Pillararene-Based Nanochannels for Para-Xylene Separation from Xylene Isomers

In industrial production, the continuous, efficient and energy-saving separation of alkylaromatic compounds has always been a challenge. Herein, we designed and synthesized the functional pillararene (TP5A) via a thiol-alkene click reaction. We modified TP5A molecules into the surface of anodic aluminum oxide nanochannels via a simple two-step condensation reaction for fabricating TP5A channel, confirming by the X-ray photoelectron spectroscopy, contact angle, laser scanning confocal microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy and current-voltage curves. This biomimetic nanochannels can be used to separate para-xylene from its structural isomers. We speculate that the host-guest interaction between TP5A and para-xylene is responsible for the emergence of selectivity, confirmed by the molecular simulation. This study provides a potential approach to membrane separation and may also contribute to the development of artificial nanofluids.