Water-in-Diesel Fuel Nanoemulsions Prepared by High Energy: Emulsion Drop Size and Stability, and Emission Characteristics

Water-in-diesel fuel nanoemulsions were prepared with mixed nonionic surfactants. The high energy emulsification method was used to form three emulsions containing different water contents: 5, 10 and 14% (v/v). These nanoemulsions were stabilized with a mixture of 20% sorbitan monooleate, and 80% polyethoxylated (20 EO) sorbitan trioleate, resulting in an HLB of 10 (HLB—hydrophilic-lipophilic balance). The effect of water on the droplet size, emulsion calorific value, and emission gases such as nitrogen oxides, carbon dioxide emissions and exhaust gas temperatures in diesel engines has been studied. It was found that the mean sizes of the droplets formed (between 19.3 and 39 nm) depend on the water content and the concentration of the blend emulsifiers.     

Influence of Surfactant on the Characteristics of W1/O/W2-Microparticles

The water-in-oil-in water (W₁/O/W₂) double emulsion evaporation technique is widely used when the microencapsulation of soluble agents like naloxone HCl is intended. The present work shows the effect of HLB emulsifiers added to phase O on microsphere morphology, size, release, drug encapsulation efficiency. The addition of sorbitan ester to first emulsion (W₁/O) and the HLB of the surfactant have an important effect on the characteristics of poly-lactide-co-glycolide (PLGA) microparticles (MP). This MP with sorbitan esters added were smaller and released the hydrophilic drug, naloxone, with no-significant difference at pH 5 versus pH 7.5 (phosphate medium). This is an important fact when long-drug release is considered since it is known that PLGA degradation leads to media acidification. The HLB value had an important effect on drug loading. Sorbitan monooleate led to the highest naloxone loading. Because of its low HLB (4.3), it is most suitable for stabilizing the W₁/O emulsion, which is fundamental for the successful entrapment of a hydrophilic compound in MP prepared by double emulsion technique. Finally, drug solubility in the MP matrixes cannot be considered as a predictive parameter for drug encapsulation. Both surfactants increased the naloxone solubility in the polymer PLGA and only sorbitan monooleate increased the drug entrapment.     

Influence of process parameters on the formation of Silicalite-1 zeolite particles

Silicalite-1 particles with minimum twinning have been synthesized inside the polar core of non-ionic surfactant/co-surfactant-stabilized water-in-oil (w/o) type emulsions at 150° ± 1 °C within a short reaction time of 5 h. The non-ionic surfactants of varying hydrophilic–lipophilic balance (HLB) values, i.e. sorbitan monooleate (Span 80, HLB: 4.3), sorbitan monolaurate (Span 20, HLB: 8.6), polyoxyethylene (4) lauryl ether (Brij 30, HLB: 9.7) and polyoxyethylene sorbitan monooleate (Tween 80, HLB: 15), the cationic surfactant, i.e. cetyl trimethyl ammonium bromide (CTAB), surfactant concentration, co-surfactant, synthesis temperature and time have been found to play significant role in controlling size and characteristics of Silicalite-1. It has been observed that the crystallinity and size of Silicalite-1 can be tailored by adjusting the interactions between the polar surfactant head groups at the w/o interface and the growing crystallographic surfaces (or silicate/TPA ions) in the aqueous medium of the emulsion.     

Enlargement of Nanoemulsion Region in Pseudo-ternary Mixing Diagrams for a Drug Delivery System

The purpose of this research was to develop the pseudo-ternary mixing diagrams for a potential drug delivery system consisting of vitamin E (potential drug) + soybean oil + surfactant + co-surfactant (anhydrous glycerol) + water. The potential drug (vitamin E) was loaded in the oil phase. The effects of different surfactants (pure and mixed) on the mixing diagrams, especially on the nanoemulsion region, were investigated. The influence of the drug loading level on the mixing diagrams was also determined. The surfactants studied were polyethoxylated (20) sorbitan monolaurate, polyethoxylated (20) sorbitan monooleate, polyethoxylated (35) castor oil and their mixtures. The size (area) of the nanoemulsion region of the mixing diagrams was found to be dependent on the type of surfactant used and the loading level of the drug (vitamin E).     

