Written by AZoM
To coincide with the launch of the latest generation of its Autosorb-iQ, the ultra-low pressure range XR version, Quantachrome announces the release of powerful new software to complement the new measurement capabilities of the Autosorb-iQ-XR, and to bring new benefits to users of all Autosorb-iQ models.
Firstly, the new AsiQWin ver2 software includes six new pore size calculation models based on microscopic density functional theory (DFT) to bring the library up to a total of twenty two. The new QSDFT (Quenched Solid DFT) kernels are applicable to micro-mesoporous carbons of various types including structures derived from hard and soft templates, and those having complex pore networks, plus a variety of pore geometries (slit, cylindical and spherical), covering pore sizes up to 50nm. The entire DFT library encompasses other adsorbent types like zeolites and silicas, a variety of adsorbates (N2, Ar and CO2), temperatures, plus specific (different) models for adsorption data and desorption data. The comprehensive nature of this calculation module ensures its applicability to a very wide range of both traditional and state-of-the-art porous materials.
This latest software version also includes a new, intelligent "wizard" to automatically select those data points to be used in the so-called B.E.T surface area calculation, thus ensuring proper exclusion of measured data points that lie at too high a relative pressure for accurate micropore surface area measurements. This represents the first known commercial software implementation of the strategy for specific surface area determination of microporous materials as described in the BET surface area standard ISO 9277:2010 (Annex C). Manual selection of B.E.T. data points is also enhanced - by the inclusion of a new, user-friendly graphical point selector; tagging of such points in a tabular format is no longer necessary.
And to support extra-long analysis times that are sometimes unavoidable when measuring fully-equilibrated (i.e. accurate) micro-mesopore analyses, the user can now choose to have the Autosorb-iQ automatically re-measure the system's effective void volume (a.k.a. dead space or free space) during the analysis to account for subtle temperature changes that can occur over tens of hours.
This feature is implemented without the need to access the sample cell volume directly (i.e. neither adsorbate nor helium is added/subtracted from the sample cell in order to make the adjustment), without software-only calculation of intermediate temperature zones, without adjusting coolant level, and without enlarging the all-important cold zone so as to ensure the highest sensitivity. Addtionally, the new capability works not only for liquid nitrogen, but also for other cryogens at other temperatures, and without any additional hardware. An incorrect void volumes impacts the quality of sorption isotherms, and so some means of minimizing it, controlling it and/or correcting it are essential in order to obtain the best results.
Users of the chemisorption-enabled model, the Autosorb-iQ-C and C-XR equipped with a TCD for flow-based measurements, can now mix-'n'-match static manometric analyses (i.e. pressure-based adsorption isotherms) with TPR/TPO/TPD and pulse titration measurements. This enhancement will be particularly appreciated by those scientists researching heterogeneous catalysts.
The new software and measurement features will be available on all newly ordered Autosorb-iQ instruments as standard, and will shortly be available to existing users as upgrade packages.