The word immiscible is not contemplated within dictionary of the Royal Spanish Academy (RAE) but, even so, it is widely used in the field of chemistry . As can be deduced from the practice, it is a concept that derives from miscibility , as the particularity or property of certain substances is known for merge or blend in different proportions and form from it a homogeneous solution .
Most commonly, this notion is applied to liquids , although it can also refer to solid materials or gases. When two substances have the ability to constitute a homogeneous solution beyond the proportions involved, they are said to be miscible . However, if they do not have such capacity, they will be qualified as immiscible .
This means that any substance that is immiscible is fails to form a homogeneous strip no way. An example of immiscible substance is the Water . The same goes for the ethyl ether . The miscibility of organic substances and lipids with water is determined by the properties of the hydrocarbon chain.
When determining or establishing what are the properties of the so-called immiscible mixtures that take place within the chemical sector, it should be stressed that various elements take center stage, such as the glass transition temperature. As Tg, this value is represented, which must be stressed that it is double in any type of immiscible mixture since each of the two amorphous polymers that give rise to it maintains its own temperature of this type.
This results in the fact that if any scientist starts analyzing a specific mixture and only discovers a glass transition temperature, his main conclusion will be that it is totally miscible.
In addition to this underlined identity sign, it is also important to make clear that such immiscible mixtures are much more fragile than those that are not of the same class. However, there are a number of techniques to ensure that they achieve greater resistance.
Thus, among the methods used to achieve this objective is, for example, to process them under flow thanks to the formation of canes that function as fibers of a reinforced composite material.
Another second technique widely used to achieve that hardness of the immiscible mixtures is to proceed to use equivalent amounts of the two polymers that shape them. The third method that can be used is to bet on including a compatibilizer thanks to which the union is achieved in a much more compact way.
When metals are immiscible, they cannot constitute alloys . Mixing is only possible by foundry although, if said metals are frozen, they will again be separated into differentiated phases or layers. He copper and the cobalt they are two immiscible metals, to name a case.
It is possible to associate miscibility with the entropy of substances: the greater the entropy, the more miscibility. This explains why gases are generally miscible, unlike solids that are usually immiscible. There are, however, various exceptions, as with solid combinations of nickel and copper .