A perspective on the application of operando characterization to probe the structure, performance, and dynamics of membranes under realistic operating conditions

Abstract

Operando membrane characterization is a relatively new experimental research methodology that is expected to have a significant impact on membrane science and engineering in the coming years because of its unique ability to probe the structure, performance, and dynamics of membranes under realistic operating conditions. It combines in-situ characterization of the atomic/molecular-scale structure of a membrane with simultaneous measurement of permeation rates on the same sample under realistic operating conditions. By performing both in-situ characterization and permeation measurements simultaneously on the same sample, operando membrane characterization allows one to directly correlate membrane structure to its performance, which conventional membrane testing and ex-situ characterization approaches cannot achieve. In this Perspective, the key components of the operando membrane characterization experimental setup are described, and three case studies are presented to demonstrate the utility and versatility of combining in-situ membrane characterization with permeation measurements. The future opportunities, challenges, and limitations of operando membrane characterization are also discussed.