In the present work, we use large-scale classical all-atom MD simulations to bridge the gap between limited experimental resolution and small-scale MD studies by 1) extending the aerosol size to a 40-nm diameter, a four-fold increase in diameter-or 64-fold increase in volume-in comparison to previous all-atom MD simulations; and 2) increasing the chemical complexity of both the organic and inorganic phases to better represent that of nascent sea spray. We simulated three different 40-nm diameter aerosol systems for 500-1000 ns, each in triplicate. For each set of replicates, we increased the chemical complexity of the organic phase in increments, beginning with a simple fatty acid (FA) and protein mixture (System A), then adding perturbations of highly-charged lipopolysaccharides and cation diversity (System B), followed by the addition of neutral glucose mono-or oligosaccharides (System C). We evaluated particle shape and size and tracked the partitioning of organic material. We then compared our simulation results to Brewster Angle Microscopy (BAM) imaging of model surfactant interfaces. Our work gives insights into how particle phase and morphology are impacted by chemical diversity, and how that in turn may impact climate-relevant properties of submicron sea spray. Our simulations also establish computational microscopy as a powerful method to explore aerosols at the singleparticle level, augmenting and extending current experimental capabilities.