Coarse-Grained Molecular Modeling of Pore Network Evolution in Particle- and Surfactant-Laden Emulsions

Macropore-infused nanocomposite emulsion thermosets (MINETs) are porous materials formed from emulsions containing high loadings of surfactants and nanoparticles, such as silica, activated carbon, alumina, and zinc oxide dispersed in the fluid mixture. After high-shear mixing, phase separation leads to the formation of a stable porous solid with a pore size that scales with the particle size. The mechanisms governing this pore network formation remain unclear. Here, we develop a coarse-grained molecular dynamics model to investigate phase separation and pore evolution in four-component systems composed of immiscible fluids, surfactants, and solid particles. Pair-correlation analysis is used to quantify domain coarsening, while pore size distributions are characterized using α-shape surface reconstruction. Results show that particles significantly alter phase separation kinetics, producing anomalous correlation-length scaling and suppressing pore coarsening. Pore size distributions evolve from monomodal to bimodal forms, with particles promoting finer pore structures. Increased surfactant concentration and near-neutral particle-fluid interactions further enhance pore stability. These findings provide mechanistic insight into MINET formation and guidance for designing porous nanocomposites with controlled microstructures.