(50g) Modeling a Mixture of Multi-Bonding Site Solute and Patchy Colloidal Solvent in Confined Systems

Patchy colloids provide engineers with a flexible system where they can control self-assembly leading to chemical sensors and designer soft materials. Variations in the number of association patches and patch geometry have been accurately predicted. More recently the BAMC theory has been shown to accurately describe colloids with multiple bonding patches in the bulk. Although some experimental and theoretical studies of bulk mixtures have been reported, few studies have considered confined systems. In this work, a new density functional theory (DFT) formalism is developed to study the structure and thermodynamics of a mixture of a multi-bonding site solute and a patchy colloidal solvent in a planar slit pore. The particles in the mixture interact with hard-sphere repulsion and short-range association. The attractive patch on the solute can bond with multiple solvent molecules, whereas the patch on the solvent is restricted to bond only once. Based on the framework of BAMC theory, the new DFT accounts for the association contribution using either weighted density approach or free energy functional approach. The new DFT is capable of predicting the density profiles and bonding state of solute and solvent molecules in the planar slit pore for a wide range of system conditions. The comparison between the theoretical results and Monte Carlo simulation results give semi-quantitative agreement.