Filtration Membranes
Some basic information on filtration membranes can be found at http://www.engineersedge.com/filtration/membrane-filtration-review.htm.
Common materials used include MCE (nitrocellulose), cellulose acetate, coated and hydrophobic teflon, nylon, polycarbonate, and glass, typically placed within an autoclave for sterilization.
The following are samples of filtration systems:
Simply put, a membrane is a barrier that is used to control the flow of certain substances, allowing some to pass through while preventing others through the use of pores. Membrane filtration is a technique that purifies a liquid by separating its particles. The goal is to create a filtered solvent composed of only whatever materials are desired in the liquid. Different types of systems are available from companies which specialize in filtration products, including replacement membranes.
The process generally involves a solvent which is passed through a semi-permeable membrane which is determined by the pores in the membrane. On one side of the membrane the fluid is passed through and has become purified, while the remaining separated solute stays on the other side of the membrane.
Techniques
Nanofiltration
Membrane blocks impurities in the fluid to only allow the fluid and some ions to pass through the membranes. Used in milk, drinking water.
Microfiltration
Pores range from 1-10 nanometers. Used in cold sterilization (bacteria), wastewater.
Ultrafiltration
Hydrostatic pressure forces a liquid against a semi-permeable membrane. Concerns macromolecular solutions, such as protein (milk, blood treatments, wastewater).
Manufacturers
http://www.nalgenelabware.com/techdata/application/filterware.asp
Nalgene Filterware. Includes membranes of various materials and sizes, including disposable filterware.
http://www.millipore.com/catalogue/module/c152 http://www.millipore.com/lab_filtration/clf/capability
Millipore. Contains multiple types of filtration systems adapted to many different uses including diameter size, capacity, rate of flow, and control.
http://www.whatman.com/FilterPapers.aspx http://www.whatman.com/FiltrationDevices.aspx
Whatman. Syringeless and Syringe Filters.
http://www.filtrationsystems.com/home.htm
Filtration Systems - Liquid Filter Housings, “Over-The-Top” design, “Zero-Bypass” bag collar, 360-degree seal, traps solids, provides lowest working heights, minimizes accidents and exposure to liquids, ensures for accurate monitoring and safe use, ASME specifications, available in T-304/T-316 Stainless Steel or Carbon Steel
http://www.anrodscreen.com/filters.html
Miniature filters, inline filters, synthetic filters, assemblies.
http://www.townerfiltration.com/
Liquid and gas filtration products, owned and operated by MEI - Marchant Enterprises, Inc. Products include string wound filters, pleated filter elements, filter bags, membrane elements, filter housings, filter paper, roll media, strainers, air filters/HVAC applications, and coalescer and separator cartridges.
http://www.keystonefilter.com/
Industrial, drinking water, and custom filter products. Standard industrial filter catridges include polypropylene filters, microfiberglass filters, “HPT” cartridges, and nano-key cartridges (used in water and wastewater filtration).
Other:
