High-performance polyurea thin-film composite membranes: Tailored interfacial polymerization for efficient bioethanol dehydration

Abstract

In this study, we developed a series of advanced polyurea composite membranes using interfacial polymerization of various amine monomers (ethylenediamine (EDA), diethylenetriamine (DETA), and 2,2′,2″-nitrilotriethylamine (NTEA)) with diisocyanate monomers (1,6-diisocyanatohexane (HDI), m-xylylene diisocyanate (XDI), and 1,3-bis(isocyanatomethyl)cyclohexane (BIMC)) on modified polyacrylonitrile (mPAN) supports. These membranes were optimized and evaluated for pervaporation-based dehydration of a 90 wt% aqueous ethanol solution. Through a detailed investigation of the chemical structure via ATR-FTIR spectroscopy and morphological analysis using SEM, we identified key factors influencing membrane performance, including the hydrolysis time of the mPAN support, monomer structure, and polymerization conditions. The optimized TFC (DETA-XDI) membrane, synthesized with 1.0 wt% DETA and XDI solutions under controlled conditions, demonstrated an exceptional balance of permeation rate (462 g/m²h) and water selectivity (99.1 wt%), positioning it as a promising candidate for efficient bioethanol dehydration processes.