Sorbitan Monooleate Research Articles

Optimization of Polysorbate 80 and Sorbitan Monooleate 80 aas Emulsifiers in Foundation Makeup Containing Ethyl Cinnamate

Cosmetic foundation is a type of decorative makeup and commonly include a sunscreen agent. Ethyl cinnamate is one of the potential organic essential oil sunscreens. Nevertheless, there is little study on ethyl cinnamate usage in cosmetics, particularly oil-in-water foundation cream. Using an emulsifier in oil-in-water foundation cream a higher concentration does not guarantee higher oil phase recovery. However, using two combinations of emulsifier such as polysorbate 80 and sorbitan monooleate 80 with the optimum combination can be the right solution. This study aims to optimize polysorbate 80 and sorbitan monooleate 80 in a cream foundation using ethyl cinnamate as an active ingredient designed to have an effective ability to protect facial skin from ultraviolet radiation and are safe to use. The optimization formulas design of the emulsifier combination in foundation cream was made using the Simplex Lattice Design method with help Design Expert version 10.0.1. Parameter optimization were the value of pH, viscosity, spreadability, adhesion, and Sun Protection Factor (SPF) value. The stability test and skin irritation test of optimum formula were also conducted. As a positive control, Revlon Colorstay Foundation as a brand cosmetic foundation was used (National Food and Drug Agency of Indonesia number : NA18140300519). The optimum ratio of polysorbate 80 and sorbitan monooleat 80 were 9.565 and 1.435 with the physical characteristics of pH 6.478+0.008; viscosity 5844.2+31.82 cPs; spreadability 6.16+0.11 cm; adhesion 3.346+0.14 seconds; SPF Value 22.385+0.48, and no irritation symptoms. The ethyl cinnamate foundation created was physically stable, had a pleasing look, and did not irritate the skin, making it safe to wear. It also provides efficient UV radiation protection.

Enhancement of Flow Properties Biodiesel Using Sorbitan Monooleate

Depletion of fossil fuel and increased pollution caused by the burning of fossil fuel is a leading factor in to use of alternate energy especially palm oil biodiesel as a mixture of diesel oil fuel (B-XX). It was reported that the use of the B-20 caused a blockage in the vehicle’s fuel filter. The blockage is caused by the presence of deposits formed from the agglomeration of monoglycerides. Three different biodiesels with monoglyceride content were used 0.40% - 0.60% by mass. The addition of monoglyceride standards (monopalmitin, monostearin, and monoolein) to biodiesel increases the volume of monoglyceride precipitates formed. The presence of these deposits decreases the flow properties of B-20. Research has been carried out to improve the flow properties of biodiesel by adding Sorbitan Monooleate (CMOST) surfactant, especially cloud points (CP) and cold filter plugging point (CFPP) parameters. The addition of 0.10%w - 1%w CMOST can reduce the CP by 4.80oC and CFPP by 2oC. This proves that the addition of SMO will improve the flow properties of B-XX as an alternative energy.

Preparation and optimization of porous regenerated cellulose microspheres from cellulose tetraethyl-ammonium/urea solution for adsorption of cationic methylene blue dye

Porous regenerated cellulose microspheres (RCMs) have attracted increasing attention due to their wide range of applications from medical carriers to environmental remediation. Here, porous RCMs were synthesized for adsorption of cationic methylene blue dye using a simple emulsification–acid coagulation–oven-drying technique after dissolving pulp cellulose with a degree of polymerization (DP) of approximately 1500 in tetraethylammonium hydroxide (TEAOH)/urea solvents at room temperature. The RCMs with controllable size (20 to 224 µm) and high pore volume (8.24 to 10.20 mL/g) were prepared by varying the dosage of the surfactant polyoxyethylene sorbitan monooleate (polysorbate 80). Moreover, the viscosity of the cellulose solution steadily decreased with storage time due to the decrease in cellulose DP, but the effect on the particle size and morphology of RCMs was negligible, which could be advantageous to the scalable production of RCMs. When used as an adsorbent for cationic methylene blue dye removal, it showed high adsorption efficiency (1 h to achieve equilibrium, 24.5 mg/g), stability, recyclability, and reusability.

Fabrication of Stable Oleofoams with Sorbitan Ester Surfactants.

