Following its well-established tradition of introducing key innovations in the field of porous solids characterization, Quantachrome Instruments is pleased to introduce a novel cryocooling accessory: The CryoSync™ (patent pending). With this compact and deceptively simple accessory, modern gas sorption analyzers can be used to generate isotherms:
- At an essentially constant temperature (down to ±0.005 K);
- Within a wide target temperature range (82-115 K); and
- For as long as needed for extended high resolution analyses (over 50 hours without optional refill).
It is now well established (see the latest IUPAC recommendations in Pure. Appl. Chem.87 (2015) 1051)) that argon molecules provide distinct advantages over nitrogen molecules for gas sorption analyses, including the following:
- Unlike nitrogen, argon has no quadrupole moment. Thus, using argon as adsorbate eliminates specific chemical interactions with polar/ionic surface sites;
- As a result, argon physisorption isotherms provide much more reliable fingerprints of the interactions modeled by today’s most advanced techniques (e.g., QSDFT) for pore size characterization; and
- Argon sorption analyses at its boiling point (87K) can be significantly faster than conventional N2/77K experiments, because the filling of similar pores can occur much more readily at much higher relative pressures;
There has been a long-felt need in the art for the means to enable Ar/87K experiments without having to resort to using compressor-based cryostats (which can be very expensive) or liquid argon cryogen (which can also be relatively expensive or even unavailable in some regions). The CryoSync™ fills this need by providing a compact accessory which is easily adaptable to modern gas sorption analyzers. With the CryoSync™ users can easily perform IUPAC-recommended argon sorption analyses at 87.3K using liquid nitrogen (instead of liquid argon) as the cryogen.