(89e) Modeling Inter-Colloidal Interactions Induced By Adsorption of Mobile Telechelic Polymers Onto Particle Surfaces

Telechelic polymers can physically absorb onto colloidal surfaces, forming loops on single particles and loops between pairs of particles, which in turn induce effective interactions between colloids. We combine self-consistent field theory and a modified Derjaguin approximation to predict the polymer-induced colloidal interactions and the non-uniform distributions of loops and bridges of telechelic polymers adsorbed onto particle surfaces when they are compressed or stretched as a function of inter-particle distance. We validate our approach by comparing its predictions to those of Brownian dynamics simulations. We also determine the dependence of inter-colloidal interactions on particle size and surface coverage as well as molecular structures of telechelic polymers, including chain length and missing associating ends, which are important parameters in the design of commercial latex coatings. By mapping the predicted inter-particle interaction strengths to Baxter temperatures, we can quantitatively predict the phase behaviors of mixtures of colloids and telechelic polymers.