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This work investigates the demixing behavior of Pickering emulsions consisting of water, n-hexadecane, and two different types of Pickering particles. The first type is uniform, and the second consists of one-side modified Janus particles influencing the emulsion behavior significantly. Both particle types are able to stabilize the emulsions, but lead to clear differences in the emulsion drop size and size distribution. This results in different creaming times varying between minutes and hours and different clearance processes of the water excess phase. Large pH effects were found in addition. At some conditions, non-adsorbed particles were observed that sediment over time in addition to the creaming of the emulsion. [ABSTRACT FROM AUTHOR]

Some photosensitive resins have poor mechanical properties after 3D printing. To overcome these limitations, a polyurethane acrylate oligomer (PUA) microsphere was prepared using the Pickering emulsion template method and ultraviolet (UV) curing technology in this paper. The prepared PUA microspheres were added to PUA-1,6-hexanediol diacrylate (HDDA) photosensitive resin system for digital light processing (DLP) 3D printing technology. The preparation process of PUA microspheres was discussed based on micromorphology, and it was found that the oil-water ratio of the Pickering emulsion and the emulsification speed had a certain effect on the microsphere size. As the oil-water ratio and the emulsification speed increased, the microsphere particle size decreased to a certain extent. Adding a suitable proportion of PUA microspheres to the photosensitive resin can improve the mechanical properties and thermal stability. When the modified photosensitive resin microsphere content was 0.5%, the tensile strength, elongation at break, bending strength, and initial thermal decomposition temperature were increased by 79.14%, 47.26%, 26.69%, and 10.65%, respectively, compared with the unmodified photosensitive resin. This study provides a new way to improve the mechanical properties of photosensitive resin 3D printing. The resin materials studied in this work have potential application value in the fields of ceramic 3D printing and dental temporary replacement materials. [ABSTRACT FROM AUTHOR]

In this study, a stable alkyl ketene dimer (AKD) Pickering emulsion was obtained using chitosan and titanium dioxide (TiO2) as effective emulsifiers to disperse AKD. Superhydrophobic filter paper was prepared, using the filter paper as the substrate, by dipping it into AKD Pickering emulsion and then drying the coating papers at different temperature. The contact angle of the treated filter papers dried at 45 °C could reach more than 150°, and these filter papers effectively separated oil–water mixtures with an efficiency of over 93%. It is worth noting that the preparation process of the superhydrophobic material was simple and mild, and all the raw material was green without secondary pollution to the environment, so it has great practical application potential. This experiment could provide a new idea for the preparation of AKD superhydrophobic coatings and broaden their application. [ABSTRACT FROM AUTHOR]

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Introduction : ce travail a pour objectif principal de stabiliser une nanoémulsion de Pickering avec des nanoparticules de Mg(OH)2. Dans cette étude, nous nous sommes focalisés sur la stabilité d’une nanoémulsion de Pickering et sa caractérisation physico-chimique. Matériel et Méthodes : Les nanoparticules stabilisantes composées d'hydroxyde de magnésium ont été obtenues par une méthode de nano-précipitation en présence de PEG-12000. Une nanoémulsion Huile- dans-Eau de Pickering stabilisée par des nanoparticules de Mg(OH)2 a été formulée selon un processus à haute énergie, à l'aide d'une sonde de sonication. L'approche expérimentale a exploré l'impact de tous les paramètres de formulation, composition et taille des nanoparticules de Mg(OH)2, sur les propriétés physico-chimiques de la nanoémulsion de Pickering. Le système a été caractérisé par diffusion dynamique d’un faisceau Laser Hélium-Néon (DLS) et par microscopie électronique à transmission. Résultats et Discussion : Les résultats ont montré la formulation d’une nanoémulsion de Pickering Huile-dans-Eau stable. La caractérisation au DLS a montré des tailles de nanoparticules comprises entre 21 et 45 nm. Les résultats ont également montré des nano-gouttelettes d’émulsion d’une dimension comprise entre 100 et 300 nm au DLS. Cette gamme de taille était fonction des nanoparticules stabilisantes. La taille des nano-gouttelettes d’émulsion a été confirmée par microscopie électronique à transmission. La caractérisation physico-chimique a aussi montré que le potentiel zêta des nano- gouttelettes était fonction du pH du milieu dispersant. Conclusion : Cette nanoémulsion de Pickering peut offrir des applications intéressantes dans la réalisation de systèmes à libération contrôlée de substances actives.

IntroductionMayonnaise is a products which is widely popular in most countries. Apart from the desirable taste of this product as a seasoning, plays an effective role in providing nutrients and energy for humans. Dietary mayonnaise, is semi-solid or liquid product prepared from emulsification fat substitutes and vegetable oils with vinegar and other additives with less energy and fat. Fat has more calories (9 kcal/g) compared to protein and carbohydrates (4 kcal/g). Mayonnaise is an oil-in-water emulsion and due to having high amounts of fat it causes cardiovascular diseases. Gums are part of construction formula in low fat products to create texture. Due to the great desire to consume low-fat products and also the wide use of this sauce, production of low-fat mayonnaise is important. The purpose of this research was to develop reduced fat mayonnaise using stabilized nano emulsion with casein complex Pickering and Gadomeh Shirazi gum. Materials and MethodsMayonnaise with reduced oilcontains 30, 40 and 50 percent Pickering emulsion replacement oil respectively at the level of 42, 32 and 22 percent produced and compared with the control sample. Centrifugal and time stability tests, textural features, color characteristics, morphology, organoleptic properties were evaluated. Results and DiscussionThe results showed as the replacement percentage increases nano emulsion containing Pickering particles and reducing the percentage of fat in mayonnaise emulsion stability she found her mayonnaise sauce although at a replacement level of 30% nano emulsion, this decrease in stability was not significant (P

Cyclodextrins (CDs) are conical molecules with a hydrophilic surface and a hydrophobic cavity. Thanks to the cavity, CDs are able to form inclusion complexes with a wide variety of guest molecules. A new oil-in-water (O/W) emulsifying system suitable for use in preparing Pickering emulsions with a large range of oils was developed. This system contains β-Cyclodextrin (β-CD) and a natural origin selected surfactant, Polyglyceryl-3 diisostearate (PG3D). The purpose of this work is to better understand the role of the PG3D in the realization and stabilization of these O/W emulsions. With this aim, O/W Pickering emulsions stabilized only by β-CD or β-CD/PG3D blends were prepared, and the effects of the presence of PG3D at different levels on the stability of emulsions were investigated. This original work was implemented using a wide range of complementary analytical methods, especially tensiometry, optical microscopy, laser granulometry, classical NMR and low field NMR measurements. The effectiveness of the β-CD/PG3D emulsifying system for preparing O/W Pickering emulsions appears due to synergistic effects between β-CD and PG3D. These molecules are both acting to stabilize the oil/water interface. The created particles have a high affinity for water with about the same contact angle as found for water. This may explain that only O/W emulsions are obtained using this system as in the case of using β-CD alone. PG3D by decreasing interfacial tension and due to its high wettability of the hydrophobic surfaces helps to get finer emulsions. An optimum β-CD/PG3D ratio must be used to obtain the most stable emulsions. [ABSTRACT FROM AUTHOR]

