Interfacial Rheology of Mixed Surfactants at the Oil/Water Interface

The interfacial rheology of surfactant mixtures (SBT and Tween^® 80) at the oil/water interface is investigated using toluene as a model oil. The surfactant ratio in the mixed system has an important impact on the interfacial properties. After adding Tween^® 80, the interfacial tension and modulus of SBT show remarkable changes. Compared with the individual SBT or Tween^® 80 systems, the interfacial properties of the mixed surfactant system improve, especially at a 1:1 ratio. At the optimum ratio, synergistic adsorption takes place resulting in improved asphalt emulsion stability.     

Insight into the Interaction Between Carbopol® 940 and Ionic/Nonionic Surfactant

Mixtures of a cross‐linked polyacrylic acid (Carbopol^® 940) and two types of surfactants, namely anionic sodium dodecylsulfate (SDS) and nonionic Tween^® 80, were investigated by viscometry, conductometry, tensiometry, spectrophotometry, fluorimetry and scanning electron microscopy (SEM). The addition of nonionic surfactant decreased the reduced viscosity and the transmittance of the Carbopol^® polymer aqueous solutions. Furthermore, the interaction between Carbopol^® 940 and SDS was characterized by two significant concentration values: the critical aggregation concentration of SDS was particularly independent of Carbopol^® polymer concentration while the polymer saturation point of both surfactants increased with the increase in polymer content. The values of critical aggregation concentration and polymer saturation point obtained using various techniques confirmed the occurrence of Carbopol^® polymer–surfactant associations. The effect of different SDS and Tween^® 80 concentrations on the conformation of Carbopol^® 940 in aqueous solution could be explained through hydrophobic association between surfactant micelles and Carbopol^® polymer tails and through hydrogen bonding in the case of Tween^® 80. Additionally, the surfactant‐induced structural changes were confirmed in Carbopol^® 940–SDS and Carbopol^® 940–Tween^® 80 aqueous solutions by SEM measurements.     

The Impact of Polyoxyethylene Sorbitan Surfactants in the Microstructure and Rheological Behaviour of Emulsions Made With Melted Fat From Cupuassu (<Emphasis Type="Italic">Theobroma grandiflorum</Emphasis>)

Cupuassu fat is a good candidate for partial substitution of cocoa butter in many products, including emulsions. However, for such use it is necessary to know the characteristics of the products prepared with cupuassu fat. Therefore, the main goal of this work is to characterize emulsions prepared with cupuassu fat using the surfactants Tween^® 60, Tween^® 80 and Tween^® 85 as emulsifiers. The emulsions were prepared at 43 °C with addition of 0.5 or 1.5 % (w/v) of surfactant and compared with an emulsion without surfactant. All emulsions were analysed by conductivity, stability, pH, optical microscopy, rheology and oxidative stability. It was verified that the emulsions prepared with Tween^® 60 and Tween^® 80 have higher stability, smaller droplet size and higher apparent viscosity. Also, these properties are positively influenced by the concentration of the surfactant. On the other hand, emulsions prepared with Tween 85 or without surfactant reached unsatisfactory results. The rheological behaviour of the emulsions was adequately described by both Herschel-Bulkley and Mizhari-Berki models revealing pseudoplastic character. These emulsions also present strong gel behaviour, with storage modulus higher than loss modulus. In conclusion, cupuassu fat can be used as oil phase for emulsions products and this characterization helps to understand their behaviour in order to increase their use in food industry.     

Encapsulation of cinnamaldehyde into nanostructured chitosan films

Recently, bioactive chitosan films featuring naturally derived essential oils have attracted much attention due to their intrinsic antimicrobial properties and applicability to a broad range of applications. Previously, the ability to form thick (t > 100 µm), chitosan‐essential oil films via solution casting has been demonstrated. However, the fabrication of well characterized ultrathin films (t < 200 nm) that contain essential oils remain unreported. Here, we systematically investigate increasing the incorporation of an essential oil, cinnamaldehyde (CIN) into ultrathin chitosan films. Films with and without the surfactant Span^®80 were spin‐coated. Qualitatively, films exhibited well‐defined structural color, which quantitatively ranged from 145 to 345 nm thick. Release studies confirmed that a 6× higher release of CIN was enabled by Span^®80 versus the chitosan control films, 30 µg versus 5 µg, respectively. These results suggest that nanostructured chitosan‐CIN coatings hold potential to delay bacterial colonization on a range of surfaces, from indwelling medical device to food processing surfaces. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41739.     