Emulsification for castor biomass oil

The effect of the emulsifier formula on the stability of castor oil-water system was studied through compounding three groups of emulsifiers from the aspects of stability factor of absorbance, centrifuge stability, demulsification time in quiescence, appearance of the droplets, and viscosity. The best emulsifier formula for castor biomass oil was the composite formula of sorbitan monooleate and polyoxyethylene sorbitan monostearate. Correlation exists between the stability of emulsion and the viscosity/particle size of the droplets, with better stability in the case of greater viscosity or narrower distribution of particle size in the emulsion of castor oil-water system. Methanol added to the castor oil-water system may decrease the viscosity of the emulsion. Comparing the castor oil-water emulsion with methanol-castor oil-water emulsion, the optimal hydrophilic and lipophilic balance (HLB) value based on castor oil-water system was acquired between 6.6 and 7.5, while the optimal HLB value based on the methanol-castor oil-water system was between 5.5 and 6.0. The optimal HLB value of methanol-castor oil-water system gradually moved to that of castor oil-water emulsion with adding more water.     

Development of Nanoemulsion of Silicone Oil and Pine Oil Using Binary Surfactant System for Textile Finishing

Nanoemulsions of silicone oil and pine oil using a binary surfactant system were prepared. Silicone oil and pine oil were used to achieve softness and mosquito repellency and antibacterial activity respectively when the nanoemulsion was applied on the fabric. A silicone surfactant (AG-pt) and a hydrocarbon surfactant (TDA-6) were used in different proportions to obtain stable nanoemulsions at the lowest possible droplet size. The various emulsification process variables such as ratio of hydrocarbon to silicone surfactant, surfactant concentration, ratio of silicone oil to pine oil, oil weight fraction and sonication time have been studied. The optimal variables include the ratio of hydrocarbon to silicone surfactant of 80:20, surfactant concentration of 8%, ratio of silicone oil to pine oil of 80:20, oil weight fraction of 20% and 15 min of sonication time at 40% of the applied power. Nanoemulsions were found to be very stable with emulsion droplet size around 41 nm. In order to compare different emulsification techniques, emulsions were also prepared using the conventional method. Emulsions analyzed using SEM showed spherical droplets ranging from 40 to 120 nm. Atomic force microscopy was used to evaluate the bounciness, fluffiness and softness of fabric. From this study, it was found that stable nanoemulsion with a lowest possible droplet size of silicone and pine oil could be prepared by ultrasonic emulsification technique in order to deliver multiple properties when applied to fabric.     

Preparation of water soluble Am–AA–SSS copolymers by inverse microemulsion polymerization

Inverse microemulsion copolymerization of acrylamide (Am), acrylic acid (AA), and sodium 4-styrenesulfonate (SSS) initiated by redox initiators composed of ammonium peroxodisulphate (APS) and sodium bisulfite, and stabilized by the mixed emulsifier system sorbitan monooleate (Span-80) and polyoxyethylene sorbitan monooleate (Tween 80) were examined as a function of the combination of hydrophilic (Tween 80) and hydrophobic (Span 80) emulsifiers, reaction temperature, AM/AA mass ratio, SSS concentration, and initiator concentration. The physicochemical and thermal properties and the structure of this copolymer were also determined and discussed. The reaction rates for all runs of the experiments exhibited two intervals, which were typical of microemulsion polymerization. The copolymer had only one glass transition temperature of 115.5 °C, indicating a random structure.     

低熔融黏度C-5石油树脂水基乳液的制备

以56#半精炼石蜡为黏度调节剂,制备了低熔融黏度的C-5石油树脂水基乳液,系统考察了非离子型复合乳化剂的HLB值和用量对石油树脂乳液稳定性、乳液粒径分布、乳液黏度和乳液表面张力的影响。结果表明,添加质量分数30%的石蜡可以明显降低石油树脂的熔融黏度,使物料在较低温度下实现均匀混合;复合乳化剂的最佳HLB值为10.75;最佳用量为16%。通过正交实验确定了优选乳化工艺条件为:乳化温度98℃、乳化时间20 min、剪切速率5 000 r/min、乳化水与水相的质量比为1∶3,在该条件下可制得固体质量分数为40%,稳定性好、粒径小、黏度低的O/W型C-5石油树脂乳液。     

Statistical Analysis of Optimal Ultrasound Emulsification Parameters in Thistle-Oil Nanoemulsions

