Preparation And Properties Of Functionalized Carbon Nanotubes / Polysulfone Composite Membrane

Polysulfone (PSF), a widely used membrane material, has broad application prospects because of its excellent thermal stability,good chemical resistance and oxidation resistance, especially in ultrafiltration membrane separation processes. Nevertheless, the inherent hydrophobic characteristic of PSF ultrafiltration membranes makes them susceptible to irreversible fouling due to the nonspecific adsorption of proteins on the surface of the membranes in separation processes.With unique properties such as excellent mechanical properties, high surface area and good separation performance, carbon nanotubes(CNTs) has become the ideal nanofiller for polymer membrane material. CNTs often lead to aggregation in the polymer matrix, so that it can be modified and attached different functional groups by using chemical modification for uniform dispersion and superior performance.In this research, firstly, carboxylated carbon nanotubes(CNTs-COOH) and carbon nanotubes functionalized with polyethylene glycol (PEG-g-CNTs) were synthesized.The modified carbon nanotubes were analyzed by FT-IR, TEM and XPS to evaluate the structure and morphology. Then the CNTs-COOH/PSF hybrid membranes and PEG-g-CNTs/PSF hybrid membranes were formed via the phase inversion process using PSF as film-forming materials, modified carbon nanotubes as additives, N,N-dimethylacetamide as solvent and water as coagulant. The morphologies, hydrophilicity, permeation performance, mechanical property and antifouling performance of hybrid membranes were studied. The results showed that the hydrophilicity and water flux of CNTs-COOH/PSF membranes were improved by the addition of CNTs-COOH. With the synergetic effects of PVP and CNTs-COOH, the hybrid membranes which have better permeation performance. The hybrid membranes with the addition of PEG-g-CNTs exhibited more excellent hydrophilicity which lead to better antifouling performances. In addition, after incorporation modified carbon nanotubes, all hybrid membranes exhibited excellent tensile strength. The mechanical properties of membranes futher enhanced.