National foreword

This Published Document is the UK implementation of ISO/TS 23361:2024.

The UK participation in its preparation was entrusted to Technical Committee NTI/1, Nanotechnologies.

A list of organizations represented on this committee can be obtained on request to its committee manager.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

This publication is not to be regarded as a British Standard.

Compliance with a Published Document cannot confer immunity from legal obligations.

This Published Document was published under the authority of the Standards Policy and Strategy Committee on 31 October 2024.

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 document 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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This document was prepared by Technical Committee ISO/TC 229, Nanotechnologies.

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.

Introduction

Cellulose nanomaterials (CNM) are a family of emerging bioproducts with significant commercial impact. Their production from abundant cellulose sources such as wood pulps makes them a candidate for use as a potentially non-toxic, biodegradable and sustainable nanomaterial for a wide range of applications, including those that currently use petroleum-based components. Several types of CNM are currently produced in a number of countries on pilot, pre-commercial or commercial scales. Realizing the full potential of these materials requires standard methods for characterization of a range of material properties, including crystallinity. Crystallinity is an indication of material quality, success of processing, and degradation of the material during processing, which can affect performance for various applications, particularly for use in nanocomposites. Crystallinity is also important for distinguishing between CNC grades and products and ensuring batch control and repeatability, and can provide information on the cellulose source and production method.

Crystallinity of CNM is defined as the fraction of the material composed of crystallites. There are several approaches for measuring crystallinity of materials, including powder X-ray diffraction, differential scanning calorimetry and solid-state nuclear magnetic resonance. Each of these techniques obviously has its merits and limitations. Use of crystallinity for quality control purposes for CNM production and further processing requires a measurement method that can be quickly, routinely and reproducibly implemented and that is easily accessible and can be run in most laboratories with the same level of proficiency. Powder X-ray diffraction addresses these criteria. This technical specification describes the measurement of CNM crystallinity by powder X-ray diffraction using deconvolution of the diffraction pattern based on Rietveld analysis. The Rietveld method allows a diffraction profile to be modelled based on known diffraction peaks for a specific crystallographic structure by attempting to minimize the difference between the calculated and observed patterns by the least-squares method.

The Rietveld method requires that the powder diffraction pattern be representative of the sample, which requires careful sample preparation and assumes a randomly oriented sample. The instrument configuration and detector sensitivity are also important. This document provides guidance on both sample preparation and instrument configuration and operating parameters. The method is applicable to all types of CNM, including cellulose nanocrystals, cellulose nanofibrils and cellulose filaments.

1 Scope

This document specifies the determination of the bulk crystallinity (crystalline contribution relative to the total crystalline and amorphous contributions in the material) of cellulose nanomaterials using powder X-ray diffraction followed by deconvolution of the diffraction patterns based on Rietveld analysis. It is applicable to all types of cellulose nanomaterials, assuming a representative sample.

2 Normative references

3 Terms and definitions

3.1 Core nanotechnology terms related to cellulose nanomaterials

3.2 Non-nanotechnology terms related to cellulose nanomaterials

3.3 Terms specific to cellulose nanomaterials

4 Principle

5 Sample preparation

5.1 General considerations

5.2 Preparation of samples from powders

6 Instrument and software requirements

6.1 Diffractometer

6.2 Software

6.3 Crystallographic information files

7 Data collection

8 Data processing and analysis

8.1 General considerations

8.2 Modelling procedure

9 Uncertainty

10 Test report

Bibliography

PD ISO/TS 23361:2024

Nanotechnologies. Crystallinity of cellulose nanomaterials by powder X-ray diffraction (Rietveld analysis)

Current

Published:

31 Oct 2024