Direct Emulsification Research Articles

Utilizing Environmentally and Recycled Materials to Formulate Drilling Mud

It is important to pay attention to environmental regulations while preparing drilling mud because it has become aspects that must be taken into consideration both now and in the future. It is essential to use sustainable and environmentally friendly materials at every stage of the oil and gas industry if possible in order to ensure high standards of sustainable practices. Oil that has been used to prepare oil base mud have bad impact on soil and human at the same time. The using of flaxseed oil instead of gas oil to preparing emulsion is done in this paper. The results were encouraging, and showed the possibility of using flaxseed oil for preparing ecological emulsion. The efficacy of walnut shell powder as an emulsifying agent has been tested as a surface tension reducer and the possibility of using it to increase the stability of an oil emulsion either in reverse or direct at high temperatures (400°F). This research includes measurements of filtration, stability and rheological properties of oil emulsion under laboratory and high temperature. Sample C showed high stability less than 3% because it is a direct emulsion composed of 10% flaxseed oil and crushed walnut shells, which acted as an excellent emulsifying agent because it was composed of cellulose with a percentage of more than 40%. Sample E gave the highest viscosity values, and the reason for this is that it is a reverse emulsion consisting of 60% flax oil with a high viscosity, as it reached more than 70 centipoises at 400 degrees Fahrenheit.

Pectin-based cinnamon essential oil Pickering emulsion film with two-sided differential wettability: A major role in the spatial distribution of microdroplets

Pickering emulsions have attracted much attention as a novel emulsifying technology. This research to explore Zein-Citrus pectin nanoparticles stabilized cinnamon essential oil (CEO) Pickering emulsion (ZCCPEs) for constructing Pickering emulsion edible film (PEF). Unlike traditional research, which focuses on antibacterial and antioxidant activities, our research examined the physical properties of PEF, specifically changes in wettability. The results show that PEF has better transparency and tensile strength than the pectin alone direct emulsion film (PAEF), and the spatial distribution of Pickering emulsion droplets gives different wettability on both sides of PEF. The partially hydrophobic upside has important application value in food packaging. At the same time, the PEF is biodegradable and environmentally non-polluting. The edible film loaded with essential oils, developed based on the Pickering stabilization mechanism in this study, possesses several desirable characteristics for potential used as bioactive packaging films in food applications.

Renewable diesel blends production from hydrothermal liquefaction of food waste: A novel approach coupling fractional distillation and emulsification

Hydrothermal liquefaction (HTL) is a promising approach for producing biocrude oil from wet biowaste, but the suboptimal properties of HTL biocrude hinder its direct utilization as transportation fuel. This study presents an innovative approach by integrating fractional distillation and emulsification to upgrade HTL biocrude derived from food waste into renewable diesel blends. Fractional distillation is effective in removing metals, heavy fractions, and impurities, thus improving the physicochemical properties of the biocrude. Subsequent emulsification of distillates (10–30 wt%) with diesel, using Atlox 4912 as the surfactant, ensures a homogeneous mixture. The solubility of biocrude in diesel increased from 34.80 wt% to 100 wt% after distillation. Compared to direct HTL biocrude emulsification, distillate emulsion exhibited a 17.22% and 20.89% reduction in oxygen and nitrogen content, respectively, as well as significant improvements in terms of higher heating value, carbon and energy recoveries, and reduction of metal elements. The resulting emulsion demonstrated comparable viscosity, molecular weight, and boiling point distributions to the commercial diesel. Moreover, the oxidation and thermal stability tests revealed superior performance of distillate emulsion, with no observable sedimentation during the storage period. In contrast, direct biocrude emulsion experienced 14.37 wt% of phase separation. The mechanism of emulsion aging was then investigated, providing the basis for obtaining emulsions with preferable yield and quality. The comparative evaluation in this study showed that the integrated approach of fractional distillation and emulsification enhances the feasibility and quality of producing renewable diesel blends from HTL biocrude.