The rheology of oil-in-water (O/W) emulsions, stabilized and thickened by cellulose nanocrystals, also referred to as nanocrystalline cellulose (NCC), was investigated over broad ranges of NCC and oil concentrations. The NCC concentration was varied from 1.03 to 7.41 wt% based on the aqueous phase. The oil concentration of the emulsion was varied from approximately 10 to 70 wt%. The emulsions produced were highly stable with respect to creaming and coalescence. The emulsions were non-Newtonian in that they exhibited strong shear-thinning behavior. The rheological data were described adequately by a power-law model. The consistency index (K) and the flow behavior index (n) of the emulsions were strongly dependent on the NCC and oil concentrations. At a fixed oil concentration, the consistency index increased whereas the flow behavior index decreased with the increase in NCC concentration. A similar behavior was observed when the NCC concentration was fixed and the oil concentration was increased; that is, the consistency index increased whereas the flow behavior index decreased. [ABSTRACT FROM AUTHOR]

In contrast to their well-known physiological properties, phytochemicals, such as flavonoids, have been less frequently examined for their physiochemical properties (e.g., surface activity). A natural quercetin self-stabilizing Pickering emulsion was fabricated and characterized in the present study. The antisolvent precipitation method was used to modify quercetin (in dihydrate form), and the obtained particles were characterized by light microscope, atom force microscope, XRD, and contact angle. The antisolvent treatment was found to reduce the particle size, crystallinity, and surface hydrophobicity of quercetin. We then examined the effects of the antisolvent ratio, particle concentration, and oil fraction on the properties of the quercetin particle-stabilized emulsions. In addition, increasing the antisolvent ratio (1:1~1:10) effectively improved the emulsification performance of the quercetin particles. The emulsion showed good storage stability, and the particle size of the emulsion decreased with the rising particle concentration and increased with the rising oil phase ratio. The findings indicate that natural quercetin treated with antisolvent method has a good ability to stabilize Pickering emulsion, and this emulsion may have good prospective application potential for the development of novel and functional emulsion foods. [ABSTRACT FROM AUTHOR]

Compartmentalization is essential for living cells to orchestrate their biological processes with controlled external influences. Thus, compartmentalization has been a constant theme for cell‐mimicking materials. Despite recent advances in engineering compartmentalized materials as synthetic cells and organelles, it remains difficult to produce robust and well‐ordered compartments with secluded environments in aqueous surroundings. Nature creates hierarchically ordered compartmentalized materials by utilizing bio‐catalyzed mineralization, inspired by which, mechanically robust all‐aqueous compartments are developed by engineering a mild biomimetic mineralization at aqueous/aqueous interfaces. The enzyme‐induced biomineralization generates a layer of densely‐packed particles, acting as an armor to enclose aqueous interiors. This strategy of in situ bio‐synthesized compartments is different from current strategies, where compartments are constructed by randomly adsorbed particles at interface, leading to inadequately controlled properties of compartments. To demonstrate the robustness and adaptiveness of the in situ bio‐synthesized all‐aqueous compartments, these are utilized as drug delivery materials by sequestering protein drugs at their aqueous interiors and releasing when exposing to gastric environments. The study provides new ways to fabricate compartmentalized materials with well‐defined properties, unlocking routes to the next generation of self‐assembled materials and structures by integrating aqueous two‐phase systems with biomineralization. [ABSTRACT FROM AUTHOR]

This study investigates the formulation of surfactant-free Pickering emulsions that release a drug at a specific pH to improve its oral bioavailability. The stabilizing particles composed of magnesium carbonate particles. Pickering oil-in-water emulsions stabilized with magnesium carbonate particles and encapsulating a hydrophobic drug model (ibuprofen) were formulated using a high-energy process with rotor-stator turbo mixer (IKA® T25 digital ultra-Turrax). The experimental approach explored the impact of all formulation parameters, dispersed phase and amount of magnesium carbonate particles on the physicochemical properties of Pickering emulsions. The O/W Pickering emulsion was characterized by a methylene blue test, pH and conductivity measurements, and droplet size determination. In addition, Pickering emulsions stabilized by magnesium carbonate particles have the advantage of being destabilized in acidic medium leading to the release of the active principle via the droplets. The acidic medium release study (pH equal to 1.2) showed ibuprofen release as a function of initial droplet loading and saturation concentration. In the simulated intestinal medium at pH equal to 6.8, we found a better release of ibuprofen from emulsions that already had saturation in an acid medium. Thus, the interest of these Pickering emulsions lies on the fact that their non-toxicity and magnesium carbonate particles allow destabilization of the emulsions and release of the drug. These emulsions not only protect patients from the side effects of acid-based drugs, but also contribute to increase the bioavailability of these acidic drugs. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel anti-solvent precipitation method to produce submicron curcumin crystals was designed. • Contact angle measurements and emulsification experiments were used to test curcumin crystals as Pickering stabilizers. • Molecular modelling was used to relate interfacial properties with curcumin crystal structure. • A crystal engineering approach is proposed and validated to design curcumin Pickering crystals. Emulsions stabilized via Pickering particles are becoming more and more popular due to their high stability and biocompatibility. Hence, developing new ways to produce effective Pickering particles is essential. In this work, we present a crystal engineering approach to obtain precise control over particle properties such as size, shape, and crystal structure, which may affect wettability and surface chemistry. A highly reproducible synthesis method via anti-solvent crystallization was developed to produce sub-micron sized curcumin crystals of the metastable form III, to be used as Pickering stabilizers. The produced crystals presented a clear hydrophobic nature, which was demonstrated by their preference to stabilize water-in-oil (W/O) emulsions. A comprehensive experimental and computational characterization of curcumin crystals was performed to rationalize their hydrophobic nature. Analytical techniques including Raman spectroscopy, powder X-ray diffraction (PXRD), Solid-State Nuclear Magnetic Resonance (SSNMR), scanning electron microscopy (SEM), Differential Scanning Calorimetry (DSC), confocal fluorescence microscopy and contact angle measurements were used to characterize curcumin particles in terms of shape, size and interfacial activity. The attachment energy model was instead applied to study relevant surface features of curcumin crystals, such as topology and facet-specific surface chemistry. This work contributes to the understanding of the effect of crystal properties on the mechanism of Pickering stabilization, and paves the way for the formulation of innovative products in fields ranging from pharmaceuticals to food science. [ABSTRACT FROM AUTHOR]

