Nature has created many organisms and cells, but in spite of this, most of the structure and functions of biological membranes are the same that allows us to consider the structure and examine its key properties without attachment to a particular type of cell.
What is membrane?
membranes - a protective element, which is an integral part of the cell of any living organism.
structural and functional unit of all living organisms on the planet is a cell.Vital functions it is inextricably linked with the environment, with which it exchanges energy, information and matter.Thus, nutritional energy necessary for the functioning of cells, comes from outside and is spent on the implementation of its various functions.
structure is simple unit structure of a living organism: the cell membrane, nucleus, organelles, a variety of inclusions.It is surrounded by a membrane, which is located within the nucleus and all organelles.It mitochondria, lysosomes, ribosomes, Golgi apparatus, endoplasmic reticulum.Each structural element has a diaphragm.
role in the life of cells
biological membranes plays a role culminating in the structure and functioning of the elementary living system.Only the cells surrounded by a protective sheath, can rightfully be called the body.Such a process as metabolism, is also carried out thanks to the membrane.If the structural integrity of its broken, this leads to a change in the functional state of the organism as a whole.
cell membrane and its functions
It separates the cytoplasm from the environment or from the shell.The cell membrane allows the proper discharge of specific functions, the specifics of cell-cell contacts and immune manifestations, supports the transmembrane electric potential difference.It has receptors designed to detect chemical signals - hormones, neurotransmitters, and other biologically active components.These receptors endow it with another ability - to change the metabolic activity of cells.
membrane functions:
1. The active transport of substances.
2. Passive transfer of substances:
2.1.Diffusion simple.
2.2.Moving through the pores.
2.3.Transport, implemented by diffusion membrane transporter with the substance, or by transmission relay agent on the molecular chain transporter.
3. Transfer of non-electrolytes thanks to a simple and facilitated diffusion.
4. Active transport of ions.
structure of the cell membrane
components of the cell membrane - lipid and protein.
Lipids: phospholipids, phosphatidylethanolamine, sphingomyelin, phosphatidylserine and phosphatidylinositol, glycolipids.The proportion of lipid is 40-90%.
Proteins: peripheral, integrated (glycoproteins), spectrin, actin cytoskeleton.
main structural element - a double layer of phospholipid molecules.
Roofing membrane: definition and typology
Some statistics.On the territory of the Russian Federation as a membrane roofing material is used not so long ago.The proportion of membrane roofing of total soft Roofs is only 1.5%.A more widespread in Russia received a mastic asphalt and roofing.But in Western Europe, the share of membrane roofs account for 87%.The difference is palpable.
Typically, the membrane as the primary material in the ceiling of the roof is perfect for flat roofs.For those who have a large slope it is suitable to a lesser extent.
volume of production and sales of membrane roofing in the domestic market have a positive growth trend.Why is that?Reasons more than clear:
- service life of about 60 years.Imagine the only use of the warranty period, which is set by the manufacturer, up to 20 years.
- Easy to install.For comparison: the installation of asphalt roofing takes 1.5 times longer than the installation of the membrane overlap.
- Easy maintenance and repair work.
thickness of roofing membranes can be 0.8-2 mm, and the average weight of one square meter is equal to 1.3 kg.
Properties roofing membranes:
- elasticity;
- strength;
- resistance to UV rays and other media aggressor;
- frost;
- fire resistance.
membrane roof is of three types.The main feature of the classification - the form of the polymer material constituting the base fabric.So, roofing membranes are:
- EPDM.Membranes belonging to the group of EPDM manufactured based on polymerized ethylene-propylene-diene-monomer, or more simply, a synthetic rubber.Advantages: high strength, elasticity, water resistance, environmental friendliness, low cost.Disadvantages: adhesive technology connection webs by using a special tape, low resistance connections.Application: used as a waterproofing material for tunnel floors, water sources, waste storage, artificial and natural water bodies and so on. D.
- PVC membrane.This shell, in the production of which is used as a base material PVC.Advantages: resistant to UV, fire resistance, an extensive range of colors of the membrane cloths.Disadvantages: low levels of resistance to bituminous materials, oils, solvents;emits harmful substances;color fabric fades with time.
- TPO.They are made of thermoplastic olefins.It can be reinforced and unreinforced.First fitted mesh of polyester or fiberglass fabric.Advantages: environmentally friendly, durable, high elasticity, heat resistance (at both high and low temperatures), welded connection joints webs.Disadvantages: high price category, the lack of manufacturers in the domestic market.
profiled membrane: characteristics, features and advantages
profiled membrane - an innovation in the construction market.Such a membrane is operated as a waterproofing material.
substances used in the manufacture of - polyethylene.Last comes in two types: high-density polyethylene (LDPE) and high density polyethylene (HDPE).
| index | LDPE | IPA |
| Tensile strength (MPa) | 13 |
23 |
| tensile elongation (%) | 400 | 100 |
| Density (kg / cu. m) | 917-930 | 948-952 |
| Compressive strength (MPa) | 12 | 20-36 |
| impact strength (notched) (kJ / kV.m) | - | 2-50 |
| flexural modulus of elasticity (MPa) | 140-250 | 600-850 |
| Hardness (MPa) | 14-25 | 45-59 |
| Operating temperature (? C) | from -60 to +80 | from -60 to +80 |
| daily rate of water absorption (%) | 0,01 | 0,01 |
profiled membrane made of high density polyethylene has a special surface - hollow pimples.The height of these structures can vary from 7 to 20 mm.The inner surface of the membrane is flat.This enables trouble-free bending of building materials.
