Emulsion Stability Research Articles

Construction and characteristics of EGCG-porcine serum albumin pickering emulsion: Based on noncovalent interactions mechanism

Pickering emulsion prepared by the interaction between polyphenols and protein can improve the stability of protein-based emulsion. The purpose of this study was to explore the complex formation mechanism of epigallocatechin gallate (EGCG)-porcine serum albumin (PSA) complex and the preparation of food-grade Pickering emulsion. By the UV and fluorescence spectral analysis, it was found that EGCG has an obvious fluorescence quenching effect on PSA, mainly static quenching. The results of synchronous, three-dimensional fluorescence and FT-IR spectroscopy showed that the hydrophobic microenvironment of aromatic amino acids and the secondary structure of PSA changed after EGCG was added. The results of molecular docking examined that EGCG and PSA form more stable complexes due to hydrogen bonds, and the binding energy was −4.43 kcal /mol. Compared with the PSA emulsion, the successfully prepared EGCG-PSA Pickering emulsion had smaller droplets and no obvious color in CLMS. The Pickering emulsion of EGCG-PSA had strong emulsification and high viscosity, which belonged to pseudoplastic non-Newtonian fluid. In addition, the free fatty acids release rate of EGCG-PSA Pickering emulsion was decreased by 9.9 %. The antioxidant performance of the EGCG-PSA Pickering emulsion was improved, and the DPPH radical scavenging rate and the ABTS+ radical scavenging rate reached the highest, which were 93.72 % and 57.16 % respectively. This study provides important insights into the interaction between EGCG and PSA, and a reference for the development of polyphenol-protein complex Pickering emulsion in food, medicine, cosmetics, and other fields.

Characterization of Novel Exopolysaccharides from Weissella cibaria and Lactococcus lactis Strains and Their Potential Application as Bio-Hydrocolloid Agents in Emulsion Stability

The aim of the present study was the isolation of high exopolysaccharide (EPS) producers, Lactic Acid Bacteria (LAB) strains, from three types of milk: goat, sheep, and camel milk. Among 112 LAB isolates tested for their ability to produce EPS on MRS-sucrose agar, only 11 strains were able to produce EPS and only three higher producers’ strains were identified by 16S rRNA gene sequencing as two strains of Lactococcus lactis subsp. lactis (SP255, SP257) isolated from camel milk and one strain of Weissella cibaria (SP213) isolated from goat milk. The physicochemical characterization of the purified EPSs revealed a significant sugar yield, with concentrations ranging from 2.17 to 2.77 g/L, while the protein content remained relatively low (0.03 g/L). The UV-visible spectrum showed high Ultra Violet (UV) absorption at 240–280 nm and the Fourier-Transform Infrared (FTIR) spectra showed the presence of a large number of functional groups, including hydroxyl (-OH), carbonyl (-C=O), and methyl groups (-CH3). The EPS solubility indicated their hydrophilic properties and the investigation of interfacial properties indicated that these EPSs could be used as natural emulsifiers and stabilizers in both acidic and neutral emulsions. Moreover, a new type of emulsion system was developed by the utilization of EPSs in the formation of multilayer interfaces in oil-in-water (O/W) emulsions stabilized by sodium caseinate (CAS). Thus, the impact of an EPS addition on the particle size distribution and electrical charge has been studied. At pH 3, the studied EPSs adhered to the surfaces of caseinate-coated droplets and the stability of O/W emulsions was improved by adding certain concentrations of EPSs. The minimum concentration required to stabilize multilayer emulsions for EPSs SP255, EPS SP257, and EPS SP213 was 1.5, 1.5, and 1.7 g/L, respectively. These findings reveal a new EPS with significant potential for industrial use, particularly as an emulsion stabilizer.

