Lyophilic and Lyophobic Sols:
The following are the points of difference between lyophilic and lyophobic sols-
| Property | Lyophilic Sols | Lyophobic Sols |
|---|---|---|
| Mode of Preparation | These can be easily prepared by simply shaking or warming the dispersed phase with the dispersion medium. | These require some special methods for their preparation. |
| Visibility | The particles cannot be easily detected even under an ultra-microscope. | The particles can be easily detected under an ultra-microscope. |
| Stability | These are self-stabilized. | These are unstable and require a small amount of a stabilizing agent like gelatin to acquire stability. |
| Reversibility | These are reversible in nature i.e. once precipitated can reform the colloidal sol by simply remixing with the dispersion medium. | These are irreversible in nature i.e. once precipitated cannot form the colloidal sol by the simple addition of the dispersion medium. |
| Action of Electrolytes | These require a large amount of electrolyte to undergo coagulation. | These require a small amount of electrolyte to undergo coagulation. |
| Peptization | These can be easily peptized. | These cannot be easily peptized. |
| Electrophoresis | These may or may not show electrophoresis. | These always show electrophoresis. |
| Tyndall Effect | These do not exhibit the Tyndall effect and if at all these exhibits this effect, it is less distinct. | These exhibit the Tyndall effect more distinctly. |
| Viscosity | Their viscosity is much higher than that of the medium. | Their viscosity is almost the same as that of the medium. |
| Surface Tension | Their surface tension is usually lower than that of the dispersion medium. | Their surface tension is nearly the same as that of the dispersion medium. |
| Charge | Particles may or may not carry a charge. | Particles carry either positive or negative charge. |
| Concentration of the dispersed phase | A higher concentration of the dispersed phase is possible. | Only a low concentration of the dispersed phase is possible. |
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