Capillary Flow Porometry (Porometry)

Capillary Flow Porometry Main Image
Example Pore Size Distribution for two samples, ‘F1’ (red), and ‘F2’ (gray). The calculated cumulative number of pores per unit cm2 is plotted as a function of Pore Size in microns. Sample F1 shows a higher proportion of pores with size < 10 μm, and Sample F2 shows a broader distribution of pore sizes (from 10 to 55 μm) as well as a greater total porosity.

Capillary Flow Porometry (also called Porometry) is an optimal technique for characterizing through-pore size and size distribution in wettable materials, such as membranes, filtration media, ceramics, and papers.

Covalent’s Porometry services use a top-of-line porometer from Anton Paar for maximized flexibility, speed, and reproducibility.

See Also: Gas Adsorption Analysis for non-permeable solids

Strengths

  • Fast time-to-data: rapid pore for through-pores in membranes, filters, and other permeable materials
  • Highly reproducible, accurate pore size distribution

Limitations

  • Not optimized for nano-scale pore analysis
  • Analyzed pores must be open (have direct or indirect access to sample surface)

Learn More

Sample Requirements

Porometry Example Outputs

Example Pore Size Distribution for two samples, ‘F1’ (red), and ‘F2’ (gray). The calculated cumulative number of pores per unit cm2 is plotted as a function of Pore Size in microns. Sample F1 shows a higher proportion of pores with size < 10 μm, and Sample F2 shows a broader distribution of pore sizes (from 10 to 55 μm) as well as a greater total porosity.

Example plot of cumulative flow % and differential flow % contrast with pore size for the same two samples shown above. These plots are computed from the raw flow rate data and can be used to analyze minimum, maximum, and average pore sizes in each sample. Sample F1 has average through-pore diameter of 9.5 μm and Sample F2 has an average through-pore diameter of approximately 33 μm.

Raw Flow Rate versus Pressure data for the samples F1 and F2 shown above. These are collected in two phases: a wet-flow state (during liquid displacement) and dry flow state (after all liquid is removed).

Porometry Instruments Used

Anton Paar Porometer 3G zh

Anton Paar Porometer 3G zh

  • Minimum Detectable Pore Size: 13 nm
  • Maximum Detectable Pore Size: 500 μm
  • Flow Rate Range: 0.01 – 200 L/min
  • Flow Sensor Temperature Coefficient: < 0.5 % / °C (from 15 – 45 °C)
  • Maximum Pressure: up to 500 psi (34.5 bar)
  • Pressure Accuracy: ± 0.05 % f.s.
View Instrument Brochure

Porosity describes the total volume of empty pockets of space or air (voids) enclosed within solid materials. These voids are often critically important in affecting the thermal, electrical, and mechanical performance of both raw materials and engineered parts and products.

Covalent can perform Porosity analysis using the following techniques:

  1. Capillary Flow Porometry (“Porometry”)
  2. Gas Adsorption / Physisorption (“Porosimetry”)

In Capillary Flow Porometry, a sample is submerged in a wetting liquid which then fills all accessible through-pores. The porometer measures the amount of gas flow required to flush all the liquid from the sample pores, and quantifies the amount of pressure required to remove the liquid from the most constricted voids (e.g. the pressure required to displace the liquid from the parts of the pores with minimum diameter).

The measured pressure curve is inversely proportional to pore diameter, and so can be used to calculate pore size distribution, including the minimum, maximum, and average pore sizes.

Learn more about using Capillary Flow Porometry services today!