Explanation
Ultrafiltration membrane, also known as molecular sieve membrane, is a kind of microporous filtration membrane, and its rated pore size range is usually between 1 and 20 nanometers. Under appropriate pressure (usually 345 to 689 kPa), ultrafiltration membrane allows water and small molecular substances with a volume smaller than the micropore of membrane surface to pass through, while retaining substances with a volume larger than the micropore of membrane surface. ultrafiltration membrane can intercept large solute molecules with molecular weight greater than 500 and particles with diameter greater than 10 nm. The separation process of ultrafiltration membrane is realized by taking the pressure difference between the two sides of the membrane as the driving force and using ultrafiltration membrane as the filtering medium under a certain pressure. When the original solution flows through the membrane surface, water and small molecule substances pass through the membrane, becoming the permeate. However, substances in the original solution with a volume larger than the micropores on the membrane surface are intercepted on the inlet side of the membrane, forming a concentrated solution. This can achieve purification, separation, and concentration of the original solution. ultrafiltration membrane can intercept particles, colloids, bacteria, macromolecule organics and some viruses in water, but cannot intercept inorganic ions and small molecular substances. The membrane materials of ultrafiltration membrane mainly include cellulose and its derivatives, polycarbonate, polyvinyl chloride, polyvinylidene chloride, polysulfone, polyacrylonitrile, polyamide, polysulfonamide, sulfonated polysulfone, crosslinking polyvinyl alcohol, modified acrylic polymer, etc. ultrafiltration membrane can be made into flat facial mask, roll membrane, tubular membrane or hollow fiber membrane and other forms, which are widely used in the pharmaceutical industry, food industry, environmental engineering and other fields.
Classification
Special functional materials -> Environmental treatment materials -> Water pollution treatment and purification materials