ISO 15901-2:2022 PDF

Overview - What ISO 15901-2:2022 covers

ISO 15901-2:2022 specifies a standardized method for evaluating porosity and pore size distribution of solid materials by physical adsorption (physisorption). The document focuses on the manometric (volumetric) gas adsorption technique to measure the quantity of gas adsorbed per unit mass as a function of pressure at controlled temperature. It is intended for characterization of nanopores (pore widths from about 0.4 nm up to ≈100 nm), covering micropores and mesopores, and complements mercury porosimetry (see ISO 15901‑1) for larger pores. Surface area determination is defined elsewhere (ISO 9277).

Key technical topics and requirements

• Measurement principle: Static manometric (volumetric) physisorption is recommended for nitrogen, argon and krypton at cryogenic temperatures (77 K and 87 K) and CO2 at ~273 K for ultramicropores.
• Pore size range: Focus on nanopore analysis from approximately 0.4 nm to 100 nm; micropore/mesopore/macropore classification follows IUPAC guidance.
• Gases and temperatures: Common adsorptives include N2 (77 K), Ar (87 K), Kr (77 K/87 K) and CO2 (273–293 K); krypton is highlighted for low-surface-area materials and thin films.
• Procedures covered: Sampling, sample pretreatment, measurement protocol, apparatus verification, calibration and reporting requirements.
• Analysis methods: Classical macroscopic thermodynamic approaches for micro/mesopore evaluation and advanced microscopic methods such as density functional theory (DFT) and molecular simulation (e.g., NLDFT kernels) for improved pore-size distributions.
• Scope limits: Closed (isolated) pores are not characterized by this method. This Part 2 focuses on the manometric approach and excludes gravimetric technique details.

Practical applications and users

ISO 15901-2 is directly applicable to laboratories and organizations that require robust nanopore characterization:

• Materials scientists and R&D groups developing adsorbents, catalysts, porous carbons, zeolites, membranes and battery electrodes.
• Pharmaceutical developers concerned with controlled drug release and porous carriers.
• Environmental and process engineers working on gas separation, filtration and pollution control.
• Quality control and metrology laboratories performing routine porosity and pore-size distribution testing.
• Instrument manufacturers and service providers validating or calibrating gas adsorption instrumentation.

Practical benefits include standardized, reproducible pore-size distributions, guidance on adsorptive selection (N2, Ar, Kr, CO2), and advanced analysis options (DFT/NLDFT) for more accurate nanopore characterization.

Related standards

• ISO 15901-1 - Mercury porosimetry (macropore analysis)
• ISO 9277 - Specific surface area by gas adsorption (BET method)
• ISO 3165, ISO 8213, ISO 14488 - Sampling and sample-handling guidance

Keywords: ISO 15901-2, pore size distribution, porosity, gas adsorption, physisorption, manometric method, nanopores, BET, DFT, NLDFT, nitrogen adsorption, argon adsorption, CO2 adsorption.