Mixed Matrix Cellulose Acetate Membrane Incorporated with Poly(amidoamine) Dendrimer Functionalized Multiwalled Carbon Nano Tubes for Effective Anionic Dyes Rejection

A mixed-matrix nanofiltration membrane was fabricated by introducing a PAMAM dendrimer functionalized multiwall carbon nanotubes as a hydrophilic nanofiller and the membrane was prepared by phase inversion method. Fourier transform infrared spectra (FTIR), Transmission electron microscopy (TEM) and Field emission scanning electron microscope (FE-SEM) image analyses were used to identify the modified membranes and nanocomposite. The hydrophilicity and surface roughness of the prepared membrane was determined by Atomic force microscopy (AFM), Zeta potential, Thermogravimetric analysis (TGA) and Water contact angle (WCA), respectively. These results showed higher surface roughness and hydrophilicity of the modified membrane. The rejection performance of the membrane was measured by filtering Direct red 2 and Direct blue 1 solution (100 mg/L). The cellulose acetate (CA) membrane that was mixed with 1.0 wt% exhibited optimum performance above 90% rejection of both dyes with pore diameter of 0.73 nm and molecular weight cut off (MWCO) of 570 Da. Also, the antifouling properties of the prepared membrane were studied by filtration of bovine serum albumin (BSA) protein as a fouling agent. According to the data, compared to the bare CA membrane, the membrane containing nanofiller shows better antifouling. In addition, the membranes containing hydrophilic nanofiller showed better mechanical strength compared to the empty membrane.