Porosimetry

At Micromeritics, we offer advanced instruments for porosimetry analysis, crucial for applications such as pharmaceuticals, energy storage, filtration, medical devices and material science. This page covers the fundamentals of porosimetry and how our instruments can enhance both R&D and Quality Control efforts.

What is Porosimetry?

Porosimetry is a scientific method used to measure and analyze the porous structure of materials. It involves studying various properties related to the pores within a material, such as pore size, volume, and connectivity. Porosimetry techniques include methods like mercury intrusion, capillary flow, and gas adsorption. The information gathered from these methods is valuable in understanding the physical characteristics and performance of materials.

Pore Types

Blind Pore

Open at one end but closed at the other, accessible from one external surface
Methods: Mercury intrusion and gas adsorption

Through Pore

Open at both ends, connecting two external surfaces and allowing fluid or gas to pass through from one side to the other
Methods: Mercury intrusion, capillary flow, and gas adsorption

Closed Pore

Completely isolated pore with no connection to the external surface
Methods: Not accessible by mercury intrusion, capillary flow, or gas adsorption

Mercury Intrusion

Mercury porosimetry analysis is based on the intrusion, and often subsequent extrusion, of mercury into a porous structure under stringently controlled pressures. Mercury is a non-wetting liquid to most materials and resists entering voids except when pressure is applied. This technique offers speed, accuracy, and a wide measurement range (typically 3 nm – 600 µm), allowing you to calculate numerous sample properties such as pore size distribution, total pore volume, total pore surface area, median pore diameter, and sample densities (bulk and skeletal).

Capillary Flow

Capillary Flow Porometry (CFP) – also known as Gas Liquid Porometry (GLP) – is a fast, reliable method to determine the size and relative abundance of through-pores in sheets and membranes. Pore sizes ranging from 0.015 to 500 micrometers in diameter can be measured. This technique calculates pore properties by analyzing fluid flow when gas displaces a wetting fluid impregnated within the sample’s porous network. As the pressure increases, it reaches a critical point where the first air bubble pushes through the sample, known as the bubble point. As the pressure continues to rise, air flows through progressively smaller pores until all the liquid in the pores is expelled by the high-pressure air.

Gas Adsorption

Gas adsorption refers to the process by which gas molecules adhere to the surface of a material. It enables the characterization of a material’s porosity, revealing insights into its structure and properties. As gas pressure increases, pores within the material begin to fill. This process starts with smaller pores and progresses to larger ones until all are saturated. Overall, this technique is applicable to pores ranging from ~0.35 nm to ~400 nm in diameter. Once details of the isotherm curve are accurately expressed as a series of pressure vs quantity adsorbed, a number of different methods (theories or models) can be applied to determine the pore size distribution.

Our Solutions

Instruments

AutoPore V

The AutoPore V Series Mercury Porosimeters can determine a broader pore size distribution more quickly and accurately than other methods. This instrument also features enhanced safety features and offers new data reduction and reporting choices that provide more information about pore geometry and the fluid transport characteristics of your material.

AccuPore

The Easiest, Most Accurate, Most Versatile Measurement Of Through-porosity

Services

We provide a comprehensive range of characterization services whether it is the analysis of a single sample, a complex method development or validation, new product assessments, or addressing large-scale manufacturing projects.

Available options

Mercury intrusion analysis (pore size range 360 to 0.003 μm)
Mercury Intrusion and extrusion analysis (pore size range 360 to 0.003 μm)
High-resolution macropore analysis (pore size range 900 to 4 μm)
High-resolution macropore plus a complete intrusion and extrusion analysis

Reverberi method for pore throat and pore cavity
High-resolution intrusion (pore size range 900 to 0.003 μm)
Advanced Hg calculations
Scanning porometry of pore sizes down to 30 nm using a POROLUXTM 100/l OONW; 500