IEC TS 62607-6-35:2025

IEC TS 62607-6-35 ®
Edition 1.0 2025-08
TECHNICAL
SPECIFICATION
Nanomanufacturing - Key control characteristics -
Part 6-35: Graphene-related products - Density: free-pouring, tapping and
compressing method
ICS 07.120  ISBN 978-2-8327-0655-8

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or
by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either
IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC copyright
or have an enquiry about obtaining additional rights to this publication, please contact the address below or your local
IEC member National Committee for further information.

IEC Secretariat Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - IEC Products & Services Portal - products.iec.ch
webstore.iec.ch/advsearchform Discover our powerful search engine and read freely all the
The advanced search enables to find IEC publications by a
publications previews, graphical symbols and the glossary.
variety of criteria (reference number, text, technical With a subscription you will always have access to up to date
committee, …). It also gives information on projects, content tailored to your needs.
replaced and withdrawn publications.

Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published containing more than 22 500 terminological entries in English
details all new publications released. Available online and and French, with equivalent terms in 25 additional languages.
once a month by email. Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or
need further assistance, please contact the Customer
Service Centre: sales@iec.ch.
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
3.1 General terms . 6
3.2 Terms related to general material description . 7
3.3 Terms related to measurements . 8
4 Apparatus . 9
5 Measurement . 10
5.1 Sampling . 10
5.2 Apparent density . 10
5.3 Tap density . 11
5.4 Compressed density . 11
5.4.1 Positioning of cylinder holder . 11
5.4.2 Compressing . 12
5.5 Calculation . 12
5.5.1 Calculation of apparent density . 12
5.5.2 Calculation of tap density . 12
5.5.3 Calculation of compressed density . 13
5.5.4 Calculation of compressibility . 13
6 Test report . 13
Annex A (informative) Format of the test report. 14
Annex B (informative) Case study . 16
B.1 rGO sample 1 with high fluffiness and relatively low apparent density . 16
B.2 rGO sample 2 with high fluffiness and relatively low apparent density . 18
B.3 Exfoliated graphene (sample 3) with relatively high apparent density . 21
B.4 Exfoliated graphene (sample 4) with relatively high apparent density . 24
B.5 Sample comparison plots. 26
Bibliography . 28

Figure 1 – Example of measuring cylinder . 10
Figure 2 – Apparatus for apparent density measurement . 11
Figure 3 – Apparatus for compressed density measurement. 12
Figure B.1 – rGO sample 1 and correlation plot of compressed pressure (p) as a
function of compressibility (β) . 18
Figure B.2 – Correlation plot of compressed density (d ) as a function of pressure (p) . 18
c
Figure B.3 – rGO sample 2 and correlation plot of compressed pressure (p) as a
function of compressibility (β) . 20
Figure B.4 – Correlation plot of compressed density (d ) as a function of pressure (p)
c
for rGO sample 2 . 21
Figure B.5 – Exfoliated graphene sample 3 and correlation plot of compressed
pressure (p) as a function of compressibility (β) . 23
Figure B.6 – Correlation plot of compressed density (d ) as a function of pressure (p)
c
for exfoliated graphene sample 3 . 24
Figure B.7 – Exfoliated graphene sample 4 and correlation plot of compressed
pressure (p) as a function of compressibility (β) . 26
Figure B.8 – Correlation plot of compressed density (d ) as a function of pressure (p)
c
for exfoliated graphene sample 4 . 26
Figure B.9 – Comparison plot of compressed pressure (p) as a function of

compressibility (β) of four graphene samples . 27
Figure B.10 – Comparison plot of compressed density (d ) as a function of pressure (p)
c
of four graphene samples . 27

