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In this work, in order to elucidate the three-dimensional (3D) resonant sloshing dynamics of the oil–water interface in an offshore cylindrical wet storage tank, a series of model experiments are conducted in a completely filled cylindrical tank containing two immiscible liquids. To begin with, a series of free damping tests are performed to experimentally determine the viscous damping rate of the system and to examine the corresponding theoretical solutions. Subsequently, the separation surface wave responses at a series of excitation frequencies including the natural frequencies of first five modes are examined. Finally, the rotary sloshing dynamics at the natural frequencies of the first and second natural modes are systematically explored. Interestingly, it is found that the separation surface rotary sloshing in a two-layer liquid system is much more intricate than one-layer liquid rotary sloshing due to the generation of multitudinous short waves in the long wave. As far as we know, this is the first investigation of 3D separation surface rotary wave motion in a two-layer liquid system without a free surface. [ABSTRACT FROM AUTHOR]

[Display omitted] Healable electronic skins, an essential component for future soft robotics, implantable bioelectronics, and smart wearable systems, necessitate self-healable and pliable materials that exhibit functionality at intricate interfaces. Although a plethora of self-healable materials have been developed, the fabrication of highly conformal biocompatible functional materials on complex biological surfaces remains a formidable challenge. Inspired by regenerative properties of skin, we present the self-assembled transfer-printable liquid metal epidermis (SALME), which possesses autonomous self-healing capabilities at the oil–water interface. SALME comprises a layer of surfactant-grafted liquid metal nanodroplets that spontaneously assemble at the oil–water interface within a few seconds. This unique self-assembly property facilitates rapid restoration (<10 s) of SALME following mechanical damage. In addition to its self-healing ability, SALME exhibits excellent shear resistance and can be seamlessly transferred to arbitrary hydrophilic/hydrophobic curved surfaces. The transferred SALME effectively preserves submicron-scale surface textures on biological substrates, thus displaying tremendous potential for future epidermal bioelectronics. [ABSTRACT FROM AUTHOR]

The phase behavior of block copolymers (BCPs) at the water‐oil interface is influenced by the segmental interaction parameter (χ ${\chi }$) and chain architecture. We synthesized a series of star block copolymers (s‐BCPs) having polystyrene (PS) as core and poly(2‐vinylpyridine) (P2VP) as corona. The interaction parameters of block‐block (χ ${\chi }$ PS‐P2VP) and block‐solvent (χ ${\chi }$ P2VP‐solvent) were varied by adjusting the pH of the aqueous solution. Lowering pH increased the fraction of quaternized‐P2VP (Q‐P2VP) with enhanced hydrophilicity. By transferring the equilibrated interfacial assemblies, morphologies ranging from bicontinuous films at pH of 7 and 3.1 to nanoporous and nanotubular structure at pH of 0.65 were observed. The nanoporous films formed hexagonally packed pores in s‐BCP matrix, while nanotubes comprised Q‐P2VP as corona and PS as core. Control over pore size, d‐spacing between pores, and nanotube diameters was achieved by varying polymer concentration, molecular weight, volume fraction and arm number of s‐BCPs. Large‐scale nanoporous films were obtained by freeze‐drying emulsions. Remarkably, the morphologies of linear BCPs were inverted, forming hexagonal‐packed rigid spherical micelles with Q‐P2VP as core and PS as corona in multilayer. This work provides insights of phase behaviors of BCP at fluids interface and offer a facile approach to prepare nanoporous film with well‐controlled pore structure. [ABSTRACT FROM AUTHOR]

Herein, microemulsion mediated controlled lanthanide metal based nanoparticles are employed in the preparation of a pH responsive Pickering emulsion. Lanthanum sulfide (LaS) nanoparticles are synthesised in the core of a water-in-oil microemulsion, prepared by Tween 80/1-butanol/water/toluene. The TEM images obtained, were used to evaluate the stages of the progress of nanosphere preparation. Novel oil-in-water (O/W) Pickering emulsions have been produced with the assistance of negatively charged, size and shape regulated lanthanum sulfide nanoparticles (0.05 wt%) and an adequate amount of a cationic CTAB surfactant. Adsorption of an ionic surfactant onto the surface of oppositely charged nanoparticles typically occurs in slightly acidic or neutral environments (pH 5.33 to 6.16), converting hydrophilic nanoparticles to hydrophobic ones through in situ hydrophobization. Because the emulsions are sensitive to pH alterations, an effective demulsification can be accomplished by pH changes. Demulsification occurs at two distinct pH ranges: a lower pH (3.50) and a higher pH (10.50). Surfactant molecules are desorbed from the surfaces of nanoparticles at these two pH ranges, causing the particles to revert to their hydrophilic form. Desorption of hydrophilic nanoparticles from the water–oil interface caused the Pickering emulsion to become unstable. Remulsification is achieved by just adjusting the pH with the addition KOH or HCl. It is feasible to produce eight consecutive cycles of emulsification and demulsification by just changing the pH. Thus, by using size- and shape-controlled nanoparticles, this study introduces an entirely new scientific perspective on the synthesis of distinct characteristics (likewise to pH responsiveness) of the Pickering emulsion. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the impact of process parameters such as interfacial tension, type of surfactants, and their concentration on simple oil-in-water dispersion. Explored systems were prepared with 5% liquid paraffin oil and aqueous phase with emulsifiers Tween 40 of concentrations from 0.008325 mM to 0.025 mM and Tween 80 with concentrations ranging from 0.00375 mM to 0.011 mM. All systems were characterized in terms of their density and interfacial tension. In the next step analysis of droplet size distributions and mean droplet diameter was performed. The results showed that the size of paraffin droplets decreased as the concentration of surfactants grew. This trend is accompanied by decrease in the interfacial tension between phases. The correlation between mean drop size and the energy input and physical properties of both liquids was developed. The last step provides scientific evidence for the formulation of stable droplets of liquid paraffin. [ABSTRACT FROM AUTHOR]

Separating anionic surfactant-stabilized oil-in-water emulsions remains a critical challenge due to the presence of surfactants. In this study, we developed a unique collagen fiber-based CFM-PEI-TiO 2 with superhydrophilic and underwater superoleophobic properties, enabling efficient separation of various anionic surfactant-stabilized oil-in-water microemulsions and nanoemulsions through charge demulsification effects. The membrane achieved high separation flux (1458.50 L·m−2·h−1) and separation efficiency (99.94%) simultaneously. Importantly, the membrane exhibited remarkable mechanical durability, as it remained capable of separating diverse oil-in-water emulsions even after being subjected to abrasion with sandpaper for 500 cycles, highlighting its long-term durability and economic viability. The robust membrane also demonstrated excellent recyclability, with a separation efficiency of over 99% after twelve cycles and a flux of 1299.10 L·m−2·h−1 after fifteen cycles. These properties can be attributed to the PEI-induced electrostatic interactions and the enhanced superhydrophilic-superoleophobic interaction provided by TiO 2 on the unique collagen fiber membrane. The outcomes emphasize the versatility and potential of our membrane in overcoming the challenges associated with emulsified oily wastewater. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] Epoxidation of allyl chloride and hydrogen peroxide (H 2 O 2) carried out in heterogeneous catalytic systems suffer from poor reaction efficiency due to their heavy mass transfer resistance present at the liquid-liquid interface. Pickering interfacial catalysis (PIC) provides an elegant solution by involving the design of amphiphilic heterogeneous catalysts, which can act as emulsifiers simultaneously. In this study, interface-active polyoxometalate-loaded hyper-crosslinked nanoparticles (HCNPs) were designed. The structural properties of materials were characterized in detail by elemental analysis, Zeta potential, ICP-OES, SEM, TEM, BET, FT-IR, TGA, and XPS. The prepared nanoparticles can build efficient W/O PIC systems with allyl chloride and H 2 O 2. Systematic experiments indicate that catalysts' surface properties, catalyst dosage, and water/oil volume ratio significantly affect the PIC system's catalytic activity and emulsion properties. Moreover, this PIC system maintains high stability after the reaction and can be reused for at least 8 cycles. Excitingly, these interface-active HCNPs can also efficiently promote allyl chloride epoxidation in the absence of solvent and external stirring, illustrating that this approach holds great potential for developing catalytic systems suitable for multiphase reactions. [ABSTRACT FROM AUTHOR]