Direct emulsification of liquid perfluorobutane: an improved method to formulate superheated perfluorocarbon nanodroplets

This talk will describe a simple and robust method to produce perfluorobutane (PFB) nanodroplets by direct sonication, and will compare the properties of the resultant emulsions with those obtained with the current advocated microbubble condensation method. We found that nearly 100% of particles produced by direct emulsification of PFB liquid at low temperature are liquid PFB-filled, whereas the emulsion produced by microbubble condensation if the microbubbles are not washed, contains 2000 times more non-PFB filled than PFB-filled particles. Consequently, when such suspensions are used to target receptors, the abundance of non-PFB particles will act as competitive inhibitors, and when used to extravasate to reach extravascular targets, the lower count of PFB-filled particles will require larger doses decreasing efficacy and increasing side effects. Adopting this direct formulation could be a game changer for all applications when experimental outcome is dependent on nanodroplet concentration, stability, purity and size. As a result, this method should accelerate the translation of these ultrasound activatable nanodroplets to both image and potentially treat diseased tissues.

Development of a laboratory setup for destruction of oil-water emulsions

The work describes a laboratory setup developed by the authors for destruction of oil-water emulsions. The setup can be used in chemical analytical testing laboratories as new auxiliary equipment for preparing samples of crude oils, which are oil-water emulsions, for obtaining dehydrated oil. The setup includes two borosilicate glass units: heating unit and desiccating unit. The heating unit consists of a conical vessel equipped with a heating element for programmable heating and thermostating of the vessel. The desiccating unit consists of a vessel with a drain hole at the bottom, into which, if necessary, a water-absorbing reagent (calcium chloride) is placed for deeper dehydration of the separated oil phase. The units are connected to each other by a glass adapter, which is equipped with two PTFE or KhN-1 type taps, for collecting water and oil phases into different receiving bottles. Feasibility of using calcium chloride as a drying agent was confirmed by a series of experiments on a model oil sample, in which fractions that boiled away at temperatures below 300 °C were preliminary removed. The data obtained confirmed the absence of partial adsorption of resinous-asphaltene substances during the passage of the separated oil phase through the drying reagent layer. Metrological characteristics of determining separated water fraction were calculated to assess the effectiveness of the laboratory installation. The result of using the developed laboratory setup is the complete destruction of direct and reverse type water-oil emulsions of varying degrees of stability, which could not be demulsified by known laboratory methods. As a result, separated oil phases with a water content of below 1% were obtained, which allows carrying out laboratory studies of oils to determine their composition and properties both to characterize the oils themselves and to establish the reasons for stability of analyzed emulsions.

Quality characteristics of peanut protein-based patties produced with pre-emulsified olive oil as a fat replacer: Influence of acylglycerol type

The emulsion (O/W) may be used as a fat replacer to develop healthier meat analogs. The purpose of this work was to evaluate the effects of oil incorporation methods (direct oil addition and emulsion addition) and oil types [triacylglycerol (TAG) and diacylglycerol (DAG)] on the quality characteristics of peanut protein-based patties crosslinked by transglutaminase (TGase). The patties formulated with emulsions showed larger texture parameters (springiness, cohesiveness and gumminess), lower cooking loss and higher acceptability compared with directly adding oil. The rheological results confirmed that the presence of emulsions strengthened the gel structure in patties, which allowed the patties containing emulsions to stabilize free water. Whereas, TAG-based emulsion was more effective than DAG-based emulsion in improving quality of products, possibly because the competitive adsorption at oil-water interface of DAG reduced the crosslinking between the interfacial protein and adjacent protein molecules. This study revealed the relationship between the acylglycerol type in emulsion and the patty quality, providing a reference for the development of plant-based patties.

Electrospun Polymeric Fibers Decorated with Silk Microcapsules via Encapsulation and Surface Immobilization for Drug Delivery.

