Water In Microemulsions Research Articles

Preparation of allyl isothiocyanate nanoparticles, their anti-inflammatory activity towards RAW 264.7 macrophage cells and anti-proliferative effect on HT1376 bladder cancer cells.

Allyl isothiocyanate (AITC), a volatile and water-insoluble compound present in several cruciferous vegetables, has been shown to possess several biological qualities such as anti-bacterial, anti-fungal, and anti-cancer activity. In this study, water-soluble allyl isothiocyanate nanoparticles (AITC-NPs) were prepared by oil dispersed in water (O/W) microemulsion and complex coacervation techniques and evaluated for their anti-inflammatory activity towards macrophage cell RAW 264.7 and anti-cancer effect on human bladder cancer cell HT1376. The AITC-NPs with a particle size of 9.4 nm were stable during heating up to 110 °C or three freeze-thawing cycles. No significant cytotoxicity was shown on Caco-2 and intestine epithelial IEC-6 cells at AITC-NP doses ranging from 0.25 to 2 g L-1 (8.75-70 mg L-1 AITC). However, at 2 g L-1 dosage, AITC-NPs could inhibit the growth of human bladder cancer cells HT1376 by 90%, while their low dosage at 0.25 g L-1 could inhibit migration ability by 83.7, 71.3, 58.4 and 31.4% after 4, 8, 12, and 24 h of incubation, respectively. Compared to AITC and NPs, AITC-NPs showed a better inhibition on lipopolysaccharide (LPS)-induced TNF-α, IL-6, NO and iNOS production in RAW 264.7 macrophage cells. The results demonstrate the potential of AITC-NPs as therapeutic agents for the treatment of bladder cancer and the enhancement of immune function. © 2018 Society of Chemical Industry.

Preparation and surface modification of magnesium hydroxide in a cetyltrimethyl ammonium bromide/isopropanol/cyclohexane/water microemulsion

A scalable technique for controlled synthesis and surface modification of magnesium hydroxide using the microemulsion method at room temperature was studied. The magnesium hydroxide nucleation and growth were carried out in numerous identical nanoreactors formed by cetyltrimethyl ammonium bromide/isopropanol/cyclohexane/water microemulsion. The crystal structure, morphology, thermostability and surface performance of the product as flame-resistant material were investigated by X-ray diffraction, scanning electron microscopy, thermogravimetry/differential scanning calorimetry, fourier transform infrared spectroscopy and dispersion tests. The results indicated that the product had a flake structure and belonged to a hexagonal system, the highly defined nanoflakes had a uniform diameter, and the diameter size can be well controlled in the range of 40–65 nm by adjusting the ratio of water to surfactant. The thermostability analyses showed a narrowed decomposition temperature range. Furthermore, the surfactant in microemulsion was adsorbed on the particles surface, making the surface of magnesium hydroxide changed from hydrophilic to lipophilic. Therefore the reported magnesium hydroxide material has a better flame resistance and compatibility with polymer materials than conventional magnesium hydroxide.

Full Tetragonal Phase Stabilization in ZrO₂ Nanoparticles Using Wet Impregnation: Interplay of Host Structure, Dopant Concentration and Sensitivity of Characterization Technique.

Here, we show that wet impregnation of ZrO2 nanoparticles with 10% and 20% Eu oxide followed by thermal anneal in air above 500 °C produces full stabilization of the tetragonal phase of ZrO2 without evidencing any phase separation. The bare ZrO2 nanoparticles were obtained using three synthetic methods: oil in water microemulsion, rapid hydrothermal, and citrate complexation methods. The homogeneity of the solid solutions was assessed using X-ray diffraction, Raman spectroscopy, high resolution transmission electron microscopy, and advanced luminescence spectroscopy. Our findings show that wet impregnation, which is a recognized method for obtaining surface doped oxides, can be successfully used for obtaining doped oxides in the bulk with good homogeneity at the atomic scale. The limits of characterization technique in detecting minor phases and the roles of dopant concentration and host structure in formation of phase stabilized solid solutions are also analyzed and discussed.