Olive oil microemulsions as a biomimetic medium for enzymatic studies: Oxidation of oleuropein

Microemulsions consisting of olive oil as the non-polar solvent, lecithin as surfactant, 1-propanol as cosurfactant, and water were prepared. The choice of the compositions of the microemulsions used was based on the pseudo-ternary phase diagrams of the system determined at 30°C, for different weight ratios of lecithin/olive oil. Lecithin solubilization and water incorporation in these microemulsion systems was limited. Tyrosinase, an oxidizing enzyme present in olives, was successfully incorporated in the water core of these microemulsions. Enzymatic oxidation of oleuropein, the most abundant olive phenolic compound, in the restricted aqueous environment of olive oil microemulsions was studied. Formation of oleuropein oxidation products was followed spectrophotometrically at 30°C for several minutes. An absorption maximum was observed at 415 nm. When the enzymatic reaction was considered at different tyrosinase and oleuropein concentrations, a rapid inactivation of the enzyme was observed. Addition of l-proline as a coupling reactor did not succeed in preventing enzyme inactivation in the microemulsions, probably owing to substrate localization and product accumulation around the entrapped enzyme molecules in the micellar interface.     

Optimized Microemulsion Systems for Detergency of Vegetable Oils at Low Surfactant Concentration and Bath Temperature

Triglycerides and vegetable oils are amongst the most difficult oils to remove from fabrics due to their highly hydrophobic nature; this is all the more challenging as cold water detergency is pursued in the interest of energy efficiency. Recently, extended surfactants have produced very encouraging detergency performance at ambient temperature, especially at low surfactant concentration. However, the salinity requirement for extended surfactants was excessive (4–14%) and there is limited research on extended‐surfactant‐based microemulsions for cold water detergency (below 25 °C). Therefore, extended‐surfactant‐based microemulsions are introduced in this study for cold temperature detergency of vegetable oils with promising salinity and surfactant concentration. The overall goal of this study is to explore the optimized microemulsion formulations with low surfactant and salt concentration using extended surfactant for canola oil detergency at both 25 and 10 °C. It was found that microemulsion systems achieved good performances (higher than those of commercial detergents) corresponding to IFT value 0.1–1 mN/m with the surfactant concentration as low as 10 ppm and 4% NaCl at 25 °C, and as low as 250 ppm and 0.1% (1000 ppm) NaCl at 10 °C. In addition, microemulsion systems were investigated with a different salt (CaCl₂, or water hardness, versus NaCl) at 10 °C, demonstrating that 0.025% CaCl₂ (250 ppm) can produce good detergency; this is in the hardness range of natural water. These results provide qualitative guidance for microemulsion formulations of vegetable oil detergency and for future design of energy‐efficient microemulsion systems.     

Preparation of SiO2/epoxy nanocomposite via reverse microemulsion in situ polymerization

Reverse water/oil (w/o) microemulsions composed of epoxy resin (EP) (the oil phase) and nonionic surfactant and ammonia aqueous solutions (the water phase) were used in the synthesis of SiO2/EP nanocomposites. The stability of reverse microemulsion was evaluated by measuring water solubilization of the microemulsion. Effects of surfactant type and content, ammonia concentration and temperature on the water solubilization were systematically investigated. Higher water solubilization capacity was obtained by nonionic surfactant TX‐100 compared with other two surfactants, Span‐80 and Tween‐80. Ammonia concentration of 5 wt% and preparation temperature at 35°C were favorable for forming a stable microemulsion and enabling the subsequent hydrolysis and condensation reaction of inorganic precursor tetraethoxysilane (TEOS). SiO2/ epoxy nanocomposites were prepared via in situ polymerization of TEOS within the nanoscale reverse microemulsion “water pool”. FTIR, SEM, and universal testing machine were used to characterize the structural and mechanical properties of the composite. The results revealed that the optimal mechanical properties were obtained at 3 wt% TEOS content. Compared with neat epoxy resin, the tensile and flexural strength of the composite were 40% and 12% higher, respectively. The formation of the silica structure in the hybrid was investigated with FTIR. The SEM and optical observations showed a ductile fracture morphology and good miscibility between inorganic and organic phases. POLYM. COMPOS., 35:1388–1394, 2014. © 2013 Society of Plastics Engineers     

