Content
A gel is a state of matter between solid Y liquid. It is a colloidal substance (mixture). That is, it is a mixture which is composed of two or more phases (the term phase is explained below). Mostly its size increases when it comes into contact with water.
There are different types of gels, within which it has a greater use in medicine, (in particular dermatological uses). However, gels are also used for aromatic products, foods, paints and adhesives.
The process by which a gel is formed is called gelation.
Phases of the gels
The gels have two phases; a continuous phase which is generally solid and one dispersed phase which is mostly liquid. Although this second phase is liquid, the gel is more of a solid than a liquid.
Example of the most common gel is jelly. There we can observe the continuous phase (gelatin in granules or powder) and dispersed phase (the gelatin mixed with water).
The continuous phase gives consistency to the gel preventing it from flowing freely, while the dispersed phase prevents it from becoming a compact mass.
Characteristics of the gels
Certain gels have the characteristic of going from one colloidal state to another just by shaking. This feature is called thixotropy. Examples of this are some paints, alkaline and latex coatings. Other thixotropic gels are: tomato sauce, clays and yogurts.
The consistency of the gels will vary between solid viscous fluids Y fluids with high stiffness. This will depend on the components of the gel. Therefore it can be said that the gels have a certain degree of instability.
However, as a general characteristic, the gels are moderately elastic.
Type of gels
Depending on the consistency of the gels, these can be sub-classified into:
- Hydrogels. They have a watery consistency. They use, as a means of dispersion, water. Most gels are found here.
- Organogels. They resemble hydrogels but use a solvent of organic origin. Example of this is the crystallization of the wax in the oil.
- Xerogeles. They are gels with a solid appearance since they do not have a solvent.
Uses of the gels
As mentioned previously, its uses are very widespread in the field of medicine, cosmetics, chemistry, etc. It is especially used in cosmetics, especially for hair treatments.
In medicine they are used for treatments in the ear canal or in the nostrils since both canals are difficult to access and the use of solid medicines would be difficult for their subsequent cleaning.
Examples of gels
- Clay
- Optical fibre wires. In these cases a petroleum derivative is used. This gel allows the fibers to remain flexible.
- Flan
- Bath gel
- Hair gel
- Reduction gel
- Common gelatin
- Jelly
- Mucous secretions (mucus or mucus). These are important because they maintain the humidity of the nasal cavity, pharynx, bronchi and respiratory system in general.
- Yellow butter
- Mayonnaise
- Fruit jams (add pectins to thicken the consistency)
- Soft cheese
- Ketchup
- Glass
- Yoghurt
It can serve you:
- Examples of Solids, Liquids and Gaseous
- Examples of Plasma State
- Examples of Colloids