The Potential Application of Mung Bean (Vigna radiata L.) Protein in Plant‐Based Food Analogs: A Review

ABSTRACTThe increasing demand for plant‐based food products by consumers along with the growing global population requires the discovery of novel and sustainable protein sources to address environmental challenges and meet nutritional requirements. Among various plant proteins, mung bean protein (MBP) exhibits several unique characteristics that make it a valuable ingredient in the field of plant‐based food analogs. This literature review aims to express the unique structure and composition of MBP, in addition to its physicochemical, functional, and nutritional properties. Furthermore, its potential applications in novel meat, dairy, and egg analogs are highlighted to meet the growing demand for sustainable, nutritious, and delicious plant‐based food alternatives. Structurally, MBP consists of a complex arrangement of amino acids, forming a globular protein with distinct functional properties. Its composition is also rich in essential amino acids, particularly leucine and lysine, making it a promising protein source for plant‐based diets. From a techno‐functional perspective, MBP exhibits remarkable gelling, emulsifying, foaming, and binding properties, which are necessary for the development of stable emulsions, airy foams, firm gels, and cohesive textures in various plant‐based food formulations. Moreover, MBP and its derivatives can possess notable bio‐functional properties, including antioxidant activity and anti‐inflammatory benefits, as well as cholesterol‐lowering, anti‐obesity, antidiabetic, antihypertensive, and anticancer effects. Consequently, the production of food analogs based on MBP not only improves the techno‐functional attributes of the final products but also can promote consumer health and well‐being.

Effect of pH-Shifting on Sunflower Meal Protein Isolate: Improved Stability and Interfacial Properties of Chitosan-stabilized Pickering Emulsion

Effect of pH-Shifting on Sunflower Meal Protein Isolate: Improved Stability and Interfacial Properties of Chitosan-stabilized Pickering Emulsion

Research and Application Progress of Crude Oil Demulsification Technology

The extraction and collection of crude oil will result in the formation of numerous complex emulsions, which will not only decrease crude oil production, raise the cost of extraction and storage, and worsen pipeline equipment loss, but also seriously pollute the environment because the oil in the emulsion can fill soil pores, lower the soil’s permeability to air and water, and create an oil film on the water’s surface to prevent air–water contact. At present, a variety of demulsification technologies have been developed, such as physical, chemical, biological and other new emulsion breaking techniques, but due to the large content of colloid and asphaltene in many crude oils, resulting in the increased stability of their emulsions and oil–water interfacial tension, interfacial film, interfacial charge, crude oil viscosity, dispersion, and natural surfactants have an impact on the stability of crude oil emulsions. Therefore, the development of efficient, widely applicable, and environmentally friendly demulsification technologies for crude oil emulsions remains an important research direction in the field of crude oil development and application. This paper will start from the formation, classification and hazards of crude oil emulsion, and comprehensively summarize the development and application of demulsification technologies of crude oil emulsion. The demulsification mechanism of crude oil emulsion is further analyzed, and the problems of crude oil demulsification are pointed out, so as to provide a theoretical basis and technical support for the development and application of crude oil demulsification technology in the future.

Functional characteristics and molecular structural modification of plant proteins. Review

