|
Hollow Fiber Membrane
Hollow fiber membranes (HFMs) are a class of artificial membranes containing a semi-permeable barrier in the form of a hollow fiber. Originally developed in the 1960s for reverse osmosis applications, hollow fiber membranes have since become prevalent in water treatment, desalination, cell culture, medicine, and tissue engineering. Most commercial hollow fiber membranes are packed into cartridges which can be used for a variety of liquid and gaseous separations. Manufacturing HFMs are commonly produced using artificial polymers. The specific production methods involved are heavily dependent on the type of polymer used as well as its molecular weight. HFM production, commonly referred to as "spinning," can be divided into four general types: * Melt Spinning, in which a thermoplastic polymer is melted and extruded through a spinneret into air and subsequently cooled. * Dry Spinning, in which a polymer is dissolved in an appropriate solvent and extruded through a spinneret i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synthetic Membrane
An artificial membrane, or synthetic membrane, is a synthetically created membrane which is usually intended for separation purposes in laboratory or in industry. Synthetic membranes have been successfully used for small and large-scale industrial processes since the middle of twentieth century.Pinnau, I., Freeman, B.D., ''Membrane Formation and Modification'', ACS, 1999. A wide variety of synthetic membranes is known.Osada, Y., Nakagawa, T., ''Membrane Science and Technology'', New York: Marcel Dekker, Inc,1992. They can be produced from organic materials such as polymers and liquids, as well as inorganic materials. The most of commercially utilized synthetic membranes in separation industry are made of polymeric structures. They can be classified based on their surface chemistry, bulk structure, morphology, and production method. The chemical and physical properties of synthetic membranes and separated particles as well as a choice of driving force define a particular membrane se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Porosimetry
Porosimetry is an Measurement, analytical technique used to determine various quantifiable aspects of a material's Porosity, porous structure, such as pore diameter, total pore volume, surface area, and Bulk density, bulk and absolute density, densities. The technique involves the intrusion of a wetting, non-wetting liquid (often Mercury (element), mercury) at high pressure into a material through the use of a porosimeter. The pore size can be determined based on the external pressure needed to force the liquid into a pore against the opposing force of the liquid's surface tension. A force balance equation known as Washburn's equation for the above material having Cylinder (geometry), cylindrical pores is given as: :P_L - P_G = -\frac :P_ = pressure of liquid :P_ = pressure of gas :\sigma = surface tension of liquid :\theta = contact angle of intrusion liquid :D_ = pore diameter Since the technique is usually performed within a vacuum, the initial gas pressure is zero. The co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microfiltration
Microfiltration is a type of physical filtration process where a contaminated fluid is passed through a special pore-sized membrane filter to separate microorganisms and suspended particles from process liquid. It is commonly used in conjunction with various other separation processes such as ultrafiltration and reverse osmosis to provide a product stream which is free of undesired contaminants. General principles Microfiltration usually serves as a pre-treatment for other separation processes such as ultrafiltration, and a post-treatment for granular media filtration. The typical particle size used for microfiltration ranges from about 0.1 to 10 μm.Baker, R 2012, ''Microfiltration, in Membrane Technology and Applications'', 3rd edn, John Wiley & Sons Ltd, California. p. 303 In terms of approximate molecular weight these membranes can separate macromolecules of molecular weights generally less than 100,000 g/mol.Microfiltration/Ultrafiltration, 2008, Hyflux Membranes, accesse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultrafiltration
Ultrafiltration (UF) is a variety of membrane filtration in which forces such as pressure or concentration gradients lead to a separation through a semipermeable membrane. Suspended solids and solutes of high molecular weight are retained in the so-called retentate, while water and low molecular weight solutes pass through the membrane in the permeate (filtrate). This separation process is used in industry and research for purifying and concentrating macromolecular (103–106 Da) solutions, especially protein solutions. Ultrafiltration is not fundamentally different from microfiltration. Both of these separate based on size exclusion or particle capture. It is fundamentally different from membrane gas separation, which separate based on different amounts of absorption and different rates of diffusion. Ultrafiltration membranes are defined by the molecular weight cut-off (MWCO) of the membrane used. Ultrafiltration is applied in cross-flow or dead-end mode. Applications Ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanofiltration
Nanofiltration is a membrane filtration process used most often to soften and disinfect water. Overview Nanofiltration is a Membrane technology, membrane filtration-based method that uses nanometer sized pores through which particles smaller than 10 nanometers pass through the membrane. Nanofiltration membranes have pore sizes from 1-10 nanometers, smaller than that used in microfiltration and ultrafiltration, but a little bit bigger than that in reverse osmosis. Membranes used are predominantly created from polymer thin films. Materials that are commonly used include polyethylene terephthalate or metals such as aluminum. Pore dimensions are controlled by pH, temperature and time during development with pore densities ranging from 1 to 106 pores per cm2. Membranes made from polyethylene terephthalate and other similar materials, are referred to as "track-etch" membranes, named after the way the pores on the membranes are made. "Tracking" involves bombarding the polymer thin fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reverse Osmosis
