Polyoxyethylene Sorbitan Monolaurate Research Articles

Effects of Homogenization Models and Emulsifiers on the Physicochemical Properties of β-Carotene Nanoemulsions

Microfluidization and high pressure valve homogenization were applied to prepare β-carotene nanoemulsions, and the mathematical relationship between homogenization pressures and emulsion temperatures, homogenization pressures/cycles, and droplet sizes, were established. Emulsions through Microfluidizer had lower temperature and much smaller droplet sizes, compared with those through high pressure valve homogenizer. Four emulsifiers were compared for their capacities to stabilize nanoemulsions. The two large molecule emulsifiers, octenyl succinate starch (OSA) and whey protein isolate (WPI), were less effective for the formation of nanoemulsions with smaller droplets than the two small molecule emulsifiers, polyoxyethylene sorbitan monolaurate (Tween 20, TW) and decaglycerol monolaurate (DML). The nanoemulsion containing WPI was the most stable, while the one containing DML was the least stable. During storage, significant degradation of β-carotene occurred in all nanoemulsions, especially in the DML stabilized one, while WPI showed the greatest capacity to protect β-carotene from degradation.

Preparation of surfactant-stabilized gold nanoparticle–peptide nucleic acid conjugates

A simple, two-step method of producing stable and functional peptide nucleic acid (PNA)-conjugated gold nanoparticles using a surfactant stabilization step is presented. PNA are DNA analogs with superior chemical stability and target discrimination, but their use in metallic nanoparticle systems has been limited by the difficulty of producing stable colloids of nanoparticle–PNA conjugates. In this work, the nonionic surfactant Tween 20 (polyoxyethylene (20) sorbitan monolaurate) was used to sterically shield gold surfaces prior to the addition of thiolated PNA, producing conjugates which remain dispersed in solution and retain the ability to hybridize to complementary nucleic acid sequences. The conjugates were characterized using transmission electron microscopy, dynamic light scattering, and UV–visible absorbance spectroscopy. PNA attachment to gold nanoparticles was confirmed with an enzyme-linked immunoassay, while the ability of nanoparticle-bound PNA to hybridize to its complement was demonstrated using labeled DNA.

Effect of various surfactants (cationic, anionic and non-ionic) on the growth of Aspergillus parasiticus (NRRL 2999) in relation to aflatoxin production

The effect of surfactants (two cationic, one anionic and three non-ionic) at 0.001, 0.01, 0.1 and 1.0 % concentrations on aflatoxin production, ergosterol content and sugar consumption by Aspergillus parasiticus (NRRL 2999) in YES liquid culture medium is reported. At 0.01% concentration, the cationic surfactants, cetyl dimethyl ammonium bromide (CDAB) and dodecyl trimethyl ammonium bromide (DTAB), and the anionic surfactant, sodium dodecyl sulfate (SDS), completely inhibited spore germination, while DTAB also inhibited the production of ergosterol and toxin (p < 0.05). At a concentration of 0.001%, CDAB was found to enhance toxin production, while SDS was found to inhibit it when compared with other surfactants. Non-ionic surfactants, polyoxyethylene sorbitan monolaurate (Tween-20), polyoxyethylene lauryl ether (Brij-35) and ethoxylated p-tert-octylphenol (Triton X-100) delayed the spore germination up to day 5 at all concentrations and inhibited toxin and ergosterol production at 0.001% concentration. The affect was found to be dose-dependent from 0.001% to 1%, for Triton X-100 only. Positive correlation between ergosterol content and toxin production in the presence of different surfactants at various time periods (3, 5, 7, 9 and 12days) was found. Tween-20 was most effective in inhibiting toxin production on day 7, when aflatoxin production was found to be maximal in control group. Sugar consumption was directly proportional to the ergosterol content, showing a significant correlation with aflatoxin production.

