How to Make Colloid

There are two method in making a colloidal mixture, it is called Dispersion. It makes colloid from a rough suspension which are stability dispersed in a base liquid.

The example to make colloid is experiment using cornstarch, a mixture in which particles of any one type of matter are suspended in another type of material. The cornstarch particles are so small you may not be able to see, they are actually separate from the water unless you look at the mixture under a microscope.

Types of Colloid

Colloids can be grouped into two different types. The first type is called Lyophilic colloids. Colloids which are grouped in this type are colloids that are fused with it's dispersed medium. Ex. agar and gelatin because they are solid inside liquid. From this info, we can also say that agar and gelatin are also Hydrophobic colloids. Hydrophobic colloids are basically Lyophilic but the dispersed medium must be water.

The other type is Lyophobic colloids. The colloids that are grouped here are those who did not fused with it's dispersed medium. Ex. milk and cooking oil since they are liquid but can't fused with another liquid, say water. In Lyophobic colloids, there is a smaller group which we call Hydrophobic colloids. It is basically Lyophobic but the dispersed medium must be water. Ex. sulfur and iron sol

Stability of Colloid

All colloidal mixtures are stable. We can see this from the way all colloids mixture will never generate a sediment. The term “stability” can have different meanings to different applications. When applied to colloids, a stable colloidal system is one in which the particles resist flocculation or aggregation and exhibits a long shelf-life. This will depend upon the balance of the repulsive and attractive forces that exist between particles as they approach one another. If all the particles have a mutual repulsion then the dispersion will remain stable. However, if the particles have little or no repulsive force then some instability mechanism will eventually take place.

- Particles in a dispersion may be attached together and form aggregates of increasing size which may settle out due to gravity itself.
- An initially formed aggregate is called a FLOC and its formation FLOCCULATION - this process is reversible (DEFLOCCULATION)
- If the aggregate changes to a much denser form it is said to undergo COAGULATION - this process is irreversible

Classification of Colloid

There are eight types of Colloidal Mixture, they are Foam, Solid Foam, Liquid Aerosol, Emulsion, Gel, Solid Aerosol, Sol, and Solid Sol. They are different from one another and is distinguished by the continuos medium and dispersed phase that made them. From the table prepared above, we can see the types of colloids and also it's examples. Colloids can't be made from gas continuos medium and gas dispersed medium since all gases are miscible, it is the property of some substances to mix in all proportions forming a homogenous solution and not colloid as a colloid mixture is actually a heterogenous one.

Property of Colloid

There are many property of colloid, each had their own characteristic and definition. from this entry, we will explain to you one by one.

~Tyndall effect: it is the scattering of light trough colloid. it was first explained by the British Physicist, John Tyndall. His theory suggest that if a beam of light were to pass trough a colloid, it would scattered.

~Brownian movement: there are a continuos collision between the particles of colloid and the molecules of dispersion and this will result a random, zig zag movement to the colloidal particle. this movement is called Brownian movement.

~Electrophoresis: it is the movement of Colloidal particle on the influence of an electric field. If an electric field is applied across a colloidal solution, the particles of that solution moves to the opposite charged electrode so they could get neutralized.

~Adsorption: it is the absorbing activity in a colloid mixture which result the absorbing of colloidal particles to a surface.

~etc

Definition of Colloid

Colloid is basically a mixture in which a substance is mixed or scattered evenly throughout another substance. It is one of the three major types of mixtures. The two others are solutions and suspensions. The three kinds of mixtures are distinguished by the size of the particles that make them up. The colloid's particles are in range of sizes, they are around 1 and 100 nanometers. For solution's particle's size, they are around 1 nanometer (about the size of a molecules) and for the size of suspension's particle, they are bigger than 100 nanometer.