Reshaping separate parts of the membrane is possible because the pressure over its entire area is evenly distributed due to the presence of the same projections.Geomembrane can be used as a ventilation insulation.In this case, the heat is provided by a free exchange within the building.
profiled membrane advantages:
- increased strength;
- thermal stability;
- stability of chemical and biological influence;
- long life (50 years);
- easy to install and maintain;
- reasonable price.
profiled membrane are of three types:
- with single blade;
- two-layer cloth = + drainage geotextile membrane;
- with a three-layer canvas slippery surface + = + drainage geotextile membrane.
profiled single-layer membrane is used to protect the main waterproofing, installation and dismantling of the preparation of a concrete wall with high humidity.A two-layer protective equipment used during the near-wall drainage.Consisting of three layers applied on the ground, which is amenable to frost heaving, soil and groundwater, located deep.
Areas of drainage membranes
profiled membrane finds its application in the following areas:
- main basement waterproofing.Provides protection from the destructive influence of groundwater, the root systems of plants, land subsidence, damage of mechanical type.
- Wall drainage foundation.Neutralizes the effects of groundwater and rainwater through ferrying them to the drainage system.
- Horizontal drainage reservoir type - protection against deformation due to structural features.
- analogue of concrete preparation.It is maintained in the case of construction work on the buildings in the low groundwater in those cases where a horizontal waterproofing to protect against capillary moisture.Also features a shaped membrane comes nontransmission cement grout into the ground.
- ventilation wall surfaces of elevated levels of humidity.It can be installed both on the inside and on the outside of the premises.In the first case, the air circulation is activated, and the second is the optimal humidity and temperature.
- used inversion roofing.
superdiffuzionnye membrane
superdiffuzionnaya membrane material is a new generation, whose main purpose - the protection of elements of the roof structure of the phenomena of wind, rain, couple.
protective material production based on the use of non-woven materials, dense fibers of high quality.In the domestic market popular three-layer and four-layer membrane.Reviews professionals and consumers confirm that the more layers underlying structure, the greater its protective function, and thus higher efficiency and space in general.
Depending on the type of roof, its design features, climate, manufacturers recommend to give preference to one or another form of diffusion membranes.So, there they pitched roofs to complex and simple structures, pitched roofs with minimum slope types for standing seam roofs with coating and so on. D.
superdiffuzionnye membrane is laid directly on the insulating layer, flooring boards.Required ventilation gap there.Fastened material special steel nails or staples.The edges of the diffusion sheets are joined mounting tape.Installation work must be carried out even under extreme conditions: in the frosty morning, with strong gusts of wind, and so on. D.
Also viewed coating can be used as a temporary overlap of the roof.
PVC membrane: the nature and purpose
TFC membrane - this is the material for the roof, made of PVC and has elastic properties.This modern roofing material does ousted bitumen roll analogs having a significant drawback - the need for systematic maintenance and repair.To date, the characteristics of PVC membranes allow to use them during the repair work on the old roofs of the flat type.They are used and the installation of new roofs.
roof of a material easy to operate, and its installation is possible on any type of surface, in all seasons and in all weather conditions.PVC membrane has the following properties:
- strength;
- stability when exposed to UV rays, various types of precipitation, surface and point loads.
It is thanks to the unique properties of PVC membrane will serve you faithfully for many years.Term of use of such a roof is equal to the life of the building, while the roll roofing materials require regular maintenance, and in some cases at all in dismantling and installing a new ceiling.
between a membrane made of PVC fabric joined by welding with hot breath, the temperature is in the range of 400-600 degrees Celsius.This connection is absolutely airtight.
Advantages of PVC membranes
dignity of their obvious:
- flexible roofing system that best suits the construction project;
- durable, having leakproof properties connecting seam between the diaphragm blades;
- perfect portability of climate change, weather conditions, temperature, humidity;
- increased water vapor permeability, which promotes evaporation of moisture accumulated in the roof space;
- many options of colors;
- fire properties;
- ability to maintain a long period of initial properties and appearance;
- PVC membrane - completely harmless material, which is confirmed by the relevant certificates;
- installation process is mechanized, so do not take long;
- operating rules allow the installation of various architectural additions directly on top of the roof membrane of PVC;
- -layer stacking save you money;
- easy maintenance and repair.
membrane fabric
membrane fabric textile industry has long been known.From such material produced shoes and clothing: adult and children.Membrane - based membrane cloth provided as a thin polymer film and having characteristics such as water resistance and vapor permeability.For the production of this film material is coated outer and inner protective layers.Their structure determines the membrane itself.This is done in order to preserve all the beneficial properties even in case of damage.In other words, the clothes are not waterproof membrane under the influence of precipitation in the form of snow or rain, but at the same time, great passes steam from the body to the external environment.This bandwidth allows the skin to breathe.
Considering all the above, we can conclude that the fabric is made of a similar ideal winter clothes.The membrane, which is in the basis of fabric, there may be:
- with pores;
- without pores;
- combined.
As part of the membrane having a plurality of micropores, the number of Teflon.The amount of such size has not reached even a drop of water, but most of the water molecules, which indicates the ability to excrete water resistance and sweat.
membranes, which have been usually made of polyurethane.Their inner layer concentrates in itself all potozhirovye allocation body and pushes them out.
membrane structure implies a combination of two layers of porous and smooth.This fabric has high quality characteristics and will last for many years.
Due to these advantages of clothes and shoes, made from membrane fabrics and designed to wear in the winter time of the year, durable, but lightweight, excellent protection against frost, moisture, and dust.They are indispensable for a variety of types of active winter recreation, mountain climbing.