Hollow polymer microcapsules as drug carriers have the advantages of drug protection, storage, and controlled release. Microcapsules combined with tissue engineering scaffolds such as electrospun microfibers can enhance long-term local drug retention. However, the combination methods of microcapsules and fibers still need to be further explored. Here, we developed different technical approaches to functionalize electrospun polycaprolactone (PCL) microfibers with silk fibroin (SF) microcapsules through encapsulation and surface immobilization, including direct blending and emulsion electrospinning for encapsulation, as well as covalent and cleavable disulfide-linkage for surface immobilization. The results of "blending" approach showed that silk microcapsules with different sizes could be uniformly encapsulated inside electrospun fibers without aggregation. To further reduce the use of organic solvents, the microcapsules in the aqueous phase can be uniformly distributed in the PCL organic phase and successfully electrospun into fibers using surfactant span-80. For surface immobilization, silk microcapsules were efficiently covalent binding to the surface of electrospun PCL fibers via click chemistry and exhibited noncytotoxic. Based on this method, with the incorporation of a disulfide bond, the linkages between microcapsule and fiber could be cleaved under reducing conditions. These microcapsule-electrospun fiber combination methods provide sufficient options for different drug delivery requirements. This article is protected by copyright. All rights reserved.

On the way to tempera grassa: Unraveling the properties of emulsion-based paint binders

Painting technique in Europe underwent a major change in the 15th century, when the use of egg yolk as a binder in tempera painting was gradually replaced by oil paint. This transitional period probably saw the occasional use of a mixed technique called tempera grassa, in which both types of binders, egg and oil, are mixed in the form of an emulsion. In order to better understand and document this historical painting practice, this article describes the physico-chemical aspects of emulsion-based binders, prepared with egg yolk and either raw linseed oil, or linseed oil partially saponified with lead oxide. Highly stable direct emulsions can be prepared with linseed oil (raw or lead-treated) and egg yolk. Remarkably, lead-treated oil also allows the formation of stable inverse emulsions. The rheological properties of direct emulsions are driven by the oil fraction: as this parameter increases from 0 to 70 wt% oil, the emulsion changes from a viscous liquid to a viscoelastic solid, which allows its flow to be easily tuned by the painter. The impact of egg yolk on the drying mechanism of the emulsion is elucidated thanks to the combined use of NMR relaxometry and FTIR spectroscopy.

Nanocellulose-stabilized bitumen emulsions as a base for preparation of nanocomposite asphalt binders

Pickering bitumen emulsions stabilized by 1 % aqueous dispersion of microfibrillated cellulose (MFC) were used to obtain micro- and nanocomposite asphalt binders. Initial bitumen emulsions are characterized by a yield stress for a bitumen content of up to 40 %, while higher bitumen amounts result in phase inversion with the formation of highly viscous inverse emulsions. Drying of emulsions leads to the production of nanocomposite bitumen binders containing from 0.6 % to 8.3 % of MFC. In this case, the MFC content of 1.5 % or more formed a microfibrillar network in the bitumen, which gives it gel-like properties and the yield stress, increasing its cohesive strength and resistance to rutting. The effect of addition of 5 % sodium dodecyl sulfate (SDS) on the properties of the bitumen emulsions and the resulting binders is considered. SDS increases the emulsifying ability of MFC, making it possible to obtain 70 % direct bitumen emulsions and reducing their effective viscosity together with the yield stress. However, the presence of SDS in the dried binders increases the aggregation of MFC, reducing the stiffness of the resulting microcomposite binders, their yield stress, and rutting resistance.

Semifluorinated Alkanes as New Drug Carriers-An Overview of Potential Medical and Clinical Applications.

Fluorinated compounds have been used in clinical and biomedical applications for years. The newer class of semifluorinated alkanes (SFAs) has very interesting physicochemical properties including high gas solubility (e.g., for oxygen) and low surface tensions, such as the well-known perfluorocarbons (PFC). Due to their high propensity to assemble to interfaces, they can be used to formulate a variety of multiphase colloidal systems, including direct and reverse fluorocarbon emulsions, microbubbles and nanoemulsions, gels, dispersions, suspensions and aerosols. In addition, SFAs can dissolve lipophilic drugs and thus be used as new drug carriers or in new formulations. In vitreoretinal surgery and as eye drops, SFAs have become part of daily clinical practice. This review provides brief background information on the fluorinated compounds used in medicine and discusses the physicochemical properties and biocompatibility of SFAs. The clinically established use in vitreoretinal surgery and new developments in drug delivery as eye drops are described. The potential clinical applications for oxygen transport by SFAs as pure fluids into the lungs or as intravenous applications of SFA emulsions are presented. Finally, aspects of drug delivery with SFAs as topical, oral, intravenous (systemic) and pulmonary applications as well as protein delivery are covered. This manuscript provides an overview of the (potential) medical applications of semifluorinated alkanes. The databases of PubMed and Medline were searched until January 2023.

