Adhesion interaction in water/n-alcohol mixtures between silanized silica and polymer particles

The adhesion of polyethylene and nylon particles to silanized silica plates was investigated in water/n-alcohol (methanol, ethanol, I-propanol, and l-butanol) mixtures. Silica plates were treated with gamma-aminopropyltriethoxysilane, methyltriethoxysilane, and perfluoroethyltrimethoxysilane. The number of particles adhering to the plate at 60 min as an apparent equilibrium adhesion value increased as a result of the silanization of silica and decreased with increasing volume ratio of n-alcohol in the water/n-alcohol mixtures. The acid-base components of the surface free energies of the substrates and liquids were decreased by the silanization of silica and by the addition of ethanol to water. The apparent equilibrium particle adhesion is discussed in terms of the total potential energies of interaction which were calculated as the sum of the electrical double layer, Lifshitz-van der Waals, and acid-base interactions, using the electrokinetic potentials and the surface free energy components. In addition, the relationship between the extent of particle adhesion and the work of adhesion was investigated. The particle adhesion in the present systems was found to be dominated by the acid-base interaction between the particle and the substrate.