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The affinity between the dispersion medium and the dispersion phase determines if the colloids are lyophilic or lyophobic. If the affinity between the dispersion medium and the dispersion phase is strong, the colloids are lyophilic. The dispersed phase has a significant attraction to the dispersion medium in this sort of colloidal system. They’re also known as reversible sols since they can be rebuilt after separation by adding dispersion media. They’re fairly stable and don’t readily coagulate. The dispersed phase particles are covered by a thin layer of dispersion medium in lyophilic sols, which have a high solvation level. An electrolyte or a suitable solvent can be used to coagulate lyophilic colloids. Gelatin, starch, rubber, protein, gum, and other lyophilic colloids are examples.
Lyophilic Colloids
Lyophilic sols are colloidal sols made by mixing substances with the right dispersion medium.
The dispersed phase is attracted to the dispersion medium strongly. If the affinity between the dispersion medium and the dispersion phase is strong, the colloids are lyophilic.
A high affinity is the outcome of the formation of a large number of hydrogen bonds.
Some examples are gelatin, gum, and starch.
- They are reversible in nature.
- If two elements of the sol are separated in any way, they can be reassembled by mixing the dispersion medium with the dispersion phase and shaking it correctly.
- Lyophobic sols have no affinity for the dispersion media or solvent.
- Solventaverse sols are what they’re called.
- It can be stabilised due to the adsorption of ions by the scattered particles.
They are, by definition, irrevocable.
- Ferric hydroxide or aluminium hydroxide, for example, can be found in water.
- Because the charge on the particle stabilises hydrophobic sols, they coagulate quickly.
- The particles prefer to settle when the charge is decreased by employing a suitable electrolyte.
- They form an aggregation or precipitate as they draw closer.
What is the difference between lyophilic and lyophobic colloids?
Lyophilic | Lyophobic |
These colloids love solvent. | These colloids do not love solvents. |
Lyophilic colloids are stable when it comes to thermodynamics. | Lyophobic colloids are not thermodynamically steady. |
They form a lyophilic sol. | They form a lyophobic sol. |
The process of precipitation in any lyophilic solution is reversible. | The process of precipitation in any lyophobic solution is irreversible. |
The viscosity of the colloid is high. | The viscosity of the colloid is the same as the solvent. |
Lyophilic colloids can be prepared by directly adding colloids into the liquid. | Special techniques like mechanical agitation can prepare this. |
There is very little or no attraction between the liquids and the colloids. | There is a strong, attractive force between the liquids and the colloids |
The coagulation of lyophilic colloids comprises discrete and aggregated particles. | The formation of a gel follows the coagulation. |
The refractive index of the lyophilic colloids does not have any definite pattern. | The refractive index in most lyophobic colloids has a definite pattern similar to accurate solutions. |
The lyophilic colloids consider water as their solvent and are called hydrophilic colloids. | When the lyophobic colloids consider water as their solvent, they are called hydrophobic colloids. |
Surface tension is very close or similar to the dispersion medium. | Surface tension is not very close and lower than the dispersion medium. |
These colloids have a little charge or no charge at all. | These colloids have a characteristic charge, either positive or negative. |
The Tyndal effect of lyophilic colloids is less scattering. | The Tyndal effect of lyophobic colloids is more scattering. |
The particles or colloids do not migrate and may carry a charge. | These colloids move towards the cathode or anode. |
The nature of the lyophilic colloids is organic. | The nature of the lyophobic colloids is inorganic. |
The particles are generally solvated. | There is no further solvation takes place. |
Colloids are classified into three groups
- Sols is a word that means “solid in liquid.”
- Gels are solidified liquids.
- Emulsions are liquidinliquid mixtures.
Example of Such Colloids
- The examples of colloids are as follows
- Solid aerosol – smoke, dust particles in the air
- Liquid aerosol – fog, mist, clouds
- Solid emulsion – cheese, butter
- Liquid emulsion – milk, mayonnaise
- Solid Foam – marshmallow
- Liquid Foam – whipped cream, shaving cream
- Sol and Gel – paint, jellies, mud
Based on the interaction between the dispersion medium and the dispersed phase, sols are categorised into two categories
- The ones that are attracted to solvents are known as lyophilic sols or lyophilic colloids.
- The ones that repel solvents are known as lyophobic sols or lyophobic colloids.
Preparation of Lyophilic Colloids
- Because lyophilic colloidal particles have such a strong affinity for liquids, they are relatively easy to make.
- In most cases, forming a colloid is as simple as mixing the particles with the solvent.
- In the presence of cold or heat, the particles may form a colloid more easily.
Purifications of Lyophilic Colloids
Purification of colloids can be accomplished in a number of ways, including
- Dialysis with ultrafiltration
- Ultracentrifugation
What are Lyophilic Sols, and what do they do?
Lyophilic sols are those in which the dispersed phase and dispersion medium (water) have a high affinity. 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.
What are Lyophobic Sols, and what do they do?
‘Liquid loathing’ is the definition of lyophobic. Lyophobic sols are those in which the dispersed phase and dispersion medium (water) have little or no attraction or contact.
The dispersed phase particles in these sols have little or no affinity for the dispersion medium. These are not stable sols, and they can be readily separated.
When a tiny amount of an electrolyte is introduced to these sols, the dispersed phase and dispersion medium can simply be separated. Stabilisers must be added to the sols when they are being prepared in order for them to be stable. Hydrophobic sols are another name for these. Ferric hydroxide sol is an example of a lyophobic sol. Ferric chloride is hydrolyzed to make it. Boiling water is used in this recipe. This procedure also produces hydrochloric acid, which is eliminated from the sol since it makes it unstable. The ferric hydroxide sol is dialyzed to eliminate it (lyophobic sol).
Conclusion
Waterloving solvents are lyophilic, whereas waterhating solvents are lyophobic and not easily miscible with water.Lyophilic solvents mix easily with water without any treatment, but lyophobic solvents require the addition of special chemicals known as stabilisers in order to become water miscible.