Emulsified Silica Gel for Deep Reservoir Water Conformance Control

Large volumes of water are produced with the production of oil, posing challenges of corrosion, scaling, and an increased water–oil ratio. Silica-based gels have previously been used as water sealants; however, reservoirs with high temperature and/or salinity cause early gelation, thereby preventing deep penetration into the reservoir. This work discusses factors affecting gel formation from colloidal silica and mixing methods for the preparation of a thermally stable Pickering emulsion and the effect of various parameters on its rheology. Sensitivities include salinities ranging from 5 to 20 wt % for seven different salts, silica gel concentrations from 20 to 28 wt %, pH values from 4 to 9, and temperatures from 80 to 150 °C. The effect of each parameter on the gelation time and gel strength was studied at a constant shear rate and pressure of 100 s–1 and 1100 psi, respectively. A commercial phyllosilicate (organoclay) has been used with diesel to form an invert emulsion of 28% silica gel, with diesel as a continuous phase and colloidal silica as a dispersed phase. Dynamic gel tests were performed to study the effect of the emulsion mixing method, temperature, and organoclay concentrations on the emulsion stability, strength, and viscosity. A lower concentration of salt has a longer gelation time with a lower gel strength. Increasing pH increases the gel strength but reduces the gelation time. The Pickering emulsion formed is stable to high shear, high temperatures, and high salinities. The bulk mixing method produces a direct emulsion, whereas drop-by-drop mixing results in an invert emulsion. A comparison of the gelation time and viscosity has also been provided with non-emulsified silica gel to highlight the benefit of encapsulation in terms of increased gelation time. This work will help academia and industry in designing a cost-effective system for water conformance control in harsh reservoir conditions.

Dynamics of Nonmagnetic and Magnetic Emulsions in Microchannels of Various Materials

The formation of droplets in microchannels (droplet microfluidics) has a large number of applications, such as in micro-dosing and gas meters. This paper considers the dynamics of direct and inverse emulsions based on water, polydimethylsiloxane, and synthetic and mineral oil in microfluidic chips based on two technologies: glass–parafilm–glass sandwich structures and removable scaffold in a silicone compound. It is shown that wettability, roughness and chip wall material; channel thickness; magnetic fluid flow rate; and magnetic field strength affect the size of emulsion droplets formed in a microfluidic chip. The addition of another mechanism for regulating the hydrodynamics of emulsions using a magnetic field opens up new possibilities for the development of promising devices.

Flavor Formation of Stable Double Emulsion Systems with Encapsulated Biologically Active Substances

Ensuring the functional food ingredients stability and the flavor formation of foods fortified with them meets the healthy nutrition principles, which contributes to the human and future generations health, as well as reduces the disease risk. The research aim was to study the biologically impact of the active substances encapsulation into double emulsion food systems (DEFS) on the organoleptic profile formation and the biologically active substances resistance to oxidation. The study demonstrated the comparative organoleptic analysis results of the inverse emulsion with fish oil and DEFS o/w/o with fish oil encapsulated in the internal phase of the emulsion matrix; direct emulsion with vitamin B1 (thiamine) and DEFS w/o/w with vitamin B1 encapsulated in the internal phase of the emulsion matrix; as well as the oxidation stability study results of fish oil in the composition of the inverse emulsion and dual emulsion system during storage. A man compiled organoleptic profiles of control samples and DEFS with encapsulated BAS. The results showed that the fish oil and vitamin B1 encapsulation in DEFS contributed to the color and flavor correction – deodorization and elimination of fish oil and vitamin B1 aftertaste and off-flavours. Study confirmed the effectiveness of fish oil encapsulation in DEFS, expressed in increasing its resistance to oxidation. During storage, the fat oxidation intensity in the control sample was higher than in the double emulsion system. The peroxide value in the control sample increased 6 times during storage and amounted to 7.9 mmol of active oxygen per 1 kg of fat, while in the double emulsion food system the increase was only 4 times, from 1.3 on the first day of storage to 5.1 on the 35th day. On average, for every 7 days of storage the peroxide value grew by 1.32 for the control sample and by 0.76 for the double emulsion system.

