Polymeric or steric stabilization is the alternative method to keep particles sufficiently apart from each other. Adsorption of polymers from aqueous solutions is encouraged by incorporating enough lipophilic copolymer to reduce the solubility of the polymer to where competition favors its adsorption rather than its solubility. In nonpolar solvents, where the selection of both polymer and solvent is usually open to choice, another competition appears, as a nice selection of materials is required to ensure that adsorption of solute is the outcome, in the face of competition from the solvent either for the polymer or for the surface of the particle. Also in these solutions the polymer has to be fitted with an acidic or basic segment to anchor it to the particle, and stabilizing segments to give it the requisite steric thickness. The conditions of dispersion stability are the same as the conditions for solubility of the polymer.
Key Words: acid-base interaction, adsorption rate, anchoring group, block
copolymer, depletion flocculation, diffusion rate, donor-acceptor interaction,
Drago constants, electrosteric stabilization, grafted polymer, polymeric
stabilization, random copolymer, stabilizing chain, steric stabilization,
surface acidity, surface basicity, theta conditions, Traube’s rule
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