Fabrication and characterization of a novel tannic acid coated boehmite/PES high performance antifouling NF membrane and application for licorice dye removal

We present a novel procedure for surface modification of boehmite nanoparticles via tanning-inspired coating. The impact of tannic acid coated boehmite (TA-BM) as a nanofiller on preparation of nanocomposite membranes were evaluated in terms of wettability, permeability, membrane morphology and fouling resistance capability. The surface morphology and chemical structure of TA-BM/PES blend membranes were investigated by SEM, AFM, measurement of contact angle and pore structure, FTIR and XRD analysis. Both of surface hydrophilicity and permeation flux of pure water improved significantly with incorporating of TA-BM nanofiller. The SEM image exhibited the wider finger-like pore of TA-BM/PES embedded membranes compared to bare PES membrane. The AFM image analysis indicated that, the roughness parameters of membranes reduced remarkably in presence of TA-BM nanostructures. In order to assessment of nanofiltration performance, the removal capability of Direct Red 16 and licorice dye was studied. The results revealed that, the TA-BM embedded membranes possessed superior dye removal capability (more than 96%) in comparison of bare membrane (90%). The antifouling performance tests of membranes studied by protein rejection. It was shown that, the best antifouling performance was belonged to 0.5 wt% TA-BM/PES blend membrane (FRR = 96.4%, Rir = 3.604). The TA-BM nanostructures had a great potential for surface treatment of hydrophobic membranes.