Nanotechnologies - Vocabulary - Part 6: Nano-object characterization
This document defines terms related to the characterization of nano-objects in the field of nanotechnologies.
It is intended to facilitate communication between organizations and individuals in research, industry and other interested parties and those who interact with them.
Nanotechnologies - Vocabulaire - Partie 6: Caractérisation des nano-objets
Le présent document définit les termes relatifs à la caractérisation des nano-objets dans le domaine des nanotechnologies.
Il est destiné à faciliter la communication entre les organismes, les chercheurs, les industriels, les autres parties intéressées et leurs interlocuteurs.
Standards Content (Sample)
Nanotechnologies — Vocabulary —
Nanotechnologies — Vocabulaire —
Partie 6: Caractérisation des nano-objets
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1 Scope . 1
2 Normative references . 1
3 Terms and definitions (General terms) . 1
4 Terms related to size and shape measurement . 3
4.1 Terms related to measurands for size and shape . 3
4.2 Terms related to scattering techniques . 4
4.3 Terms related to aerosol characterization . 6
4.4 Terms related to separation techniques . 7
4.5 Terms related to microscopy . 9
4.6 Terms related to surface area measurement .12
5 Terms related to chemical analysis .13
6 Terms related to measurement of other properties .18
6.1 Terms related to mass measurement .18
6.2 Terms related to thermal measurement .18
6.3 Terms related to crystallinity measurement .19
6.4 Terms related to charge measurement in suspensions .19
© ISO 2021 – All rights reserved iii
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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
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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).
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iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 229, Nanotechnologies, in collaboration
with Technical Committee IEC/TC 113, Nanotechnology for electrotechnical products and systems
and with the European Committee for Standardization (CEN) Technical Committee CEN/TC 352,
Nanotechnologies, in accordance with the Agreement on technical cooperation between ISO and CEN
This second edition cancels and replaces the first edition (ISO/TS 80004-6:2013), which has been
technically revised throughout.
A list of all parts in the ISO/TS 80004 series can be found on the ISO website.
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.
iv © ISO 2021 – All rights reserved
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Measurement and instrumentation techniques have effectively opened the door to modern
nanotechnology. Characterization is key to understanding the properties and function of all nano-
Nano-object characterization involves interactions between people with different backgrounds
and from different fields. Those interested in nano-object characterization might, for example, be
materials scientists, biologists, chemists or physicists, and might have a background that is primarily
experimental or theoretical. Those making use of the data extend beyond this group to include
regulators and toxicologists. To avoid any misunderstandings, and to facilitate both comparability and
the reliable exchange of information, it is essential to clarify the concepts, to establish the terms for use
and to establish their definitions.
The terms are classified under the following broad headings:
— Clause 3: General terms;
— Clause 4: Terms related to size and shape measurement;
— Clause 5: Terms related to chemical analysis;
— Clause 6: Terms related to measurement of other properties.
These headings are intended as a guide only, as some techniques can determine more than one property.
Subclause 4.1 lists the overarching measurands that apply to the rest of Clause 4. Other measurands are
more technique-specific and are placed in the text adjacent to the technique.
It should be noted that most techniques require analysis in a non-native state and involve sample
preparation, e.g. placing the nano-objects on a surface or placing them in a specific fluid or vacuum.
This could change the nature of the nano-objects.
The order of the techniques in this document should not be taken to indicate a preference and the
techniques listed in this document are not intended to be exhaustive. Equally, some of the techniques
listed in this document are more popular than others in their usage in analysing certain properties of
nano-objects. Table 1 lists alphabetically the common techniques for nano-object characterization.
Subclause 4.5 provides definitions of microscopy methods and related terms. When abbreviated terms
are used, note that the final “M”, given as “microscopy”, can also mean “microscope” depending on the
context. For definitions relating to the microscope, the word “method” can be replaced by the word
“instrument” where that appears.
