High efficient HOF-21@SA/M-PAN membrane for accurately sieving water from alcohol

The development of ethanol dehydration membranes with superior separation performance and long-term stability is an essential objective for pervaporation. HOF-21 with pore size of 3.6 Å could make way for water transportation while rejecting ethanol molecules. Here, amine-modulated HOF-21 (HOF-21-a) was proposed to dope into the sodium alginate (SA) separation layer on the polyacrylonitrile (PAN) substrate for ethanol dehydration. Molecular simulation results confirmed the superior water permeance of the HOF-21-a membrane. To enhance the interfacial bonding strength, polyethyleneimine (PEI) and catechol (CT) were coated onto the PAN substrate and crosslinked to form a robust network between the top separation layer and the support layer. The novel HOF-21-a@SA/M-PAN membrane, incorporating a hydrogen-bonded organic framework, was designed for efficient ethanol dehydration. Experimental results demonstrated that the prepared composite membrane exhibited excellent separation performance at a PEI/CT mass ratio of 1:1 and a HOF-21-a loading of 1.0 wt%. Specifically, the permeate flux increased significantly from 606 g·m −2 ·h −1 to 2389 g·m −2 ·h −1 with the separation factor improved from 153 to 2267 at 75 °C. Additionally, the composite membrane demonstrated outstanding long-term stability. The newly developed membrane offers a promising solution for organic solvent dehydration.