Molecular Dynamics Simulation Insight into Interfacial Stability and Fluidity Properties of Microemulsions

Abstract

Although the interfacial properties of microemulsions have been extensively studied in both experimental and simulation research studies, the molecular mechanisms of stability and fluidity about microemulsion are still poorly understood. Herein, we report a molecular dynamics simulation study to elaborate the motion of an emulsion droplet involving dichain surfactant Aerosol OT (AOT) and its dynamics evolution at the oil–water interface. By varying the concentrations of AOT, we show that the interfacial thickness and emulsification rate display a piecewise change as the interfacial coverage increases and the W/O emulsion is more stable than the O/W one while O/W emulsion presents better fluidity. In addition, the dispersed system combined with water/AOT/n-heptane tends to form a W/O microemulsion instead of an O/W microemulsion due to the structural collapse of the latter. This work provides a molecular understanding of microemulsion interfacial stability and fluidity.

Role of Alcohol as a Cosurfactant at the Brine–Oil Interface under a Typical Reservoir Condition

“…Previous studies demonstrated that the molecular local fluidity mainly depends on the molecular diffusion. − To investigate the effect of propanol on the local fluidity of SDS, we present the self-diffusion coefficient of SDS, D A , (in the x-y plane and the z -direction) in Figure , which is calculated by the Einstein relation: where x i (t), y i (t), and z i (t) are the center of mass position of molecule i at time t in the x -, y -, and z -directions, respectively, n is number of dimensions ( n = 2 for the x-y plane and n = 1 for the z -direction), and ⟨...⟩ implies averaging over time and molecules. The diffusion coefficients in the x-y planes are significantly higher than those in the z -direction.…”

Enhancement of solubility and dissolution rate of ebastine fast-disintegrating tablets by solid dispersion method

“…Higher concentration of solubilizers improved the solubility and dissolution rate of ebastine many folds. This could be linked to a reduction in the size of the drug particles, which could potentially increase the fluidity of the interface and reduce the interfacial tension of the prepared system [24]. Importantly, soluplus displayed more positive findings relative to other solubilizers (poloxamer 188, tween 80) used in our experiments.…”

A theoretical perspective on the structure and thermodynamics of secondary organic aerosols from toluene: molecular hierarchical synergistic effects

“…In view of spatial and component heterogeneity, the van Hove function is introduced to describe the migration properties of the molecules. 70 For example, the corresponding van Hove function profiles at 303 Environmental Science: Nano Paper K are shown in Fig. 7F and G, which indicate that SOA nanoparticles require a long period to achieve long-distance migration and thus have a smaller probability of appearing within that limited range at the same moment.…”