In this study, styrene-acrylonitrile resin (SAN) was used for preparing microporous substrate of TFC membranes. A series of SAN substrate membranes were prepared via the non-solvent phase separation method by tailoring SAN and additive content in the casting solution. The SEM observation and contact angle measurement revealed that the series of SAN substrates prepared have basically same hydrophilicity and surface pore size but different surface pore numbers or surface porosities. With these substrates, the influence of the surface pore number of substrates on interfacial polymerization (IP) can be investigated without the influence of variation of substrate hydrophilicity and pore size.
TFC nanofiltration (NF) membranes prepared with these SAN substrates showed a correlation between the thickness of poly (piperazine amide) selective layer and surface pore number of SAN substrates. With the increase of surface pore number or surface porosity of the substrates, the polyamide selective layer becomes thicker. A simple model was proposed to describe the effect of substrate properties on IP. The substrate surface pores functioning as transport channels for aqueous phase monomer can influence the total amount of the aqueous phase monomer participating in the IP reaction and finally affect the thickness of PA layer. The TFC NF membrane based on SAN substrate showed MgSO4 rejection of 98.67% and water flux of 47.6 Lm-2h-1 at 0.5MPa, indicating that the low-cost SAN resin is a promising candidate as the substrate material for preparing TFC NF membranes.
See more of this Group/Topical: 2018 North American Membrane Society Meeting: Poster Submissions