Self-microemulsifying Formulation-based Oral Solution of Coenzyme Q10

The goal of our investigation was to develop oral solution of coenzyme Q10 (CoQ10) by using self-emulsifying systems. CoQ10 is practically insoluble in water. Therefore, it is difficult to develop oral solution of CoQ10. To solubilize CoQ10 and to develop it as oral solution, self-emulsifying systems consisted of oil, surfactant and co-surfactant were studied and using the self-emulsifying system chosen, oral solution was developed. After the evaluation of solubilizing abilities of various oils and surfactants, the self-emulsifying system consisted of acetylated monoglyceride (AM) as oil, polyoxyethylene (20) sorbitan monolaurate (P2SM) as surfactant and propylene glycol laurate (PGL) as co-surfactant, was chosen because the emulsions prepared by that system showed spontaneous emulsification and transparent appearance. All of these components could be used for the development of functional foods. Finally, a CoQ10 solution with concentrations of 100 mg/70 ml and 100 mg/100 ml could successfully be developed by the addition of water to one milliliter of self-emulsifying system consisted of AM (10%), P2SM (70%) and PGL (20%) along with 100 mg of CoQ10. This oral solution formulation was stable for more than one month.

Supernet Structures of Calcium Carbonate Mesocrystals Formed in a Blend System of Anionic/Nonionic Surfactants

A new kind of vaterite calcium carbonate mesocrystal with a self-organized supernet structure was successfully achieved in the presence of polyoxyethylene (20) sorbitan monolaurate (Tween 20) and sodium dodecyl sulfate (SDS) using the liquid-diffusion method. A well-organized two-dimensional network structure is built up successfully with a mass of sub-micrometer fanlike single crystal units. Comparative experiments showed that the mixed system of Tween 20 and SDS played important roles in the morphological control of CaCO3. SDS and Tween 20 can form complicated reticular micelles in aqueous solution, and the adsorption of SDS molecules onto a certain crystal face leads to the generation of the least stable vaterite. X-ray powder diffraction (XRD), FT-IR spectrometer, transmission electron microscopy (TEM), selected area electron diffraction (SAED), and field-emission scanning electron microscope (FE-SEM) equipped with energy-dispersive X-ray (EDX) were used to characterize the crystals.

Interfacial Behavior, Structure, and Thermodynamics of Water in Oil Microemulsion Formation in Relation to the Variation of Surfactant Head Group and Cosurfactant

Interfacial behavior, structural, and thermodynamic parameters in relation to the formation of water-in-oil (w/o) microemulsion (μE) with varied surfactant head groups and cosurfactants have been evaluated through dilution technique at different temperature and [water]/[surfactant] mole ratio. Dodecyltrimethylammonium bromide (DTAB), sodium dodecylsulphate (SDS), and polyoxyethylene sorbitan monolaurate (Tween-20) were used as surfactants and n-butanol and n-pentanol were used as cosurfactants. Distribution of cosurfactants between bulk oil and the interface using fixed amount of surfactant at varied [water]/[surfactant] mole ratio and temperature has been studied to evaluate thermodynamic parameters. Associated structural parameters, such as droplet dimension and aggregation number of surfactant and cosurfactant at the droplet interface, have also been evaluated. Spontaneity of the μE formation followed the order DTAB>SDS>Tween-20 for both butanol and pentanol in the studied range of temperature. Correlations of the results in terms of the evaluated physicochemical parameters have been attempted.

Improvement of permeation performance of polyethersulfone (PES) ultrafiltration membranes via addition of Tween‐20

AbstractIn this study, effects of Tween‐20 (polyoxyethylene sorbitan monolaurate) as a variable surfactant additive on morphology, permeation performance and antifouling properties of asymmetric polyethersulfone (PES) membranes were investigated. The membranes prepared from PES/polyethylene glycol (PEG)/N,N‐dimethylformamide (DMF) system via phase inversion induced by immersion precipitation in water coagulation bath. The membranes performances were evaluated using ultrafiltration (UF) experiments. The scanning electron microscope and atomic force microscopy analysis were performed to investigate the membrane morphology. The obtained results indicate that by increasing the concentration of Tween‐20, the membrane morphology changes slowly from thin finger‐like structure with spongy structure to long and wide finger‐like structure with some macrovoids. Addition of surfactant to the casting solution increases the porosity of the membrane sublayer. It was found out that the rejection ratio of Bovine serum albumin (BSA) decreases, while the flux recovery ratio remarkably increases and the degree of irreversible fouling decreases. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Determination of capsaicin and dihydrocapsaicin in Capsicum anuum and related products by capillary electrophoresis with a mixed surfactant system