Protein preparations from plant raw materials are widely used in the food industry as improvers, replacers or enrichers for products. However, their functional properties, as a rule, are less pronounced than those of proteins of animal origin. The aim of the review is to analyze and summarize the results of investigations dedicated to studying and characterizing the main functional properties of plant proteins (hydration, solubility, water binding capacity, fat binding capacity and gel-forming capacity, stability of emulsions, foams, rheological properties, texturization) and their modification. The objects of the research were scientific publications, most of which were published in 2017–2024. Functional properties of proteins were characterized; their dependence on the nature and variety of crop, methods of extraction, technological factors of processing and methods of modification was revealed. The search and selection of papers were carried out in the bibliographic databases eLIBRARY.RU, RSCI, Google Scholar, Scopus, Web of Science, Elsevier, and PubMed. Data analysis was performed with their systematization, generalization, intermediate conclusions and general conclusion. The special attention was paid to chemical, physical, physico-chemical and enzymatic methods for modification of protein properties, their advantages and disadvantages, as well as the interrelation of structural and physico-chemical features of proteins with their functional properties. The main regularities were revealed for an effect of modification methods on the secondary and tertiary structures of proteins, surface hydrophobicity, the ratio from fractions, aggregation, denaturation and biological activity obtained by the modern methods of investigations (IR‑spectroscopy, fluorescent microscopy, SDS-PAGE, circular dichroism, spectrophotometry and so on). It has been concluded that it is necessary to carry out further investigations aimed to studying interrelation of molecular structural features of proteins with indicators of functionality and regularities of their behavior in food systems due to an increase in the production of protein preparations from alternative raw materials (pea, chickpea, sunflower, kidney bean, rice and others). Based on the revealed and newly obtained theoretical information, the targeted modification and regulation of properties of protein ingredients for production of high-quality foods are possible.

Glycerol Carbonate as an Emulsifier for Light Crude Oil: Synthesis, Characterization, and Stability Analysis

This study focuses on the synthesis and application of glycerol carbonate (GC) as an emulsifier for light crude oil. GC was synthesized from glycerol and dimethyl carbonate via transesterification, achieving a 90% yield. Characterization through 1H-NMR, 13C-NMR, and FT-IR confirmed its structure. The emulsification properties of GC were tested by mixing it with light crude oil and water, demonstrating effective emulsification and forming stable emulsions. Stability tests with GC concentrations of 60/40, 70/30, and 80/20 revealed that emulsions remained stable for over 24 h. A particle size analysis indicated that higher GC concentrations produced smaller droplet sizes, enhancing the emulsification efficiency. This study highlights the potential applications of GC in oil spill remediation and enhanced oil recovery, emphasizing its biodegradability and low toxicity as environmental benefits. Overall, GC is presented as an effective and eco-friendly emulsifier for light crude oil, offering stable emulsions and promising industrial applications.

Study on the preparation of magnetic Janus nanofluids and oil displacement mechanism

Magnetic nanomaterials, known for their eco-friendliness, low toxicity, strong magnetic response, and reusability, have seen significant advancements in enhancing oil recovery. In this study, the surfactant and magnetic Janus nanoparticles (MJNP) were evaluated and optimized through Fourier transform infrared spectroscopy, ζ potential test, scanning electron microscope, emulsion performance evaluation and other analysis, so as to develop magnetic Janus nanofluids (MJNF). Study the flow behavior and enhanced oil recovery mechanism of this nanofluid in porous media through nuclear magnetic resonance (NMR) and numerical simulation methods. The results showed that when the concentration of surfactant (LAD-30) was 0.08%, the maximum water content of emulsion was 80%, and the viscosity increased by more than 90000%. In addition, when the MJNP concentration is 400 ppm or higher, a stable emulsion is formed at 90 °C. NMR experiment shows that through MJNF oil displacement, the oil recovery of small and medium-sized pores is significantly improved by 25.9% and 18.3%, which indicates that high viscosity emulsion can be formed in situ after MJNF injection, thus achieving consistency control. In addition, the numerical simulation results also found that MJNF injection can improve the oil-water saturation in the pore volume and enhance oil phase flow. The research results provide a new understanding for EOR of emulsion flooding.