Oil-water interfaces that are created by confining a certain amount of oil in a square shaped pixel (∼200 x 200 μ m 2 with a height of ∼10 μm) topped by a layer of water, have a curvature that depends on the amount of oil that happens to be present in the confining area. Under the application of an electric field normal to the interface, the interface will deform due to inhomogeneities in the electric field. These inhomogeneities are expected to arise from the initial curvature of the meniscus, from fringe fields that emerge at the confining pixel walls and, if applicable, from interfacially adsorbed particles. We model the shape of the confined oil-water interface invoking capillarity and electrostatics. Furthermore, we measure the initial curvature by tracking the position of interfacially adsorbed particles depending on sample tilt. We found that the pixels exhibited meniscus curvature radii ranging from 0.6-7 mm. The corresponding model based minimum oil film thicknesses range between 0.7 and 9 μm. Furthermore, the model shows that the initial meniscus curvature can increase up to 76 percent relative to the initial curvature by the electric field before the oil film becomes unstable. The pixel wall and particles are shown to have minimal impact on the interface deformation. • Deformation by an electric field of a confined liquid-liquid interface is modeled. • The meniscus curvature can be increased up to 76% by the applied electric field. • The curvature was quantified by tracking the position of interfacially adsorbed particles. • Fringe fields and colloidal particles have no significant impact on global curvature. [ABSTRACT FROM AUTHOR]

Spray drying of oil-in-water emulsions is a widespread encapsulation technique. The oil droplet size (ODS) significantly impacts encapsulation efficiency and other powder properties. The ODS is commonly set to a specific value during homogenization, assuming that it remains unchanged throughout the process, which is often inaccurate. This study investigated the impact of atomizer geometry and nozzle dimensions on oil droplet breakup during atomization using pressure-swirl atomizers. Subject of the investigation were nozzles that differ in the way the liquid is set in motion, as well as different inlet port and outlet orifice dimensions. The results indicate that nozzle inlet port area may have a significant impact on oil droplet breakup, with x90,3 values of the oil droplet size distribution decreasing from 5.29 to 2.30 µm with a decrease of the inlet area from 2.0 to 0.6 mm. Good scalability of the findings from pilot to industrial-scale was shown using larger nozzles. A simplified theoretical model, aiming to predict the ODS as a function of calculated shear rates, showed reasonable agreement to the experimental data for different atomization pressures with coefficients of determination of up to 0.99. However, it was not able to predict the impact of different nozzle dimensions, most likely due to changes in flow characteristics. These results suggest that the stress history of the oil droplets might have a larger influence than expected. Further studies will need to consider other zones of high stress in addition to the outlet orifice. [ABSTRACT FROM AUTHOR]

The waxy oil-water interface has become a topic issue in the field of a two-phase oil-water pipe flow. Although some progress has been achieved in the understanding of interfacial rheological properties of the water-in-oil emulsion (W/O), the effect of surfactants (the main constituents of petroleum crude oil) still remains unclear. To test whether the structure of hydrophobic chains of surfactants influences the waxy oil-water interface, we monitored interfacial rheological parameters under different nonionic surfactants (Span80/60/65) using a DWR interfacial shear rheometer. Among these surfactants, the oil-water interface of Span65 characterized by multi-hydrophobic chains had the largest interfacial viscosity and critical storage modulus. A weak strain overshoot interface of Span65 suggested that sorbitan tristearate molecules provided a dominant contribution to the interfacial rheological properties of the waxy oil-water interface with much fewer effects of the interaction between wax molecules and surfactants. However, Span60/80 with a single hydrophobic chain was coupled to wax molecules and reshaped the waxy oil-water interface structure, which replaced the original wax crystal position (the interfacial viscosity and critical storage modulus decrease) and yielded an interfacial structure (the critical strain increase). The wax-surfactant interactions of Span60/80 with different hydrophobic chain saturation were discussed. These interfacial properties are of practical importance for the technological operations in oil production. [ABSTRACT FROM AUTHOR]

Medium- and long-chain triacylglycerol (MLCT), as a novel functional lipid, is valuable due to its special nutritional properties. Its low content in natural resources and inefficient synthesis during preparation have limited its practical applications. In this study, we developed an effective Pickering emulsion interfacial catalysis system (PE system) for the enzymatic synthesis of MLCT by trans-esterification. Lipase NS 40086 served simultaneously as a catalyst and a solid emulsifier to stabilize the Pickering emulsion. Benefitting from the sufficient oil–water interface, the obtained PE system exhibited outstanding catalytic efficiency, achieving 77.5% of MLCT content within 30 min, 26% higher than that of a water-free system. The Km value (0.259 mM) and activation energy (14.45 kJ mol−1) were 6.8-fold and 1.6-fold lower than those of the water-free system, respectively. The kinetic parameters as well as the molecular dynamics simulation and the tunnel analysis implied that the oil–water interface enhanced the binding between substrate and lipase and thus boosted catalytic efficiency. The conformational changes in the lipase were further explored by FT-IR. This method could give a novel strategy for enhancing lipase activity and the design of efficient catalytic systems to produce added-value lipids. This work will open a new methodology for the enzymatic synthesis of structured lipids. [ABSTRACT FROM AUTHOR]

Water can accelerate a variety of organic reactions far beyond the rates observed in classical organic solvents. However, using pure water as a solvent introduces solubility constraints that have limited the applicability of efficient photochemistry in particular. We report here the formation of aggregates between pairs of arenes, heteroarenes, enamines, or esters with different electron affinities in an aqueous medium, leading to an oil-water phase boundary through substrate melting point depression. The active hydrogen atoms in the reactants engage in hydrogen bonds with water, thereby accelerating photochemical reactions. This methodology realizes appealingly simple conditions for aqueous coupling reactions of complex solid molecules, including complex drug molecules that are poorly soluble in water. [ABSTRACT FROM AUTHOR]

The construction of organic–inorganic hybrid supramolecular polymers using polyoxometalate (POM) as building block is expected to bring new opportunities to the functionalization of supramolecular polymers and the development of novel POM‐based soft materials. Here, by using the orthogonal self‐assembly based on host–guest interactions and metal‐ligand interactions, we report the in situ construction of a novel POM‐based hybrid supramolecular polymer (POM‐SP) at the oil‐water interface, while the redox and competitive responsiveness can be triggered independently. Moreover, the binding energy of POM‐SP at the interface is sufficiently strong so that the assembly of POM‐SP jams, allowing the stabilization of liquids in nonequilibrium shapes, offering the possibility of fabricating all‐liquid constructs with reconfigurability. [ABSTRACT FROM AUTHOR]

