What is Electrosteric stabilization?
What is Electrosteric stabilization?
Electrosteric stabilization is a combination of electrostatic and steric stabilization. Specifically, this type of stabilization features adsorbed polymers like in steric stabilization, however the adsorbed polymers have non-negligible electrostatic charge. Therefore, we get significant double-layer repulsion.
How are colloids stabilized?
Two traditional mechanisms for colloidal stability are electrostatic stabilization and steric stabilization. Electrostatic stabilization is the mechanism in which the attractive van der Waals forces are counterbalanced by the repulsive Coulomb forces acting between the charged colloidal particles.
How are hydrophobic colloids stabilized?
Hydrophobic colloids can be stabilized by adsorption of ions on their surface, as shown in Figure 13.29. (Adsorption refers to adherence to a surface. For example, small droplets of oil are hydrophobic. They do not remain suspended in water; instead, they separate, forming an oil slick on the surface of the water.
What is the main reason for stability of colloids?
The colloid’s stability is only due to these charges. The particles of the colloid sol repel each other due to the presence of these identical and equivalent charges and do not join together to form larger particles that hold them scattered in the medium and stabilise the colloidal remains.
What is electrostatic repulsion in chemistry?
Electrostatic repulsion is the result of interaction between the electrical double layers surrounding particles or droplet. The individual double layers can no longer develop unrestrictedly, since the limited space does not allow complete potential decay.
Are colloids stable or unstable class 9?
The problem of stability of disperse systems is one of the key problems in colloid chemistry. This is due to the fact that most colloids are thermodynamically unstable, and their dispersed phase particles tend to aggregate.
What do you mean by protection of colloids?
From Wikipedia, the free encyclopedia. A protective colloid is a lyophilic colloid that when present in small quantities keeps lyophobic colloids from precipitating under the coagulating action of electrolytes.
Why are hydrophilic colloids more stable?
Answer: Hydrophilic sols are more stable than hydrophobic sols because they have stronger interactions between the dispersed phase and water (the dispersion medium). Due to stronger interactions with water hydrophilic sol particles get highly solvated.
Can hydrophobic colloids be stabilized by coagulation?
Coagulation of a hydrophilic colloid is prevented by mutual repulsion of the double layers. Hydrophobic colloids may be stabilised by the use of a surfactant, e.g. a long chain fatty acid with a polar head and a non-polar tail.
What are protective colloids which type of colloids are used as protective colloids?
Examples. Lyophilic sols like starch and gelatin act as protective colloids.
What are electrostatic attractions and repulsions?
Attraction and repulsion of electric charges is one of three fundamental non-contact forces in nature. Positive and negative charged objects attract or pull each other together, while similar charged objects (2 positives or 2 negatives) repel or push each other apart.
