Overview
ISO/TS 23361:2024 - Nanotechnologies - Crystallinity of cellulose nanomaterials by powder X‑ray diffraction (Rietveld analysis) specifies a standardized procedure to determine the bulk crystallinity of cellulose nanomaterials (CNM) using powder X‑ray diffraction (PXRD) combined with Rietveld deconvolution. The Technical Specification applies to all types of nanocellulose (cellulose nanocrystals, cellulose nanofibrils, cellulose filaments) provided a representative, randomly oriented sample is used. The method reports the mass fraction of material composed of crystallites by separating crystalline scattering from amorphous/background contributions.
Key Topics
- Measurement principle: PXRD pattern deconvolution using the Rietveld least‑squares fitting method to model crystalline peaks and fit background (amorphous) scattering across the whole angular range.
- Scope and definitions: Terms and CNM classifications (CNC, CNF, iCNF) are aligned with existing ISO nanotechnology terminology.
- Sample preparation: Emphasis on representative sampling and ensuring random orientation to make diffraction patterns reflective of bulk crystallinity.
- Instrument and software requirements: Guidance on diffractometer setup, detector sensitivity and required crystallographic information files for Rietveld modelling.
- Data collection and processing: Parameters for PXRD acquisition and the Rietveld modelling workflow, including peak models, background fitting and deconvolution strategies.
- Uncertainty and reporting: Procedures to estimate measurement uncertainty and required contents of the test report.
- Validation: Includes results from interlaboratory comparisons (informative Annex A) to support reproducibility.
Applications
ISO/TS 23361:2024 is suitable for laboratories and organizations needing reproducible, quantitative crystallinity data for cellulose nanomaterials. Typical users and use cases include:
- Quality control and batch release for CNM producers - ensuring product consistency and grade differentiation.
- R&D and materials characterization in academia and industry studying structure–property relationships of nanocellulose and nanocomposites.
- Process optimization and degradation monitoring - tracking crystallinity changes during chemical or mechanical processing.
- Regulatory and standards testing where documented, comparable crystallinity metrics are required for specification or claims.
Keywords naturally aligned with this standard: ISO/TS 23361:2024, crystallinity measurement, cellulose nanomaterials, powder X‑ray diffraction, Rietveld analysis, nanocellulose, CNC, CNF, PXRD crystallinity.
Related Standards
These related documents provide terminology and background that complement the technical procedures in ISO/TS 23361:2024.