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Sample records for nonionic surfactant systems

  1. Phase equilibria for mixtures containing nonionic surfactant systems: Modeling and experiments

    International Nuclear Information System (INIS)

    Shin, Moon Sam; Kim, Hwayong

    2008-01-01

    Surfactants are important materials with numerous applications in the cosmetic, pharmaceutical, and food industries due to inter-associating and intra-associating bond. We present a lattice fluid equation-of-state that combines the quasi-chemical nonrandom lattice fluid model with Veytsman statistics for (intra + inter) molecular association to calculate phase behavior for mixtures containing nonionic surfactants. We also measured binary (vapor + liquid) equilibrium data for {2-butoxyethanol (C 4 E 1 ) + n-hexane} and {2-butoxyethanol (C 4 E 1 ) + n-heptane} systems at temperatures ranging from (303.15 to 323.15) K. A static apparatus was used in this study. The presented equation-of-state correlated well with the measured and published data for mixtures containing nonionic surfactant systems

  2. Packing states of multilamellar vesicles in a nonionic surfactant system

    DEFF Research Database (Denmark)

    Le, T.D.; Olsson, U.; Mortensen, K.

    2001-01-01

    -alpha(*) phase using the noninvasive small-angle neutron scattering (SANS) technique, one while heating and the other while cooling the sample. Data from the heating and cooling cycles were used to demonstrate reversibility of the system. Three states of packing can be identified from the scattering profiles......Lyotropic lamellar phases under shear flow have been shown to form multilamellar vesicles (MLVs), an onion-like structure. The size of the vesicles is governed by the shear imposed on the sample. Previously, we studied the structural transformation from multilamellar vesicles to lamellae to sponge...... under shear. Here, we focused only in the MLV region, L-alpha(*), of a temperature sensitive surfactant system (C12E4-water) to investigate the packing of multilamellar vesicles as a function of temperature under constant shear. Two sets of temperature scan experiments were performed in the L...

  3. Nanohybrid systems of non-ionic surfactant inserting liposomes loading paclitaxel for reversal of multidrug resistance.

    Science.gov (United States)

    Ji, Xiufeng; Gao, Yu; Chen, Lingli; Zhang, Zhiwen; Deng, Yihui; Li, Yaping

    2012-01-17

    Three new nanohybrid systems of non-ionic surfactant inserting liposomes loading paclitaxel (PTX) (NLPs) were prepared to overcome multidrug resistance (MDR) in PTX-resistance human lung cancer cell line. Three non-ionic surfactants, Solutol HS 15 (HS-15), pluronic F68 (PF-68) and cremophor EL (CrEL) were inserted into liposomes by film hydration method to form NLPs with an average size of around 110, 180 and 110 nm, respectively. There was an obvious increase of rhodamin 123 (Rh123) accumulation in A549/T cells after treated with nanohybrid systems loading Rh123 (NLRs) when compared with free Rh123 or liposomes loading Rh123 without surfactants (LRs), which indicated the significant inhibition effects of NLRs on drug efflux. The P-gp detection and ATP determination demonstrated that BNLs could not only interfere P-gp expression on the membrane of drug resistant cells, but also decrease ATP level in the cells. The cytotoxicity of NLPs against A549/T cells was higher than PTX loaded liposomes without surfactants (LPs), and the best result was achieved after treated with NLPs2. The apoptotic assay and the cell cycle analysis showed that NLPs could induce more apoptotic cells in drug resistant cells when compared with LPs. These results suggested that NLPs could overcome MDR by combination of drug delivery, P-gp inhibition and ATP depletion, and showed potential for treatment of MDR. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Biotoxicity and bioavailability of hydrophobic organic compounds solubilized in nonionic surfactant micelle phase and cloud point system.

    Science.gov (United States)

    Pan, Tao; Liu, Chunyan; Zeng, Xinying; Xin, Qiao; Xu, Meiying; Deng, Yangwu; Dong, Wei

    2017-06-01

    A recent work has shown that hydrophobic organic compounds solubilized in the micelle phase of some nonionic surfactants present substrate toxicity to microorganisms with increasing bioavailability. However, in cloud point systems, biotoxicity is prevented, because the compounds are solubilized into a coacervate phase, thereby leaving a fraction of compounds with cells in a dilute phase. This study extends the understanding of the relationship between substrate toxicity and bioavailability of hydrophobic organic compounds solubilized in nonionic surfactant micelle phase and cloud point system. Biotoxicity experiments were conducted with naphthalene and phenanthrene in the presence of mixed nonionic surfactants Brij30 and TMN-3, which formed a micelle phase or cloud point system at different concentrations. Saccharomyces cerevisiae, unable to degrade these compounds, was used for the biotoxicity experiments. Glucose in the cloud point system was consumed faster than in the nonionic surfactant micelle phase, indicating that the solubilized compounds had increased toxicity to cells in the nonionic surfactant micelle phase. The results were verified by subsequent biodegradation experiments. The compounds were degraded faster by PAH-degrading bacterium in the cloud point system than in the micelle phase. All these results showed that biotoxicity of the hydrophobic organic compounds increases with bioavailability in the surfactant micelle phase but remains at a low level in the cloud point system. These results provide a guideline for the application of cloud point systems as novel media for microbial transformation or biodegradation.

  5. PEGylated non-ionic surfactant vesicles as drug delivery systems for Gambogenic acid.

    Science.gov (United States)

    Lin, Tongyuan; Fang, Qingying; Peng, Daiyin; Huang, Xia; Zhu, Tingting; Luo, Qing; Zhou, Kai; Chen, Weidong

    2013-01-01

    Gambogenic acid (GNA), a popular Chinese traditional medicine, has its limitations of coming into use due to its low aqueous solubility and poor bioavailability. In this study, therefore, the PEGylated non-ionic surfactant vesicles drug delivery systems were prepared from biocompatible non-ionic surfactant of Span60, cholesterol and dicetyl phosphate (DCP) by the improved ethanol injection method, and were modified with a polyethylene glycol monostearate15 (PEG15-SA). PEG15-SA, as a biocompatible, non-toxic and non-immunogenic hydrophilic segment, was grafted onto the surface of colloidal niosomes carries to reduce the uptake by the reticuloendothelial system (RES), prolonging the circulation time and attaining higher entrapment efficiency. To our knowledge, this work is the first to report that PEG15-SA was applied to coating of niosomes for encapsulation of GNA. The optimized PEG-GNA-NISVs (P-GNA-NISVs) were characterized in terms of mean vesicles size, polydispersity index (PDI), Zeta potential and entrapment efficiency of the P-GNA-NISVs. The results showed that the mean diameter, PDI, Zeta potential, and the entrapment efficiency of the P-GNA-NISVs were 70.1 nm, 0.166, -44.3 mV and 87.74%, respectively. Furthermore, the release studies of GNA from PEGylated niosomes in vitro and the pharmacokinetics in vivo exhibited a prolonged release profile as studied over 24 h. In conclusion, the result suggests that P-GNA-NISVs prepared in this way not only have higher encapsulation capacity, more colloidal stability but also offer an approach that the PEGylated niosomes is a promising carrier for anticancer GNA.

  6. Mixed system of ionic liquid and non-ionic surfactants in aqueous media: Surface and thermodynamic properties

    International Nuclear Information System (INIS)

    Bhatt, Darshak; Maheria, Kalpana; Parikh, Jigisha

    2014-01-01

    Highlights: • Interaction of ionic liquid and ethylene oxide based non-ionic surfactants in aqueous media. • Evaluation of various surface properties and thermodynamic parameters. • Micellar growth ensues from exothermic to endothermic with increase in temperature. • Micelle formation is enthalpy driven at low temperature and entropy driven at higher temperature. • The micellization power and adsorption proficiency decreased at high IL concentrations. - Abstract: The mixed system of ionic liquid (IL) tetraethyl ammonium tetrafluoroborate [TEA(BF 4 )] and numerous ethylene oxide based non-ionic surfactants in aqueous media were studied using surface tension, viscosity and dynamic light scattering (DLS) measurements. Various surface properties like critical micelle concentration (cmc), maximum surface excess concentration (Γ max ), minimum surface area per surfactant molecule (A min ), surface tension at the cmc (γ cmc ), adsorption efficiency (pC 20 ), and effectiveness of surface tension reduction (π cmc ) as well as thermodynamic parameters of micellization have been determined. DLS and viscosity measurements revealed that the micellar growth was attributed to the bridged solvophilicity of the POE chain in surfactants at elevated temperatures. In most of the cases, the progression ensues from exothermic to endothermic with increase in temperature of the mixed system. Thermodynamic parameter indicates that the micelle formation process is enthalpy driven at low temperature and entropy driven at higher temperature

  7. Particle-size dependent sorption and desorption of pesticides within a water-soil-nonionic surfactant system.

    Science.gov (United States)

    Wang, Peng; Keller, Arturo A

    2008-05-01

    Although nonionic surfactants have been considered in surfactant-aided soil washing systems, there is little information on the particle-size dependence of these processes, and this may have significant implications for the design of these systems. In this study, Triton-100 (TX) was selected to study its effect on the sorption and desorption of two pesticides (Atrazine and Diuron) from different primary soil size fractions (clay, silt, and sand fractions) under equilibrium sorption and sequential desorption. Soil properties, TX sorption, and pesticide sorption and desorption all exhibited significant particle-size dependence. The cation exchange capacity (CEC) of the bulk soils and the soil fractions determined TX sorption capacity, which in turn determined the desorption efficiency. Desorption of pesticide out of the clay raction is the limiting factor in a surfactant-aided washing system. The solubilization efficiency of the individual surfactant micelles decreased as the amount of surfactant added to the systems increased. Thus, instead of attempting to wash the bulk soil, a better strategy might be to either (1) use only the amount of surfactant that is sufficient to clean the coarse fraction, then separate the fine fraction, and dispose or treat it separately, or (2) to separate the coarse fractions mechanically and then treatthe coarse and fine fractions separately. These results may be applicable to many other hydrophobic organic compounds such as polyaromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) strongly sorbed onto soils and sediments.

  8. Formulation and characterisation of self-microemulsifying drug delivery systems based on biocompatible nonionic surfactants

    Directory of Open Access Journals (Sweden)

    Đekić Ljiljana M.

