Study On Preparation Of Ultrafiltration Membrane With Antibacterial And Anti-fouling Performance By Blend Modification

At present,there has been enough attention on the ultrafiltration (UF) membranefor different applications. It is an extremely urgent problem to resolve the UFmembrane biofouling. In order to bring the hydrophilic and antibacterial properties toPolyether sulfone(PES).Our previous study has acquired great progress by theacrylamide with capsaicin derivate structure modified UF membrane.This paper usedthe immersion precipitation phase-inversion method and dry-wet spinning method toprepare PES flat membrane and hollow filber membrane and adopted blendingmodification to modify UF membrane.In order. to investigate characteristics of PESUF membrane,some characterization methods are applied such as the FTR-IR, SEM，AFM， contact angle etc. Through these methods we can investigat surfacecomposition morphology,surface roughness, hydrophilicand mechanical propertiesofmembrane.First of all,the acrylamide with capsaicin derivate structure is a kind of vi-nyl monomers and own polymerizability, which can prepare polymer that posses antibacterial property by applying the Thermal-Initiation solution polymerization and Photo-Initiation solution polymerization. And the polymer were synthetized by N-(4-hydroxy-3-methyl benzyl)acrylamide (HMOBA,a kind ofacrylamide with capsaicin derivate structure), acrylic acid (AA), methyl methacrylate (MMA). We studied which method is more appropriate for synthetizing this kind of polymer through antibacterial rate. The resu-lts indicate that, under the same polymerization formula, antibacterial rate of HOAM1which preparedby Thermal-Initiation polymerizing for4h is80.84%while antibacterial rate ofHOAM2which prepared by ultraviolet radiation polymerizing for1h reach upto85.05%. Antibacterial properties of antibacterial polymer with UV polymerization are better and the reaction time is shorter. Compared antibacterial rate of the HOAM2,HOAM3and HOAM4,the antimicrobial properties of HMOBAare better than that of HAM. When the ultraviolet radiation is prolonged for2.0h, the antibacterial rate of HOAM4can reach up to95.37%, which show that thelonger ultraviolet radiati-on can improve the antimicrobial properties of polymer.Secondly, the effect of HOAM4dosage on PES flat membrane is investigated inthis paper. The results indicate that the addition of PVP own pore-formingfunction.And HOAM4can’t be a pore-forming agent in this system,but it can improvethe hydrophily of UF membrane surface,Static water contact Angle of membranesuanface is57.56°when the content of HOAM4is3.0%,and it decrease14.35% compare unmodified membrane.PES UF membrane roughness reduce with theHOAM4content increasing. When the content of HOAM4is3.0%, UF membranesurface roughness is24.1%of unmodified membrane. The antibacterial property ofmembrane increases with the increasing of HOAM4. When the content of HOAM4was3%, the antibacterial rate of UF membrane for e. coli reaches up to90%.But thecontent of HOAM4range from1%to2%can bring better filtration property to UFmembrane.Last, the effect of temperature and composition of inner coagulation bath on theUF hollow fiber membrane pore structure and performance are taken intoconsideration. The results indicate that temperature and composition of innercoagulation bath have great effects on the hollow filter membrane performance. Withthe rise of coagulation bath temperature,inner membrane surface become more denseand ultra-thin skin layer become more thick. In that way,the rejection of UFmembrane increase whith the temperature increasing.And finger holes grow towardsto big hole, even produce large cave.The higher content of DMAc in the innercoagulation bath can make the pore size of membrane surface larger, ultra-thin skinlayer thinner,which result the lower rejection of membrane.The membrane possesmore hydrophilic functional groups and capsaicin derivate groups with the content ofHOAM4increase,so it can provide higher antibacterial and antifouling property tomemrane.And HOAM4can interwine with PES, this situation can improve themechanical strength and elongation at break of membrane.