Research Of Determination Of Pore Size And Distribution Of PVDF Hollow Fiber Porous Membrane

Membrane course comprised various separation problem, and in a certain course need a certain specific membrane. So the structure and function of membrane had prodigious difference. In order to choose membrane for specially separate role, we should sign the membrane, and that pore size was one of the most important parameter of membrane. At present a lot of methods have been used in determination pore size and distribution of membrane, but there had not simple method which fits for any pore size and can overlay all pore size in wide range.According to solid-liquid adsorption theory, in this paper a new method of determination pore size and distribution of porous membrane which was named liquid-liquid interfacial contact method was designed. Two mixed liquids' surface tension was lower than single part liquid's, so the pore size of porous membra ne could be determined in low press by two kinds of incompatible liquids. Alon g with testing press increased step by step, more small pore size were opened, t hat's to say, the pore number which liquid could permeate were increasing, accor dingly permeable liquid flux was increasing. According to fluid mechanical energ y balance theory, we can drew porous pore size distribution curve simply and sp eedly with measuring liquid flux under appoint press. Through the experimentatio n, surface tension of isobutanol and PVDF hollow fiber hydrophobic membrane was none, that's to say isobutanol wetted this membrane completely, and in expe rimentation excess press did not exist. So isobutanol was a good reagent for det ermination pore size and distribution of PVDF hollow fiber hydrophobic membra ne. The system of Poly(hydrogenmethyl-siloxane -co-Dimethyl-siloxane) (hydrogen content ^1.2%) and water could commendably determine pore size and distri b-ution of PVDF hollow fiber hydrophilic membrane.Then PMMA which was taken as standard substance was used in the method of solute cutting, investigating the influence of angent velocity and materials concentration to apparent cutting rate of PVDF hollow fiber membrane. Based on apparent cutting rate, the best operation condition could be found. Through the experimentation, the condition should be chose in allowable larger angent velocity as soon as possible while membrane setting achieved the flux in need. Larger angent velocity could bring on the apparent cutting rate in experimentation more adjacent real cutting rate. Materials concentration should be cortrolled lower in the range of examinable. Lower as materials concentration was, infection of difference concentration polarization and dynamic membrane in experimentation became less. Along with the concentration of PMMA standard paniculate increased, apparent cutting rate increased a little.