Influence of resins, asphaltenes and petroleum acid interactions on water/model oil interfacial properties and emulsion stability

The presence of natural lipophilic emulsifiers, such as asphaltenes (A), resin (R) and petroleum acids (PA) in crude oil, plays a crucial role in stabilizing the W/O emulsions. This study primarily focuses on elucidating the influence of their interactions on the interfacial properties of the water/model oil system, as well as its emulsion stability. First, equilibrium interfacial tension (IFT), interfacial dilational modulus (IDM) and phase angle are measured. Then, emulsion stability experiments are performed. Finally, microscopic images of the emulsions were captured to evaluate droplet size and dispersity. Results show that the addition of petroleum acid to both asphaltene-only and resin-only system reduces IFT and dilational modulus, weakening the strength of the interfacial film. The inhibitory effect of petroleum acid on resins’ adsorption at the interface is more pronounced compared to asphaltenes’. A low proportion of resin and petroleum acid (A/R ≥ 5, A/PA ≥ 7) enhances emulsion stability by co-adsorbing with asphaltenes at the oil–water interface. Conversely, a high proportion of resin and petroleum acid leads to a decrease in IDM and emulsion stability. For asphaltene/petroleum acid–water system, when A/PA ≤ 5, the presence of petroleum acid decreases the droplet size but enhances droplet dispersion while decreasing emulsion stability. It can be inferred that the presence of petroleum acids contributes more to the formation rather than stabilization of emulsions. This work deepens insights into the emulsion behavior of natural surfactants, providing theoretical guidance for the formation of stable emulsions underground and efficient demulsification above ground.

Safety and implementation of a phase 1 randomized GLA-SE-adjuvanted CH505TF gp120 HIV vaccine trial in newborns.

The neonatal immune system is uniquely poised to generate broadly neutralizing antibodies (bnAbs) and thus infants are ideal for evaluating HIV vaccine candidates. We present the design and safety of a novel glucopyranosyl lipid A (GLA)-stable emulsion (SE) adjuvant admixed with a first-in-infant CH505 transmitter-founder (CH505TF) gp120 immunogen designed to induce precursors for bnAbs against HIV. HVTN 135 is a phase I randomized, placebo-controlled trial of CH505TF+GLA-SE or placebo. Healthy infants in South Africa aged ≤5 days, born to mothers living with HIV but HIV nucleic acid negative at birth were randomized to five doses of CH505TF + GLA-SE or placebo at birth and 8, 16, 32, and 54 weeks. 38 infants (median age = 4 days; interquartile range 4, 4.75 days) were enrolled November 2020 to January 2022. Among 28 (10) infants assigned to receive CH505TF + GLA-SE (placebo), most (32/38) completed the 5-dose immunization series and follow-up (35/38). Solicited local and systemic reactions were more frequent in vaccine (8, 28.6% local; 16, 57.1% systemic) vs. placebo recipients (1, 10% local, p = 0.25; 4, 40.0% systemic, p = 0.38). All events were Grade 1 except two Grade 2 events (pain, lethargy). Serious vaccine-related adverse events were not recorded. This study illustrates the feasibility of conducting trials of novel adjuvanted HIV vaccines in HIV-exposed infants receiving standard infant vaccinations. The safety profile of the CH505TF + GLA-SE vaccine was reassuring. ClinicalTrials.gov NCT04607408. National Institute of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health (NIH). This paper summarizes the phase 1 trial design and safety profile of an experimental CH505TF immunogen + GLA-SE HIV vaccine in infants born to mothers living with HIV.

Application of reactive fatty alcohol ether sulfosuccinate emulsifier in surface sizing

AbstractIn this paper, a novel reactive fatty alcohol ether sulfosuccinate emulsifier (RAEOSS10‐9) was polymerized into macromolecular emulsifier RAFT‐PRS through reversible addition–fragmentation chain transfer (RAFT) polymerization, and then RAFT‐PRS was co‐polymerized with monomers to form anionic surface sizing agent. The structures of RAEOSS10‐9 and RAFT‐PRS were characterized by Fourier transfer infrared spectra, and the RAFT polymerization activity of RAFT‐PRS was verified by gel permeation chromatography. The effects of RAFT reagent and RAEOSS10‐9 content on the properties of sizing emulsion and sizing paper were investigated. The morphology of latex particles and sizing paper surface were observed by use of scanning electron microscope and atomic force microscope. The water resistance, bursting resistance and folding resistance of sizing paper were studied. The optimal formulation of sizing emulsion was built according to the above results. Besides, the investigation of the mechanical properties suggests that proper amount of reactive emulsifier is beneficial for enhancing the stability of emulsion and the performance of paper. The RAEOSS10‐9 displays better emulsifying properties than imported emulsifier SR‐10, and the emulsion produced by RAEOSS10‐9 display more excellent application properties.