Accuracy of fat fraction estimation using Dixon: experimental phantom study

Objective. Quantitative assessment of Dixon two-point and three-point technologies operation using phantom modeling in the range from 0 to 70%.Materials and methods. To simulate substances with different concentrations of the fat phase we chose direct oil-in-water emulsions. Tubes with ready-made emulsions were placed in a phantom. Emulsions based on vegetable oils were presented in the range from 0–70%. The phantom was scanned on an Optima MR450w MRI tomograph (GE, USA) in two Dixon modes: the accelerated two-point method “Lava-Flex” and the three-point method “IDEAL IQ”. A scan was performed on a GEM Flex LG Full RF coil. We calculated fat fraction (FF) using two formulas.Results. There is a linear relationship of the determined values when calculating the fat concentration in “IDEAL IQ” mode and using the formula based on Water and Fat. The accuracy of body fat percentage measurement in “IDEAL IQ” mode is higher than in “Lava-Flex” mode. According to the MR-sequence “Lava-Flex” draws attention to the overestimation of the measured values of the concentration of fat in relation to the specified values by an average of 57.6% over the entire range, with an average absolute difference of 17.2%.Conclusion. Using the “IDEAL IQ” sequence, the results of the quantitative determination of fractions by formulas were demonstrated, which are more consistent with the specified values in the phantom. In order to correctly quantify the fat fraction, it is preferable to calculate from the Water and Fat images using Equation 2. Calculations from the In-phase and Out-phase images provide ambiguous results. Phantom modeling with direct emulsions allowed us to detect the shift of the measured fat fraction.

FORMULATION OF CREAM CONTAINING IBUPROFEN 5%

Background: Non-steroidal anti-inflammatory drug (NSAID) is a group of drugs commonly used to treat musculoskeletal diseases. However, according to statistics, up to 25% of long-term NSAID users had peptic ulcer disease, and 2-4% had gastrointestinal bleeding or perforation. Therefore, it is necessary to study preparations for external use to minimize these undesirable effects. Objectives: The cream containing ibuprofen 5% has been formulated with good physical characteristics and high bioavailability in the in vitro test based on the support of design and optimization software. Methods: According to the D–Optimal model, the formula models of cream containing ibuprofen 5% were designed with the different concentrations of oil phase, water phase, and emulsifier. The formulas of medicinal cream were prepared by direct emulsification method, then evaluated and compared to the criteria consisting of the phase separation, spreadability, and release of the active ingredient through cellulose nitrate membrane with a 0.45 µm pore size. Results: The formulation of the cream containing ibuprofen 5% with various components consisting of ibuprofen (5 g), cetyl alcohol (3.85 g), stearyl alcohol (1.54 g), beeswax (3.85 g), paraffin oil (10.77 g), span 80 (11.70 g), sodium lauryl sulfate (3.30 g), propylene glycol (59.90 g), and nipagin M (0.10 g). The results also showed that the product had good physical characteristics with no separation between the oil and the water phases, a spread area of 618 mm2, and the release of the active ingredient through the cellulose nitrate membrane at 0.209 mg/mL. Conclusion: The cream containing ibuprofen 5% was researched based on excipients of oil and water, making an emulsion structure stable and helping meet the foundational criteria according to the medicinal cream regulations.

Temperature-induced hydrophobicity transition of MXene membrane for directly preparing W/O emulsions

Although hydrophilic membranes are desired for reducing resistance to water permeation, hydrophilic surfaces are not used in the water-in-oil (W/O) membrane emulsification process because water spreads on the hydrophilic surface without forming droplets. Here, we report that a hydrophilic ceramic membrane can form a hydrophobic interface in diesel at a higher temperature; interestingly, the experiments show that the contact angle increases when the temperature rises. The hydrophilic membrane surface evolves into a hydrophobic interface, particularly near the boiling point of water, resulting in a water contact angle of 147.5° ± 1.2°. This work established a method for preparing W/O monodispersed emulsions by direct emulsification of hydrophilic ceramic membranes at a temperature close to the boiling point of water. Additionally, it made high flux of membrane emulsification of monodispersed W/O emulsions possible, which satisfied the industrial requirements of fluidized catalytic cracking in the petrochemical industry.

