ISO 15901-1:2016

Overview

ISO 15901-1:2016, published by the International Organization for Standardization (ISO), specifies the methodology for evaluating pore size distribution and porosity in solid materials using mercury porosimetry. This standard is crucial for laboratories, research institutions, and industries that require reliable, comparative data on pore structure in powders, monoliths, extrudates, sheets, and similar solids.

Mercury porosimetry, based on the classic Ritter and Drake technique, measures the amount of mercury forced into a sample as pressure increases. The results offer detailed insights into pore diameters, specific surface area, and both interparticle and intraparticle porosity for non-wettable porous materials. Due to mercury contamination, this analysis is typically destructive.

Key Topics

• Pore Size Distribution Measurement: Mercury penetrates into pores under increasing hydrostatic pressure. The corresponding pressure at which mercury enters provides information about pore diameters ranging approximately from 4 nm to 400 µm.
• Porosity and Specific Surface Area: The technique enables quantification of both total pore volume and accessible surface area, essential for material characterization.
• Destructive Testing: Mercury porosimetry is usually destructive, given mercury's toxicity and tendency to contaminate the sample, making the method primarily comparative.
• Sample Suitability: The standard highlights suitability for most porous solids that do not amalgamate with mercury. However, some metals like gold, aluminum, copper, nickel, and silver may require passivation or alternate methods.
• Instrument Calibration and Validation: Detailed procedures for porosimeter calibration, including pressure and volume signal accuracy, ensure data reproducibility and reliability.
• Safety Practices: Given the hazard of mercury, ISO 15901-1 outlines strict safety and handling requirements for laboratory personnel.

Applications

ISO 15901-1:2016 is widely applied across multiple industries and research fields, including:

• Materials Science: Characterizing catalysts, ceramics, polymers, construction materials, and porous media to optimize mechanical strength and functional performance.
• Pharmaceuticals: Evaluating porosity in tablets for controlled drug release and dissolution rates.
• Environmental Science: Studying porous rocks and filtration media for water purification, pollution control, and reservoir analysis.
• Gas Separation and Catalysis: Assessing pore structures in membranes and catalyst supports for efficient separation and chemical processes.
• Quality Control: Vital in the quality assurance of powders, compacts, and other porous products where pore characteristics dictate end-use performance.

Related Standards

For comprehensive analysis of pore structures, practitioners often use ISO 15901-1 alongside related international standards:

• ISO 15901-2: Analysis of mesopores and macropores by gas adsorption, suitable for the 2 nm to 100 nm pore size range.
• ISO 15901-3: Analysis of micropores using gas adsorption (pore sizes between 0.4 nm and 2 nm).
• ISO 3165: Sampling of chemical products for industrial use.
• ISO 14488: Procedures for sampling and sample splitting of particulate materials.

Practical Value

ISO 15901-1:2016 offers a standardized, validated approach to pore size distribution and porosity testing via mercury porosimetry, promoting consistency across laboratories and industries. Accurate understanding of pore structure directly influences product development, process optimization, and material innovation. The standard's clear definitions, calibration guidelines, and safety recommendations help users achieve credible and reproducible results, which are essential for scientific research, industrial quality control, and regulatory compliance.

Keywords: ISO 15901-1:2016, mercury porosimetry, pore size distribution, porosity evaluation, porous materials, material characterization, interparticle porosity, specific surface area, ISO standards, laboratory testing, material science, quality control.