The effects of marinating with nano fish bone (NFB) on the physicochemical characteristics and quality of snakehead fish slices during freeze-thaw cycles (1, 3, 5, 7, and 9) were investigated. The highest alterations in surface hydrophobicity, carbonyl content and secondary structure of the slice myofibrillar protein, integrity of cellular structure, and slice quality (whiteness, thawing loss, cooking loss, and sensory) were found in the sample without cryoprotectant (Ck), followed by the sample with commercial cryoprotectant of polyphosphates (PPS), and the lowest in the NFB sample. Comparatively, more moisture but less free water was observed in the NFB sample during the freeze-thaw cycles. Furthermore, NFB surrounded the oil droplet to form a Pickering emulsion, resulting in the stabilization of oil in the marinade. The results indicated that NFB can serve as a potential alternative to commercial cryoprotectant in frozen fish slices, which is attributed to its antifreeze and antioxidant functionalities. • Cryoprotectant capabilities of nano fish bone (NFB) obtained from fish wastes assessed. • Contents of NFB reduced protein denaturation, cellular damage and ice crystal size. • NFB formed a Pickering emulsion, resulting in the stabilization of oil in the marinade. [ABSTRACT FROM AUTHOR]

In this study, four different arginine-modified lignin composites (Lig-Arg-x) were synthesized via the Mannich reaction, followed by the preparation of Lig-Arg-x/Fe 3 O 4 magnetic nanoparticles (NPs) using hydrothermal reduction. The magnetic particles were characterized, and their emulsification properties were investigated. The highest grafting degree was achieved at a 1:1 M ratio of arginine to lignin. Pickering emulsions were formulated and Lig-Arg-x/Fe 3 O 4 NPs as the emulsifier. The study examined the impact of arginine grafting degree, oil-to-water volume ratio, and nanoparticle concentration on emulsion stability and demulsification performance. Optimal emulsion stability, characterized by the smallest droplet size of 20.57 μm, was achieved with a 1:1 M ratio of lignin to arginine, a 7:3 oil-to-water volume ratio, and a nanoparticle concentration of 1.0 w/v%. Magnetic induction experiments demonstrated significant phase separation in the stable emulsion under a magnetic field, confirming the magnetic-induced demulsification capability of the composite particles. Oil displacement experiments demonstrated that Lig-Arg-x/Fe 3 O 4 NPs modulate oil droplet diffusion via the Marangoni effect, indicating their potential for oil recovery applications. After three cycles, Lig-Arg-1/Fe 3 O 4 NPs retained 80 % of their saturation magnetization, demonstrating strong reusability. This study showcases lignin-magnetite nanocomposites' versatility in stabilizing emulsions and exhibiting magnetic responsiveness, advancing demulsification and oil spill recovery technologies., Competing Interests: Declaration of competing interest The authors declare no competing financial interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Emulsion systems are prevalent components in food formulation, and researchers have engaged in enhancing their functionality and stability through the application of interfacial engineering methods. Layer-by-Layer (LBL) deposition represents a technique applicable to the oil-water interface, which have been widely employed for improving the stability of emulsion systems through the formation of thick interfacial membranes and the modification of interactions between droplets. By strategically designing the interface with diverse biopolymers, it is possible to synthesize multilayer emulsions that exhibit specialized functions. In this review, recent advances in the preparation of multilayer emulsions and Pickering emulsions via LBL technology were highlighted, with an emphasis on their stabilization and rheological properties. It discussed some research focused on comparable analysis of binary polymer-stabilized emulsion via different interfacial assembly, with the aim of understanding the influence of interfacial properties on the performance and functionality of these emulsion systems. Finally, their promising applications including forming gel structures, delaying lipid digestion, working as specific delivery systems, and acting as template to design novel materials were also summarized. Through strategic modification of their interfacial properties, it is possible to induce a transformation in the rheological behavior of emulsion systems, from a liquid-like state to solid-like gels. By designing the interface via LBL deposition, the emulsions with thicker and special interfacial membrane could be utilized to formulate food-based emulsions with high stability and functionality. [Display omitted] • Layer-by-layer (LBL) deposition at the oil-water interface enhances the stability of emulsions. • Multilayer-coated droplets can be rationally designed by manipulating experimental parameters. • The interaction between droplets and the interfacial layer affects the rheology of LBL emulsions. • Emulsion gels can be induced by controllable bridging flocculation using LBL deposition. [ABSTRACT FROM AUTHOR]

Particle-stabilized technique for fabricating foam ceramics was developed in 2006. Porous ceramics with porosity over 95% can be prepared by this newly developed method. This foaming technique was derived from the principle of Pickering foam to a large extent. The high internal phase volume, narrow distribution of pore size as well as the structural stability of the Pickering system enable the final ceramic products to realize their functionality in a variety of applications. However, the interfacial aspect of the foaming system determines the final product in many ways, which brings this novel method details to explore and possibilities to challenge. The current review introduces the particle-stabilized method combining with colloid and surface science since particles are the building block of ceramic materials. The history of this newly invented method was mentioned at first, followed by foam ceramic products prepared by this foaming technique combining with corresponding mechanism. Some representative applications involving ceramic materials made by particle-stabilized method were discussed. At last, we conclude the overall article and put forward some outlooks and challenges about the future direction of this unique foaming technique. [Display omitted] • Elaborate the relationship between colloid particles and ceramic materials. • Introducing the origin and understanding of the particle-stabilized foaming method. • Summarize the classification of the synthetic strategies using particle-stabilized foaming technique. • Illustrate the application scenarios of foam ceramics prepared by this method. • Challenging future directions of particle-stabilized foaming technique. [ABSTRACT FROM AUTHOR]

The rheology of oil-in-water (O/W) emulsions, stabilized and thickened by cellulose nanocrystals, also referred to as nanocrystalline cellulose (NCC), was investigated over broad ranges of NCC and oil concentrations. The NCC concentration was varied from 1.03 to 7.41 wt% based on the aqueous phase. The oil concentration of the emulsion was varied from approximately 10 to 70 wt%. The emulsions produced were highly stable with respect to creaming and coalescence. The emulsions were non-Newtonian in that they exhibited strong shear-thinning behavior. The rheological data were described adequately by a power-law model. The consistency index (K) and the flow behavior index (n) of the emulsions were strongly dependent on the NCC and oil concentrations. At a fixed oil concentration, the consistency index increased whereas the flow behavior index decreased with the increase in NCC concentration. A similar behavior was observed when the NCC concentration was fixed and the oil concentration was increased; that is, the consistency index increased whereas the flow behavior index decreased.