Table A.1 – Product identification (in accordance with the relevant blank detail
specification) . 14
Table A.2 – General material description (in accordance with the relevant blank detail
specification) . 14
Table A.3 – Information related to density measurement . 14
Table A.4 – Information related to compressed density . 15
Table A.5 – Information related to compressed pressure . 15
Table B.1 – Specification of rGO sample 1 . 16
Table B.2 – Information related to density measurement of rGO sample 1 . 16
Table B.3 – Information related to compressed density of rGO sample 1 . 17
Table B.4 – Information related to compressed pressure of rGO sample 1 . 17
Table B.5 – Specification of rGO sample 2 . 19
Table B.6 – Information related to density measurement of rGO sample 2 . 19
Table B.7 – Information related to compressed density of rGO sample 2 . 19
Table B.8 – Information related to compressed pressure of rGO sample 2 . 20
Table B.9 – Specification of exfoliated graphene sample 3 . 21
Table B.10 – Information related to density measurement of exfoliated graphene
sample 3 . 22
Table B.11 – Information related to compressed density of exfoliated graphene
sample 3 . 22
Table B.12 – Information related to compressed pressure of exfoliated graphene
sample 3 . 23
Table B.13 – Specification of exfoliated graphene sample 4 . 24
Table B.14 – Information related to density measurement of exfoliated graphene
sample 4 . 25
Table B.15 – Information related with compressed density of exfoliated graphene
sample 4 . 25
Table B.16 – Information related to compressed pressure of exfoliated graphene

sample 4 . 25

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Nanomanufacturing - Key control characteristics -
Part 6-35: Graphene-related products –
Density: free-pouring, tapping and compressing method

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC TS 62607-6-35 has been prepared by IEC technical committee 113: Nanotechnology for
electrotechnical products and systems. It is a Technical Specification.
The text of this Technical Specification is based on the following documents:
Draft Report on voting
113/900/DTS 113/910/RVDTS
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this Technical Specification is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts of the IEC TS 62607 series, published under the general title
Nanomanufacturing – Key control characteristics, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
– reconfirmed,
– withdrawn, or
– revised.
INTRODUCTION
Graphene materials in powder form such as reduced graphene oxide and exfoliated graphite
have high expectations for industrial applications including energy storage, composites,
conductive ink, filtration membranes, etc. Graphenes available from commercial sources have
a variety of shapes with various volumes per unit mass. The density of graphene materials
affects both the surface area and the dispersion properties within a solvent matrix to fabricate
their composites. Therefore, it is important that graphene manufacturers identify and provide
information on the density of graphene materials to enable users to select a material suitable
for their application.
Powder-type graphene sample has a very low density. Given its low mass per unit volume and
its high fluffiness, it is difficult to directly apply the existing standard methods for evaluating the
density of graphene samples, which have been used for the determination of powders
containing heavy elements such as metals or ceramics. Therefore, it is essential to develop a
new measurement method to evaluate the density of graphenes.
On the other hand, graphene has a very large volume per unit mass because of its low density,
making its storage and distribution less efficient compared to other powder materials. This issue
can be overcome by compressing graphene powder within a range that preserves its physical
properties.
This document provides the method for evaluating the bulk densities of graphene, such as
apparent density and tap density, and the compressed density of a sample compressed to a
specific volume by applying a pressure. Furthermore, the evaluation method for the pressure
required to reduce to a specific volume will be included. By measuring compressed density, it
is possible to determine the pressure required to compress the graphene to a reducing volume
for easy distribution and storage.

