Micropore Measurement
Characterizing micropores (pores with internal diameters < 1.7nm) via the gas physisorption technique is one of the most widely used pore characterization techniques. Samples are first prepared by drying, with a flow of inert gas or vacuum atmosphere, to clear the surface of any contaminants. The sample is introduced to a probe gas that is physically adsorbed to the surface of the sample. Nitrogen, Argon and CO2 are common probe gases utilized for this technique. The volume of probe gas adsorbed is measured to determine the quantity of gas required to fill the sample’s pore structure. The density functional theory (DFT) can then be used to determine the total volume in cm3/g and area in m2/g of pores < 1.7nm in size. Other data modeling options are available upon request.
The characterization of micropores is recognized by numerous standard and guidance agencies including ASTM and ISO, specifically ISO 15901-3. The ability to measure pore volume and area of these small pores without extrapolating information, as in the use of the t-plot method, makes this analysis an excellent choice for the characterization of zeolite, carbon, and metal-organic framework (MOF) samples.
Microporous materials are used in many research and industrial applications, including catalysts, controlled drug delivery, and energy conversion and storage. A comprehensive characterization of microporous materials with regard to pore size, area, and pore size distribution is required in order to select and optimize the performance of these materials.
Advantages
- Nitrogen, Argon, or Carbon dioxide available for adsorbate gases
- Micropore and mesopore combination analysis also available, which includes a multi-point BET analysis
- Several instrument options to ensure best fit for material
Considerations
- Appropriate for dry materials only
- Pores larger than 1.7nm are not characterized by micropore only analysis
Sample Requirements
The sample must be a dry solid to be analyzed. Ideal sample amount is 2 to 5 grams. If sample availability is limited, please contact PTL. Smaller sample quantities can often be accommodated depending on sample properties.
For additional questions on your sample needs, please contact us to share specifics about your sample and options for suitable sample quantities.
Detection Range
PTL’s gas adsorption micropore analyzers can measure pore size distribution and area measurements in the range of 5 Å to 20 Å (0.5 nm to 2 nm).
Micropore-mesopore combination analysis includes pore measurements in the 5 Å to 3000 Å (0.5 nm to 300 nm) range.
Data Reported
Micropore only analysis: Pore size distribution and area – DFT Pore Volume (cm3/g), DFT Total Pore Area (m2/g).
Micropore-mesopore analysis: Pore size distribution and area – DFT Pore Volume (cm3/g), DFT Total Pore Area (m2/g), BJH Pore Volume (cm3/g), BJH Average Pore diameter (nm), BET Specific Surface Area (m2/g).
Instrumentation
Particle Technology Labs has some of the top players in the industry, such as Micromeritics and Anton Paar/Quantatec.
Micromeritics 3Flex Micropore & 40pt Isotherm
