Thinking outside the box: placing hydrophilic particles in an oil phase for the formation and stabilization of Pickering emulsions

Marina, Paula Facal; Xu, Jie; Wu, Xuan; Xu, Haolan

doi:10.1039/c8sc00678d

Cited by 26 publications

(7 citation statements)

References 69 publications

(46 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was reported that the dispersed phase can influence the interfacial activity and hydrophobicity of particles [16,39] . After the dispersion of microgels in the oil phase in the presence of 20 vol% octanol, inverse W/O Pickering emulsions could be successfully prepared (Figures 2e and g).…”

Section: Resultsmentioning

confidence: 99%

“…[38] It was reported that the dispersed phase can influence the interfacial activity and hydrophobicity of particles. [16,39] After the dispersion of microgels in the oil phase in the presence of 20 vol% octanol, inverse W/O Pickering emulsions could be successfully prepared (Figures 2e and g). Water droplets laden with octanol-swollen 4VP microgels had an average diameter of 53 μm (Figure 2f), which was smaller than that of the water droplets stabilized by octanol-swollen MAA microgels (160 μm, Figure 2h).…”

Section: Emulsifying Capability Of Microgels In Stabilizing Pickering...mentioning

confidence: 99%

See 1 more Smart Citation

Temperature‐Responsive Pickering Double Emulsions Stabilized by Binary Microgels

Guan,

Li,

Jiang

et al. 2023

Chemistry An Asian Journal

View full text Add to dashboard Cite

Microgels are excellent emulsifiers that can self‐assemble to reduce interfacial tension and form a steric barrier at an oil‐water interface. Herein, we report a two‐step emulsification approach to prepare oil‐in‐water‐in‐oil (O/W/O) Pickering double emulsions through the dispersion of microgels in two immiscible phases. The stabilization mechanism depends on the uneven distribution and adsorption of hydrophilic water‐swollen microgels and hydrophobic octanol‐swollen microgels on either outer water droplets or inner oil droplets. Our results reveal that binary microgels outperformed single microgels in terms of interfacial tension reduction and emulsion stabilization. Notably, the binary microgel‐stabilized Pickering double emulsions show excellent temperature responsiveness owing to the intrinsic thermal sensitivity of microgels. Consequently, the selective and rapid release of encapsulated substances in different phases can be achieved through the adjustment of the ambient temperature.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Emulsifying Capability Of Microgels In Stabilizing Pickering...mentioning

confidence: 99%

Temperature‐Responsive Pickering Double Emulsions Stabilized by Binary Microgels

Guan,

Li,

Jiang

et al. 2023

Chemistry An Asian Journal

View full text Add to dashboard Cite

show abstract

“…37,44 Dispersing the hydrophilic particles in the oil phase rather than in the water phase initially was a novel approach for the formation and stabilization of Pickering emulsion. 45 In our previous study, the influence of the initial phase of surfactants was ignored in the formation process of O/W nanoemulsions by phase inversion temperature methods. These nanoemulsions using D230−2OA surfactant with propylene oxide (PO) units were unstable against Ostwald ripening.…”

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

“…High resistance to coalescence is an obvious advantage of Pickering emulsions compared to traditional ones. To circumvent the use of synthetic surfactants for sustainable and ecological reasons, the “surfactant-free” Pickering emulsions came into renewed interest in particular foods, pharmaceuticals, and cosmetics. , Especially, highly concentrated emulsions with the volume ratio of the internal phase higher than 74% are usually referred to as high internal phase emulsions . Except avoiding the utilization of considerable quantities of surfactants (5–50%, v/v), Pickering HIPEs also possess apparent advantages compared with conventional ones in such aspects as stability against coalescence, environmental effects, texture modification, calorie reduction, product safety, etc.…”

Section: Introductionmentioning

confidence: 99%

Facile and Robust Route for Preparing Pickering High Internal Phase Emulsions Stabilized by Bare Zein Particles

Zhou

Luo³

et al. 2021

ACS Food Sci. Technol.

View full text Add to dashboard Cite

Pickering high internal phase emulsions (HIPEs) stabilized by biological particles have attracted growing interest. However, developing Pickering HIPEs with bare zein particles (ZPs) is still a challenge. Here, we demonstrated a facile method for the development of Pickering HIPEs stabilized solely by bare ZPs. In brief, the pH value was adjusted during the emulsification; thus, the aggregation of ZPs transferred from the continuous phase of HIPEs to the oil–water interface. In detail, the strong hydrophobicity of ZPs was changed into intermediate wettability after changing pH, as indicated by the value of the three-phase contact angle (θ) decreasing from 108.4° to around 90°. Through adjusting the assembly behaviors of ZPs, the interfacial and continuous microstructures in the emulsification system were defined accordingly, therefore forming stable Pickering HIPEs. Generally, with the final NaOH concentration ranging from 0.6 to 2.0 mM in HIPEs (pH 6.6–8.9), HIPEs with an internal phase volume fraction of 80% were prepared successfully using pristine ZPs as sole eco-friendly Pickering stabilizers. The microstructure of HIPEs featured that ZPs deposited in situ at the oil–water interface, forming an effective physical barrier, while the rest of ZPs that remained in water phase functioned as the structural element and stacked into a 3D network architecture, constituting another strong barrier and facilitating the immobilization of oil droplets. This microstructure contributed to satisfactory stability, good viscoelasticity behavior, and ideal thixotropic recovery of HIPEs. Moreover, the HIPEs obtained here served as the encapsulation system for probiotics, and they maintained the viability of Lactobacillus plantarum at 4 °C. The facile method developed here paves the way for preparing Pickering HIPEs stabilized by protein-based particles.

show abstract

Thinking outside the box: placing hydrophilic particles in an oil phase for the formation and stabilization of Pickering emulsions

Abstract: Unconventionally, by placing hydrophilic particles in an oil phase before emulsification, the energy barrier is successfully eliminated and Pickering emulsions are easily formed.

Cited by 26 publications

References 69 publications

Temperature‐Responsive Pickering Double Emulsions Stabilized by Binary Microgels

Temperature‐Responsive Pickering Double Emulsions Stabilized by Binary Microgels

Nanoemulsions Stable against Ostwald Ripening

Facile and Robust Route for Preparing Pickering High Internal Phase Emulsions Stabilized by Bare Zein Particles

Contact Info

Product

Resources

About