Clause 5 provides definitions of terms related to chemical analysis. For these abbreviated terms, note
that the final “S”, given as “spectroscopy”, can also mean “spectrometer” depending on the context. For
definitions relating to the spectrometer, the word “method” can be replaced by the word “instrument”
where that appears.
This document is intended to serve as a starting reference for the vocabulary that underpins
measurement and characterization efforts in the field of nanotechnologies.
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Table 1 — Alphabetical list of the common techniques for nano-object characterization
Property Common techniques
Size centrifugal liquid sedimentation (CLS)
atomic-force microscopy (AFM)
differential mobility analysing system (DMAS)
dynamic light scattering (DLS)
variants of inductively coupled plasma mass spectrometry (ICP-MS)
particle tracking analysis (PTA)
scanning electron microscopy (SEM)
small-angle X-ray scattering (SAXS)
transmission electron microscopy (TEM)
Shape atomic-force microscopy (AFM)
scanning electron microscopy (SEM)
transmission electron microscopy (TEM)
Surface area Brunauer–Emmett–Teller (BET) method
“Surface” chemistry Raman spectroscopy
secondary-ion mass spectrometry (SIMS)
X-ray photoelectron spectroscopy (XPS)
Chemistry of the energy-dispersive X-ray spectroscopy (EDX)
inductively coupled plasma mass spectrometry (ICP-MS)
nuclear magnetic resonance (NMR) spectroscopy
Crystallinity selected area electron diffraction (SAED)
X-ray diffraction (XRD)
Electrokinetic electrophoretic mobility
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TECHNICAL SPECIFICATION ISO/TS 80004-6:2021(E)
Nanotechnologies — Vocabulary —
This document defines terms related to the characterization of nano-objects in the field of
It is intended to facilitate communication between organizations and individuals in research, industry
and other interested parties and those who interact with them.
2 Normative references
There are no normative references in this document.
3 Terms and definitions (General terms)
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
length range approximately from 1 nm to 100 nm
Note 1 to entry: Properties that are not extrapolations from a larger size are predominantly exhibited in this
[SOURCE: ISO/TS 80004-1:2015, 2.1]
discrete piece of material with one, two or three external dimensions in the nanoscale (3.1)
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]
nano-object (3.2) with all external dimensions in the nanoscale (3.1) where the lengths of the longest
and the shortest axes of the nano-object do not differ significantly
Note 1 to entry: If the dimensions differ significantly (typically by more than three times), terms such as nanofibre
(3.6) or nanoplate (3.4) may be preferred to the term “nanoparticle”.
[SOURCE: ISO/TS 80004-2:2015, 4.4]
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nano-object (3.2) with one external dimension in the nanoscale (3.1) and the other two external
dimensions significantly larger
Note 1 to entry: The larger external dimensions are not necessarily in the nanoscale.
Note 2 to entry: See 3.3, Note 1 to entry.
[SOURCE: ISO/TS 80004-2:2015, 4.6]
solid nanofibre (3.6)
[SOURCE: ISO/TS 80004-2:2015, 4.7]
nano-object (3.2) with two external dimensions in the nanoscale (3.1) and the third dimension
Note 1 to entry: The largest external dimension is not necessarily in the nanoscale.
Note 2 to entry: The terms “nanofibril” and “nanofilament” can also be used.
Note 3 to entry: See 3.3, Note 1 to entry.
[SOURCE: ISO/TS 80004-2:2015, 4.5]
hollow nanofibre (3.6)
[SOURCE: ISO/TS 80004-2:2015, 4.8]
nanoparticle (3.3) or region which exhibits quantum confinement in all three spatial directions
[SOURCE: ISO/TS 80004-12:2016, 4.1, modified — Note 1 to entry has been deleted.]
minute piece of matter with defined physical boundaries
Note 1 to entry: A physical boundary can also be described as an interface.
Note 2 to entry: A particle can move as a unit.
Note 3 to entry: This general particle definition applies to nano-objects (3.2).
