What does DLVO theory suggest?
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What does DLVO theory suggest?
DLVO theory suggests that the stability of a colloidal system is determined by the sum of these van der Waals attractive (VA) and electrical double layer repulsive (VR) forces that exist between particles as they approach each other due to the Brownian motion they are undergoing.
How this theory is applied in stabilizing the colloidal dispersion?
DLVO theory [1, 2, 3] describes the stabilization of colloidal dispersions by an interplay of van der Waals and electrostatic forces (as opposed to steric repulsions of colloids by polymeric solubilizers). The theory was developed in the 1940s by Derjaguin and Landau [4] and by Verwey and Overbeek [5].
What does DLVO stand for?
DLVO
| Acronym | Definition |
|---|---|
| DLVO | Derjaguin-Landau-Verwey-Overbeek (colloid chemistry theory) |
| DLVO | Diastolic Left Ventricular Overloading |
What is a Lyophobic colloidal system?
Lyophobic colloids: The word lyophobic means liquid-hating. The colloidal solutions in which the dispersed phase particles have no affinity for the dispersion medium are called lyophobic colloids. They are irreversible in nature.
What is zeta potential in suspension?
Zeta potential is a physical property which is exhibited by any particle in suspension, macromolecule or material surface. It can be used to optimize the formulations of suspensions, emulsions and protein solutions, predict interactions with surfaces, and optimise the formation of films and coatings.
What are the factors that contribute to the stability of a colloidal system why are they important in maintaining the stability of a colloidal system?
The stability of colloidal suspensions depends, therefore, crucially on quantities such as surface tension, electrostatic interactions involving surface charges of the solute and the electrolyte content of the solvent, and van der Waals interactions.
Why colloidal particles are stable?
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 the size of colloidal particle?
between 1 and 1000 nm
Colloidal particles are larger than simple molecules but small enough to remain suspended. Their range of diameters is between 1 and 1000 nm, i.e. from 10-9 to 10-6 m.
How are Lyophobic colloids formed?
Lyophobic colloids are prepared by mechanical agitation, which is required because of high interfacial energy of the dispersed particles. Lyophobic colloids are thermodynamically unstable. Their dispersed particles have a tendency to aggregation or coalescence.
What is lyophobic colloid with example?
Lyophobic sols are those sols in which the particles of the dispersed phase have little affinity for the particles of the dispersion medium. Example: sols of metal and their sulphides and hydroxides.
Why is colloidal stability important?
After some time, the dispersed phase could precipitate from the continuous phase in the form of flocks. In this case phase separation occurs, which influences the properties of the system. Therefore it is very important to maintenance the stability of colloidal systems.
What are the factors which influence stability of colloids?
The stability of colloidal solutions varies in a very wide range: their life lasts from fractions of a second to hundreds of years. It depends on many factors: particles’ size and concentration, process temperature, presence of electrolytes.
