Is polyelectrolyte a base or acid?
In polymer terminology, a polyacid is a polyelectrolyte composed of macromolecules containing acid groups on a substantial fraction of the constitutional units. Most commonly, the acid groups are –COOH, –SO3H, or –PO3H2.
What is the function of polyelectrolyte in water treatment?
Polyelectrolytes have many applications, mostly related to modifying flow and stability properties of aqueous solutions and gels. For instance, they can be used to destabilize a colloidal suspension and to initiate flocculation (precipitation).
Is polyelectrolyte a flocculant?
Polyelectrolyte flocculants are polymers that are either branched or linear, but carrying ionic charge along their chain. They are accordingly classified as cationic, anionic or non-ionic polymers. These flocculants neutralise surface charges on cells and bind particles together by physical or chemical forces.
What is strong polyelectrolyte?
A “strong” polyelectrolyte is one that dissociates completely in solution for most reasonable pH values. A “weak” polyelectrolyte, by contrast, has a dissociation constant (pKa or pKb) in the range of ~2 to ~10, meaning that it will be partially dissociated at intermediate pH.
What is polyelectrolyte adsorption?
Polyelectrolyte adsorption. Adsorption of polyelectrolytes on solid substrates is a surface phenomenon where long-chained polymer molecules with charged groups (dubbed polyelectrolytes) bind to a surface that is charged in the opposite polarity.
Why do Polyelectrolytes have a large surface area?
Because the polymer molecules are so long, they have a large amount of surface area with which to contact the surface and thus do not desorb as small molecules are likely to do. This means that adsorbed layers of polyelectrolytes form a very durable coating.
How does ionic concentration affect the formation of polyelectrolytes?
The ionic concentration of the solution will determine the layer formation characteristics of the polyelectrolyte as well as the conformation the polymer assumes in solution. High salt concentrations cause conditions similar to the interactions experienced by a polymer in a favorable solvent.
How do polyelectrolytes affect the conformation of polymers?
The interactions between a polyelectrolyte and the solvent it is placed in have a large effect on the conformation of the polymer both in solution and upon deposition onto the substrate.