Nanofibers as carrier systems for antimicrobial microemulsions. II. Release characteristics and antimicrobial activity

Antimicrobial nanofibers were prepared by electrospinning microemulsions composed of the essential oil component eugenol solubilized in an aqueous nonionic micellar surfactant solution (Surfynol®465) with poly(vinyl alcohol) (PVA). Nanofibers contained microemulsions composed of 0.75–1.5 wt% eugenol and 5–10 wt % Surfynol. Scanning electron microscopy revealed substantial difference in fiber morphology depending on microemulsion composition with fiber diameters increasing as the concentration of either surfactant or essential oil component in the fibers increased. Release studies suggested a burst release of the encapsulated eugenol, potentially due to the hydrophilicity of the polymeric carrier resulting in rapid dissolution of the carrier matrix and high‐fiber porosity. The eugenol release rate depended on the amount of eugenol and surfactant incorporated within the fibers. The antimicrobial activity of nanofibers carrying eugenol was evaluated against two strains of Salmonella typhimurium (2476 and 2576) and Listeria monocytogenes (Scott A and 101) using a macrobroth dilution assay. Presence of nanofibers in bacterial suspensions successfully suppressed growth of foodborne pathogens and in some cases decreased initial cell numbers. Generally, nanofibers were more efficient against Gram?negative than Gram?positive bacterial strains. Results suggest that addition of microemulsions carrying lipophilic components to polymer solutions subjected to electrospinning offers a novel means to further enhance the functionality of nanofibers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Nanofiltration membranes prepared by direct microemulsion copolymerization using poly(ethylene oxide) macromonomer as a polymerizable surfactant

A novel polymer membrane with nanosized pore structures has been prepared from the direct copolymerization of acrylonitrile (AN) with a polymerizable nonionic surfactant in water‐in‐oil (w/o) or bicontinuous microemulsions. This polymerizable surfactant is ω‐methoxy poly(ethylene oxide)₄₀ undecyl‐α‐methacrylate macromonomer [CH₃O (CH₂CH₂O)₄₀ (CH₂)₁₁ OCO(CH₃)CCH₂, abbreviated: C₁‐PEO‐C₁₁‐MA‐40]. Besides PEO macromonomer, AN, and crosslinker ethyleneglycol dimethacrylate, the microemulsion system contained varying amount of water that formed w/o microemulsions having water droplet structures and bicontinuous microemulsions consisting of interconnected water channel. The polymerized membranes prepared in this study have pore radii ranging from 0.38 to 2.4 nm as evaluated by PEG filtration. The pore size appears to vary linearly with water content in precursor microemulsions. But a sharp change in the gradient of the linear relationship is observed around 25 wt % water content. Membranes made from bicontinuous (>25 wt % water) microemulsion polymerization have a larger and interconnected (open‐cell) nanostructures. In contrast, much smaller closed‐cell (disinterconnected) nanostructures were obtained from w/o (<25 wt % water) microemulsion polymerization and the membrane exhibited a permselectivity toward water in pervaporation separation of high ethanol (>50 wt %) aqueous solutions. The separation factor (α) for 95% ethanol aqueous solution by the membrane derived from the microemulsion containing 10 wt % water is about 20. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2785–2794, 2000     

Preparation and characterization of pH dependent <Emphasis Type="Italic">κ</Emphasis>-carrageenan-chitosan nanoparticle as potential slow release delivery carrier

A polymeric carrier has high potential as active ingredient delivery vehicle owing to its biocompatibility and biodegradability. In this work, pH dependency of the oppositely charged polymers in forming nanoparticle was investigated. A positively charged chitosan and a negatively charged κ-carrageenan were mixed at varied mass ratios (v/v) with a pH ranged from 3 to 6, respectively, to form nanoparticles through polyelectrolyte complexation. The main interest of this research, is to evaluate the effect of pH on the formation of stable active ingredients encapsulated nanoparticle for sustained release. Based on the FTIR result, the presence of new absorption band at 1584 cm^?1 and slight shift in the spectrum, indicated the complexation of the polymers. The Zetasizer’s measurements showed that irrespective to the combination of chitosan and κ-carrageenan, increase in pH solution decreased the size and the zeta potential of the nanoparticles. Furthermore, depending on the combinations, the yield and the swelling percentage of the nanoparticle could reached up to 80 and 200%, respectively. Among the mass ratio combinations, the ratio 1:1 at pH 4 had the best physical properties. The encapsulation efficiency of the κ-carrageenan-chitosan nanoparticles exhibited higher preference towards more water soluble active ingredients, ascorbic acid as compared to caffeine and lidocaine. In addition, the slow release of active ingredients from the κ-carrageenan-chitosan nanoparticles, is plausibly due to the electrostatic interaction and compactness of the nanoparticles. Thus, they might be suitable for prolonged release applications.     