Clean fracturing fluid has the characteristics of being environmentally friendly and causing little damage to reservoirs. Meanwhile, its backflow gel-breaking fluids (GBFs) can be reutilized as an oil displacement agent. This paper systematically evaluates the feasibility and EOR mechanism of a GBF based on a polymer surfactant as an oil displacement system for reutilization. A rotating interfacial tensiometer and contact angle measuring instrument were used to evaluate the performance of reducing the oil–water interfacial tension (IFT) and to change the rock wettability, respectively. Additionally, a homogeneous apparatus was used to prepare emulsions to evaluate GBF's emulsifying properties. Finally, core flooding experiments were used to evaluate the EOR effect of GBFs, and the influence rules and main controlling effects of various properties on the EOR were clarified. As the concentration of GBFs increases, the IFT first decreases to the lowest of 0.37 mN/m at 0.20 wt% and then increases and the contact angle of the rock wall decreases from 129° and stabilizes at 42°. Meanwhile, the emulsion droplet size gradually decreases and stabilizes with increases in GBF concentration, and the smallest particle size occurs when the concentration is 0.12–0.15 wt%. The limited adsorption area of the oil–water interface and the long molecular chain are the main reasons that limit the continued IFT reduction and emulsion stability. The oil displacement experiment shows that the concentration of GBF solution to obtain the best EOR effect is 0.15 wt%. At this concentration, the IFT reduction and the emulsification performance are not optimal. This shows that the IFT reduction performance, reservoir wettability change performance, and emulsification performance jointly determine the EOR effect of GBFs. In contrast, the emulsifying performance of GBFs is the main controlling factor for the EOR. Finally, the optimal application concentration of GBFs is 0.15–0.20 wt%, and the optimal injection volume is 0.5 PV. [ABSTRACT FROM AUTHOR]

BACKGROUND: Hemp protein isolates (HPIs), which provide a well‐balanced profile of essential amino acids comparable to other high‐quality proteins, have recently garnered significant attention. However, the underutilized functional attributes of HPIs have constrained their potential commercial applications within the food and agriculture field. This study advocates the utilization of dynamic‐high‐pressure‐microfluidization (DHPM) for the production of stable high‐internal‐phase emulsions (HIPEs), offering an efficient approach to fully exploit the potential of HPI resources. RESULTS: The findings underscore the effectiveness of DHPM in producing HPI as a stabilizing agent for HIPEs with augmented antioxidant activity. Microfluidized HPI exhibited consistent adsorption and anchoring at the oil–water interface, resulting in the formation of a dense and compact layer. Concurrently, the compression of droplets within HIPEs gave rise to a polyhedral framework, conferring viscoelastic properties and a quasi‐solid behavior to the emulsion. Remarkably, HIPEs stabilized by microfluidized HPI demonstrated superior oxidative and storage stability, attributable to the establishment of an antioxidative barrier by microfluidized HPI particles. CONCLUSION: This study presents an appealing approach for transforming liquid oils into solid‐like fats using HPI particles, all without the need for surfactants. HIPEs stabilized by microfluidized HPI particles hold promise as emerging food ingredients for the development of emulsion‐based formulations with enhanced oxidative stability, thereby finding application in the food and agricultural industries. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Ultrasonic mixing is a well‐established method to disperse and mix substances. However, the effects of ultrasound on dispersed soft particles as well as on their adsorption kinetics at interfaces remain unexplored. Ultrasound not only accelerates the movement of particles via acoustic streaming, but recent research indicates that it can also manipulate the interaction of soft particles with the surrounding liquid. In this study, it evaluates the adsorption kinetics of microgel at the water‐oil interface under the influence of ultrasound. It quantifies how acoustic streaming accelerates the reduction of interfacial tension. It uses high‐frequency and low‐amplitude ultrasound, which has no destructive effects. Furthermore, it discusses the ultrasound‐induced shrinking and thus interfacial rearrangement of the microgels, which plays a secondary but non‐negligible role on interfacial tension reduction. It shows that the decrease in interfacial tension due to the acoustic streaming is stronger for microgels with higher cross‐linker density. Moreover, it shows that ultrasound can induce a reversible decrease in interfacial tension due to the shrinkage of microgels at the interface. The presented results may lead to a better understanding in any field where ultrasonic waves meet soft particles, e.g., controlled destabilization in foams and emulsions or systems for drug release. [ABSTRACT FROM AUTHOR]

Polyacrylate crude oil demulsifier is one of the hot topics in the research and development of demulsifier at present, there is a lack of systematic comparative study on performance and properties of polyether and polyacrylate crude oil demulsifier. In this paper, the demulsification performance and microscopic demulsification process of the two demulsifiers, namely polyacrylate P(MA-DBC) and polyether P199–59 are discussed. The demulsification performance of polyether P199–59 was superior to that of polyacrylate P(MA-DBC). The study of the microscopic process of demulsification established that for P199–59, the diffusion rate was faster, the saturated adsorption capacity was higher, the ability to destroy the oil-water interface film was stronger and the probability of water droplets collision coalescence was higher; therefore, it can achieve faster dehydration speed and higher dehydration rate than that of P(MA-DBC). The results of this comparative study are meaningful for improving the demulsification performance of polyacrylate demulsifier. [ABSTRACT FROM AUTHOR]

BACKGROUND: In order to study the effect of adsorption of surfactant at the two interfacial layers on emulsion stability, the kinetically stable water‐in‐oil‐in‐water (W/O/W) emulsion carriers were prepared using polyglycerol polyricinoleate (PGPR) and gum arabic (GA) as emulsifiers. The relationship between the adsorption of the surfactant and the stability mechanism of the emulsions was elucidated. RESULTS: When the contents of PGPR and GA were low, the interfaces between oil and the inner and outer water phases, respectively, could not be completely covered. However, when the concentration of PGPR was higher than 60 g kg−1, the excess PGPR was adsorbed on the interface between the oil phase and the outer water phase. When the concentration of GA reached 80 g kg−1, more GA was adsorbed to the oil‐in‐water interface. Moreover, the presence of PGPR on the interface could reduce the adsorption capacity of GA. Two types of kinetically stable emulsions were obtained by optimizing the interface composition (60 g kg−1 GA/80 g kg−1 PGPR and 60 g kg−1 PGPR/80 g kg−1 GA). The kinetically stable W/O/W emulsions prepared in this study were successfully used to encapsulate a hydrophilic vitamin (vitamin B12) with an encapsulation efficiency (EE) of 80% and release efficiency (RE) of 95%. The interfacial adsorption GA can accelerate the hydrolysis of fat. CONCLUSION: Overall, this study provides a new strategy for the preparation of W/O/W emulsions, which might be beneficial for application in food, cosmetic, chemical, and pharmaceutical industries. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Streptomyces rimosus lipases (SrLip) present an enzyme class that catalyzes the hydrolysis of triacylglycerols producing fatty acids and glycerols. The abrupt increase in catalytic activity of SrLip when found at water-oil interface is assigned as interfacial activation (IA). Since the latter is a complex function of interface charge, chemical composition, as well as substrate orientation and concentration, the role of individual factors and their combinations that trigger IA remains rather elusive. The aim of this work is to unravel the contribution of particular factor in IA by examining SrLip activity toward p-nitrophenylpalmitate (p-NPP) as a substrate incorporated in three chemically different self-assembled aggregates: gum Arabic, sodium deoxycholate and liposomes made of 1,2-dioleyl-sn-glycero-3-phosphocholine (DOPC) lipids, and at two different pH values (pH = 6.8 and pH = 10.0). Spectrophotometric (UV/Vis) study revealed that SrLip catalyzes p-NPP hydrolysis when the substrate is embedded in sodium deoxycholate at both pH values, suggesting that the coupling of favorable interface charge and substrate orientation drives the interfacial activation. Moreover, especially in alkaline conditions (pH = 10.0), hydrolysis of the ester bond of the substrate incorporated in DOPC bilayers occurs when appropriate orientation, concentration and arrangement are accomplished. All experiments were conducted in parallel on an inactive mutant SrLipS10/A as a reference. The molecular-level details of particular interface and accompanied substrates examined by all-atom molecular dynamics simulations revealed that the availability of p-NPP at these three interfaces decreases in the following order: sodium-deoxycholate > DOPC > model gum Arabic. [ABSTRACT FROM AUTHOR]

