Forward osmosis TFN membrane prepared by adjusting a PDA/GO-Fe3+-TA interlayer on porous CTA substrates

Abstract

Cellulose triacetate (CTA) is commonly used as the material for forward osmosis (FO) membranes due to its good chlorine resistance, fouling resistance and wide availability. In this work, the implications of various solvents on the appearance and desalination capacity of CTA FO membranes were systematically investigated. CTA membranes with large pore size and high porosity were constructed by using spray-modified non-solvent induced phase separation (s-NIPS). The water flux of CTA membranes fabricated by s-NIPS using DMSO as the solvent was up to 34.4 L m−2h−1, which was 5.6 times higher than HTI commercial membranes, and the reverse salt flux was only 10.9 g m−2h−1. A poly-dopamine (PDA) /graphene oxide (GO) -Fe3+-tannic acid (TA) interlayer was introduced to adjust the cross-linking degree of the polyamide (PA). And thin-film nanocomposite (TFN) membranes (PA-PDA/GO-Fe3+-TA-CTA) were fabricated successfully. The water flux was 35.8 L m−2h−1 and the reverse salt flux decreased to 5.84 g m−2h−1. These experimental results propose an emerging approach to design and develop high performance FO membranes in a rational way.