Preparation and Characterization of Hydroxylated Multi-Walled Carbon Nanotube (MWCNTs-OH) Composite Nanofiltration Membrane

Hydroxylation multi wall carbon nanotubes (MWCNTs-OH) were brought in the interfacial polymerization (IP) with piperazine (PIP) and trimesoyl chloride (TMC), and Hydroxylation multi wall carbon nanotubes composite nanofiltration membrane (MWCNTs-OH-NF) was prepared by copolymerization. As the concentration of PIP, TMC and MWCNTs-OH were 0.10 wt%, 0.05 wt% and 0.08 wt%, respectively, the performance of the MWCNTs-OH-NF got best. The pure water permeate flux of MWCNTs-OH-NF got 60 L/m2h at 0.4 MPa, which was about 2.5 times that of pure polyamide nanofiltration membrane (PA-NF). The Zeta potential test results indicated that both the MWCNTs-OH-NF and PA-NF had negative charges, and the rejection order of inorganic salts was Na2SO4 > MgSO4 > MgCl2 > NaCl. In addition, MWCNTs-OH-NF also exhibited good stability in long-term operation.