(A) study on ultramicropore tuning of carbon molecular sieve membrane via electron irradiation.

Abstract

Carbon molecular sieve (CMS) membranes are considered as promising candidates to overcome the challenges that thermal based separation faced. However, effectively separating similarly sized molecules is still a demanding problem for CMS membranes. Here, by benchmarking the electron irradiation induced structural changes in carbon particles, we reports new ultramicropore tuning method of 6FDA:BPDA(1:1)-DAM derived CMS membranes with electron irradiation. The electron beam develops ultramicropore tightening and oxygenated CMS surface that impose transport resistance on the large gas penetrants, providing high C2H4/C2H6 separation performance. Increase of irradiation dosage leads to explicit diffusivity difference between C2H4 and C2H6 and is involved with diffusion selectivity enlargement, resulting in selective C2H6 discrimination from C2H4 in CMS membranes. Electron treated CMS also shows high stabilized permeability and selectivity than that of the pristine CMS which suffered significant performance degradation from physical aging. This study successfully highlights electron irradiation as a new CMS tuning method rather the conventional factors mainly limited to pyrolysis manner.