    2014-01-01

    Full Text Available Development of self-dispersing drug delivery systems (SMEDDS is a modern strategy for oral delivery improvement of poorly soluble drugs. Self-microemulsifying drug delivery systems (SMEDDS are isotropic mixtures of oils and hydrophilic surfactants, which form oil-in-water (o/w microemulsions by dilution in aqueous media (e.g., gastrointestinal fluids. Formulation of SMEDDS carriers requires consideration of a large number of formulation parameters and their influences on process of self-microemulsifying and releasing of drug. The aim of this work was formulation and characterisation of SMEDDS for oral administration of ibuprofen. In the experimental work, two series of potential SMEDDS were prepared (M1-M10, using surfactant (Labrasol®, Gattefosse, cosurfactant (PEG-40 hydrogenated castor (Cremophor® RH40, and oil (medium chain triglycerides (Crodamol® GTCC and olive oil (Cropur® Olive, at surfactant-to-cosurfactant mass ratios (Km 9:1, 7:3, 5:5, 3:7, and 1:9, and 10 % or 20 % of the oil phase. Ibuprofen was dissolved in formulations in concentration of 10 %. Characterisation of the investigated formulations included evaluation of physical stability, self-microemulsification ability in 0,1M HCl (pH 1.2 and phosphate buffer pH 7.2 (USP and in vitro drug release. Formation of o/w microemulsions with the average droplet size (Z-ave up to 100 nm, was observed in dispersions of formulations prepared with 10% w/w of medium chain triglycerides, within the entire investigated range of the Km values (M1-M5. These formulations were selected as SMEDDS. Results of characterisation pointed out the importance of the type and concentration of the oil as well as the Km value for the self-microemulsying ability as well as drug release kinetics from the investigated SMEDDS. Ibuprofen relase was in accordance with the request of USP 30-NF 25 (at least 80 %, after 60 min from the formulations M1 (Km 9:1 and M5 (Km 1:9. Furthermore, ibuprofen release was

  9. (Cationic + nonionic) mixed surfactant aggregates for solubilisation of curcumin

    International Nuclear Information System (INIS)

    Kumar, Arun; Kaur, Gurpreet; Kansal, S.K.; Chaudhary, G.R.; Mehta, S.K.

    2016-01-01

    Highlights: • Critical micelle concentration of mixed surfactant has been measured. • Aqueous solubility and alkaline stability of curcumin has been significantly improved. • Location of curcumin within micelles has been evaluated. • Scavenging activity of curcumin has been improved. • Non-intercalative binding with ct-DNA has been observed. - Abstract: Curcumin is a potential drug for variety of diseases. Major limitations of curcumin are low water solubility, rapid hydrolytic degradation in alkaline medium and poor bioavailability. To overcome these limitations, highly potential mixed micellar system has been prepared. In order to reduce inter ionic repulsion and precipitation of surfactants, (cationic + non-ionic) mixed system have been chosen that directly influence its applicability. Hydrophobic chain of non-ionic surfactant significantly influences the cmc of mixed surfactant system as indicated by fluorescence and conductivity data. UV–visible spectroscopy analyses show that solubility, stability and antioxidant property of the curcumin is remarkably improved depending on cmc and aggregation number (N_a_g_g) of mixed surfactants, where N_a_g_g plays crucial role. Generally, curcumin undergoes complete degradation in slight basic medium, but stability has been maintained up to 8 h at pH-13 using formulated mixed micelles (only (20 to 25)% degraded). Location of curcumin which is monitored using emission spectroscopy, fluorescence quenching and "1H NMR spectroscopy techniques play the most important role. Observed results show that the major population of curcumin is located at the polar region and some are in hydrophobic region of the mixed micelles. To ensure the effect of mixed surfactants and curcumin loaded mixed surfactants on DNA, the interaction parameter indicates non-interclative interactions.

  10. Nonionic surfactant Brij35 effects on toluene biodegradation in a ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... Nonionic surfactants are usually used in the bioavailability studies due to their rela- ..... Leson G, Winer AM (1991) Biofiltration: an innovative air pollution control technology for ... thermodynamics and kinetics. Lewis publishers ...

  11. Small-angle neutron scattering studies of nonionic surfactant: Effect

    Indian Academy of Sciences (India)

    Micellar solution of nonionic surfactant -dodecyloligo ethyleneoxide surfactant, decaoxyethylene monododecyl ether [CH3(CH2)11(OCH2CH2)10OH], C12E10 in D2O solution have been analysed by small-angle neutron scattering (SANS) at different temperatures (30, 45 and 60°C) both in the presence and absence of ...

  12. Nonionic surfactant Brij35 effects on toluene biodegradation in a ...

    African Journals Online (AJOL)

    Nonionic surfactant effects on the toluene dissolved in the water phase and biodegradation kinetic behaviors of toluene in a composite bead biofilter were investigated. The toluene dissolved in the water phase was enhanced by the addition of surfactant into aqueous solution and the enhancing effect was more pronounced ...

  13. Complex phase behavior in solvent-free nonionic surfactants

    DEFF Research Database (Denmark)

    Hillmyer, M.A.; Bates, F.S.; Almdal, K.

    1996-01-01

    Unsolvated block copolymers and surfactant solutions are ''soft materials'' that share a common set of ordered microstructures, A set of polyethyleneoxide-polyethylethylene (PEG-PEE) block copolymers that are chemically similar to the well-known alkane-oxyethylene (C(n)EO(m)) nonionic surfactants...... was synthesized here. The general phase behavior in these materials resembles that of both higher molecular weight block copolymers and lower molecular weight nonionic surfactant solutions. Two of the block copolymers exhibited thermally induced order-order transitions and were studied in detail by small...

  14. Factors controlling leaching of polycyclic aromatic hydrocarbons from petroleum source rock using nonionic surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Akinlua, Akinsehinwa [Obafemi Awolowo Univ., Ile-Ife (Nigeria). Fossil Fuels and Environmental Geochemistry Group; Jochmann, Maik A.; Qian, Yuan; Schmidt, Torsten C. [Duisburg-Essen Univ., Essen (Germany). Instrumental Analytical Chemistry; Sulkowski, Martin [Duisburg-Essen Univ., Essen (Germany). Inst. of Environmental Analytical Chemistry

    2012-03-15

    The extraction of polycyclic aromatic hydrocarbons (PAHs) from petroleum source rock by nonionic surfactants with the assistance of microwave irradiation was investigated and the conditions for maximum yield were determined. The results showed that the extraction temperatures and type of surfactant have significant effects on extraction yields of PAHs. Factors such as surfactant concentration, irradiation power, sample/solvent ratio and mixing surfactants (i.e., mixture of surfactant at specific ratio) also influence the extraction efficiencies for these compounds. The optimum temperature for microwave-assisted nonionic surfactant extraction of PAHs from petroleum source rock was 120 C and the best suited surfactant was Brij 35. The new method showed extraction efficiencies comparable to those afforded by the Soxhlet extraction method, but a reduction of the extraction times and environmentally friendliness of the new nonionic surfactant extraction system are clear advantages. The results also show that microwave-assisted nonionic surfactant extraction is a good and efficient green analytical preparatory technique for geochemical evaluation of petroleum source rock. (orig.)

  15. Impact of Surface Active Ionic Liquids on the Cloud Points of Nonionic Surfactants and the Formation of Aqueous Micellar Two-Phase Systems.

    Science.gov (United States)

    Vicente, Filipa A; Cardoso, Inês S; Sintra, Tânia E; Lemus, Jesus; Marques, Eduardo F; Ventura, Sónia P M; Coutinho, João A P

    2017-09-21

    Aqueous micellar two-phase systems (AMTPS) hold a large potential for cloud point extraction of biomolecules but are yet poorly studied and characterized, with few phase diagrams reported for these systems, hence limiting their use in extraction processes. This work reports a systematic investigation of the effect of different surface-active ionic liquids (SAILs)-covering a wide range of molecular properties-upon the clouding behavior of three nonionic Tergitol surfactants. Two different effects of the SAILs on the cloud points and mixed micelle size have been observed: ILs with a more hydrophilic character and lower critical packing parameter (CPP formation of smaller micelles and concomitantly increase the cloud points; in contrast, ILs with a more hydrophobic character and higher CPP (CPP ≥ 1) induce significant micellar growth and a decrease in the cloud points. The latter effect is particularly interesting and unusual for it was accepted that cloud point reduction is only induced by inorganic salts. The effects of nonionic surfactant concentration, SAIL concentration, pH, and micelle ζ potential are also studied and rationalized.

  16. Small angle neutron scattering study of two nonionic surfactants in ...

    Indian Academy of Sciences (India)

    nonionic surfactants in water micellar solutions. RAJEWSKA ALDONA. Institute of ... water solution for concentration c = 0.17% (dilute regime) at different temperatures in the range t = 10–35°C by small .... which yields the pair distance distribution function p(r), where r is the distance in real space. The point, at which the p(r) ...

  17. The effect of electrolytes on emulsions stabilized by nonionic surfactants

    NARCIS (Netherlands)

    Boomgaard, van den A.

    1985-01-01

    The objective of this study was to investigate the effect of high electrolyte concentrations on the stability of oil-in-water- emulsions stabilized by nonionic surfactants.

    In chapter 1 several stability mechanisms are briefly outlined and the distinction between coalescence and

  18. Nonionic surfactant organoclay obtaining from Pedra Lavrada District, PB, Brazil

    International Nuclear Information System (INIS)

    Silva, I.A. da; Cardoso, M.A.F.; Figueiredo, J.M.R.; Silva, C.D.; Neves, G.A.; Ferreira, H. C.

    2012-01-01

    The oil industry has invested for many years in the use of smectite clay as a dispersing agent in the composition of drilling fluids for oil wells water based and oil based. The State of Paraiba is one of the largest producers of clays and recently discovered new deposits in the regions of Cubati and Pedra Lavrada by creating a great expectation of the expansion of mineral production in the region. The aim of this work is a smectite clays organophilization of the city of Pedra Lavrada, with the addition of nonionic surfactant. After organophilization clay was characterized by X-ray diffraction and Foster swelling in order to choose the most suitable surfactant through the organic liquid dispersant diesel. The results showed that incorporation of surfactant used in the clay interlayer spacing increased significantly, and that the dispersions showed rheological properties within the specifications of PETROBRAS, for use of organophilic clays in drilling fluids in nonionic base. (author)

  19. Surface active properties and biological activity of novel nonionic surfactants containing pyrimidines and related nitrogen heterocyclic ring systems

    Directory of Open Access Journals (Sweden)

    El-Sayed, R.

    2008-06-01

    Full Text Available A series of annelated pyrimidine derivatives has been synthesized via different heterocyclization reactions of suitably functionalized 6-(4-octadecyloxyphenyl-4-oxo-2- thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile (4 with different electrophiles and nucleophiles. These heterocycles bear an active hydrogen atom (NH, OH or COOH which could be propoxylated using propylene oxide with different moles, 5, 10 and 15, to produce nonionic surfactant having a long alkyl chain with molecular weight suitable for becoming an amphiphilic molecule with correct hydrophilic-lypophilic balance which enhances solubility, biodegradability and hence lowers the toxicity to human beings and becomes environmentally friendly. In addition, the antimicrobial activities of these compounds were screened and it was found that some of these compounds have similar or higher activity compared with commercial antibiotic drugs (sulphadiazine, which make them suitable for diverse applications like the manufacturing of drugs, pesticides, emulsifiers, cosmetics, etc.Una serie de derivados pirimidínicos y relacionados han sido preparados vía diferentes reacciones de formación de heterociclos entre 6-(4-octadeciloxifenil-4-oxo-2-tioxo- 1,2,3,4-tetrahidropirimidina-5-carbonitrilo (4 y diferentes electrófilos y nucleófilos. Estos heterociclos tienen un átomo de hidrógeno activo (NH, OH, o COOH que fue propoxilado con diferentes moles de óxido de propileno (5, 10, o 15 para producir surfactantes no iónicos con una cadena alquílica larga y peso molecular apropiado para convertirse en una molécula anfifílica con un balance hidrofílico-lipofílico correcto que aumenta la solubilidad y la biodedradabilidad, decrece la toxicidad a los seres humanos, y se convierte en respetuoso con el medio ambiente. Además, las actividades antimicrobianas de estos compuestos fueron determinadas y se encontró que algunos de estos compuestos tuvieron una actividad similar o más alta que

