The poly(isoprene-b-styrene-b-4-vinylpyridine) triblock terpolymer (ISV) used was synthesized using a sequential anionic polymerization technique. The concentration of the polymer was kept under 10 wt % throughout the procedure. ~500 mL of benzene was distilled into a 1 L reactor and the anionic initiator sec-BuLi was added to the reactor in a glove box via syringe. Distilled isoprene was added to the reactor and allowed to polymerize for a minimum of 8 hours before a 5 mL aliquot was terminated with methanol for GPC analysis. Distilled styrene was then added to the reactor in the glove box via syringe. The styrene polymerized onto the polyisoprene block for 36 h, after which a small aliquot was terminated with methanol for GPC and NMR analysis. The benzene was subsequently removed from the reactor and a 10× molar excess of diphenylethylene (DPE) was added relative to the sec-BuLi. Approximately 500 mL of THF was distilled directly into the reactor, which was then cooled to -78 °C and distilled 4- vinylpyridine was added. The 4-vinylpyridine polymerized onto the poly(isoprene-b-styrene) for 1.5 h, after which the triblock terpolymer was terminated with degassed methanol. The final terpolymer was dissolved in chloroform and twice precipitated into metanol (Taken from: Phillip, W. A., Mika Dorin, R., Werner, J., Hock, E. M., Wiesner, U. & Elimelech, M. (2001). Tuning structure and propesties of graded triblock terpolymer-based mesoporous and hybrid films. Nano letters, 11(7), 2892-2900). Three block copolymers with different molecular weights were synthesized. The chains of each polymer was expected to be similar in each block copolymer, so the relation between the molecular weight and the permeability and diffusion was not affected by the volumen fractions of each homopolymer. The ISV block copolymers had a molecular weight of 43, 99 and 119 kilograms per mol. In order to cast the membranes, each polymer was disolved in a solvent system of 1,4-Dioxane (DOX) and Tetrahydrofuran (THF) in a proportion of 7 to 3 respectively. Each solution had a different conectration of the polymer, ISV43, ISV99, and ISV119 used concetration of 15%, 12% and 11% respectively, these concentrations were found to be thin enough to cast a membrane out of the solution, but thick enough to not have bubbles of be soaked by the nylon support, The solutions were stirred for 2 hours and then casted over a 0.1 micron thick nylon support. The nylon simulates the material of the protective suit, it is permeable enough to not affect the permeability of the membrane itself. The casting was carried using a Doctor Blade with a gate height of 220um and allowed to evaporate for a hundred seconds and then plunged into a non solvent bath (deionized water) for the next 6 minutes. To keep the properties and pores unchanged, the membranes were kept in deionized water (DI) until the experiments. Membranes were caracterized with their pore size distribution, permeability and diffusion. Pore size distributions was obtain using an scattering electron microscope (SEM), SEM micrographs were acquired using a Tescan Mira3 field emission scanning electron miscrope (FE-SEM) equipped with an in lens detector. Prior to SEM imaging, samples were coated with Au-Pd for 6 s using a Denton Vacuum Desk II sputter coater. A 10 mL stirred dead-end ultrafiltration test cell (Amicon 8010, Millipore, effective area 4.1 cm2) was used in the water flux and solute rejection tests. The feed solution was stirred at 400 rpm in all of the experiments. The applied pressures on the cell were in between 0.03&ñ8722;0.25 bar. A sideby-side diffusion cell (PermeGear) was used to study the diffusion of !ve model proteins through our membranes. The system consists of two chambers with 6 mL volumes, namely the donor (right chamber) and the receptor compartment (left chamber).