Thin-film-composite hollow-fiber membranes for water vapor separation

Abstract

Polyethersulfone (PES) hollow fiber membranes were prepared using the phase inversion technique. The surface of the PES hollow fiber membranes consisted of thin film composite polymer membranes. These membranes were prepared by interfacial polymerization using four different aqueous phase monomers: 1,3-benzenedithiol (BDT), m-phenylenediamine (MPD), 1,3,5-benzenetrithol (BTT), and piperazine (PIP). The organic phase monomer, trimesoyl chloride (TMC), was used to produce the covalent organic polymers. Different types of aqueous monomers (with a number of reactive groups) and their structures were optimized to achieve maximum gas permeation efficiency and water vapor/N2 selectivity. All prepared membranes were fully characterized using different analytical techniques. Among all of the prepared thin film composite (TFC) membranes the one prepared with the 1,3-benzenedithiol monomer (TFC-HF-1) exhibited superior results as water vapor permeance 2054 GPU, and the water vapor/N2 selectivity 119. The prepared membrane substrates and TFC membranes were characterized by chemical structure, morphology and separation performance. Overall, the membranes exhibited good performance over the entire investigated range of operating conditions.