Ml Of Emulsion Research Articles

Investigating the performance of bio-based demulsifiers for the demulsification of Nigerian crude oils

Commercial demulsifiers used by Nigerian National Petroleum Corporation (NNPC) are not biodegradable, making it paramount to seek bio-demulsifiers that can be produced in Nigeria from Nigerian vegetable seed oils. In this study, three demulsifiers were produced from Nigerian vegetable seed oils namely; Neem seeds, Mahogany seeds and Calabash seeds in concentrations ranging from 0.5-2.5 mL/10 mL of emulsion. These demulsifiers were tested under the same condition as the common commercial ones used in NNPC for static, dynamic, thermal and basic sediment and water removal. They all performed very well except for the dynamic test, which had low performance. The calabash demulsifier had a high performance of 80% same as the commercial on static test followed by Neem with 75%. The dynamic test recorded low results with the Neem demulsifier at 45% as the highest among the bio-demulsifiers and the commercial demulsifier recorded at 78%. On thermal tests, Calabash tied with commercial demulsifier at 80% followed by Neem demulsifier with 75%. In the basic sediment and water test, the Neem demulsifier had 75% while the commercial had 78%. They are, therefore, good enough to replace commercial demulsifiers. Keywords: Bio-Based, Demulsifiers, Demulsification, Investigating, Performance, Nigerian Crude oils

Polymer hydrogel for water removal from naphthenic insulating oil and marine diesel

The control of water content in industrial oils and fuels is a key factor to avoid degradation during the storage period and guarantee their expected performance. Thus, our work investigated the application of polymer hydrogel to remove water from naphthenic insulating oil (NIO) and marine diesel oil (MDO). Two acrylamide-based hydrogels were synthesized by free radical polymerization: poly(acrylamide-co-sodium acrylate) and poly(acrylamide-co-acrylonitrile). Prior to batch tests for water removal, the hydrogels were characterized by SEM, pore size distribution, DVS, FTIR, and XDR. An extensive physicochemical characterization of MDO and NIO was performed, including the determination of water solubility curves. A 22 factorial design with duplicates was carried out to examine the effects of the hydrogel mass and hydrogel type on the water content in the oils. Finally, kinetic and thermodynamic studies of the water removal process were carried out. In just 60 min, the hydrogel removed approximately 80% of water from NIO and MDO, considering 1 g of hydrogel and 50 mL of emulsion at 25 °C. The two lowest temperatures studied (25 °C and 35 °C) showed the best hydrogel performance. Tests of hydrogel reuse showed the polymer can be regenerated without losing its water removal capacity.

Use of a Glass Membrane Pumping Emulsification Device Improves Systemic and Tumor Pharmacokinetics in Rabbit VX2 Liver Tumor in Transarterial Chemoembolization.

To evaluate the phamacokinetics of epirubicin in conventional transarterial chemoembolization using a developed pumping emulsification device with a microporous glass membrane in VX2 rabbits. Epirubicin solution (10 mg/mL) was mixed with ethiodized oil (1:2 ratio) using the device or 3-way stopcock. Forty-eight rabbits with VX2 liver tumor implanted 2 weeks prior to transarterial chemoembolization were divided into 2 groups: a device group (n= 24) and a 3-way-stopcock group (n= 24). Next, 0.5 mL of emulsion was injected into the hepatic artery, followed by embolization using 100-300-μm microspheres. The serum epirubicin concentrations (immediately after, 5 minutes after, and 10 minutes after) and the tumor epirubicin concentrations (20 minutes after and 48 hours after) were measured after transarterial chemoembolization. Histopathologic evaluation was performed with a fluorescence microscope. The area under the curve and maximum concentrations of epirubicin in plasma were 0.45 ± 0.18 μg min/mL and 0.13 ± 0.06 μg/mL, respectively, in the device group and 0.71 ± 0.45 μg min/mL and 0.22 ± 0.17 μg/mL, respectively, in the 3-way-stopcock group (P= .013 and P= .021, respectively). The mean epirubicin concentrations in VX2 tumors at 48 hours in the device group and the 3-way-stopcock group were 13.7 ± 6.71 and 7.72 ± 3.26 μg/g tissue, respectively (P= .013). The tumor necrosis ratios at 48 hours were 62 ± 11% in the device group and 51 ± 13% in the 3-way-stopcock group (P= .039). Conventional transarterial chemoembolization using the pumping emulsification device significantly improved the pharmacokinetics of epirubicin compared to the current standard technique using a 3-way stopcock.