不同表面活性剂对单相微乳液特性的影响

表面活性剂是影响微乳液特性的关键因素之一。本文选取聚氧乙烯脱水山梨醇单油酸酯（Tween 80）、烷基糖苷1214（APG 1214）、十二烷基苯磺酸钠（SDBS）、脂肪醇聚氧乙烯醚硫酸钠（AES）、十二烷基硫酸钠（SDS）和95%纯度鼠李糖脂（R-95%）这6种表面活性剂,通过对其乳化性能和临界胶束浓度进行筛选,结合其形成微乳液的拟三元相图、粒径分布和界面张力分析其特性,并提出微乳液增溶油能力和增溶油成本。研究表明：APG 1214、SDBS、Tween 80乳化性能好、临界胶束浓度低具有更易形成微乳液的优势;5种表面活性剂（Tween 80、SDBS、APG 1214、SDS、AES）均可与正丁醇、水和3号白油自发形成单相微乳液,单相区面积大小为AES型>SDS型>APG 1214型>Tween 80型>SDBS型,最大增溶油能力大小为SDS型>AES型>APG 1214型>Tween 80型>SDBS型,最低增溶油成本大小为AES型相似文献   

Palm oil‐based organogels and microemulsions for delivery of antimicrobial drugs

This study has been designed to develop palm oil (PO) based organogels using span 80/tween 80 mixture (OG) as a gelator system by fluid‐filled structure mechanism. The results suggested formation of organogels, emulsions, and microemulsions as the proportions of PO, OG and water were varied. The emulsions were found to be thermodynamically unstable as compared to the organogels and the microemulsions. Accelerated thermal stability test suggested that all the microemulsions and the organogels of only eight compositions were stable. The organogels showed viscoelastic property while the microemulsions showed viscous flow behavior. Both the organogels and the microemulsions were found to be highly hemocompatible and nonirritant. The antimicrobial efficiency of the ciprofloxacin HCl‐loaded formulations showed equivalent efficiency as compared to marketed formulations. The rates of drug release from the organogels were found to be relatively slower as compared to the microemulsions. The preliminary studies suggested that the developed organogel and microemulsion‐based formulations may be tried for topical delivery of antimicrobials. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 39979.     

Increasing the stability of vegetable oil solutions with the aid of monoglycerides and a cosurfactant

The conditions for an enhanced mutual miscibility of water and Canola oil, with the aid of one or two surface active components, were investigated at 25 C. First, the ability of short chain alcohols to increase the mutual solubility was charted. Such systems frequently are denoted detergentless microemulsions. Second, normal microemulsion systems were formed by using surface active monoglycerides of foodstuff grade. Third, the synergism was monitored when both the surfactant and the cosurfactant (the alcohols) were mixed either with water or oil. Finally, the combined effect was determined when all four components were mixed together into a microemulsion system. It is shown that the extension of the ternary solution phase is dependent primarily on the surfactant used. Some improvement of the mutual solubility of water and oil, however, also was produced by the alcohols. The solubilization capacity of water in the quaternary systems is easily understood when the solution phase is compared with the microemulsion phases of the ternary systems included. Although no dramatic composition dependency was found, an enhanced solubility of water was observed for the oil rich microemulsions of roughly equal weight fractions of the surfactant components. Presented in part at the 8th Scandinavian Symposium on Surface Chemistry, Lund, Sweden, 1984.     

