Effective interactions in polydisperse colloidal suspensions investigated using Ornstein–Zernike integral equations

We present a mean of calculating the effective interactions in polydisperse colloidal suspension from liquid state integral equation theory. The method is based on Lado’s expansion of correlation functions in a suitable set of orthogonal polynomials. The outlined approach is subsequently used to investigate the effects of polydispersity on the effective potentials for model systems with attractive and repulsive bare interactions. The dominant effect of polydispersity of the smaller species is to weaken the effective potentials between big colloidal particles. This can be exploited as another way of tuning the interactions in colloidal suspensions to match the desired properties.

Effective interactions between two big colloidal particles (yellow) mediated by smaller polydisperse colloidal particles (red).Figure optionsDownload high-quality image (115 K)Download as PowerPoint slide