Free online seminars on gas adsorption measurements on July 18th and September 19th, 2023
Register now for the upcoming 90-minute online seminars as part of the Sorption World event series. The event is designed for anyone interested in performing gas sorption measurements in the laboratory, regardless of the analytical instrument used. After a 45-minute presentation, you will have the opportunity to ask your questions. You cannot attend the events? No problem, you will receive the video recording afterwards!
The following seminars will take place soon:
Recording of single- and multi-component isotherms using dynamic methods
July 18th 2023, 9.30 – 11.00 a.m. (UTC +1)
Classically, single component isotherms are recorded for the characterization and suitability test of new adsorbents. Subsequently, ideal separation characteristics can be determined with the help of common adsorption models, such as the Ideal Adsorbed Solution (IAS) theory. Unfortunately, the IAST is only applicable to ideal adsorption processes because of different hypotheses the theory is based on, e.g., a thermodynamically inert framework.
The obvious solution for this problem is to investigate co-adsorption processes directly. Therefore, a new method on our dynamic breakthrough devices, namely the mixSorb S and mixSorb SHP, has been developed to record both, single component isotherms, up to a pressure of 8 bar (mixSorb S) or 50 bar (mixSorb SHP) and multicomponent isotherms on the same device.
The limits of surface and pore volume characterization
September 19th 2023, 9.30 – 11.00 a.m. (UTC +1)
Not only the IUPAC recommends the use of argon at 87 K instead of nitrogen at 77 K for the characterization of porous materials, but also the ISO 9277 describes problems when using the BET method for the determination using N2. Therefore, regardless of the fact that N2 interaction problems with a material surface can influence specific area and pore size distribution results, N2 near 77 K is still the most common technique e.g. due to comparison reasons. However, when it comes to samples with narrow ultramicropores or a very small surface area, such as thin films or non-porous samples, N2 and Ar reach their limits.
Therefore, IUPAC recommends the use of Kr with a fixed p0 value of 0.35 kPa at 77.35 K, but this does not consider the dependence of the coolant on ambient pressure. Since the p0 value of the supercooled liquid krypton adsorbate cannot be measured directly, it has to be calculated either from a temperature measurement of the coolant or an exact temperature control. For accurate measurements, we used a new temperature control (cryoTune 77), which allows the use of the correct p0 for the undercooled liquid adsorbates of Kr and Ar near 77 K.
An overview over the next events is available on our event page.