Protective Effect of Madhuca longifolia Leaves in 7, 12-Dimethylbenz(a)anthracene Induced Mammary Carcinoma in Sprague Dawley Rat model

Objectives: To evaluate the pretreatment with Madhuca longifolia leaves on 7, 12-Dimethylbenz(a)anthracene (DMBA)-induced mammary carcinoma in Sprague Dawley rat. Materials and Methods: Thirty female Sprague Dawley rats were divided into five groups, and each group is having six rats. Group I rats received vehicle (1 mL of emulsion of sunflower oil and physiological saline) subcutaneously and 1 mL of 2% dimethyl sulfoxide per orally. Groups II, III, IV, and V were induced mammary carcinogenesis by giving single dose of subcutaneous injection of 25 mg of DMBA. Group III, IV, and V rats were administered with MEML 100, 200 mg/kg and Vincristine 0.5 mg/kg dissolved in 1 ml of 2% dimethylsulfoxide given 1 week before the administration of the carcinogen, respectively, and continued for 16 weeks. At the end of experiment, the animals were sacrificed and biochemical estimations were done in all groups. Mammary tissues in all groups were dissected out and used for histopathological studies. Results: Oral administration of 200 mg/kg of MEML to DMBA-treated rats effectively prevented the tumor incidence, total number of tumors, and tumor volume and brought back the biochemical markers to normal, which was comparable with standard group. In lower dose 100 mg/kg, the effect was very less compared to normal and standard groups. Our data showed that MEML 200 mg/kg significantly restored the breast tissue biochemically and histologically which was comparable with standard. Conclusion: Our results concluded that the leaves of Madhuca longifolia may be used in the treatment of mammary carcinoma.

Reversibly pH‐Switchable Anionic‐Surfactant‐Based Emulsions

AbstractTo develop a convenient and reversible strategy for phase separation and re‐emulsification of surfactant‐based emulsions, we established a method for pH switching of emulsions formed from a pH‐switchable anionic surfactant, potassium dodecyl seleninate (C12SeO2K). Upon acidification, C12SeO2K was protonated to give a precipitate of dodecyl seleninic acid (C12SeO2H); upon basification, C12SeO2H was neutralized restore C12SeO2K. The pH‐switchable window of the emulsion thus obtained was a pH range of 7 to 8. Reversible changes in both interfacial tension by ~10.2 mN m−1, as well as the mechanical, steric, and/or electrical barriers formed by C12SeO2K at the interface of the oil–aqueous solution account for the fully reversible phase separation and re‐emulsification of the C12SeO2K‐based emulsions. A stable emulsion (i.e. the time needed to separate 1 mL of H2O from 6 mL of emulsion at 25 °C is larger than 1 h) could be cycled at least 25 times when the pH was varied between 7 and 8.

Application of the electro-Fenton process for cutting fluid mineralization

Organic compound is the main pollutant in industrial effluent. Conventional wastewater treatment processes are inefficient for the removal of toxic or non-biodegradable organic pollutants. Advanced electrochemical depollution is a very efficient and economic method, suitable when the wastewater contains toxic and recalcitrant organic pollutants. The aim of the present study was to investigate the application of the electro-Fenton (EF) process for the degradation and mineralization of a stable oil-in-water emulsion (0.01% in v/v). The effects of operating parameters such as cathode material (graphite, Ti/Pt and steel), nature (Na2SO4, NaNO3 and NaCl) and dose of electrolyte (25–75 mM), initial ferrous ions concentration (1–75 mM), current intensity (0.1–0.2 A) and operating time, on chemical oxygen demand (COD) removal efficiency, were studied. Results showed that the EF method can be used efficiently for the degradation of stable cutting oil emulsion. For considered initial conditions (bubbling compressed air at 1 L/min, 0.15 A, pH 3, [Na2SO4] = 0.05 M, [FeSO4] = 0.015 M, COD0 = 400 mg O2/L), the best removal efficiencies were obtained under the following conditions: graphite as cathode material, 180 min for treatment duration and 0.05 M [Na2SO4]. For these conditions, treatment of 250 mL of emulsion led to 93.6% of cutting fluid mineralization, which correspond to 25 mg O2/L of final COD, 19 kWh/m3 of treated wastewater and 24.039 kWh/kg of COD removal.