Reverse osmosis (RO) is a water purification process that uses a partially permeable membrane to separate ions, unwanted molecules and larger particles from drinking water. In reverse osmosis, an applied pressure is used to overcome osmotic pressure, a colligative property that is driven by chemical potential differences of the solvent, a thermodynamic parameter. Reverse osmosis can remove many types of dissolved and suspended chemical species as well as biological ones (principally bacteria) from water, and is used in both industrial processes and the production of potable water. The result is that the solute is retained on the pressurized side of the membrane and the pure solvent is allowed to pass to the other side. To be "selective", this membrane should not allow large molecules or ions through the wiktionary:pore, pores (holes), but should allow smaller components of the solution (such as solvent molecules, e.g., water, H2O) to pass freely. In the normal osmosis process, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Synthetic Polymers
Some familiar household synthetic polymers include: Nylons in textiles and fabrics, Teflon in non-stick pans, Bakelite for electrical switches, polyvinyl chloride (PVC) in pipes, etc. The common PET bottles are made of a synthetic polymer, polyethylene terephthalate. The plastic kits and covers are mostly made of synthetic polymers like polythene, and tires are manufactured from Buna rubbers. However, due to the environmental issues created by these synthetic polymers which are mostly non-biodegradable and often synthesized from petroleum, alternatives like bioplastics are also being considered. They are however expensive when compared to the synthetic polymers. Inorganic polymers *Polysiloxane *Polyphosphazene * Polyborazyline Organic polymers The eight most common types of synthetic organic polymers, which are commonly found in households are: *Low-density polyethylene (LDPE) *High-density polyethylene (HDPE) *Polypropylene (PP) * Polyvinyl chloride (PVC) *Polystyrene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cultured HFM DAPI
Culture () is an umbrella term which encompasses the social behavior, institutions, and norms found in human societies, as well as the knowledge, beliefs, arts, laws, customs, capabilities, and habits of the individuals in these groups.Tylor, Edward. (1871). Primitive Culture. Vol 1. New York: J.P. Putnam's Son Culture is often originated from or attributed to a specific region or location. Humans acquire culture through the learning processes of enculturation and socialization, which is shown by the diversity of cultures across societies. A cultural norm codifies acceptable conduct in society; it serves as a guideline for behavior, dress, language, and demeanor in a situation, which serves as a template for expectations in a social group. Accepting only a monoculture in a social group can bear risks, just as a single species can wither in the face of environmental change, for lack of functional responses to the change. Thus in military culture, valor is counted a typical be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extracorporeal Membrane Oxygenation
Extracorporeal membrane oxygenation (ECMO), also known as extracorporeal life support (ECLS), is an extracorporeal technique of providing prolonged cardiac and respiratory support to persons whose heart and lungs are unable to provide an adequate amount of gas exchange or perfusion to sustain life. The technology for ECMO is largely derived from cardiopulmonary bypass, which provides shorter-term support with arrested native circulation. The device used is a membrane oxygenator, also known as an artificial lung. ECMO works by temporarily drawing blood from the body to allow artificial oxygenation of the red blood cells and removal of carbon dioxide. Generally, it is used either post-cardiopulmonary bypass or in late-stage treatment of a person with profound heart and/or lung failure, although it is now seeing use as a treatment for cardiac arrest in certain centers, allowing treatment of the underlying cause of arrest while circulation and oxygenation are supported. ECMO is als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Membrane Oxygenator
A membrane oxygenator is a device used to add oxygen to, and remove carbon dioxide from the blood. It can be used in two principal modes: to imitate the function of the lungs in cardiopulmonary bypass (CPB), and to oxygenate blood in longer term life support, termed extracorporeal membrane oxygenation (ECMO). A membrane oxygenator consists of a thin gas-permeable membrane separating the blood and gas flows in the CPB circuit; oxygen diffuses from the gas side into the blood, and carbon dioxide diffuses from the blood into the gas for disposal. History The history of the oxygenator, or artificial lung, dates back to 1885, with the first demonstration of a disc oxygenator, on which blood was exposed to the atmosphere on rotating discs by Von Frey and Gruber. These pioneers noted the dangers of blood streaming, foaming and clotting. In the 1920s and 30s, research into developing extracorporeal oxygenation continued. Working independently, Brukhonenko in the USSR and John Heysha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hollow Fiber Bioreactor
A Hollow fiber bioreactor is a 3 dimensional cell culturing system based on hollow fibers, which are small, semi-permeable capillary membranes arranged in parallel array with a typical molecular weight cut-off (MWCO) range of 10-30 kDa. These hollow fiber membranes are often bundled and housed within tubular polycarbonate shells to create hollow fiber bioreactor cartridges. Within the cartridges, which are also fitted with inlet and outlet ports, are two compartments: the intracapillary (IC) space within the hollow fibers, and the extracapillary (EC) space surrounding the hollow fibers. Cells are seeded into the EC space of the hollow fiber bioreactor and expand there. Cell culture medium is pumped through the IC space and delivers oxygen and nutrients to the cells via hollow fiber membrane perfusion. As the cells expand, their waste products and CO2 also perfuse the hollow fiber membranes and are carried away by the pumping of medium through the IC space. As waste products build up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Synthetic Membrane")
_ECMO_for_cardiac_or_respiratory_failure.jpg "Click for more on -> Extracorporeal Membrane Oxygenation")