Properties of Colloids

Introduction

Many characteristics make the solution different from the Colloids. The properties can be the chemical nature or the light scattering tendency or even the particle solubility. Not only that but also many things such as the components particle size, nature, and filtration can differ from each other. Each type of mixture has its properties that help in the identification.

What are Colloids?

Colloids can be found in many things and many forms. The most common example of colloids is the water droplets in the fog. During the fog, those water molecules are dispersed in the gas. In daily life, there are so many examples of colloids.

Figure 1 − Colloids

Colloids can be defined as the heterogeneous mixture, where the particles can be suspended in the form of gas, liquid, or the solid dispersion medium. The Colloidal system has two completely different types of phases; those are the dispersed phase and the dispersion medium. The dispersed phase is the substance where minute particles are suspended in the other substance. On the other hand, the dispersion medium is the substance where it is suspended. In the case of fog, the dispersed phase is the water and the dispersion medium is different kinds of gases.

Examples of Colloids

There are many kinds of colloids around the earth-

• Water and dust particles are suspended in the air can scatter the blue light. It reaches the human eye, which creates the perception of the blue colour.

• Fog, rain and mist everything is an example of colloids. Clouds are made of colloidal water droplets, which is the reason when the size of the water grows and opposing charged clouds collide with each other, they fall as rain.

Figure 2 − Different types of colloids

• Blood is a form of a colloid. The blood has a styptic action of alum and ferric chloride which helps the blood clot in the time of injury and helps to prevent bleeding.

• Soil is a colloid too, and because of its colloidal nature, it can absorb moisture and nutrients.

• One common example of the colloidal clay solution is river water.

Properties of Colloids

• Physical Properties − Colloid has two different phases; Dispersed medium and dispersed phase. The colour of the colloid depends on the size of the solution’s particle. Because of the size, the colloidal fragments can be passed by the filter paper. The particles of the colloids cannot be seen because of their microscopic size.

Figure 3 − Stable and unstable colloids

SunKart,at, English Wikipedia, ColloidalStability, CC BY 3.0

• Electrical Properties − Colloid has mainly three types of electrical properties. These depend on electrical double layer theory, electrophoresis, and electro- osmosis. According to the electrical double layer theory, the charge is imparted by placing ions as the immovable points that help to form the first layer. The second layer is made of the diffused mobile ions. Electrophoresis is a process where one electrical field is applied to a colloidal solution is responsible for colloidal particle’s movement. Electro-osmosis is a process in which the dispersing medium of the colloidal solution can be brought under the influence of an electrical field which arrest the particles.

• Optical Properties − Tyndall’s effect is the phenomenon that makes the light be scattered by the particles of the colloids. The particle that is present in the solution absorbs the light. The light starts scattering in all directions when the light is absorbed. The Tyndal effect occurs because of light scattering.

• Kinetic Properties − During the colloidal dispersion, the particles of the solution have a continuous movement, is observed under the ultra-microscope. In a colloidal solution, this kind of particle movement is known as the ‘Brownian effects’. It occurs because of the bombardment of the molecules.

Application of the Colloids

The application of the colloids can be found in many sectors and it can be used in many forms. These are as follows −

• It plays a crucial role in the food industry. Many food items such as milk, cheeses etc. are in colloidal form.

• It is used in the medical field in the making of many medicines.

• These are used as the component of water purification.

• It has been seen in the formation of smoke and as artificial rain.

Conclusion

Colloid holds a major portion in the nature just like any other substance. The various kind of usages make it important in daily life. It is a mixture that can be exist regardless of the medium, it can be solid, gas or liquid. The colloids are also referred to as the colloidal dispersions.

FAQs

1. What are the main uses of colloids?

Colloids play a major role in the manufacturing of both paints and inks. For example, gel ink is the most common form of liquid-solid colloids. The majority of the pharmaceuticals are colloidal medicines. Colloids are also found as the thickening agents.

2. What is a macromolecular colloid?

The particle of the biomolecule is immersed in a suitable dispersion medium and starts combining to make solutions, this kind of solution is known as the macromolecular colloid.

3. What is a colloidal solution?

The term colloidal solution refers to one kind of mixture that is composed of a particle and the size of the particles can vary from 1 to 1000 nanometres. In this mixture, the ions are generally uniformly dispersed. The most important characteristic of the colloidal solution is that the particles do not settle down at the time of the process.

4. What is considered colloids?

In the field of chemistry, those mixtures are considered colloids where one mixture is suspended within another material, which has particles which can be microscopically scattered and can be insoluble or soluble.