  20. Thermodynamics of non-ionic surfactant Triton X-100-cationic surfactants mixtures at the cloud point

    International Nuclear Information System (INIS)

    Batigoec, Cigdem; Akbas, Halide; Boz, Mesut

    2011-01-01

    Highlights: → Non-ionic surfactants are used as emulsifier and solubilizate in such as textile, detergent and cosmetic. → Non-ionic surfactants occur phase separation at temperature as named the cloud point in solution. → Dimeric surfactants have attracted increasing attention due to their superior surface activity. → The positive values of ΔG cp 0 indicate that the process proceeds nonspontaneous. - Abstract: This study investigates the effects of gemini and conventional cationic surfactants on the cloud point (CP) of the non-ionic surfactant Triton X-100 (TX-100) in aqueous solutions. Instead of visual observation, a spectrophotometer was used for measurement of the cloud point temperatures. The thermodynamic parameters of these mixtures were calculated at different cationic surfactant concentrations. The gemini surfactants of the alkanediyl-α-ω-bis (alkyldimethylammonium) dibromide type, on the one hand, with different alkyl groups containing m carbon atoms and an ethanediyl spacer, referred to as 'm-2-m' (m = 10, 12, and 16) and, on the other hand, with -C 16 alkyl groups and different spacers containing s carbon atoms, referred to as '16-s-16' (s = 6 and 10) were synthesized, purified and characterized. Additions of the cationic surfactants to the TX-100 solution increased the cloud point temperature of the TX-100 solution. It was accepted that the solubility of non-ionic surfactant containing polyoxyethylene (POE) hydrophilic chain was a maximum at the cloud point so that the thermodynamic parameters were calculated at this temperature. The results showed that the standard Gibbs free energy (ΔG cp 0 ), the enthalpy (ΔH cp 0 ) and the entropy (ΔS cp 0 ) of the clouding phenomenon were found positive in all cases. The standard free energy (ΔG cp 0 ) increased with increasing hydrophobic alkyl chain for both gemini and conventional cationic surfactants; however, it decreased with increasing surfactant concentration.

  1. Ecotoxicological characterization of polyoxyethylene glycerol ester non-ionic surfactants and their mixtures with anionic and non-ionic surfactants.

    Science.gov (United States)

    Ríos, Francisco; Fernández-Arteaga, Alejandro; Lechuga, Manuela; Fernández-Serrano, Mercedes

    2017-04-01

    This paper reports on a study that investigated the aquatic toxicity of new non-ionic surfactants derived from renewable raw materials, polyoxyethylene glycerol ester (PGE), and their binary mixtures with anionic and non-ionic surfactants. Toxicity of pure PGEs was determined using representative organisms from different trophic levels: luminescent bacteria (Vibrio fischeri), microalgae (Pseudokirchneriella subcapitata), and freshwater crustaceans (Daphnia magna). Relationships between toxicity and the structural parameters such as unit of ethylene oxide (EO) and hydrophilic-lipophilic balance (HLB) were evaluated. Critical micellar concentration (CMC) in the conditions of the toxicity test was also determined. It was found that the toxicity of the aqueous solutions of PGE decreased when the number of EO units in the molecule, HLB, and CMC increased. PGEs showed lower CMC in marine medium, and the toxicity to V. ficheri is lower when the CMC was higher. Given their non-polar nature, narcosis was expected to be the primary mode of toxic action of PGEs. For the mixture of surfactants, we observed that the mixtures with PGE that had the higher numbers of EO units were more toxic than the aqueous solutions of pure surfactants. Moreover, we found that concentration addition was the type of action more likely to occur for mixtures of PGE with lower numbers of EO units with non-ionic surfactants (alkylpolyglucoside and fatty alcohol ethoxylate), whereas for the mixture of PGE with lower EO units and anionic surfactant (ether carboxylic derivative), the most common response type was response addition. In case of mixtures involving amphoteric surfactants and PGEs with the higher numbers of EO units, no clear pattern with regard to the mixture toxicity response type could be observed.

  2. In situ SAXS study on cationic and non-ionic surfactant liquid crystals using synchrotron radiation.

    Science.gov (United States)

    Fritscher, C; Hüsing, N; Bernstorff, S; Brandhuber, D; Koch, T; Seidler, S; Lichtenegger, H C

    2005-11-01

    In situ synchrotron small-angle X-ray scattering was used to investigate various surfactant/water systems with hexagonal and lamellar structures regarding their structural behaviour upon heating and cooling. Measurements of the non-ionic surfactant Triton X-45 (polyethylene glycol 4-tert-octylphenyl ether) at different surfactant concentrations show an alignment of the lamellar liquid-crystalline structure close to the wall of the glass capillaries and also a decrease in d-spacing following subsequent heating/cooling cycles. Additionally, samples were subjected to a weak magnetic field (0.3-0.7 T) during heating and cooling, but no influence of the magnetic field was observed.

  3. Synergism and Physicochemical Properties of Anionic/Amphoteric Surfactant Mixtures with Nonionic Surfactant of Amine Oxide Type

    Science.gov (United States)

    Blagojević, S. M.; Pejić, N. D.; Blagojević, S. N.

    2017-12-01

    The physicochemical properties of initial formulation, that is anionic/amphoteric surfactants mixture SLES/AOS/CAB (sodium lauryl ether sulfate (SLES), α-olefin sulfonates (AOS) and cocamidopropyl betaine (CAB) at ratio 80 : 15 : 5) with nonionic surfactant of amine oxide type (lauramine oxide (AO)) in various concentration (1-5%) were studied. To characterize the surfactants mixture, the critical micelle concentration (CMC), surface tension (γ), foam volume, biodegradability and irritability were determined. This study showed that adding of AO in those mixtures lowered both γ and CMC as well as enhanced SLES/AOS/CAB foaming properties, but did not significantly affect biodegradability and irritability of initial formulation. Moreover, an increase in AO concentration has a meaningful synergistic effect on the initial formulation properties. All those results indicates that a nonionic surfactant of amine oxide type significantly improves the performance of anionic/amphoteric mixed micelle systems, and because of that anionic/amphoteric/nonionic mixture can be used in considerably lower concentrations as a cleaning formulation.

  4. Impact of non-ionic surfactant chemical structure on morphology and stability of polystyrene nanocomposite latex

    CSIR Research Space (South Africa)

    Greesh, N

    2016-01-01

    Full Text Available Polystyrene (PS) colloid particles in presence of non-ionic surfactant-modified clay particles were prepared by the free-radical polymerization of styrene monomers in emulsion. Three different types of non-ionic surfactants, sorbitan monopalmitate...

  5. Phase Behaviour Study of Swiftlet Nest Using Virgin Coconut Oil with Non-Ionic Surfactants

    International Nuclear Information System (INIS)

    Siti Salwa Abd Gani; Siti Zulaika Adisah; Siti Salwa Abd Gani

    2015-01-01

    Virgin coconut oil (VCO) is the oil that obtained from fresh and mature kernel of the coconut by mechanical or natural means with or without the application of heat, which does not lead to alteration of the nature of the oil. It have advantages such as strengthens the immune system because of its lauric acid content. It also has medium-chain fatty acids which heighten metabolism and energy, thus stimulating the thyroid. Swiftlet nest as an active ingredient need to be dispersed in a carrier system. Thus, ternary phase diagrams were constructed to find the suitable and stable system for it. The phase behavior of systems has been investigated by constructing ternary phase diagrams consisting of non-ionic surfactants/VCO:bird nest/water. The surfactants used were Sorbitan tri-oleate (Span 85), Sorbitan mono-oleate (Span 80), Sorbitan monolaurate (Span 20), Polyoxyethylene(20) sorbitan tri-oleate (Tween 85) and Polyoxyethylene (20) sorbitan mono-oleate (Tween 80). These systems include several phase regions such as homogeneous, isotropic, two-phase and three-phase regions. Different hydrophilic lipophilic balance (HLB) value of non-ionic surfactants exhibit different ternary diagram characteristics. A lower HLB shows a more oil-soluble and a more water-soluble surfactant (larger homogeneous and isotropic region in ternary phase diagrams) whereas high value of HLB shows the reverse of that result. The results show that the T85/VCO:bird nest/water system gave better performance than the other four individual surfactant systems. As a conclusion, high hydrophilic lipophilic balance (HLB) values of surfactant were found to be a good surfactant for the formulation of VCO:bird nest emulsion for cosmetic and pharmaceutical purposes. (author)

  6. A study of correlations between the release of drugs from petrolatum-based gels containing nonionic surfactants and some physical and physico-chemical characteristics of the gel systems.

    Science.gov (United States)

    Colo, G D; Nannipieri, E; Serafini, M F; Vitale, D

    1986-06-01

    Synopsis The in vitro release of benzocaine and 2-ethyIhexyl p-di-methylaminobenzoate (EH-PABA) from petrolatum-based gels either containing two nonionic surfactants, or not, was compared with some physical and/or physico-chemical characteristics of the drugs, the gels and the drug-gel systems. The surfactants had no effect on the release of EH-PABA, the less polar drug, whereas they decreased the release of benzocaine. Moreover, the release data show a complex dependence of diffusive properties of ben-zocaine on drug and surfactant concentration. Benzocaine appears to form mixed micelles with each of the two surfactants and/or undergoes self-aggregation phenomena within surfactant micelles. The results indicate that drug diffusion is influenced by gel porosity, drug molecular size and polarity and molecular interactions. Etude des corrélations entre la disponibilité des medicaments dans les gels a base de vaseline contenant des surfactifs non ioniques et quelques propriétés physiques et physicochimiques des gels.

