Thin film nanocomposite membranes incorporated with graphene quantum dots for high flux and antifouling property

Thin film nanocomposite (TFN) membranes incorporated with graphene quantum dots (GQDs) were fabricated with enhanced water permeability and antifouling property. Owing to the small size, stable dispersion and active functional groups, GQDs were embedded into polyamide (PA) layer during the interfacial polymerization of piperazine (PIP) and trimesoyl chloride (TMC) in a facile way. The surface chemical features and morphologies of the resultant TFN membranes were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), water contact angle, zeta potential, scanning electron microscope (SEM) and atomic force microscopy (AFM) measurements. The surface roughness of the TFN membranes decreased and the surface hydrophilicity of the TFN membranes enhanced with the increase of the GQDs content. According to nanofiltration (NF) experiments, the highest water flux of the TFN membranes reached up to 102.0 L/(m(2)h) under operation pressure of 0.2 MPa, which was nearly 6.8 times as much as that of the pristine PA membrane. The TFN membranes also exhibited excellent antifouling performance that the steady water flux of the as-fabricated membrane under harsh fouling condition was about 4 times as much as that of the pristine PA membrane. This study may present a useful attempt of using carbon materials in fabricating high flux and antifouling membranes.