Self‐healing waterborne polyurethane coating by pH‐dependent triggered‐release mechanism

ABSTRACTIn this study, effect of high‐loaded silica capsules with corrosion inhibitor on thermal degradation and self‐healing properties of waterborne polyurethane (WPU) was investigated. Silica capsules were synthesized using an oil in water (O/W) microemulsion and WPU was prepared via the prepolymer method. Assembled capsules demonstrated pH dependent release of their core. Incorporating silica capsule as an inorganic component resulted to improve thermal and barrier properties of WPU coatings. WPU coating with 1% silica capsules demonstrated better barrier quality in corrosive media and adding more than that resulted a rapid deterioration in barrier properties. Furthermore, such coatings possess an excellent adhesive strength with steel substrate. Electrochemical impedance spectroscopy was used in corrosion monitoring and healing procedure. Moreover, capsule morphology and thermal degradation of the WPU coating has been investigated separately by scanning electron microscopy and thermal gravimetric analysis. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47082.

Synthesis of Ni/CaO-γ-Al2O3@Ru Core Shell via Micro-Emulsion Method for Bio-oil Steam Reforming of Empty Fruit Bunch

Hydrogen production from bio-oil steam reforming plays an important role in the development of renewable hydrogen from biomass to produce the cleanest fuel. However, the existence of coke and low carbon conversion are problems that have been found in some studies. The purpose of this study was to reduce coke formation and to enhance carbon conversion by using core shell nanoparticle catalysts that could increase of surface area, support interaction and its catalytic activity for hydrogen production from bio-oil steam reforming of empty fruit bunch (EFB). Ni/CaO-γ-Al2O3@Ru core shells were prepared by CTAB/n-hexanol/n-hexane/water micro-emulsion system. The catalysts were characterized by means XRD, BET, FESEM-EDS and TEM. Bio-oil aqueous fraction was analyzed by using GC-MS. Carbon conversion and hydrogen yield by using Ni/CaO-γ-Al2O3@Ru core shell are resulted more 68.4 % and 18.6% than using Ni/CaO-γ-Al2O3 catalyst, respectively. The highest hydrogen yield by using Ni/CaO-γ-Al2O3@Ru core shell for steam reforming bio-oil is 5.6% in minute 10 with 0.07 g of coke deposit. The study concludes that the effect of Ni/CaO-γ-Al2O3@Ru core shell is more efficient in hydrogen production, carbon conversion and coke deposit compared to Ni/CaO-γ-Al2O3 catalyst

Synthesis of MgO/TiO2 Nanocomposite and Its Application in Photocatalytic Dye Degradation

AbstractThe application of nanoparticles in dye degradation is one of the trending arenas of research in the present day world. In this work, we report a novel route to synthesise MgO/TiO2metal oxide nanocomposite by microemulsion technique and its application in photocatalytic dye degradation. Oil in water microemulsion was prepared using Span 80 and Tween 80 as surfactants whose proportion was regulated using hydrophilic and lipophilic Balance (HLB). The obtained microemulsion was then mechanically stirred and calcined to obtain the nanocomposite. The as-prepared nanocomposites were characterized using X Ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The prepared nanoparticles exhibited remarkable potential to degrade azo dye (Methyl red) under UV-Visible light irradiation. The effect of catalyst in the degradation was studied for different concentrations of dye (20, 40, 60, 80, 100 mg/L) and different loadings of the catalyst (0.4, 0.6, 0.8, 1.0, 1.2 g/L) so as to determine the optimum catalyst load. The consistency of the obtained data was compared with the first order reaction rate expression. Quasi steady state model was used in fitting the data and the kinetic constants were evaluated. Also, the degradation efficiency of MgO/TiO2nanocomposite was compared with the degradation efficiency of TiO2nanoparticles synthesized by microemulsion method.

The preparation and use of p(2-acrylamido-2-methyl-1-propanesulfonic acid)-tris(dioxa-3,6-heptyl)amine (p(AMPS)-TDA-1) ionic liquid microgel in hydrogen production

