Overview
ISO/TS 19808:2020 - Nanotechnologies: Carbon nanotube suspensions specifies which characteristics of suspensions containing multi-walled carbon nanotubes (MWCNTs/CNT suspensions) should be measured and how to measure them. The technical specification defines essential and additional characteristics, sampling principles and basic measurement approaches for quality reporting between suppliers and buyers. It excludes characteristics specific to health, environmental and safety issues and includes a warning that work may involve hazardous materials and should be performed by qualified personnel.
Key topics and requirements
- Scope and purpose
- Standardizes characterization of CNT suspensions to improve communication, reproducibility and commercialization.
- Focuses on suspension characteristics and corresponding measurement methods (not safety limits).
- Essential characteristics (shall be measured)
- Outer diameter (measured by TEM or SEM)
- Specific surface area
- Homogeneity
- Morphology
- Dry solid content
- CNT content
- Viscosity
- Additional characteristics (application-dependent)
- Fineness
- Elemental impurity content (e.g., ICP-AES/OES/MS methods referenced)
- pH value
- Water content
- Thermal conductivity
- Volume resistivity
- Shelf life
- Notes identify which are relevant for Li‑ion batteries, composites or adhesives
- Sampling and specimen preparation
- Representative sampling in line with ISO 15528; devices should access top/middle/bottom (disposable pipettes recommended).
- CNT retrieving: evaporate/remove liquid to obtain powder specimen, or use original powder if necessary.
- Measurement guidance
- Descriptions of measurement principles (e.g., diameter histograms, microscopy) and reporting expectations are provided.
- Annexes include a characteristics overview and a dispersion case study.
Applications and intended users
ISO/TS 19808:2020 is practical for:
- CNT suspension manufacturers and suppliers for product specification and QC
- Quality control laboratories and analytical service providers
- R&D teams in composites, batteries, adhesives, coatings and nanomaterials processing
- Downstream users specifying CNT suspension acceptance criteria
Benefits include consistent product descriptions, clearer buyer‑seller communication, and better predictability of performance in composite reinforcement, conductive inks, thermal interface materials and energy-storage formulations.
Related standards
- ISO/TR 10929 - characterization of bulk MWCNT samples
- ISO/TR 13097 - guidelines on suspension stability and specification
- ISO 15528 - sampling principles (referenced for sampling methodology)
Keywords: ISO/TS 19808:2020, carbon nanotube suspensions, CNT suspensions, multi‑walled carbon nanotubes, measurement methods, outer diameter, viscosity, specific surface area, sampling, characterization.