Protein–polysaccharide complexes have been widely used to stabilize emulsions, but the effect of NaCl on ovalbumin–xanthan gum (OVA-XG) complex emulsions is unclear. Therefore, OVA-XG complex emulsions with different XG concentrations at pH 5.5 were prepared, and the effects of NaCl on them were explored. The results indicated that the NaCl significantly affected the interaction force between OVA-XG complexes. The NaCl improved the adsorption of proteins at the oil–water interface and significantly enhanced emulsion stability, and the droplet size and zeta potential of the emulsion gradually decreased with increasing NaCl concentrations (0–0.08 M). In particular, 0.08 M NaCl was added to the OVA-0.2% XG emulsion, which had a minimum droplet size of 18.3 μm. Additionally, XG as a stabilizer could improve the stability of the emulsions, and the OVA-0.3% XG emulsion also exhibited good stability, even without NaCl. This study further revealed the effects of NaCl on emulsions, which has positive implications for the application of egg white proteins in food processing. [ABSTRACT FROM AUTHOR]

Feeding on crude oil and activator in porous medium, microbes remain active on the Oil-water interface under simulated reservoir conditions. At the same time, microbes degrade the residual oil and change the wettability of pore wall. Consequently, the displacement exhibits a decrease of 51.86% in membrane residual oil and an increase of 17.44% in recovery compared with water flooding. The Geobacillus stearothermophilus producing bio-emulsifier and its metabolic products can effectively emulsify reservoir crude oil and reduce the oil-water interfacial tension. In the end and the formed emulsion featured high viscosity can improve the oil flow rate and expanded wave volume of injected fluid. Correspondingly, the cluster-like, columnar residual oil were reduced by 64%, 68% respectively. In the micro porous test cell, the in-situ cultured microbes rely on specific life activities (interfacial tropism and in situ metabolism, etc.) to strip the residual oil off the wall of orifice deep inside the blind-ends, which cannot be achieved by the exogenous injection method. After the in-situ microbial culture process, the residual oil in deep blind-ends was reduced by about 47%, and the recovered oil was increased about 15% compared with exogenous injection method. [ABSTRACT FROM AUTHOR]

Summary: The use of two emulsifiers to fabricate a composite emulsifier is a useful strategy used to strengthen the emulsifying capacity. To investigate the feasibility of using soy protein isolate (SPI) to stabilise Pickering emulsions stabilised by soy peptide nanoparticles (SPNs), the SPI was introduced into the SPN system to fabricate SPI‐SPN complex emulsifiers, and the effects of the SPI on the properties of the SPNs and SPN‐stabilised emulsions were investigated with various oil fractions. The addition of SPI significantly reduced the particle sizes and surface hydrophobicities. Furthermore, the SPI increased the structural rearrangements of the SPNs at the oil–water interface. Compared with emulsions stabilised with the SPN alone, the droplet sizes of the SPI‐SPN emulsions were smaller, and the interface protein adsorption percentages were lower for all oil fractions. The viscosity of the SPI‐SPN emulsion was higher than that of the SPNs emulsion at Φ ≤ 0.60. Decreases in G′ and G″ were observed when the SPI was added at all Φ values tested. More importantly, the added SPI markedly enhanced the creaming stabilities of the SPN emulsions at low Φ (≤0.40). These results confirmed that SPI improved the emulsifying activity of the SPNs and enhanced the stabilities of Pickering emulsions stabilised with SPNs at low Φ. [ABSTRACT FROM AUTHOR]

In order to improve the emulsifying properties of soy protein around isoelectric point, soy protein isolate (SPI) and γ‐polyglutamic acid (γ‐PGA) complexes were prepared by electrostatic interaction. The formation of SPI–γ‐PGA electrostatic complex and emulsifying properties were investigated by monitoring turbidity, zeta potential, intrinsic fluorophores, emulsion characterization, and microstructure observation. The results showed that the formation of SPI–γ‐PGA electrostatic complex was identified through turbidimetric analysis and zeta‐potential measurement. Intrinsic fluorescence spectrum indicated internal structure changes of electrostatic complexes. Furthermore, SPI–γ‐PGA complex–stabilized emulsions showed better stability with small droplet sizes and slow growth as well as the uniform microstructure around the isoelectric point (pH 4.0–5.0) than SPI‐formed emulsions. Under the different thermal treatments and ionic strengths, emulsions stabilized by SPI–γ‐PGA‐soluble complex resulted in improved emulsion stability to environmental stresses. This may be attributed to the increased steric repulsion and electrostatic repulsion by SPI–γ‐PGA complexes at oil–water interfaces. The findings derived from this research would provide theoretical reference about SPI–γ‐PGA electrostatic complex that can be applied in acid beverages and developed a novel plant‐based sustainable stabilizer for emulsions. Practical Application: The electrostatic interaction between SPI and γ‐PGA improved the emulsifying characteristics of soy protein around isoelectric point. The results derived from this research would expand applications of SPI–γ‐PGA‐soluble electrostatic complex that can be applied in acid beverages, as well as a novel plant‐based sustainable stabilizer for emulsions. [ABSTRACT FROM AUTHOR]

Electric dehydration is the most widely used physical technology for separating water from crude oil. However, natural surfactants stabilize the oil–water interface, resulting in low dehydration efficiency and failure of the electric dehydrator due to electric field collapse. To explore the physical methods of weakening the influence of surfactants on electric dehydration, this study synchronously increased magnetization during the electric dehydration. Based on high-speed microscopy experiments, it has been demonstrated that synchronous magnetization weakens the hindrance of surfactants to droplet coalescence during electric dehydration. Within the experimental conditions, the influence of magnetization on the growth coefficient C1 ranges from 2.9% to 26.6%. In addition, based on molecular dynamics simulation, the mechanism of magnetization weakening the influence of surfactants was studied at the molecular level. It was found that water molecules and surfactant molecules undergo significant molecular clusters after magnetization, reducing the influence degree of surfactants on unit area. When the surfactant concentration increases, the decrease in the influence degree is balanced by the increase in the number of molecules, which also explains the law that the improvement rate ΔC1 decreases with the increase in surfactant concentration. The results of this work will be potentially valuable for weakening surfactant barriers to demulsification and oil–water separation. [ABSTRACT FROM AUTHOR]