Microgels of polymeric ionic liquid (PIL) combine the advantages of the both ionic liquids and polymeric microgels. The microgel in this work was prepared from 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) treated with tris(dioxa-3,6-heptyl) amine (TDA-1) (p(AMPS)-TDA-1), synthesized in a water in oil micro-emulsion via photo-irradiation, with a wavelength of 420 nm, for 2 h. The synthesized p(AMPS)-TDA-1 PIL microgels were then characterized via microscope, scanning electron microscope, Fourier transform infrared spectrometer, thermogravimetric analyzer, and zeta potential measurements. Applications of these PIL microgels were also investigated by using p(AMPS)-TDA-1 PIL as a template for in situ Co and Ni metal nanoparticle preparation and as a catalyst in the hydrolysis of NaBH4 for H2 production. The potential for p(AMPS)-TDA-1 PIL microgels as metal-free catalyst in the methanolysis of NaBH4 for H2 generation was explored as well. It was found that the metal-free p(AMPS)-TDA-1 PIL microgel displayed superior catalytic activity in methanolysis of NaBH4 reaction with a hydrogen generation rate (HGR) of 854 ± 51.6 mL H2/(min g of catalyst) and very low activation energy (Ea), 14.3 kJ/mol Ea. Reusability tests on the p(AMPS)-TDA-1 PIL microgel as a metal-free catalysis showed promising results; At end of the 10th trail, no decrease in the 100% conversion was observed with only 14% decrease in activity.

Isophorone Diisocyanate (IPDI) Microencapsulation for Mono-Component Adhesives: Effect of the Active H and NCO Sources.

Polyurea/polyurethane (PUa/PU) shell microcapsules (MCs), containing high loadings of isophorone diisocyanate (IPDI) in the core, were developed to enable the production of mono-component, eco-friendly and safer adhesive formulations for the footwear industry. IPDI microencapsulation was obtained via oil–in–water (O/W) microemulsion combined with interfacial polymerization. A methylene diphenyl diisocyanate (MDI) compound (a commercial blend of monomeric and polymeric species), with higher reactivity than IPDI and low viscosity, was added to the O phase to competitively contribute to the shell formation, improving its quality. Four different active H sources were tested, aimed at achieving a high encapsulation yield. The successful encapsulation of IPDI was confirmed by Fourier transformed infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA), while the MCs’ morphology and size distribution were assessed by scanning electron microscopy (SEM). The incorporation of a multifunctional isocyanate silane in the O phase, as “latent” active H source, led to the formation of impermeable PUa/PU-silica hybrid shell MCs with more than 60 wt.% of pure encapsulated IPDI. A proof-of-concept study shows high peeling strength and a structural type of failure of the adhesive joint, revealing an effective IPDI release. These new engineered MCs are found to be promising crosslinkers for mono-component adhesives for high demanding applications.

Electrochemistry in Reverse Microemulsions and the Concentration of the Electroactive Probe

