(537g) Tailoring Microcavities in Thermally Rearranged (TR) Polymers for Gas Separation

Rigid and microporous polymers are expected to show high gas permeability with excellent selectivity. Thermally rearranged (TR) polymers are a new class of microporous organic polymers architecting their free volume elements or so-called microcavities during thermal conversion. Microcavities and their distribution in the TR polymers can be manipulated via degree of rearrangement, rigidity of the original chain, diverse polymer precursor design. These cavity-tuned TR polymers have been explored to hit over the limits which conventional polymers have faced with including natural gas sweetening or carbon capture.

Herein we report on another cavity-tunable TR polymers for the first time induced by hydrophobic surface coating which enhances build-up of a kinetic layer on the membrane surface. In addition, cavity size and distribution across the coated TR polymer membranes can be easily tailored. Consequently, gas transport of large gas molecules was strongly interrupted due to the tailored cavities, while small gas molecular transport was maintained, resulting in outstanding separation performance as molecular sieves with improved selectivity and good gas permeability for smaller gas molecular pairs such as helium, hydrogen and carbon dioxide or even difficult separation of oxygen and nitrogen.