초록 |
Colloidal particles attach strongly and irreversibly to the fluid-fluid interface. This adsorption reduces the interfacial tension and stabilizes the interface. Thus, conventional colloidal particles can be an alternative to costly and environmentally hazardous molecular surfactants. The behavior of the particles at the interface is determined by electrostatics and capillarites. In general, the electrostatic interaction induces repulsions between the particles, while the capillary interaction minimizes surface free energy, inducing interparticle attraction. Since the relative strength between the two interactions determines the colloidal microstructure and rheological properties, it is important to study quantitatively the interaction forces between the particles. In this work, to understand the effect of particle size on the interactions, we make polystyrene particles with well-controlled size distribution and measure their interactions when they are adsorbed on the interface. |