An easy, rapid, sensitive, and cheap capillary electrophoresis (CE) method based a mixed surfactant system formed by sodium dodecyl sulphate (SDS) and polyoxyethylene sorbitan monolaurate (Tween 20) as modifier in the buffer was reported. Quantitative analysis of capsaicin and dihydrocapsaicin in Capsicum anuum, pepper sauce and porous capsicum plaster was demonstrated. After conducting a series of optimisations, baseline separation was obtained for the analytes within 5 min under the optimum conditions (15 mM sodium tetraborate–0.05% (v/v) Tween 20–2.2 mM SDS buffer (pH 10.1), 20 kV voltage, 214 nm UV detection). The method resulted in excellent linearity, with r 2 of regression equation of 0.9994 and 0.9996 for capsaicin and dihydrocapsaicin, respectively. Recoveries were in the range 90–107% and 92–109% for capsaicin and dihydrocapsaicin, respectively.

Evaluation on Pore Structures of Organosilicate Thin Films by Grazing Incidence Small-Angle X-ray Scattering

Nanoporous thin films fabricated by both a core-shell-shaped organic-inorganic hybrid sphere (octa(2,4-dinitrophenyl)silsesquioxane, ODNPSQ) and a four-leg-numbered surfactant (polyoxyethylene sorbitan monolaurate, Tween-20) for porogens in a higher molecular weight precursor (polyphenylsilsesquioxane, PPSQ) were characterized, respectively, by grazing incidence small-angle X-ray scattering (GISAXS), and the measured 2D GISAXS profiles were analyzed quantitatively by using a GISAXS formula based on the distorted wave Born approximation (DWBA). The fitted 2D GISAXS data show that the PPSQ porous thin films imprinted with ODNPSQ porogen exhibit sphere-shaped closed pores with the average pore size within a range of 1.18-3.12 nm and pore size distribution widths about 3.0 nm when the porogen loadings increase from 10 to 40 wt % and those imprinted with Tween-20 porogen give out an average pore size of 1.07-1.29 nm and pore size distribution widths about 2.0 nm with the porogen loading varying from 5 to 30 wt %. The nanoporous dielectric thin films imprinted with ODNPSQ porogen show a reducing to the molecular aggregation of porogens and significant antiphase separation behavior in the cross-linked matrix.

Studies on crystallinity state of puerarin loaded solid lipid nanoparticles prepared by double emulsion method

In this work, solid lipid nanoparticles (SLN) have been prepared from water-in-oil-in-water double emulsion, using monocaprate as solid lipid, sorbitan monooleate (Span 80) and polyoxyethylene sorbitan monolaurate (Tween 20) as emulsifier, and puerarin as target drug. The morphology of SLN with drug loaded or not was investigated by the transmission electron microscope (TEM). The crystal order and structure of particles were studied by differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD), respectively. The results indicate that the diameters of SLN with puerarin inside are larger than those without drugs. The analysis of WAXD and DSC shows that the state of crystallinity SLN prepared by double emulsion method was worse than that of SLN prepared by microemulsion. And also the drug-loaded SLN presents a less ordered crystallinity than the drug-free SLN. But both the drug-free and drug-loaded SLN exist in an amorphous state. The reasons of the phenomenon have been discussed.

The Ste20 Kinases Ste20-related Proline-Alanine-rich Kinase and Oxidative-stress Response 1 Regulate NKCC1 Function in Sensory Neurons

NKCC1 is highly expressed in dorsal root ganglion neurons, where it is involved in gating sensory information. In a recent study, it was shown that peripheral nerve injury results in increased NKCC1 activity, not due to an increase in cotransporter expression, but to increased phosphorylation of the cotransporter (Pieraut, S., Matha, V., Sar, C., Hubert, T., Méchaly, I., Hilaire, C., Mersel, M., Delpire, E., Valmier, J., and Scamps, F. (2007) J. Neurosci. 27, 6751-6759). Our laboratory has also identified two Ste20-like kinases that bind and phosphorylate NKCC1: Ste20-related proline-alanine-rich kinase (SPAK) and oxidative-stress response 1 (OSR1). In this study, we show that both kinases are expressed at similar expression levels in spinal cord and dorsal root ganglion neurons, and that both kinases participate equally in the regulation of NKCC1. Using a novel fluorescence method to assay NKCC1 activity in single cells, we show a 50% reduction in NKCC1 activity in DRG neurons isolated from SPAK knockout mice, indicating that another kinase, e.g. OSR1, is present to phosphorylate and activate the cotransporter. Using a nociceptive dorsal root ganglion sensory neuronal cell line, which expresses the same cation-chloride cotransporters and kinases as native DRG neurons, and gene silencing via short hairpin RNA, we demonstrate a direct relationship between kinase expression and cotransporter activity. We show that inactivation of either kinase significantly affects NKCC1 activity, whereas inactivation of both kinases results in an additive effect. In summary, our study demonstrates redundancy of kinases in the regulation of NKCC1 in dorsal root ganglion neurons.