Effect of Alkyl Sulfate on the Phase Behavior of Microemulsions Stabilized with Monoacylglycerols

In this study the effect of an anionic surfactant (sodium dodecyl sulfate SDS) and oils (hydrocarbons: C12–C16) on the formation and phase behavior of the systems of oil/monoacylglycerols (MAG):SDS/propylene glycol/water has been investigated. The effects of the surfactant mixture on the phase behavior and the concentration of water or oil in the systems were studied at three temperatures (50, 55, 60 °C). Electrical conductivity measurement, FT-IR spectroscopy and differential scanning calorimetry methods were applied to determine the structure and type of the microemulsions formed. The dimension of microemulsion droplets was characterized by dynamic light scattering. It has been stated that the concentration of SDS has a strong influence on the shape and extent of the microemulsion areas. Addition of an ionic surfactant to the mixture with MAG promotes an increase in the area of microemulsion formation in the phase diagrams, and these areas of the isotropic region change with the temperature. It was shown that the presence in the systems of a surfactant more hydrophilic than MAG caused an increase in water content in the microemulsions. It was found that, depending on temperature and concentration of the surfactant mixture, it was possible to obtain a W/O type microemulsion with a dispersed particles size distribution ranging from 20 to 50 nm and containing about 17–38% water in the system. Among different alkanes (from C12 to C16), hexadecane embedded microemulsions showed a maximum water solubilization capacity.     

Fe‐mediated ARGET atom transfer radical polymerization of methyl methacrylate in ionic liquid‐based microemulsion

Poly(methyl methacrylate) (PMMA) was synthesized by activator regenerated by electron transfer (ARGET) atom transfer radical polymerization (ATRP) of MMA in ionic liquid‐based microemulsion with polyoxyethylene sorbitan monooleate (Tween 80) as surfactant. The polymerization was carried out at 25°C with CCl₄ as initiator, FeCl₃·6H₂O/N,N,N′,N′‐tetramethyl‐1,2‐ethanediamine (TMEDA) as catalyst complex in the presence of reducing agent ascorbic acid (VC). The polymerization kinetics showed the feature of controlled/″living″ process as evidenced by a linear first‐order plot. The well‐controlled polymers were obtained with narrow polydispersity indices and the ionic liquid‐based microemulsions were transparent with a particle size less than 30 nm. The obtained polymer was characterized by ¹H NMR and gel permeation chromatography. The chain extension was successfully achieved by the obtained PMMA macroinitiator/FeCl₃·6H₂O/TMEDA/VC initiator system based on ARGET ATRP method. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Phase Behavior of Non-Ionic Surfactant-Medium Chain Triglyceride-Water Microemulsion Systems

Microemulsion systems have garnered tremendous interest in the pharmaceutical sector for a variety of drug delivery applications. Non-ionic surfactants are often the preferred surfactant class given their uncharged nature, enhanced oral safety profile, and generally regarded as safe status as compared to other surfactant classes (Myers, Surfactant science and technology, 2005, p. 29), (Malmsten, Handbook of microemulsion science and technology, 1999, p. 755), (Grove & Mullertz, Chapter 5-liquid self-microemulsifying drug delivery systems, 2007), (Liu et al., Water-insoluble drug formulation, 2008), (Hauss, Advanced Drug Delivery Reviews, 2007, 59, pp. 667–676), (Balazs, Solubility, delivery and ADME problems of drugs and drug-candidates, 2011, p. 68). In this work, the phase behavior and microemulsion formation potential of four commonly used non-ionic surfactants, PEG-40 hydrogenated castor oil, Poloxamer 188, Polysorbate 80, and d -α-tocopherol polyethylene glycol succinate were studied via ternary phase diagram (TPD) mapping using a medium chain triglyceride, Miglyol 812. Results indicated notable differences in phase behavior despite similarities in hydrophilic–lipophilic balance value (13–15). All surfactants produced Winsor Type I, oil-in-water microemulsions at water concentrations above 40% wt/wt. Winsor Type II water-in-oil microemulsions were difficult to obtain even at high oil concentrations of ≥70% wt/wt. Winsor III microemulsions, though rare, were generally obtained in the middle regions of the TPD between 10% and 30% wt/wt water while Winsor IV microemulsions dominated at high surfactant concentrations of ≥45% wt/wt. Opaque emulsion areas were particularly notable in wax state surfactants. Polysorbate 80 and PEG-40 hydrogenated castor oil demonstrated a high degree of synergism as well as the largest oil-in-water (o/w) and water-in-oil (w/o) microemulsion formation potential rendering them suitable for a number of enteral and parenteral applications.     