Aspen Plus® Simulation of a Coal Gasification Process (Geometric Analysis)

A semi-batch foam-flotation in which air is continuously sparged through an emulsion, with added surfactant, a coagulant, and a solvent, has been shown to be effective in the treatment of steel-rolling mill effluents. The effect of time of flotation, effects of surfactant and alum concentrations, and effect of the solvent volume were all experimentally explored. The oil recovery increased with concentrations of alum and sodium lauryl sulphate of up to around 4 g/l, and then leveled off. Volume of the solvent layer at the top improved the separation of oil with an optimum ratio of 0.167 ml solvent per ml of emulsion. The oil separation was highest for the time of flotation of about 25 minutes, and reemulsification of the separated self-emulsifiable oil was observed beyond this time. A model reported in the literature for the semi-batch flotation has been shown to be inadequate in predicting the experimental data on separation of oil. A mathematical model developed for the separation by foam flotation based on an analogy with a chemical reaction was found to be appreciably better in its predictive capability than the one reported in literature. The new mathematical model has established the separation of oil by foam flotation as a second-order process, and its predictions can be further fine tuned using a parameter referred to as a sticking coefficient (β). The values of β for the two effluents investigated were equal to 7.9 × 10-5 and 6.7 × 10-5, respectively.

Treatment of Steel Rolling Mill Effluents Using Semi-Batch Foam Flotation

A semi-batch foam-flotation in which air is continuously sparged through an emulsion, with added surfactant, a coagulant, and a solvent, has been shown to be effective in the treatment of steel-rolling mill effluents. The effect of time of flotation, effects of surfactant and alum concentrations, and effect of the solvent volume were all experimentally explored. The oil recovery increased with concentrations of alum and sodium lauryl sulphate of up to around 4 g/l, and then leveled off. Volume of the solvent layer at the top improved the separation of oil with an optimum ratio of 0.167 ml solvent per ml of emulsion. The oil separation was highest for the time of flotation of about 25 minutes, and reemulsification of the separated self-emulsifiable oil was observed beyond this time. A model reported in the literature for the semi-batch flotation has been shown to be inadequate in predicting the experimental data on separation of oil. A mathematical model developed for the separation by foam flotation based on an analogy with a chemical reaction was found to be appreciably better in its predictive capability than the one reported in literature. The new mathematical model has established the separation of oil by foam flotation as a second-order process, and its predictions can be further fine tuned using a parameter referred to as a sticking coefficient (β). The values of β for the two effluents investigated were equal to 7.9 × 10-5 and 6.7 × 10-5, respectively.

Ultra-high throughput detection of single cell β-galactosidase activity in droplets using micro-optical lens array.

We demonstrate the use of a hybrid microfluidic-micro-optical system for the screening of enzymatic activity at the single cell level. Escherichia coli β-galactosidase activity is revealed by a fluorogenic assay in 100 pl droplets. Individual droplets containing cells are screened by measuring their fluorescence signal using a high-speed camera. The measurement is parallelized over 100 channels equipped with microlenses and analyzed by image processing. A reinjection rate of 1 ml of emulsion per minute was reached corresponding to more than 105 droplets per second, an analytical throughput larger than those obtained using flow cytometry.

Interleukin-25 Expressed by Brain Capillary Endothelial Cells Maintains Blood-Brain Barrier Function in a Protein Kinase Cϵ-dependent Manner

Interleukin (IL)-25, a member of the IL-17 family of cytokines, is expressed in the brains of normal mice. However, the cellular source of IL-25 and its function in the brain remain to be elucidated. Here, we show that IL-25 plays an important role in preventing infiltration of the inflammatory cells into the central nervous system. Brain capillary endothelial cells (BCECs) express IL-25. However, it is down-regulated by inflammatory cytokines, including tumor necrosis factor (TNF)-alpha, IL-17, interferon-gamma, IL-1beta, and IL-6 in vitro, and is also reduced in active multiple sclerosis (MS) lesions and in the inflamed spinal cord of experimental autoimmune encephalomyelitis, an animal model of MS. Furthermore, IL-25 restores the reduced expression of tight junction proteins, occludin, junction adhesion molecule, and claudin-5, induced by TNF-alpha in BCECs and consequently repairs TNF-alpha-induced blood-brain barrier (BBB) permeability. IL-25 induces protein kinase Cepsilon (PKCepsilon) phosphorylation, and up-regulation of claudin-5 is suppressed by PKCepsilon inhibitor peptide in the IL-25-stimulated BCECs. These results suggest that IL-25 is produced by BCECs and protects against inflammatory cytokine-induced excessive BBB collapse through a PKCepsilon-dependent pathway. These novel functions of IL-25 in maintaining BBB integrity may help us understand the pathophysiology of inflammatory brain diseases such as MS.