Formation and Applications of Typical Basic Protein-Based Heteroprotein Complex Coacervations.

Lactoferrin, lysozyme, and gelatin are three common basic proteins known for their ability to interact with acidic proteins (lactoglobulin, ovalbumin, casein, etc.) and form various supramolecular structures. Their basic nature makes them highly promising for interaction with other acidic proteins to form heteroprotein complex coacervation (HPCC) with a wide range of applications. This review extensively examines the structure, properties, and preparation methods of these basic proteins and delves into the internal and external factors influencing the formation of HPCC, including pH, ionic strength, mixing ratio, total protein concentration, temperature, and inherent protein properties. The applications of different HPCCs based on these three basic proteins are discussed, including the encapsulation of bioactive molecules, emulsion stabilization, protein separation and extraction, nanogel formation, and the development of formulas for infants. Furthermore, the challenges and issues that are encountered in the formation of heteroprotein complexes are addressed and summarized, shedding light on the complexities and considerations involved in utilizing HPCC technology in practical applications. By harnessing the basic proteins to interact with other proteins and to form complex coacervates, new opportunities arise for the development of functional food products with enhanced nutritional profiles and functional attributes.

Rheological investigation of heavy oil-in-water pickering emulsions for potential applications of fracturing fluids

Pickering emulsions as a kind of emulsified fracturing fluids can enhance the efficacy of shale fracturing. Investigation of the rheological properties of Pickering emulsions yields valuable insights for their in-situ fracturing applications. In this work, nano-clay particles and heavy crude oil were employed to form oil-in-water (O/W) Pickering emulsions. The impact of salinity, pH, and temperature on the rheological properties, including viscosity property and viscoelastic property, of Pickering emulsions were tested and analyzed. The results showed that the viscosity of heavy O/W Pickering emulsions were significantly affected by the change of salinity and pH values, with higher salinity or lower pH resulting in increased viscosity. Under ultra-high salinities (>5 wt% NaCl), the coalescence stability of Pickering emulsion strengthens and creaming stability declines. The massive formation of clay clusters leads to a reduction in the number of nano-clay particles used to generate the network, causing instability in the emulsion creaming. The heavy O/W Pickering emulsions exhibited high stability and high viscosity characteristics, which were mainly caused by the change of surface charge of nano-clay particles and the corresponding change of particle adsorption on droplet surface and particle-particle interactions. At a salinity of 2.5% NaCl and a pH of 4.6, the emulsion system remained stable at a temperature up to 120 °C, holding a viscosity reaching 74.1 mPa s at a shear rate of 6.81 s−1. Besides, heavy O/W Pickering emulsions were viscoelastic fluids, with both noticeable viscous property and elastic property at the same time. Elastic modulus (G′) and viscous modulus (G″) of the emulsion increased with increasing salinity and decreasing pH, enhancing great deformation capacity. Remarkably, the Pickering emulsions could maintain its viscoelastic behavior at varying temperature conditions. For the first time, rheological study of Pickering emulsions formed by nano-clay nanoparticles as a single emulsifier to heavy oil. Our study underscores the emulsifying ability of nano-clay particles to heavy crude oils, under a wide range of salinity and pH, yielding Pickering emulsions with exceptional stability and rheological properties. This novel emulsion system, possessing high resistance to temperature and salinity, holds promise for a high-performance fracturing fluid design.