Sorbitan esters have been extensively used as surfactants to stabilize emulsions in many fields. However, the preparation of an oleofoam with sorbitan ester alone has not been reported. Here, we apply a novel protocol to fabricate stable oleofoams of high air volume fraction from mixtures of vegetable oil and sorbitan ester. To incorporate more air bubbles into the oil matrix, aeration is first carried out in the one-phase region at high temperatures, during which the highest over-run can reach 280%. Due to foam instability at high temperatures, the foam is then submitted to rapid cooling, followed by storage at low temperatures. For high-melting sorbitan monostearate, the resulting foams containing many crystal-encased air bubbles are ultrastable to drainage, coarsening, and coalescence for several months. On the contrary, the cooled foams with low-melting sorbitan monooleate go through a gradual decay lasting for more than 1 month. We highlight the importance of hydrogen bond formation between surfactant and oil in enhancing foam stability. The generic nature of the above findings is demonstrated by preparing oil foams with various vegetable oils and sorbitan monooleate.

Ethylferulate-loaded nanoemulsions as a novel anti-inflammatory approach for topical application

Ethyl ferulate (EF) is a phenylpropanoid with antioxidant and anti-inflammatory activities extracted from essential oil of several plants. However, this compound is immiscible with water. In this study, different nanoemulsion (NE) formulations were prepared and have their physicochemical properties assessed to induce a stable and efficient aqueous colloidal dispersion of drug. The oil-in-water NE samples were selected from the pseudo-ternary phase diagram constructed using soybean oil as oily phase, and a mixture of surfactants composed by polysorbate 80 and sorbitan monooleate. The oil phase containing surfactants was mixed with water using a ultrasonication procedure at 25 °C. The formulation with the smallest and uniformly droplet-sized have the ethyl ferulate-loading in three concentrations (1 %, 2.5 %, and 5 % w/w). Their interactions with compounds of NE were followed using Fourier transform infrared spectroscopy. The samples exhibited an incredible physical stability, even after drug-loading. The NE showed the ability for controlling the drug release. The in vivo experiments with rats demonstrated the biocompatibility of tested formulations, no skin irritation signs were identified. In addition, an efficient reducing of paw edema was observed compared to the used control. The experimental achievements suggest an interesting and promising novel ethyl ferulate nanoemulsion, as a potential drug delivery system to be used for topical anti-inflammatory application.

Sex-specific effects of excipients on oral drug bioavailability

The mechanism of action of excipients eliciting sex differences in drug bioavailability is poorly understood. In this study, the excipients Cremophor RH 40 (PEG 40 hydrogenated castor oil), Poloxamer 188 (2-methyloxirane) and Tween 80 (polyoxyethylene (80) sorbitan monooleate) were screened at 0.07 – 5% concentrations for their effect on ranitidine bioavailability in male and female Wistar rats. We show that all excipient concentrations significantly increased ranitidine bioavailability in male, but not female, rats. The effect of these excipients on the intestinal efflux transporters P-glycoprotein (P-gp), breast cancer resistant protein (BCRP) and multi-drug resistant protein 2 (MRP2) were also monitored. Measured by ELISA assay, in male rats, peak reductions in intestinal P-gp protein expression occurred in the presence of 1% Cremophor RH 40 and Poloxamer 188 and 0.5% Tween 80. In contrast, no distinct changes were observed in female intestinal P-gp expression. Unlike P-gp, all excipients had a positive effect on MRP2 protein expression – albeit only in males – in a concentration-dependent manner. The excipients did not modulate intestinal BCRP protein expression in either sex. Endogenous hormones and a nuclear receptor (testosterone, oestradiol and pregnane X receptor; PXR) that are purported to regulate intestinal efflux membrane transporter expression were also quantified. In the presence of all excipients, testosterone levels significantly elevated in males, although PXR levels reduced at similar rates in both sexes. No significant effects were identified in oestradiol levels in male and female rats. It is clear that excipients are not inert and their pathway for modulating drug response is multi-dimensional and specific between sexes. This study showed that excipients increased drug bioavailability of a P-gp drug substrate due to its reductive effect on intestinal P-gp expression; we propose that this link may be due to the excipients modulating fundamental testosterone levels. Understanding the implication of excipients on intestinal physiology and hormone levels can therefore improve pharmaceutical design, clinical efficacy and instigate next generation personalised, sex-specific formulations.