吐温-80/正丁醇/环己烷/水系微乳液性能及对木材的渗透能力

考察了吐温-80/正丁醇/环己烷/水系微乳液各组分及其质量比对其形成的影响,通过电导率、表面张力和动态光散射(DLS)表征体系的物化性质。结果表明,以吐温-80为表面活性剂,正丁醇为助表面活性剂,环己烷为油相形成的微乳区较大。微乳体系的电导率随含水量的增加呈现规律性变化,可以判断微乳液的3种类型(油包水型、双连续型和水包油型);不同类型的微乳液均具有较低的表面张力(约24.6 mN/m)和粒径(小于100nm),且粒径随体系含水量的增加而增大。此外,采用液体吸收法考察了微乳液对木材的渗透能力,与普通溶剂相比,微乳液具有很强的渗透能力,特别是对于双连续型微乳液,10 min时,对马尾松和桉木的渗透能力分别达70%和50%。     

Polymerization of acrylamide in styrene containing inverse microemulsions: polymerization kinetics and polymer product composition studies

The kinetics of free‐radical homopolymerization and copolymerization of acrylamide (AAm) and styrene (S) initiated by water‐soluble ammonium peroxodisulfate, (APS) or by toluene‐soluble dibenzoyl peroxide (DBP) in inverse microemulsion toluene/S/AOT (sodium bis(2‐ethylhexyl)sulfosuccinate)/water/AAm characterized by a low volume fraction of the aqueous phase (Φ_aw ≈ 0.08) as a function of the concentration of S in the oil phase of the inverse microemulsion system have been studied. S strongly decreases the rate of AAm/S (co)polymerization. This is valid for both APS and DBP initiators. Kinetic measurements indicate the important role for cross‐initiation of water soluble AAm growing chains and of oil soluble S analogues activated by the primary free‐radicals generated from APS (or from DBP) in the dispersed water droplets (or in the continuous oil‐phase) of the inverse microemulsion, respectively. With inverse microemulsions containing toluene (70.73 %)/S (2.44 %)/AOT(17.56 %)/water (7.32 %)/AAm (1.95 %), after polymerization (initiator APS, 3.04 × 10⁻² mol dm⁻³ of water) and separation of the polymeric components, the following yields were obtained: AAm/S (co)polymer (89.20 mass%; ie 62.24 mass% of AAm structural units and 26.96 mass% of S structural units), polyacrylamide (9.4 mass%) and polystyrene (1.4 mass%). © 2000 Society of Chemical Industry     

Effect of Hydrophobic Modification on the Properties of Polymer‐Blended Microemulsion Gels

Phase behavior of sodium oleate (NaOl)/isoamyl alcohol‐based lamellar gel phase in cedar oil/water medium in the presence of the nonionic polymer hydroxyethyl cellulose (HEC) and its hydrophobic modified product (HMHEC) is investigated for the development of polymer‐embedded surfactant gels. HMHEC is more soluble in oil‐in‐water (o/w) microemulsions, but nonionic HEC shows limited solubility in the lamellar microemulsion (o/w type). Quantitative estimation of rate of adsorption of the polymer on lamellae bilayers can be easily done by Sudan solubilization and methylene blue complexation methods. Addition of HMHEC to the lamellar gel phase increases the polymer solubilization limit of lamellar gels as well as the viscoelasticity and thermal stability. The polymer‐embedded microemulsion gel acts as a “clean gel” since it exhibits good solubilization in different hydrocarbon media at ambient conditions. Elastic modulus of the polymer‐embedded gel influences directly the suspension performance of gels at high temperature and yields a reasonable sand‐settling velocity acceptable according to fracturing standards. The thermal characteristics and viscoelastic properties of polymer‐embedded gel were found to be suitable for moderate‐temperature reservoir stimulation where the bottom hole temperature is in the range 70–75 °C. Already a large amount of experimental data on pure microemulsions (without polymer) exists. Our studies indicate that the developed polymer‐embedded microemulsion gel has great potential as a model system for the study of polymer–microemulsion interactions.     

柴油微乳液的制备及其性能研究

介绍了-10<'#>,0<'#>柴油微乳液的组成,确定了柴油、水、表面活性剂的质量配比,采用超声波处理为分散手段制备了微乳化柴油;并将-10<'#>柴油制备的微乳液与0<'#>柴油制备的微乳液作了对比;对制得的微乳化柴油的十六烷值、闪点、密度、黏度、粒径、凝点、热值、胶质质量浓度等理化性能指标进行了测定与分析对比;同时...