Introduction Reverse microemulsions are homogeneous dispersion of water droplets (1 to 100 nm diameter) in an oil, stabilized by a surfactant. In order to improve their stability, aliphatic alcohols (cosurfactants) are often added to the microemulsions1 . Among the different applications of the microemulsions, the use as a reaction media to synthesize nanoparticles has attracted attention in the last decade2 . Since the size and shape of nanoparticles are directly affected by those of the water droplets in the reverse microemulsions3 , the characterization of the reverse microemulsion is necessary. Among the techniques to characterize a reverse microemulsion, cyclic voltammetry has been proposed as an alternative. For this, it is considered that, in most of the cases, the electroactive probes are insoluble in the oil phase, and accordingly the current will depend on the concentration and the diffusion towards the electrode of the water droplets4 and on the concentration of the probe as well. It is important to point out that in order to obtain reliable results for other systems, the concomitant contribution of these factors must be comprehended. For this, a proposal is founded on: i) the concentration ratio water/surfactant determines the size, and hence the diffusion of the water droplets 5,6 ii) the occupancy number, defined as the number of probe units per water droplets in the reverse microemulsion7 . In this work, the effect that both variables have on the electrochemical behavior of reverse microemulsions is studied. The results suggest that cyclic voltammetry can be used as a characterization method of reverse microemulsions as long as these variables are considered. Methodology Hexadecyltrimethylammonium tosilate (CTAT), n-pentanol, hexanes, potassium ferricyanide and double distilled water were used as received. A platinum microelectrode (25 µm diameter) was used as working electrode, a platinum foil as counter-electrode and a platinum wire as pseudo-reference electrode. The cyclic voltammetries were performed in a potentiostat PGSTAT 128N. The sweep rate was varied between 2 and 5 mV/s. Results It has been proposed that the limiting current in a reverse microemulsion decreases as the water content increases, this is because the droplets are the carriers of the electroactive probe and as they grow they diffuse slower, therefore the electrical current declines as the water content increases. Contrary to the expected, the limiting current clearly has a positive slope, see figure 1, passing through a maximum that changes its location with the amount of the aqueous phase and the probe concentration. As reported in the literature, the parameter that links these two variables is known as the occupancy number, and its physical meaning is the average number of ions contained by each droplet. But in order to choose the best concentration of the probe to be used in the characterization of the reverse microemulsion it is necessary to understand the correlation between the water content, the probe concentration, the occupancy number and the limiting current. Conclusions The limiting current measured in a reverse microemulsion depends on the concomitant effect of the diffusion of the water droplets and the occupancy number. Figure 1. Limiting current as function of the water content for two different concentrations of potassium ferricyanide Bibliography (1) Moldes, Ó. A.; Morales, J.; Cid, A.; Astray, G.; Montoya, I. A.; Mejuto, J. C. Electrical Percolation of AOT-Based Microemulsions with N -Alcohols. J. Mol. Liq. 2016, 215, 18–23.(2) Gutiérrez-Becerra, A.; Martínez-Martínez, F.; Bárcena-Soto, M.; Casillas, N.; Ceja, I.; Prévost, S.; Gradzielski, M.; Escalante, J. I. Direct Synthesis of Different Metal Hexacyanoferrate Nanoparticles in Reverse Microemulsions by Using a Ferrocyanide Functionalized Surfactant. Colloids Surfaces A Physicochem. Eng. Asp. 2014, 444, 63–68.(3) Lemyre, J.-L.; Ritcey, A. M. Synthesis of Lanthanide Fluoride Nanoparticles of Varying Shape and Size. Chem. Mater. 2005, 17 (11), 3040–3043.(4) Charlton, I. D.; Doherty, A. P. Electrochemistry in True Reverse Micelles. Electrochem. commun. 1999, 1 (5), 176–179.(5) Martínez-Martínez, F.; Gutiérrez-Becerra, A.; Casillas, N.; Gradzielski, M.; Escalante, J. I.; Bárcena-Soto, M. Characterization of Reverse Microemulsion Formed with Functionalized Surfactants Based on Ferrycianide Ions. Colloids Surfaces A Physicochem. Eng. Asp. 2018, 541 (January), 10–16.(6) Giustini, M.; Palazzo, G.; Colafemmina, G.; Monica, M. Della; Ceglie, A. Microstructure and Dynamics of the Water-in-Oil CTAB / N-Pentanol / N-Hexane / Water Microemulsion : A Spectroscopic and Conductivity Study. J. Phys. Chem. 1996, 100 (8), 3190–3198.(7) Florez Tabares, J. S.; Correa, N. M.; Silber, J. J.; Sereno, L. E.; Molina, P. G. Droplet–droplet Interactions Investigated Using a Combination of Electrochemical and Dynamic Light Scattering Techniques. The Case of water/BHDC/benzene:n-Heptane System. Soft Matter 2015, 11 (15), 2952–2962. Figure 1

Nanocomposites of Polyaniline with Silver Nanoparticles Prepared Using Water in Oil Microemulsions as Antibacterial Agents

Polyaniline (PAni) was synthesized by chemical oxidative polymerization of aniline monomer by ammonium peroxydisulfate using w/o microemulsion and from aqueous solution. Ag/PAni nanocomposites were then prepared using w/o microemulsion by the same polymerization method in pre‐formed Ag nanoparticles prepared by the reduction of metal salts in microemulsion. PAni and Ag/PAni nanocomposites were characterized by UV‐visible and Fourier transform infrared (FTIR) spectroscopy. Dynamic light scattering (DLS) results and scanning electron microscopic (SEM) SEM images showed that PAni synthesized in microemulsion was smaller in particle dimension than that obtained from the bulk. Thermogravimetric analysis (TGA) results showed that PAni from microemulsion has a lower thermal stability than PAni from bulk synthesis. Ag/PAni nanocomposites, however, showed somewhat better thermal stability compared to that of PANI from microemulsion. The antibacterial properties against Gram‐negative, Escherichia coli and Gram‐positive, Staphylococcus aureus were tested by zone of inhibition method and the results demonstrated that Ag/PAni nanocomposites have enhanced antibacterial efficiency compared to PAni generated in microemulsion which is more efficient than PAni prepared from aqueous solution.