Synthesis of cationic waterborne polyurethane via thiol-ene click reaction and catechol chemistry to improve the performance of soybean meal adhesives

The development of bio-based adhesives comprised of low-cost, renewable, and accessible biomass resources with high adhesion and toughness is needed in wood-based panel industry. Herein, a novel cationic waterborne polyurethane (CWPU) emulsion was prepared with a hydrophobic long alkyl chain and catechol structure via thiol-ene click reaction and direct emulsification. Then, the obtained emulsions were applied as efficient crosslinkers to enhance the bonding performance of soybean meal (SM) adhesives. The catechol group on polyurethane acted as a secondary reaction platform that formed multiple hydrogen bonds with protein molecules to optimize the mechanical strength and adhesion toughness of the SM resins. In addition, the hydrophobic alkyl chains grafted intertwine and served as a “water-proofer” that hindered the intrusion of water molecules. Consequently, the modified SM/HD@CCWPU resin presented an impressive improvement in its wet bonding strength and toughness to 165.9% and 378.1%, respectively, compared with the pure SM resin. This efficient, ecofriendly, and low-cost design enables the utilization of agricultural byproducts instead of traditional formaldehyde-based products to prepare high-performance adhesives.

Влияние соединений полисахаридной природы на устойчивость прямых эмульсий при хранении

Polysaccharides interact synergistically to form sedimentation-resistant emulsions. However, data on the effect of polysaccharide combinations on oxidative stability are scarce. Sedimentation and oxidative stability are equally important for fat emulsion products. In fact, emulsions owe their stability to various substances of polysaccharide nature. The research objective was to study the effect of polysaccharides and their combinations on the oxidative and sedimentation stability of direct emulsions during storage.
 The study involved direct emulsions of sunflower oil, stabilized polysaccharides, and their combinations. The dispersed phase of sunflower oil was gradually added to the continuous phase of dissolved polysaccharides with intensive stirring. The emulsions were stored at 60°C for eight days. The sedimentation stability was assessed by analyzing sedimentation rate, fractal dimension, lacunarity, and droplet size. The oxidative stability was studied using standard methods for determining the peroxide value and conjugated dienes.
 The emulsions had an average particle size from 6.78 ± 2.50 to 12.67 ± 6.53 µm. The samples based on xanthan gum and its combinations with other polysaccharides showed the highest sedimentation stability: exfoliated liquid proportion was 0–5.3%, highly esterified pectin being the only exception. The samples based on locust bean gum and its combination with low esterified pectin demonstrated the highest oxidative stability: peroxide value – 9.85 ± 0.45 mEq/kg. The lowest oxidative stability was found in the sample of locust bean gum with highly esterified pectin: peroxide value – 1.44 ± 0.85 mEq/kg. The combination of locust bean gum and xanthan gum provided satisfactory sedimentation (exfoliated liquid proportion – 2.2%) and oxidative (peroxide value – 11.8 ± 1.1 mEq/kg) stability of the emulsion. The experiment revealed weak correlation (r = – 0.096) between the sedimentary and oxidative stability parameters. Therefore, it was the nature of the polysaccharides themselves that affected these systems. The authors proposed such modes of action as metal chelating, free radical scavenging, and adding polysaccharide phenolic com-pounds.
 Combinations of different polysaccharides increased the sedimentation and oxidative stability of direct emulsions. The research results can help food producers to develop new types of stable emulsion-based fat products.