Thistle oil (INCI: Silybum marianum seed oil) is known as an anti-oxidant, moisturizing and skin regenerating cosmetic raw material. Nanoemulsions are a new form of cosmetic product showing very good user properties (ease of spreading over the skin with no greasy feeling). Moreover, due to their structure, they can also transport both hydrophilic and hydrophobic active substances to the skin. The aim of this work was the preparation and characterization of nanoemulsions, based on thistle oil. The non-ionic surfactants polysorbate 80 (PEG-20 sorbitan monooleate), decyl glucoside, and a polyglyceryl-4 ester blend were applied to stabilize the nanosystems. All formulations were obtained by a high energy method, using an ultrasonic device (Labsonic U, an ultrasound homogenizer). Variations in the emulsification parameters were tested, including surfactants concentration, pre-emulsification time, ultrasound power and sonication time. On the basis of statistical analysis (experimental design, cluster analysis, classification and regression trees) the best emulsification process parameters were determined. In order to verify the results of statistical analysis, once more an experimental study was conducted. The results obtained confirmed that statistical analysis can be a useful method in determining the conditions for obtaining stable nanoemulsions with desired properties. Formulations obtained with the use of Silybum marianum seed oil were characterized by long-term stability, a low polydispersity index, low viscosity and an average droplet size less than 200 nm.     

Effects of Sorbitan Monostearate and Monooleate on the Crystallization and Consistency Behaviors of Cocoa Butter

The crystallization behavior of cocoa butter (CB) is the essential structuration issue in the development of chocolate products. An alternative to modify and control the crystallization patterns of CB in chocolate production is the incorporation of specific emulsifiers in their formulations. In this work, the effects of sorbitan monostearate (SMS) and sorbitan monooleate (SMO) in the crystallization and consistency behaviors as well as on the microstructure of CB were evaluated. CB samples at three different concentrations (0.5, 1.0 and 1.5 % w/w) of SMS and SMO were prepared and their main physical–chemical attributes determined. CB added with 1.5 % of SMS showed the largest effects with a sharp increase in the onset of the crystallization temperature (from 19.3 to 23.8 °C) and doubling the yield value (consistency) of pure cocoa butter. The classic two-step isothermal crystallization behavior and morphology of CB were also modified with the addition of SMS. A possible explanation based on the solubility of SMS in an organic medium and its ability of self-assembling was suggested as a mechanism for SMS performance in CB. SMS was considered as a potential crystal modifier for CB by changing its crystal structure and enhancing its thermal resistance—factors that favor the use of this emulsifier in the production of improved thermally stable chocolates.     

Technological Aspects of Nanoemulsion Formation of Low‐Fat Foods Enriched with Vitamin E by High‐Pressure Homogenization

Formation of a low‐fat oil‐in‐water (O/W) nanoemulsion enriched with vitamin E using the nonionic surfactant Tween 40 is studied by means of a high‐pressure homogenizer. The effect of different process variables of the emulsification process, including pressure, temperature, and concentration of the emulsifying agent, is evaluated. The relation between pressure and the obtained mean droplet diameter is derived and described by an equation which can be taken as a basis of any process design. The droplet size can be decreased by increasing the vitamin E concentration. A higher fat content slightly affects the droplet size distribution and the mean droplet diameter of the nanoemulsion, so it is recommended to use preparations of nanoemulsions with low fat contents enriched with vitamin E for dietary supplement.     

Dishwashing performance of mixed palm stearin sulfonated methyl esters and polyoxyethylene sorbitan esters

The detergency profiles of sodium salt α-sulfonated methyl esters derived from palm stearin (α-SMEPS) and polyoxyethylene (20) sorbitan monoesters (POESE) in mixed micelle systems were evaluated as a function of the weight ratios of α-SMEPS/POESE [polyoxyethylene (20) sorbitan monolaurate (12), polyoxyethylene (20) sorbitan monostearate (18∶0), and polyoxyethylene (20) sorbitan monooleate (18∶1)] at different water hardness values (5.12, 51.2, and 512.0 ppm CaCO₃) and temperatures (20, 30, 45, and 65°C), respectively. All the mixtures of α-SMEPS/POESE (12, 18∶0, and 18∶1) systems exhibited a synergistic effect at 65°C in the absence of hardness. This was evaluated by measuring the percentage of soil removed. The systems showed an increase in detergency with both the temperature and water hardness. Maximal detergency was observed with 5.12 ppm CaCO₃ in the mixed surfactant solution.     

