(319e) Structure And Phase Behavior Of Melts And Dense Solutions Of Polymer Tethered Nanoparticles

The microscopic Polymer Reference Interaction Site Model (PRISM) theory has been generalized and applied to study dense solutions and melts of polymer tethered spherical particles. Intermolecular pair correlation functions, collective structure factors, and bulk moduli are calculated to understand the equilibrium organization and tendency of the tethered particles to macro-micro phase separate. The complex interplay of entropy (translational, conformational and packing) and enthalpy (particle-particle attraction) leads to different spatial arrangements with distinctive scattering signatures. The location of the peaks in the structure factors suggest that these tethered particles prefer to organize themselves in a specific geometry that is dictated by the subtle competition of depletion attraction, osmotic repulsion, and grafting constraints. The effect of the particle radius, number of tethered polymers per particle, length of the tethered polymers, position of the grafting sites, total fluid packing fraction, and particle-particle interfacial attraction strength on the statistical structure, properties and phase behavior will be discussed.