Anisotropic droplets with uniform internal structure prepared in batch-scale by combination of vortex mixing and phase separation

Ding, Chenguang; Ge, Lingling; Guo, Rong

doi:10.1016/j.molliq.2022.119616

Cited by 3 publications

(1 citation statement)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Unlike miniemulsions always used in polymerization and prepared via high-energy methods with a low concentration of surfactant, nanoemulsions prepared via low-energy methods are unstable to Ostwald ripening − due to the high concentration of surfactant. Ostwald ripening is characterized by an increase in the average droplet size and a broadening of the size distribution in a short time. − Because Ostwald ripening leads to creaming, sedimentation, coalescence, and demulsification of the nanoemulsions, this process must be hindered to ensure long-term physical stability.…”

Section: Introductionmentioning

confidence: 99%

Nanoemulsions Stable against Ostwald Ripening

Guo,

Zhang,

Wang

et al. 2024

Langmuir

View full text Add to dashboard Cite

Ostwald ripening, the dominant mechanism of droplet size growth for an O/W nanoemulsion at high surfactant concentrations, depends on micelles in the water phase and high aqueous solubility of oil, especially for spontaneously formed nanoemulsions. In our study, O/W nanoemulsions were formed spontaneously by mixing a water phase with an oil phase containing fatty alcohol polyoxypropylene polyoxyethylene ether (APE). By monitoring periodically the droplet size of the nanoemulsions via dynamic light scattering, we demonstrated that the formed O/W nanoemulsions are stable against Ostwald ripening, i.e., droplet growth. In contrast, the nanoemulsion droplets grew with the addition of micelles, demonstrating the pivotal role of the presence of micelles in the water phase in the occurrence of Ostwald ripening. The influence of the initial phase of APE, the oil or water phase in which APE is present, on the micelle formation is discussed by the partition coefficient and interfacial adsorption of APE between the oil and water phase using a surface and interfacial tensiometer. In addition, the spontaneously formed O/W nanoemulsion, which is stable against Ostwald ripening, can be used as a nanocarrier for the delivery of water-insoluble pesticides. These results provide a novel approach for the preparation of stable nanoemulsions and contribute to elucidating the mechanism of instability of nanoemulsions.

show abstract