1 Scope
This part of IEC TS 62607 establishes standardized methods to determine the structural key
control characteristics
– apparent density (d ),
a
– tap density (d ), and
t
– compressed density (d )
c
for graphene in powder form by
– free-pouring, tapping and compressing method.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
3.1 General terms
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology 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
3.1.1
nanomanufacturing
intentional synthesis, generation or control of nanomaterials, or fabrication steps in the
nanoscale, for commercial purposes
[SOURCE: ISO/TS 80004-1:2015, 2.11]
3.1.2
blank detail specification
BDS
structured generic specification providing a comprehensive set of key control characteristics
which are needed to describe a specific product without assigning specific values or attributes
Note 1 to entry: Examples of nano-enabled products are: nanocomposites and nano-subassemblies.
Note 2 to entry: Blank detail specifications are intended to be used by industrial users to prepare their detail
specifications used in bilateral procurement contracts. A blank detail specification facilitates the comparison and
benchmarking of different materials. Furthermore, a standardized format makes procurement more efficient and more
error robust.
[SOURCE: IEC TS 62565-1:2023, 3.2]
3.1.3
sectional blank detail specification
SBDS
specification based on a blank detail specification adapted for a subgroup of the nano-enabled
product
Note 1 to entry: In general, the sectional blank detail specification contains a subset of those key control
characteristics listed in the blank detail specification. In addition, sectional specific key control characteristics may
be added if they are not listed in the blank detail specification.
Note 2 to entry: The templates defined in the sectional blank detail specification may contain key control
characteristics with and without assigned values and attributes.
Note 3 to entry: The section can be defined by application, manufacturing method or general material properties.
3.1.4
detail specification
DS
specification based on a blank detail specification with assigned values and attributes
Note 1 to entry: The characteristics listed in the detail specification are usually a subset of the key control
characteristics listed in the relevant blank detail specification. The industrial partners define only those
characteristics which are required for the intended application.
Note 2 to entry: Detail specifications are defined by the industrial partners. Standards development organizations
will be involved only if there is a general need for a detail specification in an industrial sector.
Note 3 to entry: The industrial partners may define additional key control characteristics if they are not listed in the
blank detail specification.
[SOURCE: IEC TS 62565-1:2023, 3.3]
3.1.5
key control characteristic
KCC
key performance indicator
material property or intermediate product characteristic which can affect safety or compliance
with regulations, fit, function, performance, quality, reliability or subsequent processing of the
final product
Note 1 to entry: The measurement of a key control characteristic is described in a standardized measurement
procedure with known accuracy and precision.
Note 2 to entry: It is possible to define more than one measurement method for a key control characteristic if the
correlation of the results is well-defined and known.
[SOURCE: IEC TS 62565-1:2023, 3.1, modified – "material property or intermediate" has been
added at the start of the definition.]
3.2 Terms related to general material description
3.2.1
graphene
graphene layer
single-layer graphene
monolayer graphene
single layer of carbon atoms with each atom bound to three neighbours in a honeycomb
structure
Note 1 to entry: It is an important building block of many carbon nano-objects.
Note 2 to entry: As graphene is a single layer, it is also sometimes called monolayer graphene or single-layer
graphene and abbreviated as 1LG to distinguish it from bilayer graphene (2LG) and few-layer graphene (FLG).
Note 3 to entry: Graphene has edges and can have defects and grain boundaries where the bonding is disrupted.
[SOURCE: ISO/TS 80004-13:2024, 3.1.2.1, modified – Note 4 to entry has been deleted.]
3.2.2
graphene powder
powder
dry form of graphene, bi-layer graphene, few-layer graphene, graphene oxide, or
reduced graphene oxide in the form of individual flakes that are not supported on a substrate
or suspended in a dispersion medium
EXAMPLE Result of spray-drying a graphene oxide dispersion retrieved from the cyclone of the spray-dryer.
Note 1 to entry: Powders may be mechanically compressed to increase their effective density and facilitate
transport.
Note 2 to entry: Powders may be functionalized or chemically modified in other ways.
Note 3 to entry: For a general definition of the term, see also ISO 15901-1:2016, 3.4.
3.2.3
graphene flake
flake
<2D material> nanoplate of graphene, graphene oxide (GO), reduced graphene
oxide (rGO) or any other 2D material, which may have multiple domain and multiple number of
layers
3.2.4
graphene oxide
chemically modified graphene prepared by oxidation and exfoliation of graphite, causing
extensive oxidative modification of the basal plane
Note 1 to entry: Graphene oxide is a single-layer material with a high oxygen content, typically characterized by
C/O atomic ratios of approximately 2,0 depending on the method of synthesis.
3.2.5
reduced graphene oxide
rGO
reduced oxygen content form of graphene oxide
Note 1 to entry This can be produced by chemical, thermal, microwave, photo-chemical, photo-thermal or microbial
or bacterial methods, or by exfoliating reduced graphite oxide.
Note 2 to entry: If graphene oxide was fully reduced then graphene would be the product. However, in practice,
3 2
some oxygen containing functional groups will remain and not all sp bonds will return back to sp configuration.
Different reducing agents will lead to different carbon to oxygen ratios and different chemical compositions in reduced
graphene oxide.
Note 3 to entry: It can take the form of several morphological variations such as platelets and worm-like structures.
Note 4 to entry: The O/C atomic ratio is approximately 0,1 to 0,5 (C/O ratio 2 to 10).
[SOURCE: ISO/TS 80004-13:2024, 3.1.2.16]
3.3 Terms related to measurements
3.3.1
bulk density
mass of a quantity of a bulk solid divided by its total volume
[ISO 12749-3:2015, 3.4.3]
IEC
...