Pickering emulsions stabilized by the interaction of palmitic acid (PA) and silica nanoparticles (SiNPs) at the water/oil interface have been studied using different alkane oil phases. The interaction of palmitic acid and SiNPs has a strong synergistic character in relation to the emulsion stabilization, leading to an enhanced emulsion stability in relation to that stabilized only by the fatty acid. This results from the formation of fatty acid-nanoparticle complexes driven by hydrogen bond interactions, which favor particle attachment at the fluid interface, creating a rigid armor that minimizes droplet coalescence. The comparison of emulsions obtained using different alkanes as the oil phase has shown that the hydrophobic mismatch between the length of the alkane chain and the C16 hydrophobic chain of PA determines the nature of the emulsions, with the solubility of the fatty acid in the oil phase being a very important driving force governing the appearance of phase inversion. [ABSTRACT FROM AUTHOR]

This paper presents examples of bicontinuous interfacially jammed emulsion gels ("bijels") with a designed gradient in the channel size along the sample. These samples are created by quenching binary fluids which have a gradient in particle concentration along the sample, since the channel size is determined by the local particle concentration. A gradient in local particle concentration is achieved using a two-stage loading process, with different particle volume fractions in each stage. Confocal microscopy and image analysis are used to quantitatively measure the channel size of the bijels. Bijels with a gradient in channel size of up to 2.8% mm-1 have been created. Such tailored soft materials could act as templates for energy materials optimized for both high ionic transport rates (high power) and high interfacial area (high energy density), potentially making them useful in novel energy applications. [ABSTRACT FROM AUTHOR]

The modification of graphene oxide (GO) with octadecylamine was performed to emulsify dimethyl formamide droplets in octane via Pickering mechanism for copolymerization of styrene and n-butyl acrylate monomers. The copolymerization in oil in oil Pickering emulsion was led to obtain appropriate copolymer composition. To confirm the modification, different characterization techniques were applied comprising Fourier-transform infrared spectroscopy (FT-IR), X-ray diffractometer, Atomic force microscopy, dynamic light scattering technique, contact angle and thermal analysis. The successful preparation of Pickering emulsion was followed by imaging and stability observations. The 1HNMR, FT-IR and conversion measurements were applied to identify the composition and chemical structure of the obtained copolymer. The St–BA copolymer film was formed after polymerization in Pickering emulsion by ODA–GO. The conductivity value (0.077*10–6) or the amount of resistance volume (13 MΩ) were gained for copolymer film which depended on the components amounts. These findings will help explore Pickering mechanism along with modification of GO structures and their eventual application in copolymerization of monomer with different polarity nature. [ABSTRACT FROM AUTHOR]

According to the multiple role of fat in food products, it is necessary to use a substance as a substitute of fat to maintain the rheological, texture and sensory characteristics of low-fat products. In this study, oleogel system was applied to produce low-fat product. Pickering emulsion-templated was applied to produce oleogels. Isolated soy protein (ISP) and basil seed gum (ISP-BSG) were used for the preparation of Pickering. ISP-BSG particles were prepared with different mass ratios of ISP-BSG, 1:0, 1:1, 2:1 and 3:1 and named 1S:0B, 1S:1B, 2S:1B and 3S:1B, respectively. The type and structure of the Pickering used affected the amount of oil retention in the oleogel (p < /em>

El objetivo de este trabajo fue aumentar el rendimiento y selectividad en la reacción de obtención de α-terpineol a partir de limoneno, componente mayoritario del aceite esencial de pomelo, con el uso de emulsiones pickering de agua:aceite. Se utilizaron carbón activado, bentonita, sílica y alúmina como sólidos estabilizantes de la emulsión. Se caracterizaron las emulsiones midiendo su conductividad en distintas relaciones agua:aceite para determinar el punto donde ocurre la inversión de fase de la emulsión. Se prepararon las emulsiones pickering de tipo aceite/agua (o/w), estableciendo las concentraciones másicas óptimas de cada sólido. El rendimiento máximo obtenido en α-terpineol fue de un 43 % utilizando sílica, un 36 % más que en medio de reacción sin sólidos. También se logró reutilizar los sólidos dos veces sin diferencias en el rendimiento de la reacción.

In contrast to their well-known physiological properties, phytochemicals, such as flavonoids, have been less frequently examined for their physiochemical properties (e.g., surface activity). A natural quercetin self-stabilizing Pickering emulsion was fabricated and characterized in the present study. The antisolvent precipitation method was used to modify quercetin (in dihydrate form), and the obtained particles were characterized by light microscope, atom force microscope, XRD, and contact angle. The antisolvent treatment was found to reduce the particle size, crystallinity, and surface hydrophobicity of quercetin. We then examined the effects of the antisolvent ratio, particle concentration, and oil fraction on the properties of the quercetin particle-stabilized emulsions. In addition, increasing the antisolvent ratio (1:1~1:10) effectively improved the emulsification performance of the quercetin particles. The emulsion showed good storage stability, and the particle size of the emulsion decreased with the rising particle concentration and increased with the rising oil phase ratio. The findings indicate that natural quercetin treated with antisolvent method has a good ability to stabilize Pickering emulsion, and this emulsion may have good prospective application potential for the development of novel and functional emulsion foods.

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[Display omitted] Aqueous Two-Phase Systems (ATPS) are aqueous droplets dispersed in an aqueous phase. This specific behavior arises from interactions between at least two water-soluble entities, such as thermodynamically incompatible polymers. A simple, fast, and "green" process to produce ATPS with an aqueous core would be of high interest to the pharmaceutical field for drug delivery. However, to date, rapid destabilization of ATPS represents the main hurdle for their use. Herein we present a novel process to achieve a stabilized microparticle-ATPS, without the use of organic solvents. ATPS composed of dextran and polyethylene oxide were prepared. A Pickering-like emulsion technique was used to stabilize the ATPS by adsorbing semi-solid particles (chitosan-grafted lipid nanocapsules) at the interface between the two aqueous phases. Finally, microparticles were formed by a polyelectrolyte complexation and gelation. The structure and stability of ATPS were characterized using microscopy and Turbiscan analysis. Adding chitosan-grafted lipid nanocapsules induced ATPS stabilization. Adding a polyelectrolyte such as sodium alginate allowed the formation of microparticles with a gelled shell that strengthened the formulation against shear stress and improved long-term stability, thus demonstrating that is possible to use ATPS to form delivery systems to encapsulate hydrophilic molecules. [ABSTRACT FROM AUTHOR]

