Functionalized multi-walled carbon nanotube thin-layered hollow fiber membrane for enantioselective permeation of racemic β-substituted-α-amino acids

Utilization of carbon materials having excellent selectivity and robustness can have tremendous influence in the field of membrane-based separation. Herein, a hybrid polysulfone multi-walled carbon nanotube Hollow Fiber (HF) membrane was fabricated for enantioseparation of β-substituted-α-amino acids. Thin Film Nanocomposite (TFN) membrane was prepared via interfacial polymerization between D-tryptophan with carboxylated multi-walled carbon nanotubes and trimesoylchloride. The enantioseparation performance of the membranes was demonstrated through sorption and permeation study. On passing a racemate solution through the cross-linked membranes, the D-tryptophan-linked chiral probe adsorbed the D-isomer of the racemate, and L-isomer was passed to permeate side through the membrane. In a nutshell, the thin film nanocomposite enacts as the effective layer over the HF membrane which ensured that the apportioned chiral selectors were adequate to attain 99% of enantioselectivity.

Graphical abstract

Hybrid nanocomposite membranes were prepared via interfacial polymerization between D- tryptophan with carboxylated multi-walled carbon nanotubes and trimesoyl chloride over polysulfone support. On passing a racemate solution of β-substituted-α-amino acids through the hybrid membranes, the chiral probe selectively adsorbed the D-isomer. The thin-film nanocomposite enacts as the effective layer over the hollow fiber membrane which ensures the apportioned chiral selectors were adequate to attain 99% of enantioselectivity.