  7. Novel designed polyoxyethylene nonionic surfactant with improved safety and efficiency for anticancer drug delivery

    Directory of Open Access Journals (Sweden)

    Li C

    2014-04-01

    Full Text Available Chang Li,1 Chunmeng Sun,1 Shasha Li,1 Peng Han,2 Huimin Sun,3 Ammar Ouahab,1 Yan Shen,1 Yourui Xu,1 Yerong Xiong,1 Jiasheng Tu11State Key Laboratory of Natural Medicines, Department of Pharmaceutics, China Pharmaceutical University, Nanjing, 2Chinese Pharmacopoeia Commission, Beijing, 3National Institute for Food and Drug Control, Beijing, People's Republic of ChinaAbstract: In order to limit the adverse reactions caused by polysorbate 80 in Taxotere®, a widely used formulation of docetaxel, a safe and effective nanocarrier for this drug has been developed based on micelles formed by a new class of well-defined polyoxyethylene sorbitol oleate (PSO with sorbitol as the matrix in aqueous solution. The physicochemical properties of the amphiphilic surfactant and the resulting micelles can be easily fine-tuned by the homogeneous sorbitol matrix and pure oleic acid. Composition, critical micelle concentration, and entrapment efficiency were investigated by ultraviolet visible spectroscopy, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, fluorospectrophotometry, and high-performance liquid chromatography. In vitro and in vivo evaluation revealed that PSO had exceptionally low hemolysis and histamine release rates compared with commercial polysorbate 80. Moreover, the tumor targeting delivery of PSO was investigated by in vivo imaging in S180 tumor-bearing mice. The results suggest that this novel delivery system, PSO, provides an acceptable alternative to polysorbate 80 for delivery of docetaxel. Further, due to the hypoallergenic nature of PSO, the mechanism of pseudoallergy caused by the polyoxyethylene nonionic surfactant was investigated. Based on in vitro cell analysis, it was assumed that the initial contact of polyoxyethylene nonionic surfactant with mast cells provoked pseudoallergy via polyamine receptor-mediated endocytosis.Keywords: polyoxyethylene nonionic surfactant, sorbitol, isosorbide, pseudoallergy

  8. Microwave-assisted nonionic surfactant extraction of aliphatic hydrocarbons from petroleum source rock

    Energy Technology Data Exchange (ETDEWEB)

    Akinlua, A., E-mail: geochemresearch@yahoo.com [Fossil Fuels and Environmental Geochemistry Group, Department of Chemistry, Obafemi Awolowo University, Ile-Ife (Nigeria); Jochmann, M.A.; Laaks, J.; Ewert, A.; Schmidt, T.C. [Instrumental Analytical Chemistry, University Duisburg-Essen, Universitaetsstr, 5, 45141 Essen (Germany)

    2011-04-08

    The extraction of aliphatic hydrocarbons from petroleum source rock using nonionic surfactants with the assistance of microwave was investigated and the conditions for maximum yield were determined. The results showed that the extraction temperatures and kinetic rates have significant effects on extraction yields of aliphatic hydrocarbons. The optimum temperature for microwave-assisted nonionic surfactant extraction of aliphatic hydrocarbons from petroleum source rock was 105 deg. C. The optimum extraction time for the aliphatic hydrocarbons was at 50 min. Concentration of the nonionic surfactant solution and irradiation power had significant effect on the yields of aliphatic hydrocarbons. The yields of the analytes were much higher using microwave assisted nonionic surfactant extraction than with Soxhlet extraction. The recoveries of the n-alkanes and acyclic isoprenoid hydrocarbons for GC-MS analysis from the extractant nonionic surfactant solution by in-tube extraction (ITEX 2) with a TENAX TA adsorbent were found to be efficient. The results show that microwave-assisted nonionic surfactant extraction (MANSE) is a good and efficient green analytical preparatory technique for geochemical evaluation of petroleum source rock.

  9. Microwave-assisted nonionic surfactant extraction of aliphatic hydrocarbons from petroleum source rock

    International Nuclear Information System (INIS)

    Akinlua, A.; Jochmann, M.A.; Laaks, J.; Ewert, A.; Schmidt, T.C.

    2011-01-01

    The extraction of aliphatic hydrocarbons from petroleum source rock using nonionic surfactants with the assistance of microwave was investigated and the conditions for maximum yield were determined. The results showed that the extraction temperatures and kinetic rates have significant effects on extraction yields of aliphatic hydrocarbons. The optimum temperature for microwave-assisted nonionic surfactant extraction of aliphatic hydrocarbons from petroleum source rock was 105 deg. C. The optimum extraction time for the aliphatic hydrocarbons was at 50 min. Concentration of the nonionic surfactant solution and irradiation power had significant effect on the yields of aliphatic hydrocarbons. The yields of the analytes were much higher using microwave assisted nonionic surfactant extraction than with Soxhlet extraction. The recoveries of the n-alkanes and acyclic isoprenoid hydrocarbons for GC-MS analysis from the extractant nonionic surfactant solution by in-tube extraction (ITEX 2) with a TENAX TA adsorbent were found to be efficient. The results show that microwave-assisted nonionic surfactant extraction (MANSE) is a good and efficient green analytical preparatory technique for geochemical evaluation of petroleum source rock.

  10. Micellization and microstructural studies between amphiphilic drug ibuprofen with non-ionic surfactant in aqueous urea solution

    International Nuclear Information System (INIS)

    Rub, Malik Abdul; Azum, Naved; Kumar, Dileep; Asiri, Abdullah M.; Marwani, Hadi M.

    2014-01-01

    Highlights: • Micellization behavior of (ibuprofen + non-ionic surfactant) mixtures has been investigated. • Ion–dipole type of interaction between ibuprofen drug and non-ionic surfactant. • The negative β values propose attractive interactions between the components. • Stern–Volmer binding constants (K sv ) and dielectric constant of mixed systems have also been evaluated. • The results have applicability in drug delivery. - Abstract: Herein, we have accounted for the interaction between a non-steroidal anti-inflammatory drug ibuprofen (IBF) and non-ionic surfactant polyethoxyglycol t-octylphenyl ether (TX-100 (4-(1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol) and TX-114 ((1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol)), in aqueous urea solutions using tensiometric and fluorimetric techniques at T = 298.15 K. Surface tension measurements were carried out to evaluate the critical micelle concentrations (cmc) of the drug and surfactant as well as their mixtures of varying compositions. An increase in the surface charge of the micelles was observed with the addition of urea followed by halt of micelles formation. Various physicochemical parameters, such as, cmc values of the mixture, micellar mass fraction (X 1 Rub ) of surfactants (TX-100/TX-114), interaction parameters (β) at the monolayer air–water interface and in bulk solutions, different thermodynamic parameters and activity coefficients (f 1 m ,f 2 m ) for the non-ionic surfactant and drug in the mixed micelles, were determined by using the approach of Clint, of Rubingh, and of Rosen. All results identified synergism and attractive interactions in the mixed systems of (drug–surfactant) mixtures and showed effective involvement of the non-ionic surfactant (TX-100/TX-114) component in the mixture. Micelle aggregation numbers (N agg ), evaluated by using steady-state fluorescence quenching studies, suggest that the contribution of non-ionic surfactant was always more than that of

  11. Effect of fluid velocity, temperature, and concentration of non-ionic surfactants on drag reduction

    International Nuclear Information System (INIS)

    Cho, Sung-Hwan; Tae, Choon-Seob; Zaheeruddin, M.

    2007-01-01

    The drag reduction (DR) and heat transfer efficiency reduction (ER) of non-ionic surfactant as a function of fluid velocity, temperature, and surfactant concentration were investigated. Several types of new surfactants, which contain amine-oxide and betaine, were developed. An experimental apparatus consisting of two temperature controlled water storage tanks, pumps, test specimen pipe and the piping network, two flow meters, two pressure gauges, a heat exchanger, and data logging system was built. From the experimental results, it was concluded that existing alkyl ammonium surfactant (CTAC; cethyl trimethyl ammonium chloride) had DR of 0.6-0.8 at 1000-2000 ppm concentration with fluid temperature ranging between 50 and 60 o C. However, the DR was very low when the fluid temperature was 70-80 o C. The new amine oxide and betaine surfactant (SAOB; stearyl amine oxide + betaine) had lower DR at fluid temperatures ranging between 50 and 60 o C compared with CTAC. However, with fluid temperature ranging between 70 and 80 o C the DR was 0.6-0.8 when the concentration level was between 1000 and 2000 ppm

  12. Influence of nonionic surfactants on the potentiometric response of hydrogen ion-selective polymeric membrane electrodes.

    Science.gov (United States)

    Espadas-Torre, C; Bakker, E; Barker, S; Meyerhoff, M E

    1996-05-01

    The influence of poly(ethylene oxide)-based nonionic surfactants (i.e., Triton X-100 and Brij 35) in the sample phase on the response properties of hydrogen ion-selective polymeric membrane electrodes containing mobile (lipophilic amines) or covalently bound (aminated-poly-(vinyl chloride)) hydrogen ion carriers is reported. In the presence of these nonionic surfactants, membrane electrode response toward interfering cation activity (e.g., Na+) in the sample phase is increased substantially and the pH measuring range shortened. The degree of cation interference for pH measurements is shown to correlate with the basicity of the hydrogen ion carrier doped within the membrane phase. The observed deterioration in selectivity arises from the partitioning of the surfactant into the membrane and concomitant extraction of metal cations by the surfactants in the organic phase. The effect of nonionic surfactants on pH electrodes prepared with aminated-PVC membranes is shown to be more complex, with additional large shifts in EMF values apparently arising from multidentate interactions between the surfactant molecules and the polymeric amine in the membrane, leading to a change in the apparent pKa values for the amine sites. The effects induced by nonionic surfactants on the EMF response function of hydrogen ion-selective polymeric membrane electrodes are modeled, and experimental results are shown to correlate well with theoretical predictions.

  13. Separation and recycling of nanoparticles using cloud point extraction with non-ionic surfactant mixtures.

    Science.gov (United States)

    Nazar, Muhammad Faizan; Shah, Syed Sakhawat; Eastoe, Julian; Khan, Asad Muhammad; Shah, Afzal

    2011-11-15

    A viable cost-effective approach employing mixtures of non-ionic surfactants Triton X-114/Triton X-100 (TX-114/TX-100), and subsequent cloud point extraction (CPE), has been utilized to concentrate and recycle inorganic nanoparticles (NPs) in aqueous media. Gold Au- and palladium Pd-NPs have been pre-synthesized in aqueous phases and stabilized by sodium 2-mercaptoethanesulfonate (MES) ligands, then dispersed in aqueous non-ionic surfactant mixtures. Heating the NP-micellar systems induced cloud point phase separations, resulting in concentration of the NPs in lower phases after the transition. For the Au-NPs UV/vis absorption has been used to quantify the recovery and recycle efficiency after five repeated CPE cycles. Transmission electron microscopy (TEM) was used to investigate NP size, shape, and stability. The results showed that NPs are preserved after the recovery processes, but highlight a potential limitation, in that further particle growth can occur in the condensed phases. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. The influence of nonionic surfactant Brij 30 on biodegradation of ...

    African Journals Online (AJOL)

    ONOS

    2010-09-06

    Sep 6, 2010 ... polluted air stream using biological process is highly efficient and has low ... Brij 30 was the most biodegradable surfactant among Brij 30, Tween 80 and ... The filter material contained surfactants that would enhance the ...

  15. Conductometric study of sodium dodecyl sulfate - nonionic surfactant (Triton X-100, Tween 20, Tween 60, Tween 80 or Tween 85 mixed micelles in aqueous solution

    Directory of Open Access Journals (Sweden)

    Ćirin Dejan M.

    2012-01-01

    Full Text Available The present study is concerned with the determination of the critical micelle concentration (cmc of mixed micelles of sodium dodecyl sulfate with one of five nonionic surfactants (Triton X-100, Tween 20, Tween 60, Tween 80 or Tween 85 from conductance measurements. Based on the calculated values of the β parameters we have noticed that SDS-nonionic surfactants mostly showed strong synergistic effect. It was found that nonionic surfactants with mainly longer and more hydrophobic tail show stronger interactions with hydrophobic part of SDS, thus expressing stronger synergism. In SDS-Tween 80 binary system the strongest synergistic effect was noticed. SDS-Tween 85 micellar system showed antagonistic effect, most probably because the presence of the double bond in its three hydrophobic tails (three C18 tails makes it sterically rigid.

  16. Interaction between cholesterol and non-ionic surfactants studied by thin-layer chromatography

    Czech Academy of Sciences Publication Activity Database

    Forgács, E.; Cserháti, T.; Farkas, O.; Eckhardt, Adam; Mikšík, Ivan; Deyl, Zdeněk

    2004-01-01

    Roč. 27, č. 13 (2004), s. 1981-1992 ISSN 1082-6076 Grant - others:CZ-HU(CZ) Cooperation program Institutional research plan: CEZ:AV0Z5011922 Keywords : cholesterol * non-ionic surfactant * thin - layer chromatography Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.836, year: 2004

  17. Simple determination of nonionic surfactants in highly-polluted aqueous samples

    Czech Academy of Sciences Publication Activity Database

    Šváb, M.; Švábová, Martina; Mečířová, P.