Surfactant-assisted synthesis of colloidosomes for positional assembly of a bienzyme system

In this study, using sorbitan monooleate (Span-80), we developed a new strategy to achieve the positional assembly of a horse radish peroxidase/glucose oxidase bienzyme system within the zeolitic imidazolate framework-8 (ZIF-8)-based colloidosomes. Span-80 with self-adsorption property, was used as an auxiliary stabilizer to endow the enzyme-loaded ZIF-8 (enzyme@ZIF-8) with proper wettability in the formation of water–in–oil Pickering emulsion templates. Benefited from this, simultaneous immobilization of the bienzymes in the lumen and shell of the colloidosomes could be achieved. Meanwhile, Span-80 was found to act as a mediator to induce and control the overgrowth of the ZIF-8 crystallites on the enzyme@ZIF-8 layers, by which a “bricklaying” solidification protocol was established for the shell preparation. The resulting colloidosomes enabled the flexible positional change of the bienzymes, its shell exhibited the monolayer structure with increased compactness and homogenized micropores. Furthermore, the multi-enzyme cascade reaction was exemplified with the oxidization of o-phenylenediamine. An in-depth investigation showed that the assembly strategies of the bienzymes significantly affected their biocatalytic efficiency by influencing the utilization efficiency of the H2O2 intermediate between the step reactions. This study provides an insight towards a facile synthetic route for constructing multi-enzyme biocatalyst.

Improving the colloidal stability of PEGylated BaTiO3 nanoparticles with surfactants

Barium titanate, BaTiO3, nanoparticles (NPs) have been widely used as a ferroelectric/piezoelectric/ pyroelectric material in the electronic-optical ceramic industry. However, the stability of BaTiO3 NP suspension is a matter of concern for their advanced applications in wet-ceramic manufacturing, imaging, and electrorheological fluids. In this study, we investigated the effect of three different surfactants (sodium dodecylbenzenesulfonate (anionic), cetyltrimethylammonium bromide (cationic), and sorbitan monooleate (non-ionic)) on the stability of PEGylated BaTiO3 nanoparticles in two solvents (water and ethylene glycol) by means of dynamic light scattering, ζ potential, UV–visible spectroscopy, scanning electron microscopy, and visual observation. Our findings indicate that the anionic surfactant acted as the best stabilizer for BaTiO3 nanofluids, while the cationic surfactant was the least favorable stabilizer in both water and ethylene glycol, due to the balance between attraction and repulsive forces. The results of this research provide a simple and effective approach to control and improve the colloidal stability of BaTiO3 nanoparticles.

Encapsulation of black cumin seed (Nigella sativa) oil by using inverse gelation method

Black cumin seed oil (BCO) is an important oil source in the food industry. Alginate capsules with aqueous cores can be made by reversing the gelation technique with alginate and CaCl2. The research aims to investigate the physicochemical properties of the capsules as well as to analyze the storage stability of BCO emulsions (emulgators; polyglycerol polyricinoleate (A) and sorbitan monooleate (B)) coated using the inverse gelation method. The peroxide value in group A increased rapidly on the first day and then declined without any significant difference between the third and sixth days (p > 0.05). The peroxide value of group B increased significantly (p < 0.05) on the first day and then declined like in the other groups. BCO (7.42 ± 0.16) had the lowest p-anisidine value at the beginning with the initial p-anisidine value of encapsulated BCO groups A and B (21.74 ± 0.84 and 11.48 ± 1.31, respectively) having significantly higher (p < 0.05). The reverse gelation technique utilized in this study raised the p-anisidine value while lowering the peroxide value of the seed oil. The shelf life of black seed oil can be increased by using this technique in the industry.

Stabilization of Carbon Nanotubes and Graphene by Tween-80: Mechanistic Insights from Spectroscopic and Simulation Studies.

