A semipermeable membrane is a type of biological or synthetic polymeric membrane that will allow certain molecules or ions to pass through it by diffusion - or sometimes with a more specialized process of facilitated diffusion, passive transport or active transport.. The rate of diversion depends on the pressure, concentration, and temperature of the molecule or solute on both sides, as well as the permeability of the membrane to each solute. Depending on the membrane and solute, permeability may depend on the size of solute, solubility, properties, or chemistry. How membranes are built to be selective in their permeability will determine their level and permeability. Many of the thicker natural and synthetic materials of the membrane are also semipermeable. One example is a thin film on the inside of an egg.
Note that the semipermeable membrane is not the same as the permeable selective membrane. The semipermeable membrane describes a membrane that allows some particles to pass through (by size), whereas the permeable selective membrane "selects" what passes (size is not a factor).
Video Semipermeable membrane
Biological membrane
Examples of biological semi-permeable membranes are lipid bilayers, which are based on the plasma membrane that surrounds all biological cells. A group of phospholipids (consisting of a phosphate head and two fatty acids) are arranged into a double layer, the phospholipid bilayer is a very specific semipermeable membrane in its permeability. The hydrophilic phosphate head is located in the outer layer and exposed to the water content outside and inside the cell. Hydrophobic tail is a hidden layer on the inside of the membrane. The most permeable bilayer of phospholipids for small charged charged solutes. The protein channels float through the phospholipids, and, collectively, this model is known as the liquid mosaic model.
Maps Semipermeable membrane
Reverse osmosis
The diffusion of water through a permeable selective membrane is called osmosis. This allows only certain particles to enter including water and leaving solutes including salts and other contaminants. In the reverse osmosis process, thin film composite membranes (TFC or TFM) are used. It is a semipermeable membrane that is manufactured primarily for use in water purification systems or desalination. They also have use in chemical applications such as batteries and fuel cells. Basically, TFC materials are molecular sieves that are constructed in the form of films of two or more layered materials. Prof. Sidney Loeb and Srinivasa Sourirajan invented the first practical synthetic semi-permeable membrane. Membranes used in reverse osmosis are generally made of polyamide, selected mainly because of their permeability to water and the impermeability relative to various dissolved impurities including salt ions and other non-filterable molecules. Another example of a semipermeable membrane is a dialysis tube.
Role in mobile communications
Semipermeable membrane is related to cellular communication. The cell membrane consists of proteins and phospholipids. Molecular signaling sends chemical messages to proteins in the cell membrane. The signaling molecule binds to the protein, which converts the protein. Messages are sent into cells and certain mobile responses are enabled or enabled.
Other types
Other semipermeable membrane types are cation exchange membranes (CEM), mosaic membrane load (CMM), bipolar membrane (BPM), anion exchange membrane (AEM) membrane anion exchange membrane (AAEM) and proton exchange membrane (PEM).
References
Further reading
-
Koros, W. J.; Ma, Y. H. & amp; Shimidzu, T. (1996). "Terminology for Membrane and Membrane Processes (Recommendation IUPAC 1996)" (PDF) . Pure Appl. Chem. 68 (7): 1479-1489. doi: 10.1351/pac199668071479. < span> Ã, See this document for the definition of permeant, synthetic (synthetic), and anion exchange membranes. - Rozendal, R.A.; Sleutels, T.H.; Hamelers, H.V. & amp; Buisman, C.J. (2008). "Effect of Membrane Ion Exchange Type on Performance, Ion Transport, and pH in Biocatalyzed Wastewater Electrolysis". Water Sci Technol . 57 (11): 1757-1762. doi: 10.2166/wst.2008.043. PMIDÃ, 18547927.
- "High Flow Porous Membranes to Separate Water from US Copy of Solution 3133132 A". May 12, 1964 . Retrieved April 22 2014 .
External links
- The European Membrane House, a nonprofit international association created to resume networking and parternships work developed at NanoMemPro, a network of European Union-funded European membrane researchers.
- The WiseGeek article is short, unscientific, "What is a Semipermeable Membrane.
Source of the article : Wikipedia
0 Comments