DEVELOPMENT OF SELECTIVE GROUTING COMPOSITIONS BASED ON BITUMINOUS EMULSIONS FOR WATER INSULATION WORKS

To increase the efficiency of water inflow isolation in oil wells, selective grouting compositions are preferred. The use of selective isolation methods provides for selective clogging of water inflow channels while maintaining the permeability of oil-saturated reservoir intervals. The mechanism of selectivity realization for different groups of grouting compositions is shown. It is noted that the selectivity of the action of these compositions is significantly affected by the permeability heterogeneity of the formation. In this case, the water primarily flows through the high-permeable interlayers, where the grouting composition will be pumped in a larger volume than in the low-permeable interlayer during water insulation works. In this paper, we continue to study selective grouting compositions that clog the pore space with a material that is subsequently soluble in oil and insoluble in water. The possibility of using bitumen emulsions, including commercially available road emulsions, is analyzed. The use of bituminous emulsions as water-insulating compositions has a number of advantages: due to the low viscosity of the direct emulsion, it easily penetrates into the porous medium. At the same time, bituminous emulsions have high thermal stability. The resulting bitumen film is impervious to water and is sufficiently resistant to aggressive media (acids and alkalis). The objects of the study were used bitumen road emulsion cationic grade EBDK B-52 and acrylic dispersions, which were intended to increase the adhesion of bitumen to the surface of rock and metal. Commercially produced reagents of the Lacroten brands (E-081, E-31, E-082, E-43), Lacryl 4443 were used as acrylic dispersions. Studies of bituminous emulsions and acrylic dispersions for adhesion to the surface of metal, carbonate and terrigenous rocks have been carried out, from which it follows that acrylic dispersions with a low pH (3.0-3.6) are an effective means of processing samples. Filtration studies indicate the selective properties of the bitumen emulsion. When injecting B-52 bitumen emulsion for both the bulk model and the ideal crack model, there is a general tendency to reduce water permeability: 32.8 % for the bulk model and 33.6 % for the ideal crack model. When conducting filtration studies with the initial injection of acrylic dispersion followed by injection of the emulsion, in all experiments, filtration attenuation is observed in both the water-saturated and oil-saturated reservoir models. According to the results of the conducted studies, for the isolation of water-saturated interlayers, it is proposed to carry out works according to the scheme of selective isolation using bituminous emulsion B-52; and when carrying out works on the elimination of behind-the-casing flows, disconnecting water-filled layers and eliminating the leakage of production columns in the coupling joints, sequential injection of acrylic dispersion and bituminous emulsion is provided.

Stabilisation of cosmetic compositions using combined emulsifiers

Objectives.This study investigated the surface properties and micelle formation of combinedstabilizers, which are a mixture of ionic and nonionic surfactants or different nonionic surfactants,to establish a correlation between the composition of stabilizers and the colloidal–chemicalproperties of direct emulsions obtained in their presence.Methods.The surface tension at the interface between the aqueous solutions of the combinedstabilizers with air and toluene was measured using a digital tensiometer. The sedimentationstability of the emulsions was assessed by the volume of the exfoliated water and oil phasesfor seven days. The particle sizes of the dispersed phase were determined using an OlympusCX3 bright field microscope equipped with a universal serial bus video camera connection. Therheological properties of the emulsions were evaluated using a rotary viscometer.Results.According to the isotherms of the surface tension of aqueous surfactant solutions atthe interface with air and toluene at emulsion preparation temperatures of 50 °C and 65 °C,a mixture of nonionic surfactants exhibited a higher surface activity and lower critical micelleconcentration at the interface with toluene. The optimal amount of stabilizers providing stabilityto the compositions for one month was 4 mass % for a mixture of anionic surfactants and nonionicsurfactants and 7 mass % for mixtures of different nonionic surfactants. Emulsions obtained in thepresence of a mixture of anionic and nonionic surfactants exhibited higher kinetic sedimentationstability values due to the formation of electrostatic and steric stabilization factors in the system.The developed compositions were microheterogeneous systems, the average droplet diameter ofwhich varied within the range of 1.0–5.7 µm. In terms of rheological properties, emulsions wereclassified as liquid-like structured systems with coagulation structures; the strength of singlecontacts between particles of the dispersed phase was (1.6–27.0) × 10-10N.Conclusions.A comparison of the physicochemical characteristics of the compositions obtainedin the presence of organic emulsifiers showed that emulsions stabilized using a mixture of ionicand nonionic surfactants, which form mixed adsorption layers, exhibited the best set of properties.