As at recent, various chemical enhanced oil recovery (CEOR) approaches including nanotechnology have gain global attraction. This is due to their ability to reduce interfacial tension (IFT), reduce crude oil viscosity and effectively yield better mobility ratio. This study explored the effect of silica nanoparticles (SiO2-NPs) and Terminalia mantaly exudate (TME) hybrid solution in improving oil recovery. Various laboratory investigations were conducted ranging from interfacial tension and zeta potential measurements to core flooding test. From the result, SiO2-NPs presence had great effect on IFT for oil-water interface but caused slight reduction of IFT for oil-polymer interface. The zeta potentials of TME polymer recorded constant potential increase of -35.87 to -26.95mV and at TME polymer concentration range of 0.1%wt to 0.28%wt, a helix with peak point at 0.21%wt was observed. From the core flooding test, TME biopolymer had significant incremental oil recovery with 0.2%wt TME concentration recording the best recovery as it yielded additional 19.44% recovery and displacement efficiency of 58.33%. SiO2-NPs solutions (nanofluids) at various concentrations also had significant incremental oil recovery with 0.1%wt SiO2-NPs concentration recording the best recovery as it yielded additional 18.54% oil recovery with displacement efficiency of 63.33%. Comparison of the performance of the SiO2-NPs-TME biopolymer hybrid solution, showed huge improvement in incremental oil recovery and this was attributed to the synergy that existed between TME biopolymer and SiO2-NPs. [ABSTRACT FROM AUTHOR]

An excellent oil–water interface is one of the prerequisites for effective lipase catalysis. Therefore, this study aimed to improve lipase activity in terms of catalytic interface optimization. A novel approach for constructing oil–water interfaces was proposed. The structural similarity and the hydrophilic differences between polyvinyl pyrrolidone gel–fiber membranes (GFMs) and poly(lauryl methacrylate) (PLMA) organogel inspired us to hybridize the two to form PVP/PLMA hybrid gel–fiber membranes (HGFMs) based on electrospinning and gelation. The prepared PVP/PLMA-HGFMs were capable of being adopted as novel carriers for lipase catalysis due to their ability to swell both in the aqueous phase (swelling ratio = 187.5%) and the organic phase (swelling ratio = 40.5%). Additionally, Confocal laser scanning microscopy (CLSM) results showed that abundant network pores inside the carriers enabled numerous effective microscopic oil–water interfaces. The catalytic activity of Burkholderia cepacia lipase (BCL) in PVP/PLMA-HGFMs ranged between 1.21 and 8.70 times that of the control ("oil-up/water-down" system) under different experimental conditions. Meanwhile, PVP/PLMA-HGFMs increased lipase activity by about eight times at −20 °C and had good application characteristics at extreme pH conditions. [ABSTRACT FROM AUTHOR]

We investigated the development of water‐in‐oil (W/O) emulsions using only candelilla wax (CW), evaluating the effects of different water to CW oleogel ratios (40:60, 50:50, 60:40) and the CW concentration (0.75% to 3%). The emulsions were developed by shearing the systems with an ultra‐turrax type homogenizer (60 s at 25°C) at the different water to CW oleogel ratios. After 0 and 20 days of storage (25°C) the emulsions were evaluated through microscopy, rheology, water droplet diameter, emulsion stability, and x‐ray diffraction measurements. The results showed that at all water to CW oleogel ratios the surface‐active components of the CW (i.e., triterpenic alcohols, aliphatic alcohols, and fatty acids) stabilized the oil–water interface, while the n‐alkanes and long chain esters formed an oleogel in the oil phase. Independent of the storage time, all the CW emulsions showed frequency independent rheological behavior. However, after applying a strain within the plastic region the 40:60 and 50:50 emulsions formulated with 1.5% to 3% CW provided the higher elasticity and emulsion stability, even after two freeze‐thaw cycles. In particular, the 40:60 and 50:50 emulsions with 1.5% CW had a recovery profile similar to commercial mayonnaise. In contrast, independent of the CW concentration, the 60:40 emulsions showed the lowest recovery profile and highest emulsion instability. These results showed the CW as a multifunctional material capable to develop structured W/O emulsions at room temperature without adding surfactants. The structured W/O emulsions developed by CW could be useful in the formulation of trans‐free, stable low‐fat edible spreads. [ABSTRACT FROM AUTHOR]

As a commercially available ingredient, the mono- and diglycerides (MDG) were widely used in a plant protein-based emulsion to provide effective, functional, emulsifying properties. The simultaneous addition of the MDG and pea protein isolate (PPI) was investigated by the methods of interfacial rheology and quantitative protein proteomics. The physicochemical quantitative analysis of the oil–water interface revealed an interfacial stability mechanism for the protein adsorption layer. For a low MDG concentration, the interfacial quantities of vicilin and albumin were increased, which could be attributed to the adsorption rate. For a high MDG concentration, both vicilin and albumin were displaced by MDG and desorbed from the interface, while legumin was more difficult to displace due to its slow adsorption and the complex structure of protein molecules. The protein molecules with the structural rearrangement interacted with MDG, exhibiting potential effects on the interfacial film structure. Combined with some nanotechnologies, the new comprehension of protein-emulsifier interactions may promote food delivery systems. The research aims to develop an in-depth analysis of interfacial proteins, and provide more innovative and tailored functionalities for the application of the plant protein emulsion. [ABSTRACT FROM AUTHOR]

Tight sandstone reservoir has the characteristics of low porosity, low permeability and strong reservoir heterogeneity, which leads to a rapid decline in single well production after hydraulic fracturing. Adding nano emulsion to fracturing fluid can not only realize the dual function of fracturing and imbibition oil displacement, but also effectively prolong the stable production time of oil wells. In order to improve the understanding of the interaction between nano emulsion and reservoir, this paper based on the basic physical property test and analysis of nano emulsion, macroscopic and microscopic spontaneous imbibition oil displacement experiments, the mechanism of imbibition displacement of nano emulsion in tight sandstone reservoirs and the influence of related factors is clarified. The results show that: ©The particle size of the three types of nano emulsions ranges from 11 to 16 nm, and they can enter the nanopore throats deep in the reservoir, and can achieve good injectivity in tight reservoirs. The anionic AES nano emulsion is superior to cationic ADT and nonionic AEO-9 nano emulsion in terms of injectability, oil-water interfacial tension and wetting modification effect in tight sandstone cores, and the optimal concentration is 0.30 wt%. ©Spontaneous imbibition oil displacement experiments show that the nano emulsion concentration is not the higher the better. Since the nano emulsion adsorption on the solid surface reaches a dynamic equilibrium, the excessive nano emulsion cannot further change the wettability of the solid surface, and the lower oil-water interfacial tension has the opposite effect on the imbibition displacement. ©The migration and gathering of emulsified oil droplets in solution mainly included five processes: Saturated oil core/Nano-surfactant fluid emulsion reaction, Aqueous/Emulsified oil droplets, Emulsified oil droplet gathering phase, Demulsifying and emulsifying oil droplets, Oil phase after demulsification. The generation of remaining oil in porous media is due to the non-uniform wetting modification in different regions. This study further improves the understanding of the mechanism of spontaneous imbibition of nano emulsion in tight sandstone reservoirs. [ABSTRACT FROM AUTHOR]