Surfactant Recovery from Water Using a Multistage Foam Fractionator: Effect of Surfactant Type

The purpose of this study was to investigate the recovery of surfactants using a multistage foam fractionator for three types of surfactants: cationic (cetyl pyridinium chloride, CPC); anionic (sodium dodecyl sulfate, SDS); and nonionic (polyoxyethylene(20) sorbitan monolaurate, Span80). The studied system was operated at a constant temperature of 25°C with a surfactant concentration in the range of 50 to 100% of CMC (critical micelle concentration). For any surfactant system, the enrichment ratio of surfactant increased with increasing foam height and number of stages but decreased with increasing effects of the air flow rate and feed concentration. For all studied surfactants, the removal efficiency of the surfactant was not significantly affected by changing the air flow rate, foam height, and feed concentration in the studied ranges. An increase in the number of stages showed a great improvement of both the enrichment ratio and the removal fraction for all three types of surfactants. In a comparison among the three studied surfactants, the separation performance, in terms of the enrichment ratio and removal was found to lie in the following order: CPC >Span80 > SDS, which can be explained by the foamability and foam stability of each surfactant.

Surfactant Effects on the Affinity of Plant Cuticles with Organic Pollutants

To precisely predict organics accumulation and crop safety, the affinity of fruit cuticles for naphthalene and 1-naphthol was investigated with the presence of three surfactants below and above the critical micelle concentration (CMC), including anionic sodium dodecylbenzene sulfonate (SDBS), cationic cetyltrimethylammonium bromide (CTMAB), and nonionic polyoxyethylene (20) sorbitan monolaurate (Tween 20). Tomato and apple cuticles with distinct compositions were selected. With increasing SDBS concentrations, apparent sorption coefficients (K(d)*) of 1-naphthol by both cuticles first increased a bit and then decreased slightly. The K(d)* of naphthalene by tomato cuticle is sensitive to SDBS concentration with a sharp increase and then decrease, whereas SDBS has little effect on naphthalene K(d)* by apple cuticle. For CTMAB with lower CMC, the naphthalene K(d)* decreased more quickly. Tween 20 seems to be ineffective on naphthalene sorption by both cuticles. Nevertheless, the intrinsic sorption coefficients (K(d)) were almost promoted by the coexisting surfactants, resulting from the cuticle-sorbed surfactant's plasticizing effect.

Effect of thermal treatments on the properties of coconut milk emulsions prepared with surface-active stabilizers

Previously we have demonstrated improved stability of coconut milk emulsions homogenized with various surface-active stabilizers, i.e., 1 wt% sodium caseinate, whey protein isolate (WPI), sodium dodecyl sulfate (SDS), or polyoxyethylene sorbitan monolaurate (Tween 20) [Tangsuphoom, N., & Coupland, J. N. (2008). Effect of surface-active stabilizers on the microstructure and stability of coconut milk emulsions. Food Hydrocolloids, 22(7), 1233–1242]. This study examines the changes in bulk and microstructural properties of those emulsions following thermal treatments normally used to preserve coconut milk products (i.e., −20 °C, −10 °C, 5 °C, 70 °C, 90 °C, and 120 °C). Calorimetric methods were used to determine the destabilization of emulsions and the denaturation of coconut and surface-active proteins. Homogenized coconut milk prepared without additives was destabilized by freeze–thaw, (−20 °C and −10 °C) but not by chilling (5 °C). Samples homogenized with proteins were not affected by low temperature treatments while those prepared with surfactants were stable to chilling but partially or fully coalesced following freeze–thaw. Homogenized coconut milk prepared without additives coalesced and flocculated after being heated at 90 °C or 120 °C for 1 h in due to the denaturation and subsequent aggregation of coconut proteins. Samples emulsified with caseinate were not affected by heat treatments while those prepared with WPI showed extensive coalescence and phase separation after being treated at 90 °C or 120 °C. Samples prepared with SDS were stable to heating but those prepared with Tween 20 completely destabilized by heating at 120 °C.