Polyoxyethylene sorbitan monooleate is commonly used to obtain stable dispersions of nanoparticles (NPs) such as carbon nanotubes (CNTs) and graphene. However, the mechanism underlying dispersion is poorly understood. The present study aimed at investigating the mechanism of stabilization of carbon NPs (CNPs), namely, single-walled CNTs (SWCNTs), multi-walled CNTs (MWCNTs), and graphene, by Tween-80 using attenuated total internal reflection-Fourier transform infrared and nuclear magnetic resonance (NMR) spectroscopy. Molecular dynamics (MD) simulations were performed to identify, at the atomic scale, the significant interactions that underlie the adsorption and the stabilizing effect of Tween-80 on CNPs, in this way corroborating the spectroscopy results. Spectroscopic analysis revealed that the alkyl chain tether to SWCNT, MWCNT, and graphene surface, presumably through π-π interactions between the carbon-carbon double bond in the alkyl chain and the aromatic rings of CNPs. The hydrophilic polyethoxylate chains extend into the aqueous environment and stabilize the suspension by steric hindrance. MD simulations also showed that Tween-80 molecules interact with the CNP surface via the alkyl chain, thus corroborating spectroscopy results. MD simulations additionally revealed that Tween-80 aggregates on the CNP surface shifted from planar to micelle-like with increasing Tween-80 ratios, underscoring concentration-dependent changes in the nature of these interactions.

Phase inversion emulsification of paraffin oil/polyethylene wax blend in water: A comparison between mixed monomeric and monomeric/gemini surfactant systems

• Natural-based gemini surfactant (GS) reduced water surface tension more than Tween80. • Using GS reduced water phase volume fraction at phase inversion point (f w,inv ). • Change in f w,inv with polyethylene was alike change in phases interfacial tension. • Rheological properties of emulsions highly depended on crystallinity of oil phase. • Higher stability of emulsions was achieved by GS due to their higher zeta potential. Despite the environmental attractiveness of phase inversion emulsification, polyethylene wax-based emulsions are prepared by high-energy emulsification methods. In this research, phase inversion emulsification of paraffin oil/high density polyethylene wax (PEW) blend in water was conducted using mixed surfactants systems. Sorbitan monooleate (Span 80) was used as the oil-soluble surfactant, while either polysorbate 80 (Tween 80) or a synthesized sunflower oil-based gemini surfactant (SF6) was utilized as the water-soluble surfactant. In order to conduct phase inversion emulsification, the 85 °C water phase containing 5 wt% Tween 80 or SF6 was added to the melted oil phase containing 30 to 60 wt% PEW in the blend and 5 wt% Span 80 at 120 °C with the addition rate of 5 mL/min. Phase inversion point was detected by monitoring the dissolution of the emulsion in water during emulsification and proved by electrical conductivity measurements. A lower effectiveness was found for the mixed monomeric surfactant system compared to the gemini surfactant-containing system. For each surfactant system, the trend of change in water phase volume fraction at phase inversion point upon increase in the PEW content in the oil phase was in accordance with the trend of change in the interfacial tension between the water phase and the oil phase. Using the mixed monomeric/gemini surfactant system resulted in emulsions with larger values of absolute zeta potential and drop sizes comparable to their monomeric surfactant-containing counterparts. The absolute zeta potential of the emulsions containing 30, 50, and 60 wt% PEW in the blend was about 70, 54, and 13 mV higher in case of using the mixed monomeric/gemini surfactant system. The gemini surfactant-containing emulsions demonstrated less shear-thinning behavior and the general trend of change in their viscosity and storage modulus with formulation was in agreement with that in the enthalpy of melting of the dried emulsions. Usage of the mixed monomeric/gemini surfactant system led to higher long-term stability of the emulsions, revealed by lower rate of water evaporation from the emulsions. The results of the current study can be applied for preparation of non-polar polyethylene wax-based emulsions using phase inversion emulsification technique. This investigation also opens up the opportunity to use efficient gemini surfactants in low-energy phase inversion emulsification.

