Innovative Polyelectrolyte Multilayer Nanofiltration Membrane Fabricated Through Spin-Spray Assisted Layer-by- Layer Assembly

Spin Assisted Layer-by-Layer (SA-LbL) assembly is one of the Layer-by-Layer (LbL) assembly variants. It is considered as the fastest LbL assembly, however, the deficiency of layering quality on bigger polymeric support size poses a significant challenge to the application of SA-LbL assembly at a larger or industrial scale. To address the challenge, combined spin-spray assisted Layer-by-Layer (SSA-LbL) is employed to prepare membrane. In this study, nanofiltration (NF) thin film composite membranes were prepared by alternate deposition of branched-polyethyleneimine (PEI) and poly(sodium 4-styrenesulfonate) (PSS) on polyethersulfone (PES) ultrafiltration (UF) membrane support. The resulting membrane was then tested to separate NaCl from water. One of the membranes produced in this work, i.e., (PEI/PSS)10 achieved rejection rate of 76.2 %; permeability of 2.79 l/h·m2·bar tested at pressure of 10 bar, temperature of 24.58 ± 0.51 °C , and NaCl-Feed concentration of 2076.75 ± 40.51 ppm. The membrane fouling resistance was also examined in 5 days-test. The membrane showed stable performance and lost only about 30% flux from the initial flux due to fouling which was comparable to that of commercial NF membrane such as NF90. Hence, this work shows that SSA-LbL can be considered as a promising and innovative membrane fabrication technique as it offers flexibility and applicability for preparing membrane from various materials as well as pertinence to industrial scale.