    2011-01-01

    Roč. 9, č. 6 (2011), s. 1150-1157 ISSN 1895-1066 Institutional research plan: CEZ:AV0Z30460519 Keywords : nonionic surfactant * soil leachate * spectrophotometric determination Subject RIV: DD - Geochemistry Impact factor: 1.073, year: 2011 http://www.springerlink.com/content/k6401t0237878488/

  18. Preparation of Organized Mesoporous Silica from Sodium Metasilicate Solutions in Alkaline Medium using Nonionic Surfactants

    Czech Academy of Sciences Publication Activity Database

    Zukalová, Markéta; Rathouský, Jiří; Zukal, Arnošt

    2003-01-01

    Roč. 68, č. 10 (2003), s. 2019-2031 ISSN 0010-0765 Institutional research plan: CEZ:AV0Z4040901 Keywords : mesoporous SiO2 * sodium metasilicate * nonionic surfactants Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.041, year: 2003

  19. Characterization of a Biomimetic Mesophase Composed of Nonionic Surfactants and an Aqueous Solvent.

    Science.gov (United States)

    Adrien, V; Rayan, G; Reffay, M; Porcar, L; Maldonado, A; Ducruix, A; Urbach, W; Taulier, N

    2016-10-11

    We have investigated the physical and biomimetic properties of a sponge (L 3 ) phase composed of pentaethylene glycol monododecyl ether (C 12 E 5 ), a nonionic surfactant, an aqueous solvent, and a cosurfactant. The following cosurfactants, commonly used for solubilizing membrane proteins, were incorporated: n-octyl-β-d-glucopyranoside (β-OG), n-dodecyl-β-d-maltopyranoside (DDM), 4-cyclohexyl-1-butyl-β-d-maltoside (CYMAL-4), and 5-cyclohexyl-1-pentyl-β-d-maltoside (CYMAL-5). Partial phase diagrams of these systems were created. The L 3 phase was characterized using crossed polarizers, diffusion of a fluorescent probe by fluorescence recovery after pattern photobleaching (FRAPP), and freeze fracture electron microscopy (FFEM). By varying the hydration of the phase, we were able to tune the distance between adjacent bilayers. The characteristic distance (d b ) of the phase was obtained from small angle scattering (SAXS/SANS) as well as from FFEM, which yielded complementary d b values. These d b values were neither affected by the nature of the cosurfactant nor by the addition of membrane proteins. These findings illustrate that a biomimetic surfactant sponge phase can be created in the presence of several common membrane protein-solubilizing detergents, thus making it a versatile medium for membrane protein studies.

  20. Effect of selected non-ionic surfactants on the flow behavior of aqueous veegum suspensions.

    Science.gov (United States)

    Kennedy, Ross A; Kennedy, Michelle L

    2007-03-30

    The aim of this work was to investigate the influence of some non-ionic surfactants, Tween 80 and Brij 98, on the viscosity and flow behavior of a commercial montmorillonite clay, Veegum Granules. The effect of different concentrations of the surfactants on the shear stress-shear rate rheograms of hydrated concentrated clay suspensions was determined by shear viscometry. The addition of either surfactant increased the plastic viscosity and the yield stress of the suspensions. Furthermore, both surfactants altered the thixotropy of the suspensions to an extent that depended on both the surfactant concentration and the time of equilibration of the surfactant and Veegum. Brij 98 had a greater and more rapid effect. It is proposed that the surfactant polar head-groups anchor at the tetrahedral sheet surface, leaving the alkyl chains extending away from the edges and faces. Consequently, the alkyl chains undergo hydrophobic interactions that facilitate the association between the platelets and increase the physical structure within the suspension. Stereochemical differences between the polar groups may lead to differences in the way the surfactants associate with the tetrahedral sheet and hence their ultimate effect on the rheological behavior. There is a significant interaction between these surfactants and montmorillonite clays, and the rheological changes that occur could have a major impact on any pharmaceutical formulation that uses these ingredients.

  1. Small-angle neutron scattering studies of nonionic surfactant: Effect ...

    Indian Academy of Sciences (India)

    celle above a concentration called critical micelle concentration (CMC) where their properties are different from those of the ... It is well-known that SANS is an ideal technique to study the micellar structure of surfactants [8,9] and this has also ... ment at the Dhruva reactor, Mumbai [11]. The mean wavelength of the incident.

  2. Evaluation of an ODS column modified with zwitterionic/nonionic mixed surfactants and its application to direct injection determination of inorganic anions.

    Science.gov (United States)

    Hasegawa, Takuya; Umemura, Tomonari; Koide, Akira; Chiba, Koichi; Ueki, Yuji; Tsunoda, Kin-ichi; Haraguchi, Hiroki

    2005-08-01

    An octadecylsilica (ODS) column modified with zwitterionic/nonionic mixed surfactants was evaluated for the direct injection determination of inorganic anions in biological fluids by ion chromatography. A zwitterionic surfactant (sulfobetaine-type) and a nonionic surfactant (polyoxyethylene-type) were used for a stationary-phase modification. When aqueous electrolyte solutions with concentrations of sub-mM to several mM were used as a mobile phase, the zwitterionic surfactant coated on the ODS surface exhibited unique separation selectivity for ionic species, while the nonionic surfactant coated on the ODS might have formed a hydrophilic network over the ODS surface and restricted matrix proteins from adsorbing on the stationary phase. Consequently, the mixed surfactant-modified column system allowed an efficient ion chromatographic separation of inorganic anions as well as a size-exclusive removal of column-fouling proteins. This separation system was applied to the direct injection determination of UV-absorbing anions in human saliva. The detection limits for nitrite, nitrate, iodide and thiocyanate were 3.1, 2.7, 4.5 and 25 microM, respectively, with UV detection at 210 nm (injection volume; 20 microl), and their relative standard deviations for 5 replicate measurements of saliva samples spiked with 100 microM each of those anions were 1.4, 0.9, 2.2 and 5.5%, respectively.

  3. Investigation of extractive microbial transformation in nonionic surfactant micelle aqueous solution using response surface methodology.

    Science.gov (United States)

    Xue, Yingying; Qian, Chen; Wang, Zhilong; Xu, Jian-He; Yang, Rude; Qi, Hanshi

    2010-01-01

    Extractive microbial transformation of L-phenylacetylcarbinol (L-PAC) in nonionic surfactant Triton X-100 micelle aqueous solution was investigated by response surface methodology. Based on the Box-Behnken design, a mathematical model was developed for the predication of mutual interactions between benzaldehyde, Triton X-100, and glucose on L-PAC production. It indicated that the negative or positive effect of nonionic surfactant strongly depended on the substrate concentration. The model predicted that the optimal concentration of benzaldehyde, Triton X-100, and glucose was 1.2 ml, 15 g, and 2.76 g per 100 ml, respectively. Under the optimal condition, the maximum L-PAC production was 27.6 mM, which was verified by a time course of extractive microbial transformation. A discrete fed-batch process for verification of cell activity was also presented.

  4. Kinetics and mechanism for the sonochemical degradation of a nonionic surfactant.

    Science.gov (United States)

    Singla, Ritu; Grieser, Franz; Ashokkumar, Muthupandian

    2009-03-26

    The sonolytic degradation of the nonionic surfactant, octaethylene glycol monododecyl ether (C(12)E(8)), has been studied at various initial concentrations below and above its critical micelle concentration (CMC). It has been observed that the degradation rate increases with an increase in the initial concentration of the surfactant until the CMC is reached. Above the CMC an almost constant degradation rate is observed, suggesting that the surfactant in its monomer form is involved in the degradation process. The degradation process of C(12)E(8) involves two distinct primary processes occurring at the bubble/solution interface: (a) hydroxylation/oxidation of the surfactant and (b) pyrolytic fragmentation of the surfactant. The oxidative cleavage of ethylene oxide units provides evidence for OH radical attack. Hydroxylation of the ethoxy chain gives rise to various short-chain carboxyalkyl-polyethylene glycol intermediates. The polyethylene glycol chain formed, due to the scission of the C(12)E(8) molecule, undergoes rapid hydroxylation/oxidation to yield simple compounds that have the potential to undergo further degradation. The detection of multiple intermediates indicates that several processes affect the complete degradation pathways of the surfactant molecule. TOC analysis, however, indicates that the sonolytic mineralization of the surfactant is difficult to achieve at reasonable rates due to the relatively low surface activity of the degradation products formed during sonolysis.

  5. FLOTATION DE-INKING OF 50% ONP/ 50% OMG RECOVERED PAPERS MIXTURES USING NONIONIC SURFACTANT, SOAP, AND SURFACTANT/SOAP BLENDS

    Directory of Open Access Journals (Sweden)

    Jeremy Allix

    2010-11-01

    Full Text Available A laboratory flotation column equipped with Venturi aerators and an adjustable froth removal system was used to study the effect of calcium soap and a mixture of calcium soap/alkyl phenol ethoxylate surfactant on ink and fibres transfer during flotation de-inking of a 50% old newprint (ONP / 50% old magazines (OMG recovered papers mixture. Mass transport phenomena determining the yield of the flotation process were interpreted using model equations describing particle removal in terms of flotation, entrainment, and drainage in the froth. A decrease in the ink and mineral fillers flotation rate constant, drainage through the froth, and in fibre entrainment was observed when increasing the surfactant concentration. These trends were consistent with the typical dispersing action of the studied nonionic surfactant. An opposite effect on ink and fillers was observed when using calcium soap alone, and the increase in the flotation rate constant and drainage through the froth were consistent with the collecting and defoaming action of the calcium soap. Moreover, fibre entrainment decreased when increasing the soap concentration. The study of the surfactant/soap mixture highlighted the absence of synergy between the calcium soap and the surfactant.

  6. Ordered silica particles made by nonionic surfactant for VOCs sorption

    Energy Technology Data Exchange (ETDEWEB)

    Difallah, Oumaima; Hamaizi, Hadj, E-mail: hamaizimizou@yahoo.fr [University of Oran, OranMenaouer (Algeria); Amate, Maria Dolores Urena; Socias-Viciana, Maria Del Mar [University of Almeria (Spain)

    2017-07-15

    Adsorption of light organic compounds such acetone, 1-propanol and carbon dioxide was tested by using mesoporous silica materials made from non ionic surfactant with long chain and silica sources as tetraethyl orthosilicate TEOS and modified Na-X and Li-A Zeolites. X-ray powder diffraction (XRD), nitrogen adsorption-desorption analysis and scanning electron microscopy (SEM) were applied to characterize the silica particles of a variety prepared samples. Acetone, 1-propanol and CO{sub 2} adsorption at 298K was evaluated by a volumetric method and indicate a high sorption capacity of organic compounds depending essentially on the porous texture of adsorbents. An adsorption kinetic model was proposed to describe the adsorption of VOCs over template-free mesoporous silica materials. A good agreement with experimental data was found. (author)

  7. Stabilization of liquid crystal dispersion by nonionic surfactant/acrylamide copolymer containing hydrophobic moieties

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.J.; Kim, M.H.; Lee, J.R. [Korea Research Institute of Chemical Technology, Taejon (Korea)

    1999-07-01

    The effect of nonionic surfactant (H(OCH){sub 2}-OC{sub 6}H{sub 4}-C{sub 9}H{sub 19}, NP-8) and acrylamide copolymer containing nonylphenyl groups as hydrophobic moieties on the stabilization of liquid crystal (LC)-in-water dispersion has been studied. According to cloud point and adsorption measurements, the hydrophobically strong interaction between NP-8 and the nonylphenol moieties is formed. And the addition of surfactant increases the stability of LC dispersion and improve the electrooptical properties of the nematic curvilinear aligned phase (NCAP) composite film. It is due to the presence of surfactant which allows the formation of nonpolar microenvironment in the round of LC droplet and finally reduces the anchoring effect between LC and the polymeric wall. 21 refs., 8 figs.