Optimization of high pressure homogenization conditions to produce nanostructured lipid carriers using natural and synthetic emulsifiers

Lipid-based nanoparticles are one of the most promising encapsulation technologies in the field of nanotechnology, and solid lipid nanoparticles were the first generation of such structures. The second generation of lipid nanostructures is the nanostructured lipid carriers (NLC), which are composed of lipid materials with different melting points (MP). High pressure homogenization (HPH) is one of the main methods used on an industrial scale to produce NLC, and the process conditions affect the characteristics and physical stability of the produced NLC. The objective of this study was to optimize the HPH process conditions (number of cycles and homogenization pressure) to produce NLC formulated with different emulsifiers. The pre-emulsion for producing NLC was composed of an aqueous phase (90 %) with a single emulsifier (ethoxylated sorbitan monooleate (Tween 80), sorbitan monostearate (Span 60), soy protein isolate (SPI), whey protein isolate (WPI), or enzymatically modified soy lecithin (SL) in a 2 % (w/w) proportion, and a lipid phase composed of glyceryl tristearate (TS) and glyceryl trioleate (TO) in a 40:60 (w/w) proportion, corresponding to a model system containing similar contents of saturated and unsaturated fatty acids. The influence of the homogenization pressure (HP) (500 to 900 bar) and the number of cycles (NC) (1 to 3) on the characteristics of the NLC was assessed separately for each emulsifier using a2-level full factorial design. The NLC were characterized by the particle size (PS), polydispersity index (PI), and zeta potential (ZP) at 24 h and 15 days after production. The results indicated that SL,Tween 80, and WPI promoted the production of NLC in the nanometric range (PS ranging from 136.00 to 277.17 nm) that were stable (ZP > |20 mV|) during 15 days of storage at 25 °C. Of all the process conditions, 700 bar and 2 cycles were the optimal conditions for producing NLC with the different emulsifiers used in this study.

Effect of silica dispersed by special dispersing agents with green strategy on tire rolling resistance and energy consumption

AbstractThe state‐of‐art approach to realize the low rolling resistance of green tires is the high addition of SiO2. However, its dispersion capacity and the interface strength with rubber dominant the final properties of green tires. Here, we systematically study amphiphilic polyoxyethylene sorbitan monooleate, oleylamine, sorbitan monooleate, and oleamide to modify SiO2 through simple hydrogen‐bonded self‐assembly in order to replace the traditional silane coupling agent with low modification efficiency, many side reactions and complex reaction process. The results show that the rolling resistance and processing energy loss of the rubber composite prepared by SiO2 modified with polyoxyethylene sorbitan monooleate and oleylamine are significantly reduced, and other physical and mechanical properties (tensile strength, tear strength, and wear resistance) are also significantly improved compared with the silane coupling agent commonly used in green tire tread. Meanwhile, carbon–carbon double bonds belonging to polyoxyethylene sorbitan monooleate and oleylamine can participate in vulcanization of rubber to strongly improve the dispersion ability of SiO2 and the interface interaction between SiO2 and rubber matrix, so as to develop the fuel‐efficient green tire tread with high performance and low rolling resistance.

Investigation on aquathermolysis desulfurization by cutting off C-S bond in thiophene over Fe-Zr-Al catalyst facilitated by surfactants

ABSTRACT This study aimed to apply aquathermolysis technology to remove thiophene sulfur in vacuum residue to obtain qualified petroleum coke products based on a well-designed Fe-Zr-Al catalyst. A coprecipitation method was first developed to synthesize Fe-Zr-Al composite metal oxide catalyst. The thiophene model oil was selected as the reaction system to investigate the process conditions. By adding surfactants into the reaction system to strengthen the mass transfer process of oil–water two-phase, the desulfurization rate of aquathermolysis was improved. It was shown in this study that under the conditions of oil–water ratio of 3:7, temperature of 280°C, pressure of 4 MPa and reaction duration of 60 h, the desulfurization rate could reach 44.39%. The further introduction of 2.4% Sorbitan oleate into the above reaction system could significantly enhance the desulfurization rate to 60.20%. Under the action of Fe2O3 lattice oxygen, thiophene was oxidized and C-S bond was broken, so as to achieve the purpose of desulfurization. The decomposition of water generated active oxygen to continuously replenish lattice oxygen of Fe2O3. The current founding can provide a new way for the effective desulfurization of vacuum residue to produce qualified petroleum coke products.