Fabrication of Magnetically Stirrable Anisotropic Microparticles via the Microfluidic Method

AbstractA one‐step strategy to fabricate magnetically stirrable microparticles with geometric/chemical anisotropies via a microfluidic technique combined with partial phase separation is presented. Monodisperse oil‐in‐water microemulsions composed of magnetite nanoparticles (MNPs) and two polymers, polystyrene and poly(d,l‐lactide‐co‐glycolide) (PLGA), dissolved in chloroform are generated using the microfluidic method. Upon incubating the microemulsions in pure water at ambient conditions, the solvent contained in the microemulsions is gradually removed and partial phase separation between the two polymers occurs spontaneously. In the meantime, the microemulsion droplets are vertically aligned due to the density difference of the two polymer phases. During the spontaneous phase separation, the MNPs become unstable and the aggregated MNPs segregate downward by gravity to the denser PLGA phase. After complete removal of the solvent, the resulting particles adopt geometric/chemical anisotropies, and they are magnetically rotatable under an external magnetic field. It is demonstrated that the morphology of the anisotropic particles can be controlled readily by adjusting the ratio of the two polymers as well as the concentration of MNPs. It is believed that the developed method based on the partial phase separation and the gravity‐induced segregation of the MNPs enables large‐scale production of magnetically stirrable microparticles.

Fabrication of benzylisothiocynate encapsulated nanoemulsion through ultrasonication: Augmentation of anticancer and antimicrobial attributes

The present work has been conceded with an observation to support the inherent advantages of nanoemulsions over microemulsions. This simply involves comparison of the difference in the synthesis of two formulations. Firstly, lemon oil/miglyl 812, oil in water and water in oil microemulsions were synthesized using tween 80 as a stabilizer. Secondly, the same formulation was used for the preparation of nanoemulsions. However, low concentration of Tween 80 failed to stabilize the nanoemulsion with simple stirring, shaking etc. Therefore, non toxic surfactant decyl-β-d-glucopyranoside was incorporated in the nanoformulation. Further, high energy ultrasound was utilized in the fabrication of nanoemulsion. The average size of nanoemulsion and microemulsion was found to be 31.68 ± 1.78 nm and 20.98 ± 2.88 nm, respectively. After the successful comparison of the systems, nanoemulsion was chosen for further study for encapsulation of Benzylisothiocynate. The system was characterized at pH (2−12) and various salt concentrations (0–500 mM) for 60 days. Time kill kinetics revealed that benzylisothiocynate nanoemulsion has stronger antibacterial/antifungal activity as compared to pure nanoemulsion. The cell viability of developed formulation tested on MDA-MB 231 cell lines have been found to be non toxic below concentration 4 μg/ml.

N-cyanoethyl polyethylenimine as a water-soluble binder for LiFePO4 cathode in lithium-ion batteries

N-cyanoethyl polyethylenimine (CN-PEI) is synthesized by modifying polyethylenimine (PEI) with acrylonitrile through a Michael addition reaction. Depending on cyanoethylation level, CN-PEI can be obtained as a form of solution, micro-emulsion or emulsion in water. CN-PEI micro-emulsion is investigated as water-soluble binder for the application of lithium iron phosphate (LFP) cathode in lithium-ion batteries. CN-PEI binder not only maintains the outstanding dispersion capability of PEI but also exhibits an excellent adhesion strength and higher ionic conductivity because of the introduction of polar cyano groups. As a result, CN-PEI binder can effectively maintain the mechanical integrity and decrease the polarization of LFP electrode during the operation of the battery. LFP electrode with CN-PEI binder exhibits good cycle stability and enhanced rate performance delivering a capacity of 99.6% at a rate of 0.5 C after 100 cycles and a high discharge capacity of 102.4 mAh g−1 at 5 C.

Effective charges and zeta potentials of oil in water microemulsions in the presence of Hofmeister salts.

