Tyndall Effect - Definition, Example and Causes

The Tyndall Phenomenon is a light scattering effect in colloidal dispersion that seems to exhibit no light in a real solution. This effect has been used to detect whether a true solution or a colloid is present in a combination. The Tyndall effect may also be seen when sunlight travels through a thick forest cover.

What is the Tyndall effect?

The dispersion of light as a light beam travels through a colloid is known as the Tyndall effect. The Tyndall effect occurs when light beams are focused at particles in a colloid. This effect may be seen in all colloidal solutions including certain very tiny suspensions. As a result, it may be used to determine if a particular solution is a colloid.

The intensity of dispersed light is dependent on the density and frequency of the suspended particles. The Tyndall effect, like Rayleigh scattering, scatters blue light more than red light. When a beam of light travels through some kind of colloid, colloidal particles within the solution prevent the beam from passing fully through.

The light is dispersed when it collides with colloidal particles. It diverges away from its usual path, which would be a straight line.

Example of Tyndall effect

- When comparing red and blue light, blue light scatters more. This is why motorbike exhaust might seem blue at times. John Tyndall, an Irish scientist, was the first to discover the Tyndall effect. Particles that generate the Tyndall effect can have sizes ranging from 40 to 900 nanometres range.

- Colloids such as milk are a mixture of fat and proteins. A beam of light disperses when it is aimed at a glass of milk. Tyndall's effect is demonstrated here perfectly.

- The path of light becomes evident when a torch is turned on in a misty atmosphere. The light scattering in this situation is caused by water droplets in the fog.

- When seen from the side, opalescent glass has a bluish tint to it. When light is shone through the glass, however, orange-coloured light is produced.

- The light from the projector seems bright in a movie theatre because aerosol particles scatter light.

What Causes Blue Eye Color Due to the Tyndall Effect?

- The quantity of melanin from one of the iris' layers is the fundamental distinction between brown, blue, and black irises. When opposed to a black iris, the layer of a blue iris contains a lesser quantity of melanin, making it transparent. Because of the Tyndall effect, the light that strikes this transparent layer is dispersed.

- The wavelength of blue light is shorter than that of red light, so it is more dispersed. Irises absorb unscattered light from a deeper layer. The iris' colour is blue since the majority of the light dispersed is blue.

- The scattering of light is involved in a number of processes. Mie scattering and Rayleigh scattering are two such examples. A clear sky is blue because the light is scattered by air particles, which would be an instance of Rayleigh scattering.

- When the sky is overcast, however, light scattering is caused by the comparatively large cloud droplets, which would be an instance of Mie scattering.

Conclusion

In conclusion, it is a phenomenon that is noticed when light passes through the colloidal solutions. The light scatters and this phenomenon is to measure the particle size of aerosols, the Tyndall effect is employed in commercial and laboratory applications.