Encapsulation of resveratrol in nanosheet structured sodium caseinate dialdehyde β-cyclodextrin conjugate with enhanced physicochemical properties

The poor solubility and stability of resveratrol (Res) represent significant obstacles to its utilization and efficacy. Encapsulating in sodium caseinate (NaCas) has also faced issues concerning low encapsulation efficiency and stability. This study presented the synthesis of a novel NaCas and dialdehyde β-cyclodextrin (DA-β-CD) conjugate through the Schiff base reaction using a wet-heating method, which was then utilized to encapsulate resveratrol. Results showed the DA-β-CD was formed in the form of needle-like crystals, whereas the NaCas-DA-β-CD conjugate had a nanosheet structure. The NaCas-DA-β-CD exhibited a substantial increase in surface hydrophobicity, emulsifying activity index, and emulsion stability index. The incorporation of resveratrol into NaCas-DA-β-CD demonstrated a consistent and uniform dispersion at the nanoscale level. It achieved an encapsulation efficiency of 96.8% and exhibited excellent chemical stability, which surpasses those of the NaCas system. Furthermore, the water solubility and antioxidant capacity of resveratrol in NaCas-DA-β-CD exhibited characteristics similar to those in NaCas. The compacted nanosheet structure of the Res-NaCas-DA-β-CD complex, as observed in TEM and SEM, is likely responsible for those enhancements. Hence, the DA-β-CD can serve as an effective polysaccharide for protein modification, while the NaCas-DA-β-CD conjugate can function as an innovative delivery carrier for resveratrol and other hydrophobic bioactives.

Design of stimuli-responsive minimalist heptad surfactants for stable emulsions

Peptide surfactants have been extensively investigated with various applications in detergents, foods, and pharmaceutics due to their biodegradability, biocompatibility, and customizable structures. Traditional peptide surfactants are often designed in a head-to-tail fashion mimicking chemical surfactants. Alternatively, a side-by-side design pattern based on heptad repeats offers an approach to designing peptide surfactants. However, minimalist peptide design using a single heptad for stabilizing interfaces remains largely unexplored. Here, we design four heptad surfactants (AM1.2, 6H, 6H7K, and HK) responsive to metal ions and compare their emulsification performance with a three-heptad peptide, AM1. Among them, the HK peptide generates emulsions exhibiting good stability over months. We further optimize factors such as buffering salts, ionic strength, and emulsion dilutions to uncover their impacts on emulsion properties. Our findings deepen the understanding of emulsion properties and provide practical insights for characterizing peptide-based emulsions, paving the way for their broader utilization in diverse applications.

Physicochemical and Antioxidative Properties of Protein Hydrolysates from Residual Goat Placenta Extract by Two Different Methods.

Protein hydrolysates from the goat placenta provide multiple benefits, such as immune system enhancement, antioxidant activities, and reductions in uric acid levels. Despite these benefits, their industrial applications have been underexplored. This study aimed to prepare extract protein hydrolysates (GPERPs) from residual goat placenta extract (GPER) and assess their functional properties, focusing on how different drying methods influence these properties. The essential amino acid contents were 30.94% for the GPER and 34.11% for the GPERPs. Moreover, all the essential amino acids were present, and the amino acid score (AAS) for each exceeded 1.0 in the GPERPs. The foaming properties of the spray-dried GPERPs (95.56 ± 5.89%) were significantly greater than those of the freeze-dried GPERPs (49.13 ± 4.17%) at pH values of 4.0~10.0. The emulsion stability (ES) of the spray-dried GPERPs (453.44 ± 8.13 min) was notably greater than that of the freeze-dried GPERPs (245.58 ± 7.12 min). Furthermore, the water retention capacity (WRC) of the freeze-dried GPERPs (201.49 ± 6.12%) was significantly greater than that of the spray-dried GPERPs (103.35 ± 7.13%), except at pH 10.0 (101.44 ± 8.13%). Similarly, at pH values of 6.0, 8.0, and 10.0, the oil retention capacity (ORC) of the freeze-dried GPERPs (715.58 ± 12.15%) was significantly greater than that of the spray-dried GPERPs (560.56 ± 11.15%), although the opposite trend was noted under acidic conditions. In terms of the antioxidant activity, the ability of the goat placenta extract residual protein hydrolysates (GPERPs) to scavenge DPPH radicals and superoxide anion radicals increased with the increasing peptide powder concentration, and the maximum scavenging rates of the DPPH radicals (39.5 ± 0.56%) and superoxide anions (81.2 ± 0.54%) in the freeze-dried peptide powder were greater than those in the spray-dried peptide powder. These findings contribute to the understanding of the physicochemical and antioxidant properties of GPERPs under various drying methods and provide fundamental data for the development of functional foods based on GPERPs.