Effect of surface-active stabilizers on the surface properties of coconut milk emulsions

Recently we have shown how surface-active stabilizers (≤1 wt% sodium dodecyl sulfate, polyoxyethylene sorbitan monolaurate, whey protein isolate, and sodium caseinate) added either before or after homogenization affect the stability and properties of coconut milk emulsions [Tangsuphoom, N., & Coupland, J. N. (2008). Effect of surface-active stabilizers on the microstructure and stability of coconut milk emulsions. Food Hydrocolloids, 22(7), 1233–1242]. In this work, we propose a mechanism to explain these observations based on changes in surface composition and properties. Coconut milk has a high surface protein load (∼7 mg m −2), of which the major component is cocosin. Small-molecule surfactants (>0.25%) added to the homogenized coconut milk displaced the coconut proteins from the surface resulting in a change in ζ-potential. Dairy proteins added to the coconut milk after homogenization did not accumulate at the droplet surface. Addition of small-molecule surfactants to the coconut milk prior to homogenization completely displaced coconut proteins from the oil–water interface. Homogenization of coconut milk with proteins resulted in a decrease in total protein surface concentration (to about 2 mg m −2) and a significant replacement of coconut proteins by the dairy proteins. The change in ζ-potential also reflected the change in protein and surface composition as the values moved close to the value of coconut oil emulsions stabilized solely with the corresponding added stabilizer.

계면활성제를 이용한 수분산 Tocopherol 유화물의 개발

This study was carried out to make water-soluble tocopherol emulsion which can be applicable directly in water. The molecular weight of tocopherol was 340 to 360 and tocopherol emulsion model was decided as O/O/W/W type. In correlation between stability of emulsion and surface tension, the stability in surface tension of emulsion was from 40 to 46 dyne/㎝. In the case of lower than 40 dyne/㎝ of surface tension, the stability of the emulsion was lower. Lipophilic surfactants, especially for a polyglycerine polyricinoleate in 20%, 30% and 40% tocopherol emulsion, was the most effective in emulsion stability. A higher stability of the emulsion among hydrophilic surfactants in the tocopherol emulsion was obtained in the following order; polyglycerine monostearate＞ polyglycerine monooleate＞ polyoxyethylene (20) sorbitan monooleate≥ polyoxyethylene (20) sorbitan monolaurate.

Aggregation Behavior of Polyoxyethylene (20) Sorbitan Monolaurate (Tween 20) in Imidazolium Based Ionic Liquids

Surface tension measurements were carried out for the solutions of polyoxyethylene (20) sorbitan monolaurate (Tween 20) in 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF 4) and hexafluorophosphate (bmimPF 6) at various temperatures. Two transition points were found in the surface tension-concentration curves at each temperature. The freeze-fracture transmission electron microscopy revealed that two kinds of particles with different sizes are formed at the concentrations of each transition point. Thus, the surfactant concentrations of the two transition points are regarded as critical aggregation concentrations, CAC 1 and CAC 2. From the CAC values and their temperature dependence, we estimated the thermodynamic parameters of the aggregate formation, Delta G agg (0), Delta H agg (0), and Delta S agg (0). The thermodynamic parameters related to CAC 1 are almost independent of temperature. On the other hand, as for the aggregate formation at CAC 2, a positiveDelta S agg (0) contributes to a negative Delta G agg (0) at low temperature, while a negative Delta H agg (0) contributes to a negative Delta G agg (0) at high temperature. The behavior of the thermodynamic parameters as a function of temperature, combined with the variation of (1)H NMR chemical shifts of the bmim (+) protons as a function of the surfactant concentration, demonstrated that the aggregates formed at CAC 1 are nanodroplets of Tween 20 segregated from the solution phase, while those formed at CAC 2 are similar to the usual surfactant micelles formed in aqueous solution.