[SOURCE: ISO/TS 80004-2:2015, 3.1]
collection of weakly or medium strongly bound particles (3.9) 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
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[SOURCE: ISO/TS 80004-2:2015, 3.4]
particle (3.9) comprising strongly bonded or fused particles where the resulting external surface area
is significantly smaller than the sum of surface areas of the individual components
Note 1 to entry: The forces holding an aggregate together are strong forces, for example covalent or ionic bonds,
or those resulting from sintering or complex physical entanglement, or otherwise combined former primary
Note 2 to entry: Aggregates are also termed “secondary particles” and the original source particles are termed
[SOURCE: ISO/TS 80004-2:2015, 3.5]
system of solid and/or liquid particles (3.9) suspended in gas
[SOURCE: ISO 15900:2020, 3.1]
heterogeneous mixture of materials comprising a liquid and a finely dispersed solid material
[SOURCE: ISO 4618:2014, 2.246]
multi-phase system in which discontinuities of any state (solid, liquid or gas: discontinuous phase) are
distributed in a continuous phase of a different composition or state
Note 1 to entry: This term also refers to the act or process of producing a dispersion; in this context the term
“dispersion process” should be used.
Note 2 to entry: If solid particles (3.9) are distributed in a liquid, the dispersion is referred to as a suspension (3.13).
If the dispersion consists of two or more immiscible liquid phases, it is termed an “emulsion”. A suspoemulsion
consists of both solid and liquid phases distributed in a continuous liquid phase.
[SOURCE: ISO/TR 13097:2013, 2.5, modified — In the definition, “in general, microscopic” has been
deleted and “distributed” has replaced “dispersed”. Notes 1 and 2 to entry have replaced the original
Note 1 to entry.]
4 Terms related to size and shape measurement
4.1 Terms related to measurands for size and shape
linear dimension of a particle (3.9) determined by a specified measurement method and under specified
Note 1 to entry: Different methods of analysis are based on the measurement of different physical properties.
Independent of the particle property actually measured, the particle size can be reported as a linear dimension,
e.g. as the equivalent spherical diameter.
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particle size distribution
distribution of the quantity of particles (3.9) as a function of particle size (4.1.1)
Note 1 to entry: Particle size distribution may be expressed as cumulative distribution or a distribution density
(distribution of the fraction of material in a size class, divided by the width of that class).
Note 2 to entry: The quantity can be, for example, number, mass or volume based.
external geometric form of a particle (3.9)
[SOURCE: ISO 3252:2019, 3.1.59, modified — “powder” has been deleted before “particle”.]
ratio of length of a particle (3.9) to its width
[SOURCE: ISO 14966:2019, 3.7]
diameter of a sphere that produces a response by a given particle-size measurement method that is
equivalent to the response produced by the particle (3.9) being measured
Note 1 to entry: Physical properties are, for example, the same settling velocity or electrolyte solution displacing
volume or projection area under a microscope. The physical property to which the equivalent diameter refers
should be indicated using a suitable subscript (see ISO 9276-1:1998), e.g. subscript “V” for equivalent volume
diameter and subscript “S” for equivalent surface area diameter.
Note 2 to entry: For discrete-particle-counting, light-scattering instruments, an equivalent optical diameter is used.
Note 3 to entry: Other parameters, e.g. the effective density of the particle in a fluid, are used for the calculation
of the equivalent diameter such as Stokes diameter or sedimentation equivalent diameter. The parameters used
for the calculation should be reported additionally.
Note 4 to entry: For inertial instruments, the aerodynamic diameter is used. Aerodynamic diameter is the
diameter of a sphere of density 1 000 kg m that has the same settling velocity as the particle in question.
4.2 Terms related to scattering techniques
radius of gyration
measure of the distribution of mass about a chosen axis, given as the square root of the moment of
inertia about that axis divided by the mass
Note 1 to entry: For nano-object (3.2) characterization, physical methods that measure radius of gyration to
determine particle size (4.1.1) include static light scattering, small-angle neutron scattering (4.2.2) and small-angle
X-ray scattering (4.2.4).