We present a theory which allows us to calculate the effective charge and zeta potential of oil droplets in microemulsions containing Hofmeister salts. A modified Poisson-Boltzmann equation is used to account for the surface and ion polarizations and hydrophobic and dispersion interactions. The ions are classified as kosmotropes and chaotropes according to their Jones-Dole viscosity B coefficient. Kosmotropes stay hydrated and do not enter into the oil phase, while chaotropes can adsorb to the oil-water interface. The effective interaction potentials between ions and oil-water interface are parametrized so as to accurately account for the excess interfacial tension.

Food-grade Water in Oil Microemulsion as a Potential Approach for Tea Polyphenols Encapsulation

Abstract Food-grade water in oil (W/O) microemulsions were developed and characterized in order to use them as potential tea polyphenols (TP) carriers. The physicochemical characteristics of microemulsions (TP-loaded and blank microemulsions) were investigated by rheological measurements, differential scanning calorimetry (DSC), dynamic light scattering (DLS) and 1H nuclear magnetic resonance (1H NMR). The thermal behavior of the microemulsion system implied that the water molecules were competitively bound. Chemical shift patterns for all samples were not sensitive to the addition of TP. The microscopic images showed that both the non-loaded and the TP-loaded microemulsions had a spherical shape, in particular the TP-loaded microemulsions had a specific core-shell morphology. TP solubilized in the microemulsions was much more stable than that dissolved in water solution. The release process of TP in water solution was faster than that of microemulsions.

Studying the morphological features of plasma treated silver and PEGylated silver nanoparticles: antibacterial activity

A strategy to treat the silver and PEGylated silver nanoparticles with plasma was being purposed. Oil in water (o/w) microemulsion method was used for the synthesis of Ag nanoparticles (AgNPs). Polyethylene glycol (PEG) having molecular weight 600 was used to coat the surface of AgNPs. Optical emission spectroscopy (OES) was used to characterize the plasma and it is noted that plasma treatment is useful to modify the structural characteristic of silver nanoparticles. The nanoparticles were treated with helium-oxygen mixture plasma, generated in plasma needle at atmospheric pressure. Both AgNPs and PEGylated AgNPs before and after plasma treatment were characterized by x-rays diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The crystallite size of silver nanoparticles after the treatment of plasma decreases from 71 nm to 27 nm. The SEM micrographs show that the size of Ag nanoparticles was nearly 118 nm whereas the thickness of the silver needle was around 135 nm. All the characteristics IR bands associated to the silver nanoparticles were detected. The FTIR spectrum also support the accumulation of OH radicals in the plasma treated samples. The samples before and after plasma treatment were screened against Gram positive (Bacillus Subtilis and Staphylococcus Aureus) and Gram negative (Escherichia Coli and Pseudomonas Aeruginosa) bacteria. The promising response was detected when plasma treated PEGylated AgNPs was tested against bacterial strains.

Formulation and Extension of Diesel-Based Microemulsion Fuels for Compression Ignition Engines

There is a need for sustainable alternative fuels which can address and alleviate both economical and environmental issues. The current work is based on alcohol–diesel–water microemulsion fuels. Microemulsions are thermodynamically stable and isotropic dispersions of oil, water, and an amphiphile. Diesel is used as the oil phase in microemulsion while water in it reduces the combustion temperature which, in turn, reduces the NOx and smoke emissions. In this work, an alcohol has been used, that acts both as a surfactant and a co-surfactant, thereby making the process facile and economical. The microemulsion regions are mapped out in ternary phase diagrams. The initial measurements suggest that the microemulsions have a higher calorific value, and lesser soot and residue formation as compared to that with neat diesel. The microemulsions also have properties such as density, viscosity, flash and fire points, and cloud and pour points close to those of neat diesel. The effect of various ionic and non-ionic surfactants on the extent of microemulsion region has also been studied. Hydrophilic surfactant expands the microemulsion domain while hydrophobic surfactant shrinks the same. Cationic surfactant does not have much influence on the microemulsion domain, while an anionic surfactant surprisingly does not yield any microemulsions by the current methodology.

