News tagged with membrane
High-purity hydrogen generated from a single device
(PhysOrg.com) -- There are many ways to generate hydrogen, such as water electrolysis and steam reforming of gas, but the hydrogen produced by these methods tends to be combined with other byproduct and residual ...
Oct 07, 2011 |
4.5 / 5 (15) |
17
|
New method offers control of strain on graphene membranes
(PhysOrg.com) -- Graphene could be the superhero of materials – it’s light, strong and conducts heat and electricity effectively, which makes it a great material for potential use in all kinds of ...
Nanotechnology / Nanomaterials
Apr 02, 2012 |
5 / 5 (3) |
0
|
Researchers present a shiny new tool for imaging biomolecules
At the heart of the immune system that protects our bodies from disease and foreign invaders is a vast and complex communications network involving millions of cells, sending and receiving chemical signals ...
Mar 23, 2012 |
5 / 5 (4) |
0
|
Unique salt allows energy production to move inland
Production of energy from the difference between salt water and fresh water is most convenient near the oceans, but now, using an ammonium bicarbonate salt solution, Penn State researchers can combine bacterial ...
Technology / Energy & Green Tech
Mar 01, 2012 |
4.5 / 5 (15) |
2
|
New insights on an old polymer material, Nafion, will enable design of better batteries
Designing new materials depends upon understanding the properties of today's materials. One such material, Nafion, is a polymer that efficiently conducts ions (a polymer electrolyte) and water through its ...
Jun 19, 2011 |
4.8 / 5 (6) |
0
|
Researchers get a first look at the mechanics of membrane proteins
In two new studies, researchers provide the first detailed view of the elaborate chemical and mechanical interactions that allow the ribosome – the cell's protein-building machinery – to insert a ...
Apr 17, 2011 |
5 / 5 (2) |
2
|
First macro-scale thin-film solid-oxide fuel cell demonstrated
(PhysOrg.com) -- Materials scientists at the Harvard School of Engineering and Applied Sciences (SEAS) and SiEnergy Systems LLC have demonstrated the first macro-scale thin-film solid-oxide fuel cell (SOFC).
Nanotechnology / Nanomaterials
Apr 04, 2011 |
4.8 / 5 (14) |
8
|
Rapid, high-definition chemistry with new imaging technique
With intensity a million times brighter than sunlight, a new synchrotron-based imaging technique offers high-resolution pictures of the molecular composition of tissues with unprecedented speed and quality. ...
Chemistry / Analytical Chemistry
Mar 20, 2011 |
5 / 5 (5) |
0
|
A second pathway for antidepressants: New fluorescent assay reveals TREK1 mechanism
(PhysOrg.com) -- Using a unique and relatively simple cell-based fluorescent assay they developed, scientists with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) ...
Medicine & Health / Medical research
Feb 07, 2011 |
5 / 5 (3) |
0
|
Polymer membranes with molecular-sized channels that assemble themselves
(PhysOrg.com) -- Many futurists envision a world in which polymer membranes with molecular-sized channels are used to capture carbon, produce solar-based fuels, or desalinating sea water, among many other ...
Nanotechnology / Nanomaterials
Jan 11, 2011 |
5 / 5 (2) |
1
|
Bioengineers discover how particles self-assemble in flowing fluids
(PhysOrg.com) -- From atomic crystals to spiral galaxies, self-assembly is ubiquitous in nature. In biological processes, self-assembly at the molecular level is particularly prevalent.
Dec 13, 2010 |
4.6 / 5 (5) |
0
|
Speeding up drug discovery with rapid 3-D mapping of proteins
A new method for rapidly solving the three-dimensional structures of a special group of proteins, known as integral membrane proteins, may speed drug discovery by providing scientists with precise targets ...
May 30, 2012 |
5 / 5 (2) |
0
|
A cell's first steps: Building a model to explain how cells grow
A collaboration between Lehigh University physicists and University of Miami biologists addresses an important fundamental question in basic cell biology: How do living cells figure out when and where to grow?
May 18, 2012 |
5 / 5 (2) |
0
|
'Copper pump's' potential benefit in cancer treatment
(Phys.org) -- A team of University of California, San Diego researchers has made new discoveries about a copper-transporting protein in the membranes of human cells that drug-discovery scientists can co-opt ...
May 17, 2012 |
4 / 5 (3) |
0
|
Research reveals novel transport mechanism for large ribonucleoproteins
The movement of genetic materials, such as RNA and ribosomes, from the nucleus to the cytoplasm is a critical component in a cell's ability to make the proteins necessary for essential biological functions. Until now, it ...
May 10, 2012 |
5 / 5 (1) |
0
|
Membrane
A membrane is a layer of material which serves as a selective barrier between two phases and remains impermeable to specific particles, molecules, or substances when exposed to the action of a driving force. Some components are allowed passage by the membrane into a permeate stream, whereas others are retained by it and accumulate in the retentate stream.
Membranes can be of various thickness, with homogeneous or heterogeneous structure. Membrane can also be classified according to their pore diameter. According to IUPAC, there are three different types of pore size classifications: microporous (dp < 2nm), mesoporous (2nm < dp < 50nm) and macroporous (dp > 50nm). Membranes can be neutral or charged, and particles transport can be active or passive. The latter can be facilitated by pressure, concentration, chemical or electrical gradients of the membrane process. Membranes can be generally classified into three groups: inorganic, polymeric or biological membranes. These three types of membranes differ significantly in their structure and functionality.
For more information about Membrane, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