Hepatic arterial infusion (HAI) of oxaliplatin allows greater liver tumour drug exposure compared to systemic infusion. However, the therapeutic index of HAI oxaliplatin remains poor. Using Pickering emulsion technology, we developed a platform able to provide sustained releases of oxaliplatin. The goal of this study was to evaluate the pharmacokinetic advantages of sustained-HAI oxaliplatin over HAI using a preclinical animal tumour model. Injections of 0.6 mg oxaliplatin in 20 min were selectively done in left hepatic arteries of 20 rabbits bearing a VX2 liver tumour in the middle left-lobe, using HAI (n = 10) or sustained-HAI (n = 10). In each group, half of the rabbits were sacrificed at 24 h and half at 72 h. Mass spectrometry was used to quantify drug pharmacokinetics in blood and oxaliplatin concentrations in tumour tissues, right- and middle left-liver lobes, spleen and lung. Compared to HAI, sustained-HAI of oxaliplatin resulted in lower plasmatic peak (Cmax: 275 ± 41 vs. 416 ± 133 ng/mL, p = 0.02) and higher concentration in the tumour at 24 h (2118 ± 2107 vs. 210 ± 93 ng/g, p = 0.008). After HAI, oxaliplatin concentration in tumours was significantly higher than in lung at 24 h (p = 0.03) but no other difference was found between oxaliplatin concentrations in tumours and in liver lobes, spleen or lung, neither at 24 h nor at 72 h. On the opposite, sustained-HAI resulted in higher concentrations of oxaliplatin in tumour compared to oxaliplatin concentrations in the middle left lobe (163 ± 86 ng/g at 24 h, p = 0.01, and 90 ± 15 ng/g at 72 h, p = 0.04), right lobe (174 ± 112 ng/g at 24 h, p = 0.01, and 112 ± 35 ng/g, p = 0.04 at 72 h), spleen (142 ± 21 ng/g at 24 h, p = 0.01, and 98 ± 12 ng/g at 72 h, p = 0.04), and lung (85 ± 11 ng/g at 24 h, p = 0.01, and 52 ± 4 ng/g at 72 h, p = 0.03). Sustained-HAI improves the therapeutic index of HAI oxaliplatin and offers a great potential for patients suffering from unresectable colorectal liver metastases or hepatocellular carcinoma. [ABSTRACT FROM AUTHOR]

This review discusses the application of oleogel technology in emulsified systems. In these systems of mimetic fats, water‐in‐oil or oil‐in‐water emulsions can be obtained, but, here, we cover emulsions with an oil continuous phase in detail. Depending on the percentage of water added to the oleogels, systems with different textures and rheological properties can be developed. These properties are affected by the characteristics and concentration of the added components and emulsion preparation methods. In addition, some gelators exhibit interfacial properties, resulting in more stable emulsions than those of conventional emulsions. Oleogel‐based emulsion are differentiated by continuous and dispersed phases and the structuring/emulsification components. Crucially, these emulsions could be applied by the food industry for preparing, for example, meat products and margarines, as well as by the cosmetics industry. We present the different processes of emulsion elaboration, the main gelators used, the influence of the water content on the structuring of water‐in‐oleogel emulsions, and the structuring mechanisms (Pickering, network, and combined Pickering and network stabilization). Finally, we highlight the applications of these systems as alternatives for reducing processed food lipid content and saturated fat levels. [ABSTRACT FROM AUTHOR]

To expand the application of emulsion gels as fat replacers in food systems, they were applied as fat analogs for plant-based meats by single-channel and dual-channel 3D printing. Spirulina platensis protein, as sustainable food sources, exhibits excellent emulsifying ability and has been generated into nanoparticles to stabilize emulsions. Three novel fat analogs: spirulina platensis protein nanoparticle based Pickering emulsions gels (SPP); nanoparticles/xanthan gum-based emulsions gels (SPP-XG); nanoparticles/xanthan gum/sunflower wax-based emulsions gels (Bigel); and three conventional oils: coconut oil; palm oil; and oleogel were regarded as fat components. The fat and protein components blended for printing by single-channel 3D printing, resulting in a new type of plant-based meats with extremely high printing accuracy and exhibiting "print inflation". It exhibited lower hardness, which was conducive to chew compared with control ones. The water mobility was weakened as showed in LF-NMR, meaning the improved water holding capacity of plant-based meats. Protein and oil matrix were loaded into two printing cartridges respectively for dual-channel 3D printing, Bigels and palm oil (PO) served as a comparison of oil types. The cooking loss and shrinkage of Bigel-based plant-based meats obtained by this method were at extremely low level with 4.81% ∼ 6.20% and 5.16% ∼ 7.72%, respectively. As the oil content increased to 60%, the PO-plant-based meats collapsed and lost their printing structure, while Bigel-plant-based meats exhibited better printing effects, which can be regarded as an ideal special fat for 3D printing to construct plant-based meats. • Spirulina platensis protein-based emulsion gels can be used as fat analogs. • Single/Dual-channel 3D printing can produce novel plant-based meats. • Higher emulsion gel content contributes to the juiciness and tender meat perception. • Dual-channel 3D printing can obtain plant-based meats with visible fat structure. [ABSTRACT FROM AUTHOR]

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The distribution of particles in Pickering emulsions can be estimated through a percolation-type approach coupled to the evolution of their rheological features with the dispersed phase volume fraction ϕ. The rheological behavior of water-in-dodecane Pickering emulsions stabilized with hydrophobic silica nanoparticles is addressed. The emulsions viscosity and elastic modulus are investigated at ϕ varying from 0.1 to 0.75. Various rheological models are adjusted to the experimental data. The comparison of the elastic modulus evolution of the Pickering emulsions with those of emulsions stabilized with surfactants confirms a major contribution of the particles to the rheological behavior of Pickering emulsions and supports the existence of a three-dimensional network between the droplets. The applied percolation approach allows to quantitively estimate a nanoparticles viscoelastic link between the droplets and opposes the classic vision of interfacial monolayers stabilizing the Pickering emulsions. This network of interconnected particles and droplets contributes significantly to the viscosity as well as the elastic modulus of these emulsions. To our knowledge, the applied percolation-based model is the only one capable of providing a structural explanation while describing the abrupt viscosity and elastic modulus growth of Pickering emulsions across the range of ϕ. [ABSTRACT FROM AUTHOR]

Pickering emulsions stabilized by the interaction of palmitic acid (PA) and silica nanoparticles (SiNPs) at the water/oil interface have been studied using different alkane oil phases. The interaction of palmitic acid and SiNPs has a strong synergistic character in relation to the emulsion stabilization, leading to an enhanced emulsion stability in relation to that stabilized only by the fatty acid. This results from the formation of fatty acid-nanoparticle complexes driven by hydrogen bond interactions, which favor particle attachment at the fluid interface, creating a rigid armor that minimizes droplet coalescence. The comparison of emulsions obtained using different alkanes as the oil phase has shown that the hydrophobic mismatch between the length of the alkane chain and the C16 hydrophobic chain of PA determines the nature of the emulsions, with the solubility of the fatty acid in the oil phase being a very important driving force governing the appearance of phase inversion.

