Surface forces arising from adsorbed ionic copolymers with hydrophobic and hydrophilic segments in colloidal dispersions

The effects of ZrO₂ copolymers on surface forces was explored. At low hydrophobic ionic copolymer concentrations, a much greater reduction in the maximum yield stress was observed as compared with the more hydrophilic polyacrylic acid and this was because of a thicker steric layer formed on the interacting particle. At high hydrophobic ionic copolymer concentrations, hydrophobic effects become important. These effects caused the maximum yield stress to increase as a result of an overall increase in entropy when the interacting particles are flocculated than when they are far apart.