Use Of Antifreeze Compounds Biology Essay

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Antifreeze compounds are those substances which when mixed with some other liquid, lower its freezing points. in cold countries they are used in cooling system of cars and buses get frozen in winter months.

Antifreeze compounds are to prevent this freezing. In other instances, snows get deposited on the wings of the aircraft flying in the cold areas. To prevent this, antifreeze compounds are used. In cold storage, special materials are used as antifreeze compounds.

The main ingredient of an antifreeze compounds is, alcohol. Ethylene glycol is the basis of the most common antifreeze compounds. This compounds mixed with water is used in radiator of automobiles to lower its freezing point. It help the internal combustion system of an engine to function normally without being frozen in cold. In winter, this is also used with or without water, in order to prevent the freezing of the cooling system. Sometimes methyl alcohol is also used as an antifreeze compounds in internal combustion engines.

Ice is a big problem for organisms that live in cold climates.

Once the temperature dips below freezing, ice crystals steadily grow and burst cells. This danger, however, has

not limited the spread of life on Earth to temperate regions.

Fish have antifreeze compounds in their blood

Organisms of all types-plants, animals, fungi and

Bacteria-have developed ways to combat the deadly growth of ice crystals. In

some cases, they pack their cells with small antifreeze compounds like sugar

or glycerol. But in cases where extra help is needed, cells

make specialized antifreeze proteins to protect themselves as the temperature drops.

Antifreeze proteins don't stop the growth of icecrystals,

but they limit the growth to manageable sizes. For this reason, they are also known as ice-restructuring proteins. This is necessary because of an unusual property of ice called recrystallization. When water begins to freeze,many small crystals form, but then a few smallcrystals dominate and grow larger and larger,stealing water molecules from the surroundingsmall crystals. Antifreeze proteins counteract this, recrystallization effect.

They bind to the surface of the small ice crystals and slow or preventthe growth into larger dangerous crystals


Antifreeze proteins lower the freezing point of water by a few degrees, but surprisingly, they don't change the melting point. This process of depressing the freezing point while not effecting the melting point is termed thermal hysteresis.

The most effective antifreeze proteinsare made by insects, which lower the freezing point by about 6 degrees. However, antifreezeproteins, even the ones from plants and bacteria that have smaller effects on freezing point, are useful in another way. They are placed outside cells where they control the size of ice crystals and prevent catastrophic ice crystal formation when the temperature drops below the) freezing point.

Icy Ice Cream

Antifreeze proteins have been useful in industry. For instance, natural antifreeze proteins purified from cold-water ocean pout (shown here from PDB entry 1kdf) have been used as a preservative in ice cream. They coat the fine ice crystals that give ice cream its smooth texture, and prevent it from re crystallizing during storage a delivery into chunky, icy ice cream. Researchers are also experimenting with antifreeze proteins as a way to preserve tissues and organs that are stored at low temperatures, reducing the possible damage from ice crystals.

Ice is a big problem for organisms that live in cold climates. Once the temperature dips below freezing, ice

Crystals steadily grow and burst cells. This danger,

However, has not limited the spread of life on Earth to temperate regions


In some cases, they pack their cells with small antifreeze compounds like sugars or glycerol. But in cases where extra help is needed, cells make specialized antifreeze proteins to protect themselves as the temperature drops.


It is widely used in an automotive context, corrosion inhibitors are also added to help protect vehicles' cooling systems, which often contain a range of electrochemically incompatible metals (aluminium ,cast iron, copper, lead solder, etc.).

It is developed to overcome the shortcomings of water as a heat transfer fluid. In most engines, freeze plugs are placed in the engine block which could protect the engine if no antifreeze was in the cooling system or if the ambient temperature dropped below the freezing point of the antifreeze.

If the engine coolant gets too hot,

It might boil while inside the engine, causing voids (pockets of steam), leading to the catastrophic failure of the engine.

If plain water is used to cool an engine, it would promote galvanic corrosion. Using proper engine coolant and a pressurized coolant system can help alleviate all three problems.

Some antifreezes can prevent freezing till -87°C (-124.6°F).



Methanol, also known as methyl alcohol, is a chemical compound with chemical formula CH3OH (often abbreviated MeOH)

It has following characteristics:

It is the simplest alcohol, and is a light, volatile, colourless, flammable, poisonous liquid

with a distinctive odour that is somewhat milder and sweeter than ethanol (ethyl alcohol).

At room temperature it is a polar liquid and is used as an antifreeze, solvent, fuel, and as a denaturant for ethyl alcohol.

It is not very popular for machinery, but it can be found in automotive windshield washer fluid, de-icers, and gasoline additives to name a few.

Ethylene glycol

Ethylene glycol solutions were marketed as "permanent antifreeze," since the higher boiling points provided advantages for summertime use as well as during cold weather.

They are still used today for a wide variety of applications, including automobiles. Being ubiquitous, ethylene glycol has been ingested on occasion, causing ethylene glycol poisoning.


Ethylene glycol antifreeze

It has a sweet taste that can contribute to its accidental ingestion or its deliberate use as a murder weapon, as attributed by the many sensational media reports concerning.

Its symptoms of antifreeze poisoning include severe diarrhoea and vomiting; usually farther into the intoxication, signs of delirium, paranoia and intense hallucinations manifest.