  8. Synthesis, surface properties and antimicrobial activity of some germanium nonionic surfactants.

    Science.gov (United States)

    Zaki, Mohamed F; Tawfik, Salah M

    2014-01-01

    Esterification reaction between different fatty acid namely; lauric, stearic, oleic and linoleic acids and polyethylene glycol-400 were performed. The produced polyethylene glycol ester were reacted with p-amine benzoic acid followed by condensation reaction with germanium dioxide in presence of sodium carbonate to form desired germinate surfactants. The chemical structures of the synthesized surfactants were determined using different spectra tools. The surface parameter including: the critical micelle concentration (CMC), effectiveness (π(cmc)), efficiency (Pc20), maximum surface excess (Γ(max)) and minimum surface area (A(min)), were calculated from the surface tension measurements. The synthesized surfactants showed higher surface activity. The thermodynamic parameters showed that adsorption and micellization processes are spontaneous. It is clear that the synthesized nonionic surfactants showed their tendency towards adsorption at the interfaces and also micellization in the bulk of their solutions. The synthesized surfactants were tested against different strain of bacteria using inhibition zone diameters. The synthesized surfactants showed good antimicrobial activities against the tested microorganisms including Gram positive, Gram negative as well as fungi. The promising inhibition efficiency of these compounds against the sulfate reducing bacteria facilitates them to be applicable as new categories of sulfate reducing bacteria biocides.

  9. Small angle neutron scattering study of the gemini nonionic surfactant in heavy water solutions

    International Nuclear Information System (INIS)

    Rajewska, A

    2012-01-01

    The nonionic gemini surfactant α α'-[2,4,7,9-tetramethyl-5-decyne-4,7diyl]bis[ω hydroxyl-polyoxyethylene] (S-10) was investigated in heavy water solutions only for concentrations: 2.3%, 2.5%,3%, 3.4%, 4% and 5% at temperature 25 C with small angle neutron scattering (SANS) method. All of surfactants solutions were prepared using D 2 O (99.9% deuterated, Prikladnaia Chimia, St. Petersburg, Russia) as a solvent. The nonionic gemini surfactant S-10 was obtained from Air Products and Chemicals, Inc., and used without further purification. All SANS measurements were performed on V-4 SANS spectrometer at BENSC, Berlin (Germany). Neutrons were used in wavelength range of 0.02 - 4 nm - 1. For the measurements quartz cells of were used during experiment. Up to 14 such cells were placed in a holder. Results from experiment was calculated and evaluated with PCG 2.0 program from Graz University (Austria). In the investigated solutions two axis ellipsoidal micelles was observed.

  10. Effective Surfactants Blend Concentration Determination for O/W Emulsion Stabilization by Two Nonionic Surfactants by Simple Linear Regression.

    Science.gov (United States)

    Hassan, A K

    2015-01-01

    In this work, O/W emulsion sets were prepared by using different concentrations of two nonionic surfactants. The two surfactants, tween 80(HLB=15.0) and span 80(HLB=4.3) were used in a fixed proportions equal to 0.55:0.45 respectively. HLB value of the surfactants blends were fixed at 10.185. The surfactants blend concentration is starting from 3% up to 19%. For each O/W emulsion set the conductivity was measured at room temperature (25±2°), 40, 50, 60, 70 and 80°. Applying the simple linear regression least squares method statistical analysis to the temperature-conductivity obtained data determines the effective surfactants blend concentration required for preparing the most stable O/W emulsion. These results were confirmed by applying the physical stability centrifugation testing and the phase inversion temperature range measurements. The results indicated that, the relation which represents the most stable O/W emulsion has the strongest direct linear relationship between temperature and conductivity. This relationship is linear up to 80°. This work proves that, the most stable O/W emulsion is determined via the determination of the maximum R² value by applying of the simple linear regression least squares method to the temperature-conductivity obtained data up to 80°, in addition to, the true maximum slope is represented by the equation which has the maximum R² value. Because the conditions would be changed in a more complex formulation, the method of the determination of the effective surfactants blend concentration was verified by applying it for more complex formulations of 2% O/W miconazole nitrate cream and the results indicate its reproducibility.

  11. Synthesis of mesoporous aluminophosphate and silicoaluminophosphate in the presence of nonionic poly(ethylene oxide) surfactant

    International Nuclear Information System (INIS)

    Zhao, G.L.; Zhang, X.J.; Chen, T.H.; Yuan, Z.Y.

    2006-01-01

    Thermally stable mesoporous aluminophosphate and silicoaluminophosphate materials have been synthesized by using nonionic PEO-surfactant C 16 H 33 (PEO) 10 OH as a structure-directing agent. The synthesized aluminophosphate and silicoaluminophosphate possess disordered wormhole-like mesostructures with pore sizes of 3.8 and 5 nm, respectively. BET surface areas of 376-412 m 2 /g are obtained. Both four- and six-coordinate Al and tetrahedrally coordinated P were observed. It is believed that these materials may find potential applications in the fields of catalysis and material sciences

  12. Organophilization of bentonite clays with non-ionic surfactants aiming their use in drilling fluids base oil

    International Nuclear Information System (INIS)

    Silva, I.A.; Costa, J.M.R.; Neves, G.A.; Ferreira, H.C.; Ferreira, H.S.

    2010-01-01

    The use of nonionic surfactants has been replacing the traditional ionic surfactants among others by its high potential for resistance to thermal degradation. This work aims at the development of organoclay by the addition of nonionic surfactants for use in drilling fluids for oil wells based oil. The bentonite clay was organophilized and then characterized by X-ray diffraction and swelling Foster, seeking the most appropriate choice of surfactant to liquid organic dispersing media: ester, diesel and paraffin. With the obtained dispersions were measured apparent viscosities and plastic. The results showed that incorporation of surfactants used in the clay interlayer spacing increased significantly and that the dispersions showed rheological properties within the specifications of PETROBRAS, for the use of organophilic clays in drilling fluids in a non-aqueous base. (author)

  13. Effects of ionic and nonionic surfactants on milk shell wettability during co-spray-drying of whole milk particles.

    Science.gov (United States)

    Lallbeeharry, P; Tian, Y; Fu, N; Wu, W D; Woo, M W; Selomulya, C; Chen, X D

    2014-09-01

    Mixing surfactants with whole milk feed before spray drying could be a commercially favorable approach to produce instant whole milk powders in a single step. Pure whole milk powders obtained directly from spray drying often have a high surface fat coverage (up to 98%), rendering them less stable during storage and less wettable upon reconstitution. Dairy industries often coat these powders with lecithin, a food-grade surfactant, in a secondary fluidized-bed drying stage to produce instant powders. This study investigated the changes in wetting behavior on the surface of a whole milk particle caused by the addition of surfactants before drying. Fresh whole milk was mixed with 0.1% (wt/wt) Tween 80 or 1% (wt/wt) lecithin (total solids), and the wetting behavior of the shell formed by each sample was captured using a single-droplet drying device at intermediate drying stages as the shell was forming. The addition of surfactants improved shell wettability from the beginning of shell formation, producing more wettable milk particles after drying. The increase in surfactant loading by 10 times reduced the wetting time from around 30s to 30s). We proposed that Tween 80 could adsorb at the oil-water interface of fat globules, making the surface fat more wettable, whereas lecithin tends to combine with milk proteins to form a complex, which then competes for the air-water surface with fat globules. Spray-drying experiments confirmed the greatly improved wettability of whole milk powders by the addition of either 0.1% (wt/wt) Tween 80 or 1% (wt/wt) lecithin; wetting time was reduced from 35±4s to drying system has been used to elucidate the complex interactions between ionic or nonionic surfactants and milk components (both proteins and fat), as well as the resultant effect on the development of milk particle functionality during drying. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  14. Desorption of hydrocarbon chains by association with ionic and nonionic surfactants under flow as a mechanism for enhanced oil recovery.

    Science.gov (United States)

    Terrón-Mejía, Ketzasmin A; López-Rendón, Roberto; Goicochea, Armando Gama

    2017-08-29

    The need to extract oil from wells where it is embedded on the surfaces of rocks has led to the development of new and improved enhanced oil recovery techniques. One of those is the injection of surfactants with water vapor, which promotes desorption of oil that can then be extracted using pumps, as the surfactants encapsulate the oil in foams. However, the mechanisms that lead to the optimal desorption of oil and the best type of surfactants to carry out desorption are not well known yet, which warrants the need to carry out basic research on this topic. In this work, we report non equilibrium dissipative particle dynamics simulations of model surfactants and oil molecules adsorbed on surfaces, with the purpose of studying the efficiency of the surfactants to desorb hydrocarbon chains, that are found adsorbed over flat surfaces. The model surfactants studied correspond to nonionic and cationic surfactants, and the hydrocarbon desorption is studied as a function of surfactant concentration under increasing Poiseuille flow. We obtain various hydrocarbon desorption isotherms for every model of surfactant proposed, under flow. Nonionic surfactants are found to be the most effective to desorb oil and the mechanisms that lead to this phenomenon are presented and discussed.

  15. Dispersion of Waxy Gas Oil by Some Nonionic Surfactants

    International Nuclear Information System (INIS)

    Khidr, T.T.; Mahmoud, S.A.

    2004-01-01

    Straight chain fatty alcohols having the following number of carbon atoms C 12 , C 14 , C 18 and C 21 each alcohol was ethoxylated to the same of ethylene oxide content, characterized through average molecular weight and elemental analysis. The surface properties of these compounds were studied through surface tension measurements. The synthesized additives were tested as flow improvers for improving the cold flow properties of two waxy gas oils through pour point test. The results show the right efficiency of these compounds in improving the flow ability. Comparative evaluation of the synthesized products with available commercial additive (com) showed their efficiency and suitability to use in gas oils. Wax modification was assisted through photo analysis. Correlation between wax modification and flow improvement in term of pour point depression appeared to be merely qualitative in such heterogeneous gas oil systems

  16. Synthesis and characterization of dialkanolamides from castor oil (Ricinus communis) as nonionic surfactant

    Science.gov (United States)

    Anwar, M.; Wahyuningsih, T. D.

