Colloidal Monolayers with Short-Range Attractions and Dipolar Repulsions

This study investigates the structure and phase behavior of monolayers composed of model colloids that exhibit both short-range attractions and long-range repulsions. The model is motivated by recent experiments of hard-sphere-like microspheres that effectively interact via depletion attractions and dynamically tunable dipolar repulsions. Brownian dynamics simulations, grand canonical Monte Carlo methods, and approximate thermodynamic models are combined to investigate how the model's equilibrium and kinetically accessible solid and cluster fluid states depend on the relative strengths of the attractive and repulsive interactions. The results may help guide the understanding and design of quasi-two-dimensional colloidal assemblies with magnetic field tunable interactions.