The current study focuses on the preparation of polydopamine (PD) modified-PVDF membrane and its application for drug removal. The effect of adding inorganic compound (TEOS) on the characteristics and performance of the PD/PVDF thin-film composite (TFC) membrane has also been investigated. For this purpose, the PD layer was coated using TEOS for in situ synthesis of the silica layer. The resultant membrane was coated at different dosages of as-synthesized TNTs to prepare thin film nanocomposite membranes (TFN(S-T)). The prepared TNTs, TFC, and TFN membranes were characterized by employing transmission electron microscopy (TEM), attenuated total reflection Fourier transform infrared (ATR-IR) spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), atomic force microscopy (AFM), zeta potential and contact angle measurements. The results confirmed the formation of a hydrophilic nanocomposite layer with a negative charge. The separation performance of as-prepared membranes was evaluated via diclofenac removal. The results revealed that diclofenac rejection increased from 81.5% for the PVDF membrane to 91.6% for PD/Silica/PVDF membrane with the permeability of 2.5 L/(m2.h.bar). In the case of the TFN(S-T) membrane, drug rejection increased to 93.2% at 0.1% of TNTs and improved permeability to 5.8 L/(m2.h.bar). Also, the effects of pH and feed concentration on diclofenac separation performance were studied. The results implied that the rejection of diclofenac increased from 93.2% to 95.6% after an increase in pH from 7 to 10.

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