Surface By The Techniques Of Preparation Of The Charged Membrane And Its Properties

Acrylic acid (AAc) and an epoxy-group-containing polymer chain, glycidyl methacrylate(GMA), were respectively grafted onto the polypropylene hollow fiber(PP) membrane by ultraviolet(UV) irradiation induced graft polymerization . FTIR-ATR spectroscopy, SEM and X- photoelectron spectroscopy (XPS) provided that the membrane of PP — g—AAc and PP—g—GMA were gained successfully, and ring opening of the PP-g—GMA was induced in the presence of glycin(Gly) including amido and carboxyl, Amphoteric-Charged Porous Membrane of PP-g-Gly was obtained.The conditions of the AAc-grafted and GMA-grafted polymerizations were discussed. Concentration of BP and AAc were 4%-6%, 15% respectively, and irradiation time about 25min-30min were appropriate for AAc-grafted polymerizations. At the same time concentration of BP and GMA were 6 % -8 %, 25 %, irradiation time about 30min were appropriate for synthesizing PP—g—GMA. The molar conversion of the epoxide into the functional group was 15%-34% under the instance of pH=13 and 80℃ and 0.3mol/l Gly water solution .Connection between the pure water flux and the rate of AAc grafting was analysed, indicating the rate of AAc grafting was less than 10 % , permeability was little, while more than 10%, with increasing of grafting rate , the flux increase , when arriving at 17 %, the flux was maximum, subsequently reducing. And PP — g—AAc was sensitive to pH, the flux was more in acidic solution than that in alkaline solution, with "on-off" characteristic. The influence of pH on the flux of PP—g—Gly was not apparent, and it was used to solution with a great range of pH.Filtration performances on the bovine serum albumin(BSA) and membrane fouling were studied. The results suggested the rate of BSA filtrating for PP—g—AAc and PP —g —Gly membrane were higher than for PP membrane.pH affected on membrane fouling. pH=4.7, The pure water flux of PP—g—AAc and PP—g—Gly membrane, decreased rapidly, and fouling was the worst.While pH=3 and pH=8, the capability of anti-fouling of PP —g—Gly was better than PP —g—AAc.