Antifreeze Poisoning can be identified from the growth of calcium oxalate crystals in the kidneys.

An embittering agent such as denatonium can be added to ethylene glycol to help discourage either accidental or deliberate poisoning.


Ethylene glycol is toxic to many animals, including cats and dogs, so waste antifreeze should be disposed properly or recycled.

In some places, it is permitted to pour moderate amounts down the toilet, but there are also places where it can be taken for processing.

Propylene glycol

It is considerably less toxic and may be labelled as "non-toxic antifreeze."

It is used as antifreeze where ethylene glycol would be inappropriate, such as in food-processing systems or in water pipes in homes, as well as numerous other settings.

It is also used in food, medicines, and cosmetics, often as a binding agent. Propylene glycol

Is "generally recognized as safe" by the Food and Drug Administration (FDA) for use in food.

However, propylene glycol-based antifreeze should not be considered safe for consumption. In the event of

accidental ingestion, emergency medical services should be contacted immediately.

Propylene glycol oxidizes when exposed to air and heat. When this occurs lactic acid is formed.

If not properly inhibited, this can be very corrosive.

Protodin is added to propylene glycol to act as a buffer, preventing low pH attack on the system metals.

It forms a protective skin inside the tank and pipelines which helps to prevent acid attack that cause corrosion.

Besides cooling system breakdown, biological fouling also occurs.

Once bacterial slime starts, the corrosion rate of the system increases.

In regular systems where a glycol solution is maintained on a continuous basis, monitoring of freeze protection, pH, specific gravity, inhibitor level, colour and biological contamination should be checked routinely.

Propylene glycol should be replaced when it turns reddish in colour.



Most commercial antifreeze formulations it includes corrosion inhibiting compounds, and a coloured dye (commonly a green, red, or blue fluorescent) to aid in identification.

Where in the 1:1 dilution with water is usually used, which results and then gives a freezing point in the range of -35 °C to -40 °C, depending on the formulation. In warmer or colder areas, weaker or stronger dilutions are used, respectively, but a range of 40%/60% to 60%/40% must be maintained to assure corrosion protection and optimum freezing prevention.

Glycol antifreeze solutions should

generally be replaced with fresh mixture every two years.



In the modern time, certain cars are built with organic acid technology (OAT) and sometime with antifreeze (e.g., DEX-COOL), or with a hybrid organic acid technology (HOAT) formulation (e.g., Zerex G-05),which of both have guaranteed to have an extended service life of five years or 240,000 km (150,000 miles).

DEX-COOL specifically has caused controversy. Litigation has linked it with intake manifold gasket failures in GM's 3.1L and 3.4L engines, and sometime a failures in 3.8L and 4.3L engines.

Class action lawsuits were registered in several states, and in Canada, to address some of these claims.

The first of these to reach a decision was in Missouri where a settlement was announced early in December, 2007.

Late in March 2008, GM agreed to

Compensate complainants in the remaining 49 states.

There are rumours that mixing DEX-COOL with standard green (non-OAT) coolant can lead to a chemical reaction that produces sludge in the cooling system.

According to the DEX-COOL manufacturer, however, "mixing a 'green' [non-OAT] coolant with DEX-COOL reduces the batch's change interval to 2 years or 30,000 miles, but will otherwise cause no damage to the engine."

According to internal GM documents, the ultimate that has been the culprit appears to be operating vehicles for long periods of time with low coolant levels.

The low coolant is caused by pressure caps that fail in the open position. This exposes the hot engine components to air and vapours, causing corrosion and contamination of the coolant with iron oxide particles, which in turn can aggravate the pressure cap problem as contamination holds the caps open permanently.

All automotive antifreeze formulations, including the newer organic acid (OAT antifreeze) formulations, are environmentally hazardous because of the blend of additives (around 5%), including lubricants, buffers and corrosion inhibitors.

Because of the properties of additives in antifreeze the material safety data sheets provided by the manufacturer list only those compounds which are considered to be significant safety hazards when used in accordance with the manufacturer's recommendations.


Sodium Silicate

disodium phosphate

sodium molybdate

sodium borate


A green dye

disodium fluorescein


It helps to trace the source of leaks, and as an identifier because the different formulations are incompatible).


What are the main components of antifreeze?

There are two main types of antifreeze categorized by the main component in each: the

synthetic solvent ethylene glycol (EG), and propylene glycol (PG).

Additional components added to antifreeze products include corrosion inhibitors, anti-foaming agents, colouring agents, and metal and glycol antioxidants.


If antifreeze is necessary, how does it contribute to:

QUESTION. Systematically increasing concentrations of substances from the earth's crust?

• Used antifreeze contains heavy metals

(e.g. lead, mercury, cadmium, chromium, copper, and zinc) and other contaminants (e.g. oils, benzene from gasoline) that are picked up as antifreeze circulates through the engine, particularly in older vehicles that have metal radiators with soldered joints.

The disposal of used antifreeze, therefore, contributes to systematic increases of concentrations of the heavy metals in nature, even though these elements were not introduced into the system in the antifreeze itself.

Pycnogonid loving - all legs... the males carry the fertilized eggs around until they hatch. Pycnogonids don't have a pelagic larval stage, so don't spread very far