Emulsions stabilized by solid nanoparticles, referred to as Pickering emulsions, are becoming increasingly important in applications as they are free of surfactants. However, the bulk properties and stability of Pickering emulsions are far from being well understood. In this work, the rheological behavior and catastrophic phase inversion of emulsions in the presence of starch nanoparticles were studied using in-situ measurements of viscosity and electrical conductivity. The aqueous phase consisting of starch nanoparticles was added sequentially in increments of 5% vol. to the oil phase under agitation condition to prepare the emulsions. The emulsions were water-in-oil (W/O) type at low to moderate concentrations of aqueous phase. At a certain critical volume fraction of aqueous phase, catastrophic phase inversion of W/O emulsion to oil-in-water (O/W) emulsion took place accompanied a sharp jump in the electrical conductivity and a sharp drop in the emulsion viscosity. The W/O emulsions were nearly Newtonian at low concentrations of aqueous phase. At high concentrations of aqueous phase, prior to phase inversion, theW/O emulsions exhibited a shear-thickening behavior. The O/Wemulsions produced after phase inversion were shear-thinning in nature. The comparison of the experimental viscosity data with the predictions of emulsion viscosity model revealed only partial coverage of droplet surfaces with nanoparticles. With the increase in the concentration of starch nanoparticles (SNPs) in the aqueous phase of the emulsions, the phase inversion of W/O emulsion to O/W emulsion was delayed to higher volume fraction of aqueous phase. Thus SNPs imparted some stability to W/O emulsions against coalescence and phase inversion. [ABSTRACT FROM AUTHOR]

Objective: The development of medicinal plants for clinical use represents an important direction in biomedical research, despite the technological difficulties. Significance: The aim of this study was to compare pharmaceutical characteristics and in vitro release of Classical and Pickering emulsions containing crude or fractionated extracts of Libidibia ferrea. Methods: After evaluating the extract's solubility in formulation, a dispersion of hydroxypropyl methylcellulose (HPMC) was prepared in water. For Pickering emulsions, the aqueous phase was HPMC and the oil phase was Miglyol® 812; for Classical emulsions, water with Tween® 20 and Miglyol® 812 with Span® 80 were used for aqueous and oil phases, respectively. Crude or fractionated extracts were added to the aqueous phase (5% w/v). Both phases were heated (40 °C); then, the oil phase was poured into the aqueous phase and homogenized using an Ultra-Turrax. Emulsions were characterized for 90 days by pH, polyphenol content, phytomarker content, macroscopic characteristics, droplet size, and zeta potential. Results: These formulations displayed satisfactory stability for 90 days when stored at 25 °C. Regarding the investigation of rheological properties, Pickering emulsions displayed higher viscosity with lesser deformation than Classical emulsions. Moreover, the emulsions displayed similar in vitro release behavior. Conclusion: Based on the results of present study, the Pickering emulsions were obtainable and displayed higher stability than Classical emulsions. Additionally, maintenance of system integrity points to promising systems for delivery of active pharmaceutical ingredients in the internal phase, despite the complex chemical mixture added to the external phase. [ABSTRACT FROM AUTHOR]

According to the multiple role of fat in food products, it is necessary to use a substance as a substitute of fat to maintain the rheological, texture and sensory characteristics of low-fat products. In this study, oleogel system was applied to produce low-fat product. Pickering emulsion-templated was applied to produce oleogels. Isolated soy protein (ISP) and basil seed gum (ISP-BSG) were used for the preparation of Pickering. ISP-BSG particles were prepared with different mass ratios of ISP-BSG, 1:0, 1:1, 2:1 and 3:1 and named 1S:0B, 1S:1B, 2S:1B and 3S:1B, respectively. The type and structure of the Pickering used affected the amount of oil retention in the oleogel (P<0.05). The presence of basil seed gum in a suitable ratio with protein (2S:1B) caused a more stable oleogel, higher mechanical strength, and more compact network. Finally, the oleogels were prepared with better oil bonding capacity. The highest and lowest thermal stability rates were for the 2S:1B and 1S:1B samples, respectively. The highest and lowest consistency levels were observed in 2S:1B and 1S: 0B samples, respectively (P<0.05). Investigation of the viscoelastic properties confirmed the gel formation in the oleogel system. According to the stability and textural properties of oleogel samples, two formulas 1S:0B and 2S:1B were used to produce cream with reduced fat (5, 10 and 15%). The highest overall acceptance was obtained in the 2S:1B sample with a 5% reduction in fat, which had no significant difference with control cream. [ABSTRACT FROM AUTHOR]

Objective: The increasing interest for the Pickering emulsions is based on the possibility to replace classical emulsifiers by the solid particles. This approach is extremely attractive for the cosmetic field. But, the main difficulty is to obtain stable emulsions with appreciable skin feel. However, there is no information about the texture of such systems. The aim of this study is to formulate and describe the textural properties of cosmetic Pickering emulsions compared with conventional systems. Methods: Three metal oxides were selected: titanium dioxide, zinc oxide and silicon dioxide, able to form stable and totally emulsified systems. A conventional emulsifier was used to formulate the emulsion of reference. Finally, the mixture of two emulsifying systems, combining both, surfactant and particles, was also studied. Then, a sensory panel was asked to quantify the intensities of the perception of the seven discriminating attributes. Results: Each particle brought its properties to the textural perception of the emulsion. TiO2 particles ensured the whitening effect of the emulsions, SiO2 provided the screech residue, whereas ZnO gave intermediate results. The conventional surfactant was perceived as glossy, greasy and more difficult to spread. The particle/surfactant mixtures gave mostly in‐between results. Conclusions: The study shows that the sensory profile of Pickering emulsions is indirectly and directly governed by the particle properties used for the emulsion stabilization: indirectly, through affecting the emulsion orientation (oil in water or water in oil), the droplet organization and viscosity, and directly, through the particle perception on the skin surface. [ABSTRACT FROM AUTHOR]

Silica-wax colloidosomes find application in various fields, for instance through their use as microencapsules for triggered release of chemical components or as precursors for the production of Janus particles. The characteristics of these colloidosomes are highly dependent on the particles/water-oil system composition and experimental parameters. Different colloidosomes were prepared using silica particles (D ¯ ≈ 295 nm) and a positively charged surfactant (cetyltrimethylammonium bromide, CTAB) as co-stabilizers of a wax in water. The CTAB concentration, type of stirring and wax addition procedure were systematically varied. The silica particles and colloidosomes formed were analysed by Scanning Electron Microscopy (SEM) and Dynamic Light Scattering (DLS). The final percentage of the silica particles embedded on the wax colloidosomes (embedding yield) was estimated by a gravimetric method and the formation of monolayer or multilayer/clusters of silica particles at the wax surface was inspected with SEM. The CTAB concentration and the wax addition procedure play a major role in obtaining an embedding yield close to 100% and a monolayer coverage of the colloidosomes surface. The results indicate the existence of a mechanism consisting of a dynamic redistribution of the surfactant between the interfaces present in the emulsion. The practical and theoretical insights provided can be used towards an efficient production and scale-up of silica-wax colloidosomes. [ABSTRACT FROM AUTHOR]

