| Preparing new organic-inorganic hybrid ultrafiltration membranes becomes a hot topic in material field for the disadvantages of the traditional organic ultrafiltration membranes, such as inferior temperature resistance and pressure resistance, short lives et al. People recently try to put TiO2 which is one of the most active inorganic nanomaterials into organic materials to make up different systems to prepare ultrafiltration membranes. Polyether sulphone (PES) is a good membrane material with excellent overall performance, and research reports on preparing ultrafiltration membrane with PES and TiO2 are not yet seen. One of the aims of this paper is to prepare and characterize the novel polyether sulphone ultrafiltration membrane made from PES and TiO2.Aromatic polyamide is a typical composite nanofiltration membrane material with inferior chlorine resistance. That would affect the lives of membranes to limit their applications due to the existences of soluble chlorine in the natural and waste water, and the use of chlorine and bleaching powder during the water treatment. It's very significative to develop polymer membrane materials with new functions to promote the researches on ultrathinization and activation, and to prepare the composite membranes which could bear oxidation,chlorination and pollution. In dimethyl aniline (m-XDA), a methylene exists between the amino group and the benzene ring, so the polyamide made from dimethyl aniline (m-XDA) has better oxidation resistance than that made from the traditional fragrant amine. The research reports on taking methyl aniline (m-XDA) as the monomer of aqueous phase to prepare the composite nanofiltration membrane by interfacial polymerization are not yet seen. Taking dimethyl aniline (m-XDA) and trimesoyl chloride (TMC) as the monomer of aqueous phase and organic phase respectively, by interfacial polymerization, this paper manages to prepare and characterize the polyamide composite nanofiltration membrane.The whole paper consists of the following two parts: 1 Preparation and characterization of novel polyether sulphone ultrafiltration membranesA polyether sulphone(PES)ultrafiltration membrane was prepared by the phase conversion, using polyether sulphone as membrane material, N, N- dimethyl acetamide (DMAc) as solvent, polyethylene glycol (PEG) and titanium dioxide (TiO2) as chemical additives. The performances of membranes made from diffirent casting solutions were studied. The effects of the type and content of chemical additives on the membrane performance were investigated. The pore size, porosity and antifouling of membranes were also characterized. When casting solutions contained 15% PEG with the molecular weight of 400, we got the maximum flux of pure water of the membrane. The surface and structure of membranes were characterized by scanning electronic microscopy (SEM). When PEG-400 was the exclusive additive, the surface of the membrane was even and the cross section of the membrane had typical asymmetry fingered structure. When TiO2 was added, it could uniformly distribute in the pore and on the surface of the membrane, changing the structure of inner layer to form big cavity structure. The ultrafiltration membrane containing TiO2 not only maintained the high flux but also improved the water affinity of the membrane to enhance the antipollution of the membrane. The performance of the ultrafiltration membrane which contained 18% PES 15% PEG-400 and 19%-20% TiO2 was the best. The flux of pure water was over 148 L?m-2?h-1, and the rejection of 500mg/L pepsin was over 56% at 0.1 MPa.2 Preparation and characterization of polyamide composite nanofiltration membranes A polyamide composite nanofiltration membrane was prepared on the polysulfone support membrane, with m-xylylenediamine(m-XDA) and trimesoyl chloride (TMC) as reactants, by interfacial polymerization. The effects of different preparing conditions on the membrane performance were studied, including the concentration of reactants, pH, reacting time, curing temperature and curing time. The optimal preparation conditions were given as follows: 0.5% m-XDA in water and pH at 9.5, 0.2% TMC in hexane, reacting time about 2 min, curing temperature at 100℃and curing time about 10 min. The rejection was about 82.98%, and the flux was about 28.48 L?m2?h-1 at 1.4MPa for 1000mg/L Na2SO4. The effects of phenol and isopropyl alcohol as chemical additive in aqueous phase on the membrane performance were investigated respectively.IR analysis suggested the presence of polyamide. Scanning electronic microscopy (SEM) and atomic force microscopy (AFM) showed that there was an active layer with apparent structure of peaks and valleys on the polysulfone support membrane. The effects of various operating conditions on the composite membrane performance were also studied, including operating pressure, feed temperature, feed concentration, and feed type et al. Negative electricity of this membrane was determined by measuring the streaming potential of the membrane. Water affinity of membrane was evaluated by measuring the pure water penetration coefficient and the swelling capacity. By means of the practical running polyamide membranes in humic acid (HA) simulated solution, the effects of the ion concentration and pH of the feed on the pollution degree of the membrane were studied. Chlorine resistance was studied by static and dynamic experiments. After exposure to active chlorine (up to 2300 mg·L-1·h), the salt rejection of the polyamide membrane kept relatively high, whereas its flux was improved. That was to say, compared with usual polyamide membrane, the membrane possessed relatively high chlorine resistance.
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