Rapid determination of experimental sorption isotherms from non-equilibrium sorption kinetic data

Summary

Herein, we report a new method for rapid determination of experimental sorption isotherms that exploits gravimetric non-equilibrium sorption kinetics data in a thin sorbent bed. In comparison with equilibrium-based isotherm determination methods, this sorption kinetics isotherm determination (SKID) method needs only two equilibrium points, P/P_0min and P/P_0max. SKID requires up to an order of magnitude less data collection time than conventional methods and is suitable for high-throughput sorbent discovery and evaluation. SKID was validated by testing a library comprising 30 sorbents, including rigid and flexible metal-organic frameworks (MOFs), inorganics (zeolites), and organics (microcrystalline cellulose). Average data collection time for water vapor was 3.1 vs. 23 h for dynamic vapor sorption experiments. SKID was also demonstrated for other vapors (C8 aromatics) and a gas (CO₂), making it a promising tool for rapid screening of new or existing sorbents for applications such as water harvesting and dehumidification and carbon capture.