[Display omitted] • IMs and NAs induce emulsification but are not enough to guarantee stabilization. • Removing IMs changes the colloidal structures and increases emulsion stability. • Removing NAs does not cause significant changes in stability. Different Brazilian crude oils form stable emulsions, although they have low asphaltenes content. The present study aimed to extract and characterize interfacial materials (IMs) from these oils to understand the factors driving this phenomenon. Polarized microscopy and small-angle X-ray scattering (SAXS) revealed that IMs can self-organize in certain conditions, and the formed aggregates could be related to the emulsification process. IMs promoted the formation of model emulsions of mineral oil and brine, but they were not enough to keep them stable. The original and residual oils from the extraction were also used to form emulsions with brine. SAXS, rheology, time-domain nuclear magnetic resonance (TD-NMR), and interfacial tension measurements allowed the comparison of these emulsions. Removal of IMs promoted self-organization of aggregates present in the oil, increasing the viscosity and stability of the emulsions. One of the crude oils had a significant content of naphthenic acids (NAs), which are known to behave as surfactants in some conditions. This fraction was also investigated, but it did not significantly affect the physicochemical properties of the emulsions in comparison with IMs. Hence, the aggregates formed by IMs combined with other components of the crude oils were probably responsible for the rheological properties affecting stability. [ABSTRACT FROM AUTHOR]

Vegetal by-product powders, such as apple pomace powder, represent an efficient green alternative to conventional emulsifiers to stabilize oil-in-water Pickering emulsions. The natural material being used without purification, its multiple components shall impact differently the emulsion stability and interact with each other. These effects might be either synergic, competitive, or both depending on their ratio. Herein, the co-stabilizing effects of the apple pomace compounds on Pickering emulsions were explored from microscopic to macroscopic scales. The apple pomace powder was first fragmented into several fractions which were characterized (particle sizes, shape and wettability, oil-water surface activity). Emulsions were then prepared by varying the stabilizing material composition using the different fractions obtained from the apple powder. Emulsions properties (droplet size, rheological properties) and stability were monitored over a month. The key role of solid particles in the surface activity of the apple pomace powder was shown by interfacial tension measurements. All particle-stabilized emulsions were stable against coalescence during storage despite high droplet diameters (up to 80 μm) and low surface coverage. Soluble matter and particles show a synergic behavior to stabilize oil-in-water emulsions. The soluble matter drives droplet size whereas insoluble cellulosic particles are responsible for emulsion stability by both Pickering adsorption to the oil droplet and oil droplet trapping in a three-dimensional network. This study provides new insights into the understanding of natural powders stabilizing mechanisms that may lead to a better prediction of the potential of vegetal by-products as stabilizing agents from their chemical composition. [Display omitted] • Solid particles play a key role in the apple pomace powder surface activity. • Interactions between solid particles and apple pomace soluble compounds are either synergistic or competitive depending on their ratio. • Soluble compounds drive the emulsion droplet size at fixed particle content. • Solid particles prevent emulsion coalescence even at very low surface coverage (below 5% of total interfacial areas covered by solid particles). [ABSTRACT FROM AUTHOR]

Following the resurgence of interest in particle-stabilised or Pickering emulsions recently, the preparation of capsules from such templates has become feasible. We review some of the recent activity in this area and focus on both the methods used to reinforce the particle shell and the applications of these novel capsules, which may be empty or liquid-filled. The methods reported include interfacial polymerisation or crystallisation, interfacial cross-linking, the use of a sacrificial template, formation of polymer layers, gelation and evaporation from multiple emulsions. Potential applications are in the areas of wastewater treatment, perfume encapsulation, drug/dye release and as self-healing coatings. [ABSTRACT FROM AUTHOR]

Liquid foam exhibits remarkable rheological behavior although it is made with simple fluids: it behaves similar to a solid at low shear stress but flows similar to a liquid above a critical shear stress. Such properties, which have been proved to be useful for many applications, are even enhanced by adding solid particles. Depending on their hydrophobicity and size, the particles can have different geometrical configurations at the mesoscopic scale, that is, at the air–liquid interfaces, in the films, or in the interstices between the bubbles. In this review, we present rheological studies performed on granular rafts and films, on spherical armored interfaces, on gas marbles, and on aqueous foams laden with hydrophilic grains. Image 1 [ABSTRACT FROM AUTHOR]

An in-situ method of measuring the viscosity of unstable and stable emulsions on a continuous basis under agitation conditions was developed and utilized to investigate the viscous behaviour of surfactant-stabilized and nanoparticles-stabilized oil-in-water (O/W) emulsions at different volume fractions of the dispersed phase (oil). The stability characteristics (droplet size and phase-separation) of emulsions under quiescent conditions were also determined with the aging of emulsions. Emulsions are Newtonian at low volume fractions of the dispersed phase. At high concentrations of the dispersed phase, emulsions behave as non-Newtonian shear-thinning fluids. The nanoparticles-stabilized (Pickering) emulsions are unstable in comparison with the surfactant-stabilized emulsions. The droplet sizes of Pickering emulsions increase rapidly with aging, whereas the droplet sizes of surfactant-stabilized remain nearly the same over a period of 24 h. However, Pickering emulsions are much more viscous than the surfactant-stabilized emulsions when comparison is made at the same volume fraction of the dispersed phase. [ABSTRACT FROM AUTHOR]

Abstract A facile one-step microwave-assisted method was proposed for kaolinite intercalation and grafting. The structure, morphology, composition, and size distribution of kaolinite sheets were investigated using various methods, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric (TG) analysis. The potential application of the modified kaolinite as an oil/water emulsion stabilizer was studied. The results verified that intact kaolinite sheets were obtained. The dodecane/water emulsion stabilized by the modified kaolinite remained stable for more than 60 days. The effective performance suggests that the effectiveness of the proposed kaolinite modification method may be useful for Pickering emulsion stabilization in oil recovery applications. Highlights • A facile one-step microwave-assisted method was proposed for modifying kaolinite. • Intact modified kaolinite platelets were obtained for emulsion stabilization. • The modified kaolinite was verified to be an efficient emulsion stabilizer. • The modified kaolinite has great potential for application in oil recovery. [ABSTRACT FROM AUTHOR]