    2017-12-01

    Nonionic surfactant of dialkanolamide derivates was synthesized and characterized from castor oil (Ricinus comunnis). Ricinoleic acid was isolated from castor oil by hydrolysis in alkaline (KOH) condition at 65 °C. Oxidation of ricinoleic acid by dilute potassium permanganate (KMnO4) in alkaline condition at 75-90 °C gave dicarboxylic acid which was then reacted with ethanolamine at 140-160 °C for 6 hours. The product was recrystallized with isopropanol, and the structure elucidation was performed by FTIR, 1HNMR spectrometer, and GC-MS with silylation method. Characterization of surfactants was carried out by surface tension measurement (capillary rise method), Critical Micelle Concentration (CMC) based on turbidity method and calculation of Hydrophilic-Lipophilic Balance (HLB) value with Griffin method and Bancroft rule. The result showed that ricinoleic acid in castor oil is 86.19 % and it is oxidation give an azelaic acid and octanedioic acid in 53.25 %. Amidation of a dicarboxylic acid and ethanolamine at 140-160 °C for 6 hours yielded of N1,N9-bis(2-hydroxyethyl)nona diamide in 49.35 %. Surfactant characterization indicates that dialkanolamide derivates can be used as a surfactant due to its ability to reduce the surface tension of ethanol with CMC at 1.2 g/L, HLB value is 5.58 and can be used as emulsifier water in oil (W/O).

  17. Metal-ion retention properties of water-soluble amphiphilic block copolymer in double emulsion systems (w/o/w) stabilized by non-ionic surfactants.

    Science.gov (United States)

    Palencia, Manuel; Rivas, Bernabé L

    2011-11-15

    Metal-ion retention properties of water-soluble amphiphilic polymers in presence of double emulsion were studied by diafiltration. Double emulsion systems, water-in-oil-in-water, with a pH gradient between external and internal aqueous phases were prepared. A poly(styrene-co-maleic anhydride) (PSAM) solution at pH 6.0 was added to the external aqueous phase of double emulsion and by application of pressure a divalent metal-ion stream was continuously added. Metal-ions used were Cu(2+) and Cd(2+) at the same pH of polymer solution. According to our results, metal-ion retention is mainly the result of polymer-metal interaction. Interaction between PSMA and reverse emulsion globules is strongly controlled by amount of metal-ions added in the external aqueous phase. In addition, as metal-ion concentration was increased, a negative effect on polymer retention capacity and promotion of flocculation phenomena were produced. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Experimental investigation of wettability alteration on residual oil saturation using nonionic surfactants: Capillary pressure measurement

    Directory of Open Access Journals (Sweden)

    Masoud Amirpour

    2015-12-01

    Full Text Available Introducing the novel technique for enhancing oil recovery from available petroleum reservoirs is one of the important issues in future energy demands. Among of all operative factors, wettability may be the foremost parameter affecting residual oil saturation in all stage of oil recovery. Although wettability alteration is one of the methods which enhance oil recovery from the petroleum reservoir. Recently, the studies which focused on this subject were more than the past and many contributions have been made on this area. The main objective of the current study is experimentally investigation of the two nonionic surfactants effects on altering wettability of reservoir rocks. Purpose of this work is to change the wettability to preferentially the water-wet condition. Also reducing the residual oil saturation (Sor is the other purpose of this work. The wettability alteration of reservoir rock is measured by two main quantitative methods namely contact angle and the USBM methods. Results of this study showed that surfactant flooding is more effective in oil-wet rocks to change their wettability and consequently reducing Sor to a low value. Cedar (Zizyphus Spina Christi is low priced, absolutely natural, and abundantly accessible in the Middle East and Central Asia. Based on the results, this material can be used as a chemical surfactant in field for enhancing oil recovery.

  19. Modeling the effect of structural details of nonionic surfactant on micellization in solution and adsorption onto hydrophobic surfaces

    NARCIS (Netherlands)

    Jodar-Reyes, A.B.; Ortega-Vinuesa, J.L.; Martin-Rodriguez, A.; Leermakers, F.A.M.

    2002-01-01

    Applying the classical one-gradient self-consistent-field (SCF) theory for adsorption and/or association, we can show that the molecular architecture of nonionic surfactants influences strongly the micellization in solution and the adsorption on solid-liquid interfaces. This is illustrated by using

  20. Determination of non-ionic surfactants in technologic liquors and effluents by X-ray fluorescent spectrometry

    International Nuclear Information System (INIS)

    Dankowski, P.; Majda, J.

    1977-01-01

    The method has been worked out for determination of non-ionic surfactants in technological liquors and effluents, based on the X-ray fluorescent spectrometry with an initial concentration by means of the phosphomolybdic acid. The method is suitable for a quantitative determination of ethylene oxide adducts in a wide range of applicable concentrations, the trace-ones included. (M.Z.)

  1. A Review on the Environmental Behavior of the Polyoxyethylene Type Nonionic Surfactants Adjuvants in Pesticides

    Directory of Open Access Journals (Sweden)

    KONG Xiang-ji

    2017-05-01

    Full Text Available Polyoxyethylene type nonionic surfactants such as alkylphenol ethoxylates(APEOs, alcohol ethoxylates(AEOs and alkylamine ethoxylates(ANEOs are typical pesticide adjuvants. Their unique environmental behavior characteristic is reflected in the parameters describing the fate e.g.distribution coefficient, adsorption to soil, degradation and effects of these substances. The major environmental problem related to these compounds is their part metabolites' relatively higher environmental risk. In views of their chemical structure, this paper outlined present knowledge on occurrence, fate and environment effect of the three adjuvants:AEOs, ANEOs and APEOs. The adsorption behaviour of ANEOs in contrast to AEOs was particularly variable and matrix dependent due to the ability of the compound to ionise at environmentally relevant pH. Probably because the compounds exceeded high soil adsorption and were easily degradable which were reflected in the low environmental concentrations generally found in monitoring studies.

  2. Effect of the Presence of Nonionic Surfactant Brij35 on the Mobility of Metribuzin in Soil

    Directory of Open Access Journals (Sweden)

    Eman M. ElSayed

    2013-04-01

    Full Text Available Given the water scarcity becoming endemic to a large portion of the globe, arid region irrigation has resorted to the use of treated, partially treated, or even untreated wastewaters. Such waters contain a number of pollutants, including surfactants. Applied to agricultural lands, these surfactants could affect the fate and transport of other chemicals in the soil, particularly pesticides. A field lysimeter study was undertaken to investigate the effect of nonionic surfactant, Brij35, on the in-soil fate and transport of a commonly used herbicide, metribuzin [4-amino-6-tert-butyl-3-(methylthio-1,2,4-triazin-5(4H-one]. Nine PVC lysimeters, 1.0 m long × 0.45 m diameter, were packed with a sandy soil to a bulk density of 1.35 mg m−3. Antibiotic-free cattle manure was applied (10 mg ha−1 at the surface of the lysimeters. Metribuzin was then applied to the soil surface of all lysimeters at a rate of 1.00 kg a.i. ha−1. Each of three aqueous Brij35 solutions, 0, 0.5 and 5 mg L−1 (i.e., “good”, “poor” and “very poor” quality irrigation water were each applied to the lysimeters in triplicate. Analysis for metribuzin residues in samples of both soil and leachate, collected over a 90-day period, showed the surfactant Brij35 to have increased the mobility of metribuzin in soil, indicating that continued use of poor quality water could influence pesticide transport in agricultural soils, and increase the risk of groundwater contamination.

  3. Development of Drug Loaded Nanoparticles Binding to Hydroxyapatite Based on a Bisphosphonate Modified Nonionic Surfactant

    Directory of Open Access Journals (Sweden)

    Jiabin Zhang

    2015-01-01

    Full Text Available This study aimed at development of drug loaded nanoparticles which could bind to hydroxyapatite (HA to construct drug or growth factor releasing bone graft substitutes. To this end, the terminal hydroxyl group of a nonionic surfactant Brij 78 (polyoxyethylene (20 stearyl ether was first modified with pamidronate (Pa. Using Pa-Brij 78 as both a surfactant and an affinity ligand to HA, three different Pa surface functionalized nanoparticles were prepared, named as solid lipid nanoparticles (Pa-SNPs, nanoemulsions (Pa-NEMs, and PLGA nanoparticles (Pa-PNPs. A model drug curcumin was successfully encapsulated in the three nanoparticles. The sizes of Pa-NEM and Pa-PNP were around 150 nm and the size of Pa-SNP was around 90 nm with polydispersity indexes (PDIs less than 0.20. Drug encapsulation efficiencies of the three nanoparticles were all greater than 85%. Furthermore, the order of binding affinity of the nanoparticles to HA was Pa-PNP>Pa-NEM=Pa-SNP. After lyophilization, the sizes of the three nanoparticles were increased about 0.5–2.0-fold but their binding affinities to HA were almost the same as the fresh prepared nanoparticles. In conclusion, a Pa-modified Brij 78 was synthesized and used for fabrication of a series of drug loaded nanoparticles to construct drug-eluting HA-based bone graft substitutes.

  4. Spectrophotometric determination of molybdenum with non-ionic surfactant and thiocyanate

    International Nuclear Information System (INIS)

    Hayashi, Kenjiro; Yamamoto, Atsuo; Fujimura, Yasue; Ito, Saburo.

    1980-01-01

    Although the molybdenum (V)-thiocyanate complex is quite stable in non-aqueous solvent such as ether, the complex in dilute acidic solution is unstable. However, this unstable complex was stabilized remarkably by addition of some non-ionic surfactant such as Triton X-100 (alkylphenolpolyoxyethylene ether). The application of this stabilizing effect of the surfactant to the photometric determination of trace amounts of molybdenum with thiocyanate resulted in an increase in the sensitivity. The rate of formation of the Mo(V)-SCN complex was affected by the presence of ferrous ion and its rate constant was proportional to the concentration of Fe(II). The stabilizing effect of the surfactant on the yellowish orange coloration can be understood if we assume that the Mo(V)-SCN complex is incorporated into the micelles of Triton X-100 as [H 2 + , MoO(CNS) 5 2- ]. The optimum condition for the determination of molybdenum is as follows: concentration of sulfuric acid, 0.22 mol dm -3 ; Triton X-100, 0.8%; ascorbic acid, 0.32 mol dm -3 ; thiocyanate, 0.30 mol dm -3 ; iron, 40 mg dm -3 ; standing time for coloration, 10 min and more. Beer's law was obeyed over the range (1 -- 233) μg/50 cm 3 . The molar absorption coefficient at 468 nm was 1.7 2 x 10 4 cm -1 mol -1 dm 3 . The maximum permissible limits of foreign ions (mg/50 cm 3 ) were as follows: Ni(30); Co(12); W(VI) (2); Cu, Zn, V(V) (3); Cr(VI) (5). Large amounts of iron interfered, but this interference was removed by addition of the same amount of iron to the reagent blank. Trace amounts of molybdenum in steel was determined by this method with satisfactory results. (author)

  5. Application of lactobionic acid and nonionic surfactants as solubilizing agents for parenteral formulation of clarithromycin

    Directory of Open Access Journals (Sweden)

    Mohammad-Hosein Zarrintan

    2012-06-01

    Full Text Available Purpose: The purpose of this paper is to enhance the solubility of clarithromycin (CLR using nonionic surfactants and some type of acids for preparation of the new formulations. Methods: Myrj 52 and chremophor (2.5 and 5% w/v were used in two concentrations. To investigate solubility, the formulations were shaken for 48 hours at room temperature. For stability test, lyophilized samples were maintained in refrigerator at 4° C, and in oven at 40° C. Drug analysis was performed by reverse phase high performance liquid chromatography (HPLC with ultraviolet detection. Results: Solubility tests indicated that lactobionic acid was the most effective to increase clarithromycin solubility and chremophor showed higher enhancing effect than myrj 52 on CLR solubility. The stability tests results also confirmed that shelf-lives of all formulations have been the equivalent to 24 months. Conclusion: On the whole, formulations described in this article may be very suitable for industrial-scale manufacturing and clinical application.