Immunogenicity in rhesus of the Plasmodium vivax mosquito stage antigen Pvs25H with Alhydrogel and Montanide ISA 720

Pvs25 is an ookinete surface protein from Plasmodium vivax that is the target of transmission-blocking antibodies. Two immunogenicity trials in rhesus monkeys with a recombinant form of the protein, Pvs25H, were undertaken. Monkeys were vaccinated with Pvs25H adsorbed to Alhydrogel or emulsified in Montanide ISA 720 at 0, 4 and 27 weeks (study 1) or in Montanide ISA 720 at 0 and 18 weeks (study 2) with 1.5 or 15 microg Pvs25H in 0.1 or 0.5 mL of emulsion (four combinations). Immunogenicity was assessed by ELISA and by membrane-feeding experiments using P. vivax-infected blood from human volunteers (studies 1 and 2) or from chimpanzees (study 1). Both vaccine trials generated antibodies that blocked transmission of P. vivax to mosquitoes. Antibody titres and transmission blocking were higher with Montanide ISA 720 than with Alhydrogel in the first trial and with the 15 microg Pvs25H/0.5 mL ISA 720 combination in the second trial.

Miniaturizing Chemistry and Biology in Microdroplets

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Miniaturizing chemistry and biology in microdroplets

By compartmentalizing reactions in aqueous microdroplets of water-in-oil emulsions, reaction volumes can be reduced by factors of up to 10(9) compared to conventional microtitre-plate based systems. This allows massively parallel processing of as many as 10(10) reactions in a total volume of only 1 ml of emulsion. This review describes the use of emulsions for directed evolution of proteins and RNAs, and for performing polymerase chain reactions (PCRs). To illustrate these applications we describe certain specific experiments, each of which exemplifies a different facet of the technique, in some detail. These examples include directed evolution of Diels-Alderase and RNA ligase ribozymes and several classes of protein enzymes, including DNA polymerases, phosphotriesterases, beta-galactosidases and thiolactonases. We also describe the application of emulsion PCR to screen for rare mutations and for new ultra-high throughput sequencing technologies. Finally, we discuss the recent development of microfluidic tools for making and manipulating microdroplets and their likely impact on the future development of the field.

Directed evolution by in vitro compartmentalization

aqueous droplets per ml of emulsion. The majority of droplets contain no more than a single gene along with all of the molecular machinery needed to express that gene. The expressed proteins and the products of their catalytic activities cannot leave the droplets, and so genotype is coupled to phenotype

A direct method of determining the water content in water-oil emulsions

Measurement of the volume of water precipitated from 100 ml of emulsion is proposed. Total precipitation takes place in several minutes due to the vertical movement of high-voltage electrodes. Under the effect of their field, the water drops enlarge and precipitate.

Speciation analysis of volatile and non-volatile vanadium compounds in Brazilian crude oils using high-resolution continuum source graphite furnace atomic absorption spectrometry

A method is proposed that makes possible determining total and “thermally stable” vanadium in crude oil without prior separation, and to calculate “volatile” vanadium by difference. The volatile fraction is believed to be largely vanadyl porphyrine complexes. The method is based on the unsurpassed background correction capability of high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS), which allows pyrolysis temperatures as low as 300 °C to be used. The samples were prepared as oil-in-water emulsions, and aqueous standards emulsified in the same way were used for calibration. Total vanadium has been determined using a pyrolysis temperature of 400 °C, and “thermally stable” vanadium using a pyrolysis temperature of 800 °C. The content of total vanadium in 12 Brazilian crude oil samples was found to be between less than 0.04 and about 30 mg kg −1. The volatile fraction was between 5 and 51% of the total content, and there was no correlation between the total and the volatile vanadium content. The limits of detection and quantification were 0.04 and 0.12 mg kg −1 of V in crude oil, respectively, based on a mass of 2 g of oil in 10 mL of emulsion. The precision was better than 4% at the 3 mg kg −1 level and better than 1.5% at the 30 mg kg −1 level of V in crude oil.

Peroxidation potential of lipid emulsions after compounding in all-in-one solutions