The application of chitin has significantly expanded, particularly in the formulation of protein-based complexes stabilized by electrostatic interactions, which are crucial in the development of Pickering emulsions. This study systematically investigates how variations in pH affect the molecular structure, interfacial properties, and emulsifying performance of egg white protein (EWP) complexes with chitin nanofibers (ChNFs). The findings reveal that electrostatic interactions between ChNFs and EWP substantially influence the dispersion and morphology of the complexes across a pH range of 2.0–9.0. Spectral analysis indicates that the incorporation of ChNFs leads to a slight reduction in surface hydrophobicity and fluorescence intensity of EWP, enhancing the protein's structural flexibility. Additionally, adsorption kinetics and dilational viscoelasticity measurements demonstrate that ChNFs significantly increase EWP's equilibrium interfacial pressure (up to 25 mN/m) and viscoelastic modulus, indicating improved stability at the oil-water interface. Notably, emulsions stabilized by EWP/ChNF complexes at pH values between 5.0 and 7.0 exhibit a more uniform droplet size (approximately 200 nm) and enhanced stability, with turbidity measurements reaching maximum values of 0.85. These results underscore the potential of chitin nanofibers as sustainable emulsifiers in food applications, providing a viable alternative to synthetic emulsifiers. [Display omitted] • ChNFs complexed with EWP form aggregation-enhanced biopolymer networks near the isoelectric point. • The addition of ChNFs increased the structural flexibility of the protein by promoting the formation of disordered structures. • The interfacial adsorption properties of ChNFs with EWP near the isoelectric point were analyzed. • The incorporation of ChNFs enhanced the stability and performance of EWP emulsions near the isoelectric point. [ABSTRACT FROM AUTHOR]

Emulsions stabilized by solid nanoparticles, referred to as Pickering emulsions, are becoming increasingly important in applications as they are free of surfactants. However, the bulk properties and stability of Pickering emulsions are far from being well understood. In this work, the rheological behavior and catastrophic phase inversion of emulsions in the presence of starch nanoparticles were studied using in-situ measurements of viscosity and electrical conductivity. The aqueous phase consisting of starch nanoparticles was added sequentially in increments of 5% vol. to the oil phase under agitation condition to prepare the emulsions. The emulsions were water-in-oil (W/O) type at low to moderate concentrations of aqueous phase. At a certain critical volume fraction of aqueous phase, catastrophic phase inversion of W/O emulsion to oil-in-water (O/W) emulsion took place accompanied a sharp jump in the electrical conductivity and a sharp drop in the emulsion viscosity. The W/O emulsions were nearly Newtonian at low concentrations of aqueous phase. At high concentrations of aqueous phase, prior to phase inversion, the W/O emulsions exhibited a shear-thickening behavior. The O/W emulsions produced after phase inversion were shear-thinning in nature. The comparison of the experimental viscosity data with the predictions of emulsion viscosity model revealed only partial coverage of droplet surfaces with nanoparticles. With the increase in the concentration of starch nanoparticles (SNPs) in the aqueous phase of the emulsions, the phase inversion of W/O emulsion to O/W emulsion was delayed to higher volume fraction of aqueous phase. Thus SNPs imparted some stability to W/O emulsions against coalescence and phase inversion.

Highlights • Aldehyde-functionalized cellulose nanocrystals were produced via periodate oxidation. • They were used as stabilizer for surfactant-free emulsion polymerization. • No surfactant was used to enhance the colloidal stabilization of the latex. • The nanocomposite dispersion was stable for a long time. Abstract Aldehyde-functionalized cellulose nanocrystals (CN) with two aldehyde contents were produced by periodate oxidation and gentle sonication. The aldehyde-functionalized CNCs were shown to be an effective stabilizer in the Pickering emulsion polymerization of acrylate monomers using potassium persulfate (KPS)/metabisulfite redox initiation system at 50 °C without any added surfactant. The effect of CNC content on the particle size, zeta-potential, colloidal stability and film properties were discussed. CNCs with the highest aldehyde content impart better colloidal stability to the polymer dispersion and lower particle size. The stabilization process was explained by the reaction of bisulfite with aldehyde groups borne by CNC, forming an adduct that contributes to the initiation of the polymerization and nucleation of polymer particles. This favors the effective attachment of CNCs onto the polymer particle, which is prerequisite for the effective Pickering stabilization process. The optical and mechanical properties of the nanocomposite films obtained by simple casting of the polymer dispersion and water evaporation were also investigated by transmittance and dynamic mechanical analysis (DMA). Better transparency was observed for films prepared in the presence of CNCs with the highest aldehyde content, while a reverse trend was noted for the mechanical properties. [ABSTRACT FROM AUTHOR]

Highlights • Zein and GA were fabricated into nanoparticles to stabilize Pickering emulsions. • Thymol was loaded into the ZGP-stabilized Pickering emulsions. • ZGP-thymol Pickering emulsion had a stronger antibacterial activity (E. coli). • ZGP-thymol Pickering emulsion exhibited a controlled-release effect. Abstract Zein/gum Arabic (GA) nanoparticles (ZGPs) were fabricated to stabilize the oil-water interface of a Pickering emulsion. The Pickering emulsion was successfully fabricated at an oil fraction of 0.3 with 6.25% concentration of ZGPs. The droplet size and creaming index of the Pickering emulsions were influenced significantly by the concentrations of the ZGPs and oil fractions. Morphological observations showed that droplet aggregation occurred when the concentrations of ZGPs decreased or the oil fraction increased. The interfacial tension and rheological properties of the Pickering emulsions indicated that the ZGPs formed a stable oil-water interfacial layer and limited agglomeration and Ostwald ripening. Thymol loaded ZGP-stabilized Pickering emulsion was able to significantly inhibit the growth of E. coli. In addition, the ZGP-stabilized Pickering emulsion with thymol exhibited a controlled-release effect of thymol and antibacterial activity due to the protective effect of the stable interfacial layer of the ZPGs. [ABSTRACT FROM AUTHOR]

Hypothesis The stability of particle stabilized water-in-water (W/W) emulsions depends on the position of the particles at the interface, which in turn depends on their preference for each phase. The surface properties of the particles determine their preference and it should therefore be possible to enhance the stability of W/W emulsions by modulating the surface of particles, for instance by adsorption of small molecules on their surface. Experiments Polystyrene latex particles were covered with proteins to varying extents by adding different amounts of whey proteins. The effect on the efficacy of the particles to stabilize W/W emulsions formed by mixing dextran and poly(ethylene oxide) (PEO) was studied using confocal laser scanning microscopy and visual observations. Both emulsions with droplets of the PEO rich phase in a continuous dextran rich phase (P/D) and the inverse (D/P) were investigated. Findings The preference of the particles could be modulated from strongly preferring the PEO phase in the absence of protein to preferring dextran phase in excess protein. It was found that the particles stabilized emulsions best when they preferred the continuous phase, i.e. protruded outward from the droplets. Both D/P emulsions and P/D could be stabilized at intermediate coverage. [ABSTRACT FROM AUTHOR]