[SOURCE: ISO 14695:2003, 3.4, modified — Note 1 to entry has been added.]
small-angle neutron scattering
method in which a beam of neutrons is scattered from a sample and the scattered neutron intensity is
measured for small angle deflection
Note 1 to entry: The scattering angle is usually between 0,5° and 10° in order to study the structure of a material
on the length scale of approximately 1 nm to 200 nm. The method provides information on the sizes of the
particles (3.9) and, to a limited extent, the shapes of the particles dispersed in a homogeneous medium.
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application of elastic neutron scattering for the determination of the atomic or magnetic structure
Note 1 to entry: The neutrons emerging from the experiment have approximately the same energy as the incident
neutrons. A diffraction pattern is formed that provides information on the structure of the material.
small-angle X-ray scattering
method in which the elastically scattered intensity of X-rays is measured for small-angle deflections
Note 1 to entry: The angular scattering is usually measured within the range 0,1° to 10°. This provides structural
information on macromolecules as well as periodicity on length scales typically larger than 5 nm and less than
200 nm for ordered or partially ordered systems.
[SOURCE: ISO 18115-1:2013, 3.18, modified — Notes 2 and 3 to entry have been deleted.]
change in propagation of light at the interface of two media having different optical properties
equivalent diameter (4.1.5) of a particle (3.9) in a liquid having the same diffusion coefficient as a
spherical particle with no boundary layer in that liquid
Note 1 to entry: In practice, nanoparticles (3.3) in solution can be non-spherical, dynamic and solvated.
Note 2 to entry: A particle in a liquid will have a boundary layer. This is a thin layer of fluid or adsorbates close
to the solid surface, within which shear stresses significantly influence the fluid velocity distribution. The fluid
velocity varies from zero at the solid surface to the velocity of free stream flow at a certain distance away from
the solid surface.
dynamic light scattering
photon correlation spectroscopy
DEPRECATED: quasi-elastic light scattering
method in which particles (3.9) in a liquid suspension (3.13) are illuminated by a laser and the time
dependant change in intensity of the scattered light due to Brownian motion is used to determine
particle size (4.1.1)
Note 1 to entry: Analysis of the time-dependent intensity of the scattered light can yield the translational
diffusion coefficient and hence the particle size as the hydrodynamic diameter (4.2.6) using the Stokes–Einstein
Note 2 to entry: The analysis is applicable to nanoparticles (3.3) as the size of particles detected is typically in the
range 1 nm to 6 000 nm. The upper limit is due to limited Brownian motion and sedimentation.
Note 3 to entry: DLS is typically used in dilute suspensions where the particles do not interact amongst
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nanoparticle tracking analysis
particle tracking analysis
method in which particles (3.9) undergoing Brownian and/or gravitational motion in a suspension (3.13)
are illuminated by a laser and the change in position of individual particles is used to determine particle
Note 1 to entry: Analysis of the time-dependent particle position yields the translational diffusion coefficient and
hence the particle size as the hydrodynamic diameter (4.2.6) using the Stokes-Einstein relationship.
Note 2 to entry: The analysis is applicable to nanoparticles (3.3) as the size of particles detected is typically in the
range 10 nm to 2 000 nm. The lower limit requires particles with high refractive index and the upper limit is due
to limited Brownian motion and sedimentation.
Note 3 to entry: NTA is often used to describe PTA. NTA is a subset of PTA since PTA covers larger range of
particle sizes than nanoscale (3.1).
static multiple light scattering
technique in which transmitted or backscattered light intensity is measured after multiple successive
scattering events of incident light in a random scattering medium
[SOURCE: ISO/TS 21357:— , 3.1]
4.3 Terms related to aerosol characterization
condensation particle counter
instrument that measures the particle (3.9) number concentration of an aerosol (3.12) using a
condensation effect to increase the size of the aerosolized particles
Note 1 to entry: The sizes of particles detected are usually smaller than several hundred nanometres and larger
than a few nanometres.