Effects of hydrate inhibitors on the adhesion strengths of sintered hydrate deposits on pipe walls

The effects of hydrate inhibitors on the adhesion of sintered hydrate deposits on pipe walls are still unexplored. Herein, a custom-built adhesion strength measurement apparatus was utilized to quantify the adhesion strengths of sintered cyclopentane (CyC5) hydrate deposits with thermodynamic inhibitors (ethylene glycol, glycerol) and low-dosage inhibitors (dodecylbenzene sulfonic acid (DBSA), sorbitan oleate (Span 80)). It was found that the hydrate adhesion strengths decreased by 69.82%-97.06% and 40.24%-94.36% with the concentration of ethylene glycol and glycerol increased from 2 wt% to 6 wt%, respectively. For DBSA and Span 80, the hydrate adhesion strength increased with concentration less than 0.01 wt% due to the acceleration on hydrate growth. The further increment of concentration leads to a dramatic reduction in adhesion strengths. Furthermore, the relatively large deviations with the predicted strengths led to the discussions of the effects of change in hydrate formation rate, crystal morphology, and also the adaption of the fitting model. Two modified models were proposed to give a better prediction/explanation of the hydrate adhesion with thermodynamic inhibitors and low-dosage inhibitors, respectively. This work provides a fundamental understanding of the adhesion mechanism of hydrate deposits with hydrate inhibitors, which is important in advancing the management of hydrate formation for preventing plugging in pipelines.

UV resistance, anticorrosion and high toughness bio-based waterborne polyurethane enabled by a Sorbitan monooleate

Sorbitan monooleate (SP) is considered to be a promising renewable polyol with unique molecular structures for the development and design of bio-based waterborne polyurethane (WPU) with versatility and excellent mechanical properties. In this study, SP was used as a bio-based polyol in combination with castor oil to design and prepare a series of bio-based WPU with anti-ultraviolet, corrosion resistance and excellent mechanical properties. The influence of the hydroxyl ratios between SP and castor oil on the chemical structures and properties of bio-based WPU dispersions and the resulting WPU films was systematically studied. The resulting WPU films exhibited excellent mechanical properties and thermo-physical properties due to the presence of large amounts of hydrogen bonding and rigid furan ring, and high crosslinking densities. The bio-based WPU films could lift heavy objects 10,330 times their own weight. The resulting WPU coatings could resist ultraviolet radiation in the region (200–400 nm) and exhibited excellent UV resistance in outdoor practical application tests. In addition, these WPU coatings demonstrated effectively anticorrosive effect in which the anticorrosion period of the coating on the tinplate outdoors could be as long as 6 months in terms of corrosion potential, corrosion current and corrosion protection efficiency of the coating reached −0.507 V, 2.92 × 10−6 A, and 95.39%, respectively. This study provides a new and simple method for preparing bio-based WPU with excellent anti-ultraviolet performance, anti-corrosion performance and excellent mechanical properties.

NANO SPRAY ANTI ACNE: NANOTECHNOLOGY-BASED SERUM SPRAY INNOVATION FROM BETEL LEAF EXTRACT IN OVERCOMING PROPIONIBACTERIUM ACNES BACTERIA CAUSES BY ACNE PROBLEMS

Acne is an inflammation and blockage of the oil gland ducts in the skin caused by the bacteria Propionibacterium acne, Staphylococcus epidermidis, and Staphylococcus aureus. Acne treatment is usually done by giving antibiotics and chemicals that have irritating side effects. Therefore, other alternatives are needed by using natural products that have milder side effects and are halal. The author reviews the potential of Betel Leaf Extract which can be used as an acne medication because it has a high antibacterial content. The method used in this paper is a narrative literature study. The author uses global journal publication websites such as Science Direct and Google Scholar with the keywords Betel Leaf, Antimicrobial, Propionibacterium, Acne, and Nano Spray Serum. Based on the literature obtained, the results of the ethanol extract of betel leaf have antibacterial activity against P. acne and multiresistant Staphylococcus aureus with a KBM of 0.5% w/v. Betel leaf extract is combined with distilled water, polyoxyethylene sorbitan monooleate as a solvent, chitosan as a preservative, and acetic acid by ultrasonication method which functions to break particles into nano size with the help of sound waves above 20 kHz. The spray form was chosen because it can accelerate the absorption of serum into facial skin. In conclusion, Betel Leaf Extract has the potential to be a safe and halal organic material for serum spray preparations as a halal skincare solution for acne problems. Keywords: Betel Leaf, Antimicrobial, Propionibacterium, nano spray serum, Acne.

