• Tyndall effect refers to the scattering of light by colloidal particles.
• The intensity of the scattered light depends on the difference in the refactive indices of the dispersed phase and the dispersion medium.
• Larger the difference, greater will be the intensity of the scattered light.
• In lyophobic sols, the particles are not as highly solvated as in lyophilic sols. So, the difference in refractive indices between the particles and the medium is quite large in lyophobic sols. Therefore, they show distinct Tyndall effect.
Four instances of Tyndall effect as following
• Shining a flashlight beam into a glass of milk is an excellent demonstration of the Tyndall effect. You might want to use skim milk or dilute the milk with a bit of water so you can see the effect of the colloid particles on the light beam.
• An example of how the Tyndall effect scatters blue light may be seen in the blue color of smoke from motorcycles or two-stroke engines.
• The visible beam of headlights in fog is caused by the Tyndall effect. The water droplets scatter the light, making the headlight beams visible.
• The Tyndall effect is used in commercial and lab settings to determine the particle size of aerosols.