Recently, considerable attention has been given to using magnetic nanoparticles (MNPs) for capturing oil from oil-in-water (O/W) emulsions, despite MNPs' inherent instability and agglomeration. Their stabilization through changing surface chemistry is required to increase dispersivity. In this research, we use cetyltrimethylammonium bromide (CTAB) as a cationic surfactant to increase the positive surface charge of the particles, resulting in a better stability in the aqueous solution because of increased repulsive forces. The functionalized MNPs are characterized using transmission electron microscopy (TEM), zeta potential, and contact angle (CA) measurements. The aim of this study is to investigate the oil separation efficiency (SE) and equilibrium oil adsorption capacity of the synthesized particles, which are determined using gas chromatography analysis. We also study the adsorption behavior using isotherm and kinetic models. The SE values indicate the superior performance of MNP@CTAB for oil adsorption from dodecane-in-water nanoemulsion (SE = 99.80%) compared to the bare MNPs with SE of approximately 57.46%. These findings are attributed to the stronger electrostatic attraction between the MNP@CTAB having high positive charge and negatively charged oil droplets. The adsorption isotherm results using both linear and non-linear regression methods show that the Freundlich isotherm is the best fit to the experimental equilibrium data (with calculated R2 > 0.97), verifying a multilayer heterogeneous adsorption. Moreover, the pseudo-first-order kinetic model describes the experimental equilibrium data in a greater congruence (R2 = 0.99), suggesting physical adsorption of oil onto MNPs through van der Waals and physical bonding, which is also confirmed through zeta potential measurements. [ABSTRACT FROM AUTHOR]

Soybean stover is a lignocellulose biomass that is rich in cellulose. In the present study, soybean cellulose nanocrystals (CNCs) were prepared from soybean stover by alkaline treatment, bleaching treatment, acid hydrolysis, dialysis and ultrasonication. The as-prepared soybean CNC was characterized by transmission electron microscopy (TEM), zetasizer and rheometer. The effects of NaCl on the particle size, zeta potential, and viscosity of soybean CNC was studied. Soybean CNC was explored as an emulsion stabilizer for lemongrass-essential-oil-loaded emulsions. Soybean CNCs could stabilize the oil-in-water emulsion against coalescence but not flocculation. The addition of NaCl reduced the creaming index and enhanced the encapsulation efficiency and freeze–thaw stability of the CNC-stabilized emulsion. Salted CNC (i.e., CNC in the presence of NaCl) enhanced the thermodynamic stability (i.e., heating–cooling and freeze–thaw stability) of Tween 80 stabilized emulsion, while unsalted CNC did not. Synergistic effects existed between Tween 80 and salted CNC in stabilizing oil-in-water emulsions. The nanoemulsion stabilized with Tween 80 and salted CNC had a mean particle size of ~70 nm, and it was stable against all thermodynamic stability tests. This is the first study to report the synergistic interaction between salted CNC and small molecular weight surfactants (e.g., Tween 80) to improve the thermodynamic stability of nanoemulsion. [ABSTRACT FROM AUTHOR]

The main objective of the current study was to apply chitosan as a stabilizing material to improve the quality and extend the shelf life of camel meat emulsion. Chitosan may achieve these roles through the adsorption of the protective layer at oil-water interfaces and viscosity enhancement. The addition of chitosan at a concentration of 0.8% resulted in overcoming the detrimental impact of the heat-stable camel connective tissue and improve emulsion stability. The obtained results revealed that the addition of chitosan significantly decreased the total expressible fluid, released water, released fat and Thiobarbituric Acid Reactive Substances (TBARS) of raw camel meat batter with a significant increase in the batter's viscosity and water Holding Capacity (WHC) compared to the control. After cooking, the addition of chitosan led to significant reduction of TBARS value and extended the shelf life of camel sausage to 5 months at 5°C when compared to the control that accepted only for 3 months. Moreover, the chitosan formulated sausage showed lower lightness (L*), yellowness (b*) and shear force values than the control throughout chilled storage at 5°C for 5 months. Improvement of redness (a*), the sensory parameters and ultrastructure of camel luncheon sausage was also observed by the chitosan addition. Therefore, chitosan can be applied as a thickener and stabilizer for camel meat emulsion and produce more stable products through 5 months of refrigerated storage. Furthermore, the addition of chitosan may be safely used by meat processors as a novel technique for improving the quality and extending the shelf life of camel luncheon. [ABSTRACT FROM AUTHOR]

Introduction: Through the combination of hot water and chemical agent, the low-heat synergistic chemical profile control and flooding technology can not only reduce the risks of sand production and string damage caused by high-temperature thermal recovery technology, but also further improve the recovery factor on the basis of hot water flooding. Methods: Based on laboratory testing, the synergism mechanism of thermal energy and chemical agent is studied. Results: The research results showed that in the near wellbore zone of the injection well, crude oil viscosity reduction-mainly relies on thermal energy, and chemical agents assist in improving the water oil mobility ratio and reducing the risk of cross flow. After entering the deep formation, due to the decrease in temperature, the thermal energy effect is weakened, but the chemical agents still aggregate at the oil-water interface and continue to act on heavy oil to reduce viscosity. The higher the temperature, the greater the role of heat energy, and the weaker the role of chemical agents. The higher the injection concentration of chemical agent, the more obvious the leading role of chemistry. Based on the comprehensive evaluation index, the optimized temperature is 80°C and the injection concentration is 1500mg/L. The scheme study of Bohai L Oilfield shows that compared with cold water flooding, hot water flooding can only improve oil recovery by 1.2 percentage points, and low heat collaborative chemical profile control flooding technology can further improve oil recovery by 4.7 percentage points on the basis of hot water flooding, with obvious oil increase effect. Conclusion: It is suggested that Bohai L Oilfield should apply low-heat coordinated chemical profile control and flooding technology to improve the development effect of the oilfield, and provide new technical ideas for safe and economic development of offshore heavy oil. [ABSTRACT FROM AUTHOR]

The tunable wettability by pH‐stimulus has great potential in liquid adhesion, transport, collection, and separation due to its rapid response and wide control range. However, achieving pH‐regulated wettability on the selected region of material without acid–base contamination presents a distinct challenge for the existing methods. Here, a scalable conductive network membrane is prepared with switchable wettability by regulating interfacial pH. The generation and diffusion of interfacial pH on the selected region of the membrane are regulated through the confinement electrolysis process, which is adapted to both spatial arrangements of the conductive network and the electrical potential. By regulating the interfacial pH (>13), the wettability of the selected region can change from superhydrophobicity (Water contact angle = 150°) to superhydrophilicity/underwater superoleophobicity (Water contact angle = 0°) without additional reagent in 30 s under 15 V. Based on the switchable wettability and precise controllability, the prepared membrane can efficiently realize on‐demand oil–water separation (>99%) and in situ extraction‐back extraction. The membrane with switchable wettability is programable and free of acid–base contamination, which may have broad practical application potential in intelligent fluid‐related systems. [ABSTRACT FROM AUTHOR]

Biologically extracted cellulose nanocrystals (CNCs) are rod-like and amphiphilic materials with surface-exposed (hydrophilic sites) and hidden (hydrophobic sites) hydroxyl groups. These physicochemical characteristics make CNCs suitable for use as emulsifying agents to stabilize emulsions. Stable oil-in-water emulsions, using sulfated (i.e., – SO 3 - ) CNCs that were ionically crosslinked with alkaline-earth (i.e., Mg 2 + ) or transition-d-block (i.e., Zn 2 + ) metal cations, were developed without the use of any synthetic surfactants or prior functionalization of pure CNCs with hydrophobic molecules. Various emulsion surface properties such as interfacial tension, surface charge, surface chemistry, as well as rheology were characterized. Ionically crosslinked CNCs (iCNCs) adsorbed at the interface of an oil and water and fortified the emulsion droplets (5–30 µm) against coalescence by lowering the interfacial tension from 65 mN/m (i.e., pure CNC mixture with oil) to 25 mN/m (i.e., iCNC mixture with oil) and reducing zeta potential with surface charge values (–30 mV to –10 mV), ideal to maintain droplet layer assembly at the water–oil interface. This study provided an alternative approach to achieve particle-stabilized and surfactant-free emulsions by using divalent metal nitrates to develop "clean" emulsion-based technologies for applications in many industries from agriculture to food to pharmaceuticals. [ABSTRACT FROM AUTHOR]