Preparation of platinum nanoparticles on carbon black with mixed binary surfactants: Characterization and evaluation as anode catalyst for low-temperature fuel cell

Platinum nanoparticles supported on Vulcan XC-72R prepared by a surfactant-stabilized colloidal method exhibit excellent properties as an anode catalyst for a low-temperature fuel cell. A Pt/C catalyst prepared with a 10-fold critical micelle concentration of mixed non-ionic surfactants [polyoxyethylene (23) lauryl ether + polyoxyethylene (20) sorbitan monolaurate (Brij 35 + Tween 20)] shows the highest catalytic activity and the greatest electrochemical surface-active area among those prepared. The maximum current density of this catalyst is much higher than that of a commercial Pt/C catalyst (E-TEK). Moreover, X-ray diffraction and transmission electron microscopy analyses reveal that Pt/C prepared with Brij 35 + Tween 20 has an average particle size of 2.4 nm with quite a narrow distribution between 2 and 3 nm, which is the smallest among all the catalysts prepared. This is attributed to the formation of more compact micelles. Mixtures of non-ionic and anionic surfactants result in less compact micelles.

Effect of surfactant type on microbubble formation behavior using Shirasu porous glass (SPG) membranes

We have recently proposed a new method for generating monodispersed microbubbles from Shirasu porous glass (SPG) membranes with a narrow pore size distribution. In this study, to investigate the effects of surfactant type on microbubble formation behavior from SPG membranes, the microbubble formation experiments were performed using differently charged surfactants. Sodium n-dodecylbenzenesulfonate (SDBS), polyoxyethylene (20) sorbitan monolaurate (Tween 20) and cetyltrimethylammonium bromide (CTMA) were used as anionic, nonionic and cationic surfactants, respectively. Air was pressurized into a surfactant solution of 2.0 mol m −3 through an SPG membrane with a mean pore diameter of 5.1 μm at a transmembrane/bubble-point pressure ratio of 1.1. In systems containing SDBS and Tween 20, monodispersed microbubbles with mean bubble diameters of 35.6 and 43.0 μm were generated, respectively, from the membrane. The CTMA-containing system resulted in polydispersed bubble formation, due to the adsorption of CTMA molecules (cations) onto the negatively charged membrane surface, which lowered the hydrophilicity of the membrane surface. The microbubbles generated were smaller for SDBS than for Tween 20. This is probably because for the case of SDBS, the microbubbles detached from the pores as soon as they were formed, due to a strong electrostatic repulsion between the negatively charged bubble surface and the negatively charged membrane surface, which assists in microbubble detachment from the pore openings. The gaseous-phase flux was about 11–15 times larger for Tween 20 than for SDBS, but much smaller for CTMA, which is a consequence of the fact that the proportion of active pores is significantly lower for SDBS than for both Tween 20 and CTMA.

Controlled production of oil-in-water emulsions containing unrefined pumpkin seed oil using stirred cell membrane emulsification

Membrane emulsification of unrefined pumpkin seed oil was performed using microengineered flat disc membranes on top of which a paddle blade stirrer was operated to induce surface shear. The membranes used were fabricated by galvanic deposition of nickel onto a photolithographic template and contained hexagonal arrays of uniform cylindrical pores with a diameter of 19 or 40 μm and a pore spacing of 140 μm. The uniformly sized pumpkin seed oil drops with span values less than 0.4 were obtained at oil fluxes up to 640 L m −2 h −1 using 2 wt.% Tween 20 (polyoxyethylene sorbitan monolaurate) or 2–10 wt.% Pluronic F-68 (polyoxyethylene–polyoxypropylen copolymer) as an aqueous surfactant solution. Pumpkin seed oil is rich in surface active ingredients that can be adsorbed on the membrane surface, such as free fatty acids, phospholipids, and chlorophyll. The adsorption of these components on the membrane surface gradually led to membrane wetting by the oil phase and the formation of uniform drops was achieved only for dispersed phase contents less than 10 vol.%. At high oil fluxes, Pluronic F-68 molecules present at a concentration of 2 wt.% could not adsorb fast enough, on the newly formed oil drops, to stabilise the expanding interface.