Note 2 to entry: A CPC is one possible detector suitable for use with a differential electrical mobility classifier
Note 3 to entry: In some cases, a condensation particle counter may be called a “condensation nucleus
[SOURCE: ISO/TS 12025:2012, 3.2.8, modified — Note 4 to entry has been deleted.]
differential electrical mobility classifier
classifier able to select aerosol (3.12) particles (3.9) according to their electrical mobility and pass them
to its exit
Note 1 to entry: A DEMC classifies aerosol particles by balancing the electrical force on each particle with its
aerodynamic drag force in an electrical field. Classified particles are in a narrow range of electrical mobility
determined by the operating conditions and physical dimensions of the DEMC, while they can have different sizes
due to difference in the number of charges that they have.
[SOURCE: ISO 15900:2020, 3.11]
1) Under preparation. Stage at the time of publication: ISO/DTS 21357:2020.
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differential mobility analysing system
system to measure the size distribution of submicrometre aerosol (3.12) particles (3.9) consisting of a
differential electrical mobility classifier (DEMC) (4.3.2), flow meters, a particle detector, interconnecting
plumbing, a computer and suitable software
[SOURCE: ISO 15900:2020, 3.12]
Faraday-cup aerosol electrometer
system designed for the measurement of electrical charges carried by aerosol (3.12) particles (3.9)
Note 1 to entry: A FCAE consists of an electrically conducting and electrically grounded cup as a guard to cover
the sensing element that includes aerosol filtering media to capture charged aerosol particles, an electrical
connection between the sensing element and an electrometer circuit, and a flow meter.
[SOURCE: ISO 15900:2020, 3.15, “system” has replaced “electrometer” and “aerosol particles” has
replaced “an aerosol” in the definition.]
4.4 Terms related to separation techniques
separation technique whereby a field is applied to a suspension (3.13) passing along a narrow channel
in order to cause separation of the particles (3.9) present in the liquid, dependent on their differing
mobility under the force exerted by the field
Note 1 to entry: The field can be, for example, gravitational, centrifugal, a liquid flow, electrical or magnetic.
Note 2 to entry: Using a suitable detector after or during separation allows determination of the size and size
distribution of nano-objects (3.2).
asymmetrical-flow field-flow fractionation
separation technique that uses a cross flow field applied perpendicular to the channel flow to achieve
separation based on analyte diffusion coefficient or size
Note 1 to entry: Cross flow occurs by means of a semipermeable (accumulation) wall in the channel, while cross
flow is zero at an opposing nonpermeable (depletion) wall.
Note 2 to entry: By comparison, in symmetrical flow, the cross flow enters through a permeable wall (frit) and
exits through an opposing semipermeable wall and is generated separately from the channel flow.
Note 3 to entry: Nano-objects (3.2) generally fractionate by the “normal” mode, where diffusion dominates and
the smallest species elute first. In the micrometre size range, the “steric-hyperlayer” mode of fractionation is
generally dominant, with the largest species eluting first. The transition from normal to steric-hyperlayer mode
can be affected by material properties or measurement parameters, and therefore is not definitively identified;
however, the transition can be defined explicitly for a given experimental set of conditions; typically, the
transition occurs over a particle size (4.1.1) range from about 0,5 µm to 2 µm.
Note 4 to entry: Including both normal and steric-hyperlayer modes, the technique has the capacity to separate
particles (3.9) ranging in size from approximately 1 nm to about 50 µm.
[SOURCE: ISO/TS 21362:2018, 3.4, modified — The abbreviated term “AF4” has been added.]
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centrifugal field-flow fractionation
separation technique that uses a centrifugal field applied perpendicular to a circular channel that spins
around its axis to achieve size separation of particles (3.9) from roughly 10 nm to roughly 50 µm
Note 1 to entry: Separation is governed by a combination of size and effective particle d