A suitable polyethersulfone membrane support for polyamide thin film composite nanofiltration membrane: preparation and characterization

Abstract

The main objective of this study was to introduce a suitable Polyethersulfone (PES) support for preparation of thin film composite (TFC) membranes. To this end, most important factors for preparation of an optimized support involving PES and polyethylene glycol (PEG) in casting solution, in constant temperature were studied. Morphological properties of the prepared PES samples were characterized using FE-SEM imaging. Flux performance and hydraulic resistance of samples were also examined. To evaluate nanofiltration performance for the prepared PES supports, a series of TFC polyamide top-layer membranes were prepared based on ethylenediamine (ED) (and triethylenetetraamine, TETA) and trimesoylchloride (TMC). The TFC membranes were characterized using ATR-FTIR, FE-SEM and AFM techniques. The polyamide layer thickness of the two modified TFC membranes based on ED and TETA were calculated to be 179 and 223 nm and the mean pore sizes were 1.1 and 1.4 nm, respectively. Besides, performance of the TFC membranes was evaluated via water flux and salt rejection tests. The obtained results showed that the TFC membrane with support containing 17.5 wt% PES and 10 wt% PEG, which displayed better salt rejection, water flux and uniform pore morphology, can be used as an optimized support in preparation of polyamide-based TFC membranes.