Objective We investigated the peroxidation potential of fat emulsions in all-in-one solutions (AIOs). Methods Three 20% emulsions were compared: soybean oil (SO; 60% polyunsaturated fatty acids [PUFAs], α-tocopherol:PUFAs = 0.44), soybean plus medium-chain triacylglycerol (SO-MCT; 31% PUFAs, α-tocopherol:PUFAs = 0.35), and olive oil (OO; 21% PUFAs, α-tocopherol:PUFAs = 1.42). For each emulsion, six AIO solutions were prepared by adding 250 mL of emulsion to a lipid-free solution. Lipid peroxide (LPX) and malondialdehyde (MDA) concentrations were evaluated in fat emulsions, lipid-free solutions, and AIOs immediately (T0) and 24 h (T24) after lipid addition. Statistical analysis was done with analysis of variance. Results Fat emulsion LPX in SO-MCT was lower than that in SO ( P = 0.015) and OO ( P = 0.024); LPX in SO was greater than that in OO ( P = 0.013); MDA in SO was greater than that in SO-MCT ( P = 0.001) and OO ( P = 0.013); and MDA in SO-MCT was greater than that in OO ( P = 0.001). In comparison with MDA at AIO-T0, MDA at AIO-T24 increased in SO ( P = 0.005) and SO-MCT ( P < 0.001) and decreased in OO ( P = 0.003); at AIO-T24, LPX was greater in SO, but not significantly. Conclusions In AIO bags, LPX occurred within 24 h after the addition of the lipid emulsion and seemed to be directly related to the PUFA content and inversely related to the α-tocopherol:PUFA ratio of the emulsion.

Aqueous extraction, composition, and functional properties of rice bran emulsion

AbstractThe effect of temperature (20–60°C) on the aqueous extraction of emulsified rice bran oil from commercial rice bran was described. The total solids, protein, fat, and carbohydrate contents of the rice bran emulsions extracted at various temperatures were 4.82–6.99, 1.05–1.40, 0.82–1.65, and 2.65–3.36%, respectively. The mean droplet sizes of the rice bran emulsions extracted at 20, 30, 40, 50, and 60°C were 4.35, 2.92, 3.04, 4.40, and 3.73 μm, respectively. The phenolics extracted at various temperatures ranged from 63.28 to 82.51 mg/100 mL emulsion. The antioxidant capacity (oxygen radical absorbance capacity, ORAC) of rice bran emulsions extracted at various temperatures ranged from 2087 to 3505 μmol Trolox® equivalents per 100 mL of emulsion. The relationship between ORAC and the total phenolic content was highly significant (R2=0.87). The shear stress and apparent viscosity of rice bran emulsions in response to shear strain were similar to those of homogenized whole milk. Hence, the composition and functional properties show the potential of aqueous rice bran extracts as food‐grade emulsions.

Is ultrasound-assisted lipoplasty advisable in breast reduction surgery?

To the Editor: Doctors Giuseppe and Santoli reported on their series of approximately 120 patients that underwent an ultrasound-assisted lipoplasty (UAL) breast reduction technique in the November/December issue of Aesthetic Surgery Journal (2001;21:493-506). In reading the article, I noted several areas of concern and would like to comment on them, as follows. 1. The amount of ultrasound (power) utilized by the authors appears to be quite high in relation to the amount of fat emulsion produced. The authors reported the application 10 to 15 minutes of ultrasound energy in the fat tissue of the breast, which produced approximately 250 to 300 mL of emulsion. In my experience with the VASER device, 1 minute of ultrasound energy application generally would result in approximately 100 …

Comparison of Different Perfluorocarbons as Ultrasound Contrast Agents

The sonographic properties of Fluosol 20% (F20), which was recently approved for clinical use as an oxygen carrier for coronary angioplasty, were compared to those of perflubron emulsion, which is still in clinical testing. Contrast agents were evaluated in 21 normal rabbits divided into three groups of seven rabbits each. All rabbits received 2.7 g/kg of perfluorocarbon (PFC). One group received 2.7 ml/kg of an experimental formulation of perflubron emulsion AF0102, which contains 1 g of PFC in 1 ml of emulsion (P100), the other received 13.5 ml/kg of F20 (1 ml has 0.2 g of PFC), and the third received 13.5 ml/kg of P100 diluted to a 20% concentration (P20). All rabbits were scanned by a blinded sonographer before, during, and immediately after infusion, and then again at 30 minutes and 48 hours. Doppler enhancement, echogenicity of inferior vena cava lumen, echogenic enhancement of perfused tissues, and reticuloendothelial organs were assessed. P100 and P20 had nearly identical sonographic properties at all points. During their vascular phase they enhanced Doppler signal, filled the lumen of the IVC and hepatic veins with flowing echogenic reflectors, and enhanced perfused tissues. F20 had no detectable sonographic effect during its vascular phase. All three emulsions enhanced the liver relative to kidney to a similar degree at 48 hours. Because RE enhancement was similar for F20, P100, and P20, and because P100 and P20 had similar properties during the vascular phase, the lack of vascular effect of F20 could not be due to the different PFCs used in these agents, or due to the difference in the dilution or volume. The most likely cause for the observed sonographic behavior of F20 and P100 is the difference in emulsion formulation.