In the literature, it is said that BET theory should not be applied to Type I isotherm. However, the surface area is an important parameter for the characterization of materials, and actually, the surface areas of microporous materials are often calculated. Then what are the problems and how can we evaluate the surface area?
Problems:
Adsorption image into the micropore
2. Since there is a big curvature in micropores, the use of cross sectional area to calculate the surface area underestimates the value.
Evaluation of surface area in the micropore
Type I isotherm and BET-plot
2.The calculated surface area of type I isotherm should be considered as the BET specific surface area, and not the actual geometrical specific surface area.
This BET specific surface area has a good agreement with the adsorption amount and reactivity. So it is not necessary to evaluate the geometrical specific surface area for the actual applications.
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Ultimately, the choice of whether to use a simple sieving solution or to invest in Laser Diffraction or Dynamic Image Analysis will depend on the volume of testing, the budgets and staffing available and any specific international standards or customer requirements that you face.
Why not contact Microtrac for a free consultation to find out which solution will deliver the outcome and the Return on Investment you need?