Effect of droplet charge density on stabilization of oil‐in‐dispersion emulsions co‐stabilized by binary mixed surfactants and nanoparticles

AbstractIonic surfactant and similarly charged nanoparticles can co‐stabilize oil‐in‐dispersion (OID) emulsions at extremely low concentrations (0.001 cmc/0.001 wt%), in which particles do not adsorb at the oil/water interface but distribute in the aqueous phase forming a dispersion. In this paper, the effect of droplet charge density on stabilization of the n‐decane‐in‐water OID emulsion was examined by using a cetyl trimethyl ammonium bromide (CTAB)/C12B (dodecyl dimethyl carboxyl betaine) binary mixture at a low fixed total concentration (0.01 mM) with varying molar fractions of CTAB. A model based on the Derjaguin‐Landau‐Verwey‐Overbeek (DLVO) theory is proposed to calculate interaction energies between droplets and between droplets and particles. It is found that the droplet charge density can be well compensated by particle concentration along the stabilization boundary, and the OID emulsion still follows the DLVO stabilization. Particles tend to surround droplets at large distances but may form a monolayer between approaching droplets at shorter distances, which significantly reduces the van der Waals attraction between droplets. In addition, the induced auxiliary droplet–particle repulsion is proportional to the number of particles per unit area of droplet surfaces, which together with the droplet–droplet repulsion ensures a large total repulsion preventing droplets from flocculation and coalescence. This work explains quantitatively the stabilization of OID emulsions, which have potential applications in emulsion products such as foods, cosmetics, pesticides, and various industrial emulsion systems. Moreover, the development of the OID emulsions represents an important advancement in green chemistry as it substantially reduces the required amounts of emulsifiers and their environmental impact after use.

Photo-responsive Pickering emulsions triggered by in-situ pH modulation using a photoacid generator

HypothesisPickering emulsions that respond to changes in pH by the addition of acid or alkali have been extensively studied, but the development of photo-responsive Pickering emulsions has been more challenging. This study attempts to demonstrate a novel approach to achieve photo-responsiveness in Pickering emulsions by incorporating a photoacid generator (PAG) into the oil phase. Upon UV irradiation, the PAG is expected to release protons (H+), which can then regulate the pH of the emulsion system and control its stability. ExperimentsAmphiphilic colloidal particles obtained by modifying silica particles with poly (2-(dimethylamino)ethyl methacrylate) (SiO2-PDMAEMA) are used to stabilize the Pickering emulsions. The protonation and deprotonation of the SiO2-PDMAEMA particles at different pH values allow for the tuning of emulsion stability. By introducing the PAG into the stable Pickering emulsion system and applying UV irradiation to trigger the in-situ release of H+, the pH of the emulsion is systematically decreased, and the corresponding changes in emulsion stability are investigated. FindingsThe results show that UV irradiation alone cannot induce emulsion instability. However, when PAG is added to the oil phase, the Pickering emulsions exhibit a significant decrease in pH under UV irradiation, ultimately leading to emulsion destabilization and phase separation. At a UV intensity of 20 mW/cm2 for 2 min, the H+ release from the PAG significantly lower the emulsion’s pH, causing the SiO2-PDMAEMA particles to detach from the oil–water interface and resulting in emulsion instability. Higher concentrations of SiO2-PDMAEMA particles in the emulsion require more PAG to induce instability, as confirm by confocal laser scanning microscopy (CLSM) image. This study presents a versatile approach to develop photo-responsive Pickering emulsions which can have potential applications in areas such as drug delivery, cosmetics, and responsive materials.

