Structure of Multi-Component Colloidal Lattices at Oil-Water Interfaces

摘要

We have successfully assembled two-component S-PS/AS-PS (sulfate-treatedpolystyrene/aldehyde sulfate-treated polystyrene) and three-component S-PS/AS-PS/C-PS(sulfate-treated polystyrene/aldehyde sulfate-treated polystyrene/carboxylate-treatedpolystyrene) colloidal lattices at poly(dimethylsiloxane)-water interfaces. The colloidal particlesassemble into long-range ordered structure and oscillate around their equilibrium positions.Different types of particles distribute randomly in the lattice with no obvious phase separation.In the two-component colloidal lattices, the S-PS particles form mostly 6-fold lattice sites,whereas the AS-PS particles largely form 5-fold defect sites. The calculated attractive capillaryforce is stronger for the AS-PS particles, which likely explains their tendency of aggregationcompared to the S-PS particles. In addition, we have performed total force calculation andextrapolated the surface charge densities of the particles in the oil phase.