Flow rate and holdup are two essential parameters to describe oil-water two-phase flow. The distribution of oil-water two-phase flow in the pipeline is very uneven, and there is a significant slippage between the phases. This makes it difficult to measure these two flow parameters. In this paper, a new measurement method of flow rate and holdup based on phase state regulation is proposed. The oil-water two-phase flow is adjusted to oil or water single-phase flow according to the time sequence by the phase state regulation, and the oil-water phase interface is measured with a conductance sensor. A wavelet transform based phase inflection point detection model is proposed to detect the oil-water phase change point. The experimental results show that the maximum measurement error of the flow rate of water is 3.73%, the maximum measurement error of the flow rate of oil is 3.68%, and the flow rate measurement repeatability is 0.0002. The accuracy of the measurement holdup is better than 3.23%, and the repeatability of the measurement holdup is 0.0003. The prototype designed based on this method has two advantages. One is that it is small in size, the other is that it does not depend on the accuracy of the sensor. Therefore, it can be widely used in oilfield ground measurement. [ABSTRACT FROM AUTHOR]

The enhanced oil recovery (EOR) method is widely used for recovering residual crude oil after implementing conventional oil recovery techniques. Chemical additives, such as surfactants, are considered beneficial for EOR. Their efficacy is assessed based on their ability to reduce interfacial tension, modify wettability, and establish a stable emulsion system. Understanding the mechanism of surfactant adsorption at the oil–water interface is critical for effectively implementing surfactant flooding. In this work, we have studied the adsorption of a natural surfactant synthesized from Eichhornia crassipes at the oil–water interface using numerous interfacial analyses. The results show substantial adsorption at the oil–water interface, indicated by a 27% increase in zeta potential (i.e. −25.2 to −37.2 mV) and ∼27 times increase in film elasticity (i.e. G ′ : 0.15–4.12 Pa at 0.01 Hz frequency and 0.01% strain). The synthesized natural surfactant demonstrates a noteworthy improvement in the stability of the oil-in-water emulsion and interfacial rheological properties, indicating its potential application in EOR. [ABSTRACT FROM AUTHOR]

In this paper, the caseinate-based protocell with more than ten thousand caseinate units in its membrane was established, and showed a reversible volume change to pH variation due to the collective response of the caseinate in the membrane, which could be used to control the spatial distribution of proto-organelle by regulating of the viscosity inside the protocell. This finding has implications for the development of protocells and the creation of novel biomaterials with tunable properties. [Display omitted] Volume change plays an important role in biological cells to regulate their internal microenvironment. To adapt to the rapid variation of the surface area during the volume change, the lipid membrane is dynamically modulated via membrane folding invagination, or spontaneous uptake or release of lipid molecules under osmotic pressure. Here, we demonstrate an alternative approach to design a functional protocellular system capable of dynamically adjusting its volume and intracellular microenvironment in response to the alteration of pH. By assembling and subsequently cross-linking pH-responsive caseinate at the water–oil interface, the caseinate-based protocell with more than ten thousand caseinate units in its membrane was established and showed a reversible volume and pore size change to pH variation due to the collective response of the caseinate in the membrane, which could be used to control the spatial distribution of proto-organelle by regulating of the viscosity inside the protocell. [ABSTRACT FROM AUTHOR]

[Display omitted] Phase change slurries (PCS) have emerged as a promising class of oil-in-water emulsions for energy applications, but stability remains an issue. Pickering phase change slurries (PPCS) stabilized solely by nanoparticles could offer enhanced stability. We hypothesize that stability in PPCS can be achieved by tuning environmental variables of salinity and temperature. A paraffin-based PPCS stabilized using fumed silica nanoparticles was developed and assessed under varying NaCl concentrations (up to 150 mM) and temperatures (up to 70 °C). Extended-DLVO modeling, confocal, and cryogenic electron microscopy analyzed the silica-paraffin interactions. Rheological experiments examined the impact of effective volume fraction, thermal expansion, and salinity on the viscosity and shear stability of PPCS. The stability of the resulting formulation was assessed under high pressure and temperature conditions. Increased salinity did not change the packing density of the silica at the oil–water interface (82% ± 6%) but did increase the adsorbed layer thickness and network formation, enhancing the formulation's resistance to shear-induced instability. A critical volume fraction of 0.51 ± 0.01 was identified, beyond which viscosity increased significantly. The resulting formulations remained stable under high pressures and temperatures, regardless of salinity. These findings offer insights into the variables affecting PPCS properties, assisting in designing stable PPCS formulations for diverse applications. [ABSTRACT FROM AUTHOR]

The adsorbed film of cetyltrimethylammonium chloride (CTAC) at the tetradecane (C14) - water interface undergoes a first-order surface transition from two-dimensional liquid to solid states upon cooling. In this paper, we utilized this surface freezing transition to realize a spontaneous demulsification of Pickering emulsions stabilized by silica particles. In the temperature range above the surface freezing transition, the interfacial tension of silica laden oil-water interface was lower than CTAC adsorbed film, hence, stable Pickering emulsion was obtained by vortex mixing. However, the interfacial tension of CTAC adsorbed film decreased rapidly below the surface freezing temperature and became lower than the silica laden interface. The reversal of the interfacial tensions between silica laden and CTAC adsorbed films gave rise to Pickering emulsion demulsification by the desorption of silica particles from the oil-water interface. The exchange of silica particles and CTAC at the surface of emulsion droplets was also confirmed experimentally by using phase modulation ellipsometry at the oil-water interface [ABSTRACT FROM AUTHOR]

Industrial production and domestic discharge produce a large amount of oily wastewater, which seriously affects the stability of the ecological environment. Membrane separation technology provides another path to treating oily wastewater. And appropriate surface modifi- cation of the membrane helps to achieve high efficiency of treating oily wastewater. With green, economy and stability been more concerned. The focal research reports a completely biodegradable all cellulose composite filter paper (ACCFP) composed of I-cellulose macrofibers and IIcellulose matrix. It is a simple one-step impregnation method to adjust the surface microstructure of the pristine filter paper (PFP), and it does not involve with chemical reaction. The pre-wetted ACCFP consist of II-cellulose hydrogel and I-cellulose reinforcement in the process of oilwater separation. This layer of hydrogel is the fundamental to underwater superoleophobicity, which determines their eligibility for applications of efficient oil-water mixture or oil-in-water (oil/water) emulsion separation. The separation efficiency of oil-water mixture and oil/water emulsion exceed 95% and 99.9%, respectively. In addition, excellent mechanical properties of ACCFP in dry and wet conditions ensure its stability in service and prolong service life in applications. The focal study provides a new method for high-performance oil-water separation and it is more in line with sustainable chemistry. [ABSTRACT FROM AUTHOR]

