All the gems and juices you can see in the image above are colloids. Have you felt water droplets in the fog? Yeah! Fog is also an example of colloid. In fog water molecules are dispersed in the gas. In the same way you must have observed many such examples of colloids in your daily life. So, in this article will discuss what are colloids, properties of colloids and applications of colloids.
In chemistry, colloids are heterogeneous mixtures of two substances in which minute particles of one substance are dispersed in another substance. The substance whose minute particles are suspended in another substance is called the dispersed phase while the substance in which it is suspended is called dispersion medium. For example, in fog dispersed phase is water (liquid) and dispersion medium is different gases. We can’t see particles of dispersed phase in colloids by naked eyes as they are very small in size.
We see many colloidal solutions around us. Many food items such as cake, milk, bread, butter, ice cream fruit juices, whipped cream etc. are examples of colloids. Apart from these fog, mist clay etc. are also examples of colloids. We are providing list of examples of colloids with their dispersed phase and dispersing medium below –
Colloids show following properties –
It is a heterogenous mixture.
The size of colloidal particles is very small. Their particle size ranges between 1-1000 nanometers.
It shows tyndall effect. It means it scatters the beam of light and shows its path through itself.
They don’t settle down when left undisturbed for sometime it means colloidal solutions are quite stable.
They cannot be separated by filtration process.
They can be separated by centrifugation.
Colloidal particles show Brownian movement.
Colloids have various applications in many fields. Some uses of colloids are listed below –
Colloids are used in foods and food industries at large level. Many foods which we consume are actually colloidal in nature. Such as milk, cheese etc.
Colloids have various applications in medicinal field as well. Many medicines which we use are in form of emulsions. Antibiotics such as penicillin and streptomycin are given in the form of colloidal solutions so that they can be absorbed by human body easily.
Colloids are used in water purification.
Sewage water contains impurities like dirt, stool, urine etc. which are dispersed in water. Thus, forms a colloidal system. These can be removed by electrophoresis.
Smoke is also a colloidal system of carbon particles in air. This can also be purified by electrophoresis.
These are used in artificial rain as well.
Rubber is obtained by colloidal solution called latex through coagulation.
Treatment of skin of animals to get leather is called tanning. In the process of tanning colloids are used.
Micelles formed in cleansing action of soaps are colloids.
Colloids are used in form of smoke in smoke screens to hide somethings in military.
Blue color of sky is due to a colloidal property shown by sky. Dust particles dispersed in the air scatter sunlight.
Many nanomaterials are prepared by colloids.
These are used in metallurgy during froth floatation.
These are used in the treatment of hypovolaemic patients.
Silver colloid is used as germicidal agent.
Many colloids are used as anticancer drugs such as copper colloid.
Colloids are used in preparation of anti-syphilis antibodies.
Proteins are colloids and used in various ways.
These are used for targeted drug delivery.
These are used as cosmetic ingredients for many cosmetic products.
These are used as fungicides and pesticides.
These are used in plastic surgery of many body parts.
These are used in dentistry.
These are used in wound dressing materials as well.
This was the brief on colloids with emphasis on its applications, if you want to get detailed study notes on the topic colloids then register yourself on Vedantu or download Vedantu learning app for Class 6-10, IITJEE and NEET.