Cyclic olefin polymer membrane as an emerging material for CO2 capture in gas-liquid membrane contactor

Porous flat sheet membranes were prepared with a commercial grade of cyclic olefin polymer (COP) for CO2 capture using membrane contactor (MC). The membranes were prepared via non-solvent induced phase separation technique using different types of additives, namely, polyvinylpyrrolidone (PVP), polyethylene glycol (PEG400) and sorbitan monooleate (Span 80), and coagulants (acetone and 70/30 wt% acetone/water mixture) were investigated. The prepared membranes were characterized in terms of the thickness (70–85 µm), porosity (50–80%), mean pore size (158–265 nm), bubble pore size (~ 0.6–12 µm), liquid entry pressure (1.67–4.55 bar), water contact angle (~ 94° - 111°), monoethanolamine (MEA) contact angle (~ 67° - 73°) and mechanical properties (tensile strength: 4.53 – 5.15 MPa, elongation at break: 4 – 8% and Young´s modulus: 190 – 232 MPa). The thermodynamic study of COP membranes proved that a fast phase inversion of the proposed system resulted in a more porous structure. The addition of PEG400 and Span 80 caused delayed demixing and influenced the morphological structure and MC performance. The structural and topographical characteristics of the membranes were also studied. The CO2 absorption test performed at 27 °C showed that the maximum CO2 absorption flux was around 16 × 10−5 mol/m2.s using 1 M MEA aqueous solution as absorbent with fixed liquid and gas flow rates at 150 L/h and 8.4 L/h, respectively. It was found that the considered additives enhanced the MC performance and affected the CO2 absorption flux.

Hydrophobically modified chitosan biopolymer connects halloysite nanotubes at the oil-water interface as complementary pair for stabilizing oil droplets

The integration of cationic and hydrophobic functionalities into hydrophobically modified chitosan (HMC) biopolymer facilitates complementary emulsion stabilization with negatively charged halloysite clay nanotubes (HNT). Oil-in-water emulsions with smaller droplet sizes and significantly improved interfacial resistance to droplet coalescence are obtained on complementary emulsion stabilization by HNT and HMC compared to the individual emulsifiers alone. Contact angle measurements shows that the adsorption of the cationic HMC onto the negatively charged HNT modifies the surface wettability of the nanotubes, facilitating the attachment of the nanotubes to the oil–water interface. High resolution cryo-SEM imaging reveals that free HMC chains locks the nanotubes together at the oil–water interface, creating a high barrier to droplet coalescence. The emulsion stability is an order of magnitude higher for conditions in which the aqueous HNT dispersion is stabilized by the HMC compared to conditions where the negatively charged HNT is strongly flocculated by the cationic HMC. The hydrophobic interaction between HMC chains, insertion of HMC hydrophobes into the oil phase and electrostatic interactions between HMC and HNT are proposed as key mechanisms driving the increased emulsion stability. For potential application as a dispersant system for crude oil spill treatment, the nanotubular morphology of HNT was further exploited for the encapsulation of the water-insoluble surfactant, sorbitan monooleate (Span 80). The HMC and HNT sterically strengthens the oil–water interfacial layer while release of the Span 80 surfactant from the HNT lumen lowers the oil–water interfacial tension. The concepts advanced here are relevant in the development of environmentally-benign dispersants for oil spill remediation.

Influence of different surfactants on development of nanoemulsion containing fixed oil from an Amazon palm species

Astrocaryum vulgare is an Amazon palm species, popularly known as tucumã. A. vulgare oil has diverse biological purposes, but low solubility in water. Nanoemulsions provide a solution to this problem. This study aimed to evaluate the influence of different surfactants on the development of nanoemulsions. To determine the hydrophilic-lipophilic balance (HLB), the influence of different surfactants on nanoemulsification was determined, the region of nanoemulsion formation on the pseudo-ternary phase diagram was analyzed, nanoemulsions were characterized, and the best candidate was subjected to stability assessment. The HLB was 14, and PPG-5-Ceteth-20 and sorbitan oleate were selected as surfactants. The nanoemulsion had a droplet size of 174.1 nm, a polydispersity index of 0.295, and a zeta potential of 20.7. A. vulgare oil is used in the Amazon for countless pharmaceutical applications. We demonstrate the impact of the chemical structure of surfactants, resulting in the formation of nanoemulsions containing A. vulgare oil.