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The generation and dispensing of microdroplets is a vital process in various fields such as biomedicine, medical diagnosis and chemistry. However, most methods still require the structures of nozzles or microchannels to assist droplet generation, which leads to limitations on system flexibility and restrictions on the size range of the generated droplets. In this paper, we propose a nozzle-free acoustic-based method for generating droplets using a gigahertz (GHz) bulk acoustic wave (BAW). Unlike most of the acoustofluidic approaches, the proposed method produces the droplet by pinching-off the liquid column generated by the acoustic body force at the oil–water interface. Benefitting from the focused acoustic energy and small footprint of the device, four orders of magnitude (ranging from 2 μm to 1800 μm) of droplet size could be produced by controlling the working time and power of the device. We also demonstrated cell encapsulation in the droplet and a high cell viability was achieved. The proposed acoustic-based droplet generation method exhibits capacity for generating droplets with a wide size range, versatility toward different viscosities, as well as biocompatibility for handling viable samples, which shows potential in miniaturization and scalability. [ABSTRACT FROM AUTHOR]

[Display omitted] Pharmaceutical formulation of oral dosage forms is continuously challenged by the low solubility of new drug candidates. Pickering emulsions, emulsions stabilized with solid particles, are a promising alternative to surfactants for developing long-term stable emulsions that can be tailored for controlled release of lipophilic drugs. In this work, a non-emulsifying lipid-based formulation (LBF) loaded with fenofibrate was formulated into an oil-in-water (O/W) emulsion synergistically stabilized by stearic acid and silica (SiO 2) nanoparticles. The emulsion had a droplet size of 341 nm with SiO 2 particles partially covering the oil–water interface. In vitro lipid digestion was faster for the emulsion compared to the corresponding LBF due to the larger total surface area available for digestion. Cellulose biopolymers were added to the emulsion to produce a gel for semi-solid extrusion (SSE) 3D printing into tablets. The emulsion gel showed suitable rheological attributes for SSE, with a trend of higher viscosity, yield stress, and storage modulus (G′), compared to a conventional self-emulsifying lipid-based emulsion gel. The developed emulsion gel allows for a non-emulsifying LBF to be transformed into solid dosage forms for rapid lipid digestion and drug release of a poorly water-soluble drug in the small intestine. [ABSTRACT FROM AUTHOR]

Water‐in‐oil (W/O) emulsions have attracted heightened attention because of the ever‐increasing interest in using non‐calorific water to replace calorie‐dense fat in food. However, designing clean‐label and ultra‐stable W/O emulsions is a longstanding challenge in colloid science. Herein, a novel, facile approach is introduced to designing cocoa butter (CB)‐based crystals to stabilize Pickering W/O emulsions. Results using a combination of small‐ and wide‐angle X‐ray scattering and microscopy across length scales reveal that the fat crystals formed in an oleogel of CB with vegetable oil offer high stability to water droplets (up to 60% (v/v)) against coalescence and phase inversion, over storage for 7 months. Such extraordinary stability is attributed to the nanoplatelet‐like CB crystals of βV polymorph located at the water–oil interface and to the inter‐droplet fat crystal network formation, interlocking the water droplets. The increment in water volume fraction endows gel‐like properties with the water droplets acting as "active fillers." These newly designed Pickering W/O emulsions stabilized solely by fat crystals with unusual rigidity offer great promise for fabricating advanced functional materials in food, pharmaceutics, and cosmetic applications, where long‐term stabilization of water droplets using sustainable particles is a necessity. [ABSTRACT FROM AUTHOR]

Reversible emulsification drilling fluids can achieve conversion between oil-based drilling fluids and water-based drilling fluids at different stages of drilling and completion, combining the advantages of both to achieve the desired drilling and completion effects. The foundation of reversible emulsion drilling fluids lies in reversible emulsions, and the core of a reversible emulsion is the reversible emulsifier. In this study, we prepared a reversible emulsifier, DMOB(N,N-dimethyl-N′-oleic acid-1,4-butanediamine), and investigated the reversible phase inversion process of reversible emulsions, including the changes in the reversible emulsifier (HLB) and its distribution at the oil–water interface (zeta potential). From the perspective of the acid–alkali response mechanism of reversible emulsifiers, we explored the reversible phase inversion mechanism of reversible emulsions and reversible emulsification drilling fluids. It was revealed that the reversible phase inversion of emulsions could be achieved by adjusting the pH of the emulsion system. Then the proportion of ionic surfactants changed in the oil–water interface and subsequently raised/lowered the HLB value of the composite emulsifier at the oil–water interface, leading to reversible phase inversion of the emulsion. The introduction of organic clays into reversible emulsification drilling fluid can affect the reversible conversion performance of the drilling fluids at the oil–water interface. Thus, we also investigated the influence of organic clays on reversible emulsions. It was demonstrated that a dosage of organic clay of ≤2.50 g/100 mL could maintain the reversible phase inversion performance of reversible emulsions. By analyzing the microstructure of the emulsion and the complex oil–water interface, we revealed the mechanism of the influence of organic clay on the reversible emulsion. Organic clay distributed at the oil–water interface not only formed a complex emulsifier with surfactants, but also affected the microstructure of the emulsion, resulting in a difficult acid-induced phase transition, an easy alkali-induced phase transition, and improved overall stability. [ABSTRACT FROM AUTHOR]

The chemical-enhanced oil recovery (CEOR) method is applied to change reservoir rock or fluid characteristics by injecting alkaline, surfactant, and polymer or a combination of two or three of the compounds. Surfactant flooding improves oil recovery by reducing the interfacial tension between oil and water. Selecting reservoir surfactants, especially microemulsions, requires careful screening. This study predicted waxy oil system interfacial tension using surfactant mixtures at below- and above-optimum salinity. To predict the interfacial tension, microemulsion types, HLB, ideal salinity, and HLD were used. The study predicted oil-surfactant-water interfacial tension using SAE, FEO, and their mixtures. We improved the Huh equation by adding a fitting parameter, β, to accommodate the transition from type III to type II microemulsions as salinity increases. With increasing salinity, anionic surfactant's hydrophilic-hydrophobic interactions change, affecting the CH0 values and surfactant layer thickness. This study improved hydrophilic-lipophilic deviation (HLDN) by establishing a fixed interval for nonionic surfactants. Van der Waals attraction, CH0 values and interface surfactant layer thickness are connected, reflecting the fact that lower CH0 values reduce interfacial tension better. This study also found that surfactant packing at the oil-water interface increases the order of the oil-solution ratio and the microemulsion values with polarity. [ABSTRACT FROM AUTHOR]

The stability of the vertical flow that occurs when gas displaces oil from a reservoir is investigated. It is assumed that the oil and gas areas are separated by a layer saturated with water. This method of oil displacement, called water-alternating-gas injection, improves the oil recovery process. We consider the linear stability of two boundaries that are flat at the initial moment, separating, respectively, the areas of gas and water, as well as water and oil. The instability of the interfaces can result in gas and water fingers penetrating into the oil-saturated area and causing residual oil. Two cases of perturbation evolution are considered. In the first case, only the gas–water interface is perturbed at the initial moment, and in the second case, small perturbations of the same amplitude are present on both surfaces. It is shown that the interaction of perturbations at interfaces depends on the thickness of the water-saturated layer, perturbation wavelength, oil viscosity, pressure gradient and formation thickness. Calculations show that perturbations at the oil–water boundary grow much slower than perturbations at the gas–water boundary. It was found that, with other parameters fixed, there is a critical (or threshold) value of the thickness of the water-saturated layer, above which the development of perturbations at the gas–water boundary does not affect the development of perturbations at the water–oil boundary. [ABSTRACT FROM AUTHOR]