Optimization of Novel Oil Extraction Technique From Canola Seeds: Lecithin‐Based Microemulsion

Nowadays, solvent (hexane) based oil extraction is a widely used commercial technique and there are a number of environmental, economic, and health related concerns. Overcoming such serious issues is driving research to develop alternative safe methods. In the present study, a novel technique, using lecithin‐based microemulsion system, is developed for canola oil extraction. At first, pseudoternary phase diagrams of canola oil/lecithin/propanol/water microemulsions are constructed and the effect of temperature on microemulsion formation was evaluated. So that, (lecithin/propanol)/water microemulsion premixes ([2:1]50:50 and [2:3]80:20) are selected for optimization (temperature, exposure time, premix:canola seeds ratio, and agitation rate) of oil extraction from canola seeds using one factor at a time design. Based on “one factor at a time” design, the highest extraction yield (82.6% wt) achieved at 60 °C, 60 min, 6:1 premix:canola seeds ratio without agitation; the premix composition was (lecithin/propanol)/water (2:1)50:50. From quality point of views, the microemulsion‐based extracted oils has lower peroxide value, higher acidity, as well as low phosphorous and lecithin contents in comparison with hexane extracted one. This technique confirms its simultaneous extraction, recovery, and solubilization capabilities which can be used for oil extraction and food formulation.Practical Applications: For many decades, vegetable oils are commonly extracted by mechanical pressing or extraction with solvents such as hexane. Hexane, a highly volatile and flammable solvent which requires expensive equipment for safe operation, is classified as a hazardous air pollutant and occupational exposure to n‐hexane can cause neurological symptoms and other health defects. Overcoming these serious issues is driving research to develop alternative safe methods such as microemulsion technique. This study introduces a novel technique using lecithin‐based microemulsion systems for extraction of edible oils from oilseeds. This technique, as a low energy consuming method, has great potency for being used as a safe and green oil extraction technique which is the developing direction for not only the dominant oil resources but also nutrient lipids which can be easily dissolvable in aqueous food and pharmaceutical formulations.Accurate ratios of canola seeds, lecithin, 1‐propanol and water at a moderate temperature were used to create a nano‐size canola oil lecithin‐based microemulsion which was then simply demulsified at lower temperature in order to separate the extracted oil (see picture). This technique as a low energy consuming, straightforward and environmentally friendly method could be used for solublization and extraction of oil from various sources.

Small-angle X-ray scattering study on nano-scale structures controlled by water content in a binary water/ionic liquid system.

We report the water-in-ionic-liquid microemulsions (ME) formed in a binary water/ionic liquid system, without organic solvents, using a surfactant ionic liquid (SAIL) based on 1-butyl-3-methylimidazolium (C4mIm+) as the cation and dioctyl sulfosuccinate (AOT-) as the anion. Small-angle X-ray scattering (SAXS) revealed that MEs were stably formed in the binary water/SAIL solutions in the low water content region (water volume fraction, φw < 0.1), and the ME size systematically increased with increasing φw. We further investigated the nanostructures of the high φw region using a combination of SAXS and rheological measurements and found that the MEs changed to a stacked lamellar structure comprising SAIL bilayers and water phases at φw > 0.12. At the largest water content, φw = 0.99, vesicle structures were obtained.

Formulation and Penetration Enhancement Activity of Sticks Containing Caffeine

Caffeine is a methyl xanthine alkaloid that has been widely used in cosmetic products as anti-cellulite. Caffeine has a hydrophilic character, thus it has difficulty in penetrating the lipid layer of the skin. The aims of this study were to formulate sticks containing emulsion and microemulsion caffeine (control stick), caffeine emulsions (emulsion stick), and caffeine microemulsion (microemulsion stick) and compare the penetration between them. Caffeine was made in the form of water in oil emulsions and microemulsion then form into sticks-shaped with the lipophilic component. All sticks were physically and chemically evaluated. The penetration of caffeine through Sprague-Dawley rat skin using Franz Diffusion Cell were tested for 12 hours. The penetration result of caffeine from control stick, emulsion stick, and microemulsion stick were 306.42 ± 34.92 µg/cm2, 927.75 ± 57.38 µg/cm2, and 2408.68 ± 81.65 µg/cm2 respectively, with percentage 5.90 ± 0.67%, 12.76 ± 0.78%, and 35.23 ± 1.19%. Physical and chemical stability tests were performed for 8 weeks at room temperature (29±2°C), cold temperature (4±2°C), and hot temperature (40±2°C). Microemulsion stick delivered the highest cumulative amount of caffeine in penetration test for 12 hours, followed by emulsion stick and control stick. Also, all sticks showed physical and chemical relatively stable.