calculated surface areas of the individual components
Note 1 to entry: The forces holding an aggregate together are strong forces, for example covalent bonds, or those
resulting from sintering or complex physical entanglement.
Note 2 to entry: Aggregates are also termed secondary particles and the original source particles are termed
primary particles (3.1.6).
[SOURCE: ISO/TS 80004-6:2021, 3.11]
3.1.5
particle
minute piece of matter with defined physical boundaries
Note 1 to entry: A physical boundary can also be described
...