Investigating the effect of PAMAM-G2 nanostructures dendrimer on the performance of polycarbonate thin film nanocomposite membranes for water treatment

Abstract

Abstract For the first time, thin film nanocomposite membranes (TFN) were fabricated using polyamidoamine polymer nanostructures(PAMAM-G2) through the use of the dip-coating method that polyvinyl alcohol (PVA)/PAMAM-G2 solution was applied to polycarbonate (PC) support membranes. The Fourier transform infrared (FTIR) and thermal gravimetric analysis (TGA) confirmed the synthesis PAMAM dendritic structure. At vacuum trans-membrane pressures (TMP) of 0.4 and 0.6 bar, all fabricated membranes were utilized to remove humic acid (HA) from submerged membrane filtration. PVA/ PAMAM-G2 top active layer formed on the PC support membrane was verified by images obtained using field-emission scanning electron microscopy (FESEM) and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) equipment. FESEM images show that a PVA-PAMAM.G2 top layer with a thickness of 201.85 nm was developed on the PC support layer. TFN membranes' hydrophilicity and surface roughness increased and decreased respectively as a result of the incorporation of PAMAM-G2. The TFN with 0.1 weight percent of PAMAM-G2 nanostructures demonstrated increased permeation flux at lower vacuum TMP, according to the results of HA filtration. However, TMP permeate flow significantly decreased at higher vacuum conditions. The rejection rate for TFC membranes was about 97.9% while for TFN membranes in the presence of PAMAM-G2 polymeric nanostructure it reached 98.5%.