Lyophilic

In this study material, we learn about lyophilic colloids, lyophobic colloids and the differences between lyophilic and lyophobic colloids.

The term “lyophilic” refers to a colloidal mixture made up of a colloid that is strongly attracted to the liquid in which it is dispersed. Colloids are a combination of minute particles of one material equally scattered throughout another. “Lyo” refers to a solvent, while “philic” refers to a powerful affinity. The colloidal particles and the liquid have a strong attraction in lyophilic colloids. A lyophilic colloid is made of ingredients including gum, starch and protein. The sol is created by mixing the colloid with the liquid. Hydrophilic colloids are lyophilic colloids that are dispersed in water, and a hydrophilic sol is a dispersion formed in this mixture.

Here, we will discuss lyophilic study material in detail.

Examples of lyophilic sols

  1. Starch sol: When water is the dispersion medium, starch produces lyophilic sol; its preparation involves heating the starch sol and water to 100°C. Heating accelerates the creation of sol. It is highly stable and is unaffected by the presence of electrolytic impurities.
  2. Gum sol: It forms lyophilic sol with water, just like starch sol. Warm water is enough to make gum sol instead of boiling water because gum is very soluble in warm water.
  3. Egg albumin sol: When egg albumin mixes with cold water, it forms a lyophilic sol. The sol is relatively inert and is unaffected by the presence of contaminants.

Properties of lyophilic sols

  • Lyophilic sols are colloidal sols formed by combining chemicals with a suitable liquid that serves as a dispersion medium
  • The dispersed phase has a strong attraction to the dispersion medium
  • The high affinity is due to a large number of hydrogen bonds forming
  • They are naturally reversible
  • If two constituents of the sol break up by any method, it can be reconstituted by correctly mixing the dispersion medium with the dispersion phase

Lyophobic sols

Colloidal solutions in which the dispersed phase has a limited affinity for the dispersion medium are known as lyophobic colloids. This colloid’s solution is known as lyophobic sol and cannot be prepared directly; it is cooked uniquely. In nature, lyophobic sols are irreversible.

  • The dispersed component and the dispersion medium create strong bonds with the lyophobic colloid
  • Stability: Thermodynamically, lyophobic colloids are unstable; as a result, traces of electrolytes are required for stability
  • The colloid is stable only in modest concentration (usually 0.1-1 per cent)
  • Electrolytes must be strictly controlled during dialysis as the complete elimination of electrolytes will fracture the colloid
  • Interaction: Colloids and liquid have little or no attraction to each other
  • Viscosity: The viscosity of lyophobic colloids is the same as that of the solvent, it’s roughly the same as the dispersion medium
  • Electrolyte concentration is quite sensitive, and coagulation, on the other hand, simple
  • Re-dispersion of the coagulum, after phase separation, by coagulation is challenging and requires particular treatment

Properties of Lyophobic Sols

  • Lyophobic sols have no affinity for the dispersion media or the solvent
  • They’re solvent-averse sols
  • It is stable because of the adsorption of ions by the scattered particles
  • They are inherently irreversible
  • A solution of ferric hydroxide or aluminium hydroxide in water is an example

Know the Difference Between Lyophobic & Lyophilic

Lyophobic sol

Lyophilic sol

The particles of lyophobic sols can be seen with an ultramicroscope The particles of lyophilic sols are undetectable under an ultramicroscope
The viscosity of lyophobic sols is significantly lower than that of the dispersion medium The viscosity of lyophilic sols is relatively higher than that of the dispersion medium
When compared to lyophilic sols, lyophobic sols are less hydrated Compared to lyophobic sols, lyophilic sols are substantially more hydrated
In nature, lyophobic sols are irreversible, which means they cannot decompose in their dispersed phase and medium In nature, lyophilic sols are reversible, meaning they can disintegrate in their dispersed phase and medium
Lyophobic sols have a lower stability than lyophilic sols Lyophilic sols have a better stability than lyophobic sols

Conclusion

The term lyophilic refers to a person who is fond of liquids. Lyophilic sols are those in which the dispersed phase and dispersion medium (water) have a high affinity. A colloidal solution made by dissolving starch in water, for example. The dispersion medium in this colloidal solution is water, and the dispersed phase is starch. This sol is made by boiling water to 100 degrees Celsius and dissolving starch in it. Because of the strong affinity between the dispersed phase and the dispersion medium, it is a stable sol that is difficult to separate. Another example of lyophilic sol is egg albumin sol.