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.     

页岩储层保护用O/W纳米乳液的制备

针对钻井液滤液侵入页岩储层极易导致严重的水敏损害及液相圈闭损害问题,采用两步稀释法研备出粒径极小、分散性好且长期稳定的页岩储层保护用水包油(O/W)纳米乳液。选取Gemini季铵盐型表面活性剂GTN、Tween80与正丁醇三者复配作为表面活性剂组分(记为S+A),通过室内实验研究了水相中NaCl质量分数对NaCl溶液/(S+A)/正辛烷体系微乳液特性的影响,考察了微乳液相转变温度(PIT)、制备方法及其微观构型等因素对采用两步稀释法制备的纳米乳液粒径的影响,同时对纳米乳液体系的失稳机理进行研究。结果表明,NaCl溶液/(S+A)/正辛烷体系微乳液中NaCl的加入可以显著提高表面活性剂组分的乳化效率,改变微乳液微观构型,使PIT显著降低;当剂油体积比(R_os)为7:3时,通过调节双连续微乳液的PIT接近实验乳化温度,采用两步稀释法制备的O/W纳米乳液粒径最小且分布范围最窄;NaCl溶液/(S+A)/正辛烷体系纳米乳液主要失稳机理为奥氏熟化;纳米乳液具有良好的储层保护作用。     

Development,rheological properties,and physical stability of d‐limonene‐in‐water emulsions formulated with copolymers as emulsifiers

This contribution reports the development of 30 wt % d ‐limonene‐in‐water emulsions formulated with a biopolymer (gellan gum) as stabilizer and prepared with a high‐pressure homogenizer. The role as emulsifiers of different ratios of amphiphilic copolymers (Atlas^TMG5000 and Atlox^TM4913) was assessed. The results indicated that the ratio of emulsifiers had significant effect on the physical stability, droplet size, viscoelasticity, and viscosity of these emulsions. The mean droplet diameters decreased as Atlas^TMG5000 concentration increased from 1 wt % to 3 wt %. The aging of emulsions resulted in an increase in the size of droplets for the emulsions containing high Atlox^TM4913 copolymer content. An increase of Atlas^TMG5000 enhanced both the G′ and G″ values and the viscosity providing higher stability to emulsions. Gellan gum caused in viscoelastic moduli weaker frequency dependence at the lower frequencies, according to the formation of a faint gel‐like matrix. All emulsions exhibited shear thinning flow properties that fitted the power‐law equation. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43838.     

Synthesis and characterization of polymerizable epoxy resin surfactants

Polymerizable epoxy resin (PER) surfactants have been prepared from the reaction of bisphenol A epoxy resin with acrylic acid, followed by the reaction with polyethylene glycol (PEG) with different molecular weights. The reaction procedures were monitored by chemical titrations, infrared spectroscopy, and NMR. The products show typical surface‐active properties as but much higher water solubility than nonpolymerizable nonionic surfactant OP‐10. With the increase of PEG's molecular weight, the HLB value, the water solubility, and the critical micellar concentration (CMC) of the PER surfactants, the cloud point of the PER surfactant solutions, as well as the solubilization capability of the PER surfactants to organic compounds increase under the experimental conditions. The copolymerization under UV radiation indicated that about 75–80 wt % of PER surfactants participated in the copolymerization with epoxy diacrylate (EdA), except for the PER surfactant with the lowest PEG molecular weight of 1 k. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42598.     

Gravity induced coalescence in emulsions with high volume fractions of dispersed phase in the presence of surfactants

We report studies on the effect of volume fraction and surfactant concentration on the kinetics of destabilization of emulsions under the influence of gravity. Model oil‐in‐water emulsions, designed to mimic crude oil–water emulsions, were prepared with varying volume fractions of dispersed oil but nearly identical normalized initial drop size distributions. The gravity separation process was observed by periodically withdrawing samples, and examining the droplet size distribution under the microscope. Experiments were performed for three volume fractions of dispersed phase and two surfactant concentrations (0.4 and 1.6% by weight). At higher oil fractions (20%) and a lower surfactant concentration (0.4%), it was observed that although the rate of coalescence increased, the actual oil separation was delayed. At higher surfactant concentrations (1.6%), the dominant factor in suppressing destabilization is the rate of drop to interface coalescence. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4379–4389, 2017     

