Rational Design of MXene Hollow Fiber Membranes for Gas Separations
Yiming Zhang, Yiming Zhang, Kai Sheng, Zheng Wang, Wenjia Wu, Hang Yin, Junyong Zhu, Yatao Zhang, Yatao Zhang
Abstract
One scalable and facile dip-coating approach was utilized to construct a thin CO 2 -selection layer of Pebax/PEGDA-MXene on a hollow fiber PVDF substrate. An interlayer spacing of 3.59 Å was rationally designed and precisely controlled for the MXene stacks in the coated layer, allowing efficient separation of the CO 2 (3.3 Å) from N 2 (3.6 Å) and CH 4 (3.8 Å). In addition, CO 2 -philic nanodomains in the separation layer were constructed by grafting PEGDA into MXene interlayers, which enhanced the CO 2 affinity through the MXene interlayers, while non-CO 2 -philic nanodomains could promote CO 2 transport due to the low resistance. The membrane could exhibit optimal separation performance with a CO 2 permeance of 765.5 GPU, a CO 2 /N 2 selectivity of 54.5, and a CO 2 /CH 4 selectivity of 66.2, overcoming the 2008 Robeson upper bounds limitation. Overall, this facile approach endows a precise controlled molecular sieving MXene membrane for superior CO 2 separation, which could be applied for interlayer spacing control of other 2D materials during membrane construction.