Development of thin film nanocomposite membranes incorporated with sulfated β-cyclodextrin for water vapor/N2 mixture gas separation

Abstract

In this work, thin film nanocomposite (TFN) membranes incorporated with sulfated β-cyclodextrin (sb-CD) were fabricated by interfacial polymerization using aliphatic diethylene triamine (DETA) and trimesoyl chloride (TMC) for water vapor separation. Aromatic m-phenylenediamine (MPD) was used for performance comparison with DETA. The intrinsic properties of fabricated TFN membranes were investigated by Attenuated total reflectance-Fourier transformed infrared (ATR-FTIR), field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM) and water contact angle (WCA). The contact angle (35°) of the TFC membranes with DETA was very lower than that (59°) of The TFC with MPD. Moreover, the TFN membrane with sb-CD loading of 0.15wt% showed the lowest contact angle of 14°, implying that many hydrophilic sulfonic acid groups of sb-CD nanoparticles contributed to decreased contact angle. The effect of sb-CD loading on water vapor permeance and selectivity was studied. Increase in sb-CD loading caused synergistic increase in both permeance and selectivity below the agglomeration point due to its hydrophilic and packable nature. The maximal selectivity of 503 along with 1597 GPU in permeance was obtained with the sb-CD loading of 0.15wt%. In addition, the structural characteristics were found to have a bigger impact on TFN membrane performance than intrinsic properties.