Sustainable Nanofluids Constructed from Size-Controlled Lignin Nanoparticles: Application Prospects in Enhanced Oil Recovery.

Lignin, a widely available, cost-effective, and structurally stable natural polymer, has recently attracted significant attention due to its diverse potential applications. A promising approach is to prepare lignin nanoparticles (LNPs) as a substitute for conventional nanoparticles to fulfill a variety of functions. In this study, LNPs with controlled size, regular morphology, and excellent dispersibility were synthesized by using industrial alkali lignin. The antisolvent method was employed, utilizing an aqueous solution of the anionic surfactant sodium apolyolefin sulfonate (AOS) as the antisolvent. Subsequently, the prepared LNPs were used to formulate nanofluids in combination with AOS and nonionic surfactant coconut diethanolamide (CDEA). The incorporation of LNPs has significantly enhanced the interfacial activity of the resulting nanofluids, thereby improving their emulsion stabilization, spreading on quartz surfaces, and oil droplet removal capabilities, which establish a strong foundation for the AOS/CDEA/LNPs nanofluid to achieve high performance in enhanced oil recovery (EOR), which was validated through microscopic visual physical model experiments. The quartz crystal microbalance with the dissipation monitoring (QCM-D) technique was employed to investigate the adsorption of surfactants onto quartz surfaces. It was found that the incorporation of LNPs significantly reduces the adsorption loss of surfactants, presenting a potential solution to overcome the challenges associated with surfactant adsorption in chemically enhanced oil recovery (EOR) processes, such as high cost and unreliable efficiency. This study reveals the good performance of LNPs/surfactant nanofluids and provides a potential approach to the advancement of green, sustainable, and intelligent EOR technologies.

Effects of oil-water interfacial properties on protein structuring and droplet deformation in high moisture meat analogues containing oil

Adding oil to high moisture meat analogues (HMMA) can increase juiciness, and can be achieved by incorporating emulsion droplets during extrusion. Since these droplets can coalesce when subjected to high shear, selecting appropriate emulsion stabilisers is important. For several commercial plant-protein emulsion stabilisers, it was investigated how oil-water interfacial mechanical properties affect droplet deformation and protein structuring in extrusion of HMMAs. Emulsions with 10 wt% or 15 wt% oil, stabilised by potato protein isolates (POPI-1 (Rich in patatin) and POPI-2 (rich in protease inhibitor)) and pea protein isolate PPI, were used to make extrudates with 5.7 wt% and 8.5 wt% oil, respectively. In 8.5 wt%-extrudates, POPI-2 had the most oil leakage from the cooling die, while PPI had the smallest amount despite having softer and more stretchable interfaces. Blade-cutting tests showed the highest maximum force for 8.5 wt%-extrudates with POPI-1, likely because POPI-1 formed the stiffest interfaces. Tensile stress testing showed the largest fracture strain in 8.5% wt%-extrudates with PPI, corresponding to its longer wedge length. Multiphoton excitation microscopy was used to visualise the extrudates protein structure and oil droplets. This showed that droplets near the surface of the extrudate were less deformed than droplets in the centre. There were only small differences between protein stabilisers regarding oil droplet deformation, indicating droplet deformation was dominated by deformation of the protein matrix. The O/W interfacial properties significantly affected oil leakage, cutting force, and tensile strength of extrudates. These results are important to consider when designing emulsions for HMMAs processed by extruders.