Feasibility study of water as thinner for polyvinyl chloride plastisol

In the traditional formula of polyvinyl chloride (PVC) gloves, the diluent of PVC plastisol is usually organic solvent, which causes serious environmental pollution during the molding process. The aim of this study was to develop a low viscosity PVC plastisol emulsion (PDE) using water as a thinner by blending PVC emulsion (PVCE) with diisononyl phthalate (DINP) emulsion. DINP emulsion (DINPE) was prepared by a compound emulsifier of polyoxyethylene octyl phenol ether-10 and sorbitan monooleate. The effects of compound emulsifier concentration on the stability and microstructure of DINPE were investigated. The results showed that the optimal compound emulsifier concentration of DINPE was 10 wt%. In addition, the PDE obtained by blending exhibited a relatively uniform unimodal droplet size distribution. The steady state data revealed that the emulsions were shear-thinning pseudoplastic liquid. The effect of solid content and temperature on the apparent viscosity of PDE were also evaluated. The mechanical spectra obtained suggested the presence of weak gel structure in the PDE. The mechanical test results showed that the tensile strength and elongation at break of PVC film obtained by PDE were 12.62 MPa and 310.31%, respectively. This study demonstrated that water was effective in reducing the viscosity of PVC plastisol, which would promote the application of water thinner in glove production.     

Stability of Oil-in-Water Emulsions with Sunflower (Helianthus annuus L.) and Chia (Salvia hispanica L.) By-Products

Emulsifiers and stabilizers play an important role in emulsion stability. Optical characterization and droplet size distribution of oil‐in‐water emulsions formulated with different types and concentrations of modified sunflower lecithin [phosphatidylcholine (PC) enriched lecithin and deoiled sunflower lecithin], with or without chia mucilage (0.75 % wt/wt), have been evaluated as a function of storage time at 4 ± 1 °C. Emulsions with PC‐enriched lecithin (without chia mucilage) exhibited the highest stability at the different concentrations because of the high PC/phosphatidylethanolamine ratio in comparison to Control lecithin. The addition of 0.75 % wt/wt mucilage contributed to obtain stable emulsions for all type and concentrations of emulsifiers studied, mainly with PC‐enriched lecithin due to the reduction of the mobility of oil particles by the formation of a tridimensional network.     

Physicochemical Investigation of Biocompatible Mixed Surfactant Reverse Micelles: III. Aqueous NaCl Solubilization, Thermodynamic Parameters of Desolubilization Process and Conductometric Studies

Solubilization of water and aqueous NaCl in mixed reverse micelles (RMs) comprising sodium bis(2‐ethylhexyl) sulfosuccinate (AOT), and polyoxyethylene (20) sorbitan trioleate or polyoxyethylene (20) sorbitan monooleate has been studied at different compositions (X_nonionic = 0–1.0) at a total surfactant concentration, S_T = 0.10 × 10³ mol m^?3 in biocompatible oils of different chemical structures; viz., ethyl oleate (EO), isopropyl myristate (IPM) and isopropyl palmitate (IPP) at 303 K. The enhancement in water solubilization (i.e., synergism) has been evidenced by the addition of nonionic surfactant to dioctyl sulfosuccinate/oil(s)/water systems. Addition of NaCl in these systems at different X_nonionic enhances their solubilization capacities further until a maximum, ω_NaCl,max is reached. ω_NaCl,max and [NaCl]_max (concentration at which maximization of NaCl solubilization occurs) depend on type of nonionic surfactant, its content (X_nonionic) and oil. A new solubilization efficiency parameter (SP*_water or SP*_NaCl) has been proposed to compare solubilization phenomena in these oils. The energetic parameters of the desolubilization process of water or aqueous NaCl in single and mixed RMs have been estimated. Energetically, the water dissolution process in oil has been found to be more exothermic as well as more organized in IPP. Overall, the dissolution of water and aqueous NaCl in mixed RMs is entropically driven process. Conductance behavior of these systems in the presence of NaCl has been investigated under different [NaCl] at 303 K. An attempt has been made to give an insight to the mechanism of solubilization phenomena, percolation in conductance and microstructures vis‐à‐vis role of biocompatible oils in these systems.