Thin film composite hollow fibre membrane for pharmaceutical concentration and solvent recovery

A 100-piece hollow fibre thin-film composite membrane module was successfully developed for pharmaceutical concentration and solvent recovery. To increase its packing density, thinner P84 polyimide hollow fibre substrates were spun using a smaller spinneret. The substrates were subsequently cross-linked with hexamethylene diamine to achieve organic solvent resistance. An MPD-based thin-film composite was synthesized through interfacial polymerisation to increase selectivity for solutes of less than 300 Da. The thin-film composite was then solvent-activated using N,N-dimethylformamide to increase its solvent permeability. The resulting membrane exhibited excellent performance with 24.2 m(-2) h(-1) bar(-1) acetone permeability and 90.1% methyl red (269 Da) rejection. In addition, the solvent-activated membrane maintained its performance for prolonged period, demonstrating the scalability of the thin-film composite fabrication process and stability of solvent-activated membranes. The membrane was also able to concentrate levofloxacin (361 Da) from 500 ppm to 20,000 ppm in acetone using a batch process, showing promising results for pharmaceutical applications.