Data Mining Guided Molecular Investigations on the Coalescence of Water-in-Oil Droplets

In this work, a series of molecular dynamics simulations were performed to investigate the simultaneity of model asphaltene aggregation/adsorption and water-in-oil droplet coalescence. Asphaltene was represented using violanthrone-79 (VO-79), a widely employed proxy in the literature, and the oil phase was mimicked using pentane solvents to magnify aggregation and adsorption. The mutual effects of water and VO-79 on each other were then extensively discussed. It was found that increasing the sizes of water droplets leads to a nonmonotonic trend in the prevalence of parallel stacking among polyaromatic cores of VO-79 molecules, which is resultant from the competing effects of aggregation and adsorption. An in-house developed tool was then employed to probe the coalescence mode of water droplets under the influence of VO-79 molecules. A detailed review of simulation trajectories revealed that the growth of water droplets is dominant by using the largest droplet as the nucleus site. The results reported here can greatly help to enrich our understandings of the collective behaviors of all species in multiphase systems, and the method developed can be extended to many other applications where emulsion formations are involved.

Automated summary

In this work, molecular dynamics simulations were used to investigate the simultaneity of asphaltene aggregation/adsorption and water-in-oil droplet coalescence. The effects of water and asphaltene on each other were extensively discussed. It was found that increasing water droplet sizes led to a nonmonotonic trend in the stacking of polyaromatic cores of asphaltene molecules. The study provides insights into the collective behaviors in multiphase systems and the developed method can be applied to other emulsion formation applications.