  6. Synthesis and characterization of high molecular weight hydrophobically modified polyacrylamide nanolatexes using novel nonionic polymerizable surfactants

    Directory of Open Access Journals (Sweden)

    A.M. Al-Sabagh

    2013-12-01

    Full Text Available In this article, nine hydrophobically modified polyacrylamides (HM-PAM nanolatexes, were synthesized by copolymerizing the acrylamide monomer and novel polymerizable surfactants (surfmers. The reaction was carried out by inverse microemulsion copolymerization technique. The copolymerization was initiated by redox initiators composed of potassium peroxodisulphate and sodium bisulfite. The emulsion was stabilized using mixed tween 85 and span 80 as nonionic emulsifiers. The prepared HM-PAMs were classified into three groups according to the surfmers used in the copolymerization. The chemical structures of the prepared HM-PAMs were confirmed by FT-IR, 1H NMR and 13C NMR. The thermal properties were estimated with the thermal gravimetric analysis (TGA. The size and morphology of the prepared latexes were investigated by the dynamic light scattering (DLS and the High Resolution Transmission Electron Microscope (HRTEM. Finally, the molecular weights of the prepared copolymers were determined by the GPC and the viscosity average molecular weight method. They were situated between 1.58 × 106 and 0.89 × 106.

  7. One-step synthesis, wettability and foaming properties of high-performance non-ionic hydro-fluorocarbon hybrid surfactants

    Science.gov (United States)

    Peng, Ying-ying; Lu, Feng; Tong, Qing-Xiao

    2018-03-01

    In this work, a series of non-ionic hydro-fluorocarbon hybrid surfactants (C9F19CONH(CH2)3N(CmH2m+1)2, abbreviated as C9F19AM (m = 1), C9F19AE (m = 2) and C9F19AB (m = 4) were easily synthesized by one-step reaction and characterized by 1HNMR, 19FNMR and MS spectroscopy. Unlike conventional non-ionic surfactants (most hydrophilic units consisted of hydroxy or ether groups), their hydrophilic groups were composed of amide group, an eco-friendly unit. The surface activity, wettability, thermal stability and foaming performance were investigated. The results showed that the C9F19AE (C9F19CONH(CH2)3N[CH2CH3]2) had superior surface and interface activities, which could reduce the surface tension of water down to 15.37 mN/m and the interfacial tension (cyclohexane/water/surfactants) to 5.8 mN/m with a low cmc (critical micelle concentration) of 0.12 mmol/L. Through the calculation of Amin (the minimum area occupied per-surfactant molecule), we speculated this higher surface activity was related to the compatibility between hydrocarbon and fluorocarbon chains. When used as wetting and foaming agents, the C9F19AE also outperformed great advantages over conventional non-ionic fluorocarbon and hydrocarbon surfactants, which could decrease the contact angle of water on PTFE plate from 107.7° to 3.6°, and increase the foam integrated value F to 536 500 ± 3066.5 mL s. Moreover, the decomposition temperature (Td) of C9F19AE could reach up to 173 °C. This work demonstrates a valuable strategy to develop a kind of high-efficiency foaming agent via facile synthesis.

  8. High-efficiency extracellular release of free fatty acids from Aspergillus oryzae using non-ionic surfactants.

    Science.gov (United States)

    Tamano, Koichi; Miura, Ai; Koike, Hideaki; Kamisaka, Yasushi; Umemura, Myco; Machida, Masayuki

    2017-04-20

    Free fatty acids (FFAs) are useful for generating biofuel compounds and functional lipids. Microbes are increasingly exploited to produce FFAs via metabolic engineering. However, in many microorganisms, FFAs accumulate in the cytosol, and disrupting cells to extract them is energy intensive. Thus, a simple cost-effective extraction technique must be developed to remove this drawback. We found that FFAs were released from cells of the filamentous fungus Aspergillus oryzae with high efficiency when they were cultured or incubated with non-ionic surfactants such as Triton X-100. The surfactants did not reduce hyphal growth, even at 5% (w/v). When the faaA disruptant was cultured with 1% Triton X-100, more than 80% of the FFAs synthesized de novo were released. When the disruptant cells grown without surfactants were incubated for 1h in 1% Triton X-100 solution, more than 50% of the FFAs synthesized de novo were also released. Other non-ionic surfactants in the same ether series, such as Brij 58, IGEPAL CA-630, and Tergitol NP-40, elicited a similar FFA release. The dry cell weight of total hyphae decreased when grown with 1% Triton X-100. The decrement was 4.9-fold greater than the weight of the released FFAs, implying release of other intracellular compounds. Analysis of the culture supernatant showed that intracellular lactate dehydrogenase was also released, suggesting that FFAs are not released by a specific transporter. Therefore, ether-type non-ionic surfactants probably cause non-specific release of FFAs and other intracellular compounds by increasing cell membrane permeability. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. An insight of in vitro transport of PEGylated non-ionic surfactant vesicles (NSVs) across the intestinal polarized enterocyte monolayers.

    Science.gov (United States)

    Primavera, Rosita; Palumbo, Paola; Celia, Christian; Cinque, Benedetta; Carata, Elisabetta; Carafa, Maria; Paolino, Donatella; Cifone, Maria Grazia; Di Marzio, Luisa

    2018-06-01

    PEGylated non-ionic surfactant-based vesicles (NSVs) are promising drug delivery systems for the local, oral and systemic administrations of therapeutics. The aim of this study was to test the cellular biocompatibility and transport of Nile Red-loaded NSVs (NR-NSVs) across the Caco-2-cell monolayers, which represent an in vitro model of human intestinal epithelium. The NR-NSVs assumed a spherical shape with a mean size of 140 nm, and a narrow size distribution. The NR-NSVs did not modify Caco-2 cell viability, which remained unaltered in vitro up to a concentration of 1 mM. The transport studies demonstrated that the NR-NSVs moved across the Caco-2 monolayers without affecting the transepithelial electrical resistance. These results were supported by flow cytometry analysis, which demonstrated that NR-NSVs were internalized inside the Caco-2 cells. Nanoparticle tracking and Transmission Electron Microscopy (TEM) analysis showed the presence of NR-NSVs in the basolateral side of the Caco-2 monolayers. TEM images also showed that NSVs were transported intact across the Caco-2 monolayers, thus demonstrating a predominant transcytosis mechanism of transport through endocytosis. The NSVs did not affect the integrity of the membrane barrier in vitro, and can potentially be used in clinics to increase the oral bioavailability and delivery of therapeutics. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Seasonal evolution of anionic, cationic and non-ionic surfactant concentrations in coastal aerosols from Askö, Sweden

    Science.gov (United States)

    Gérard, Violaine; Nozière, Barbara; Baduel, Christine

    2015-04-01

    Surfactants present in atmospheric aerosols are expected to enhance the activation into cloud droplets by acting on one of the two key parameters of the Köhler equation: the surface tension, σ. But because the magnitude of this effect and its regional and temporal variability are still highly uncertain [1,2], various approaches have been developed to evidence it directly in the atmosphere. This work presents the analysis of surfactants present in PM2.5 aerosol fractions collected at the coastal site of Askö, Sweden (58° 49.5' N, 17° 39' E) from July to October 2010. The total surfactant fraction was extracted from the samples using an improved double extraction technique. Surface tension measurements performed with the pendant drop technique [3] indicated the presence of very strong surfactants (σ ~ 30 - 35 mN/m) in these aerosols. In addition, these extractions were combined with colorimetric methods to determine the anionic, cationic and non-ionic surfactant concentrations [4,5], and provided for the first time interference-free surfactant concentrations in atmospheric aerosols. At this site, the total surfactant concentration in the PM2.5 samples varied between 7 to 150 mM and was dominated by anionic and non-ionic ones. The absolute surface tension curves obtained for total surfactant fraction displayed Critical Micelle Concentrations (CMC) in the range 50 - 400 uM, strongly suggesting a biological origin for the surfactants. The seasonal evolution of these concentrations and their relationships with environmental or meteorological parameters at the site will be discussed. [1] Ekström, S., Nozière, B. et al., Biogeosciences, 2010, 7, 387 [2] Baduel, C., Nozière, B., Jaffrezo, J.-L., Atmos. Environ., 2012, 47, 413 [3] Nozière, B., Baduel, C., Jaffrezo, J.-L., Nat. Commun., 2014, 5, 1 [4] Latif, M. T.; Brimblecombe, P. Environ. Sci. Technol., 2004, 38, 6501 [5] Pacheco e Silva et al., Method to measure surfactant in fluid, 2013, US 2013/0337568 A1

  11. Role of a non-ionic surfactant in direct electron transfer-type bioelectrocatalysis by fructose dehydrogenase

    International Nuclear Information System (INIS)

    Kawai, Shota; Yakushi, Toshiharu; Matsushita, Kazunobu; Kitazumi, Yuki; Shirai, Osamu; Kano, Kenji

    2015-01-01

    Highlights: • Addition of Triton ® X-100 (1%) completely quenches the FDH-catalyzed current at hydrophobic electrode, but causes only small competitive effect at hydrophilic electrode. • Quartz crystal microbalance measurements support the adsorption of FDH and Triton ® X-100 on both of the electrodes. • The surfactant forms a monolayer on the hydrophobic electrode and FDH adsorbs on the surfactant monolayer. • The surfactant forms a bilayer on the hydrophilic electrode and FDH is embedded in the bilayer to communicate with the electrode. - ABSTRACT: A heterotrimeric membrane-bound fructose dehydrogenase (FDH) from Gluconobacter japonicus NBRC3260 contains FAD in subunit I and three heme C moieties in subunit II as the redox centers, and is one of the direct electron transfer (DET)-type redox enzymes. FDH-catalyzed current density of fructose oxidation at hydrophilic mercaptoethanol (MEtOH)-modified Au electrode is much larger than that at hydrophobic mercaptoethane (MEtn)-modified Au electrode. Addition of a non-ionic surfactant Triton ® X-100 (1%) completely quenches the catalytic current at the MEtn-modified Au electrode, while only small competitive effect is observed at the MEtOH-modified Au electrode. Quartz crystal microbalance measurements support the adsorption of FDH and Triton ® X-100 on both of the modified electrodes. We propose a model to explain the phenomenon as follows. The surfactant forms a monolayer on the hydrophobic MEtn-modified electrode with strong hydrophobic interaction, and FDH adsorbs on the surface of the surfactant monolayer. The monolayer inhibits the electron transfer from FDH to the electrode. On the other hand, the surfactant forms a bilayer on the hydrophilic MEtOH-modified electrode. The interaction between the surfactant bilayer and the hydrophilic electrode is relatively weak so that FDH replaces the surfactant and is embedded in the bilayer to communicate electrochemically with the hydrophilic electrode

  12. Adsorption of proteins at the solution/air interface influenced by added nonionic surfactants at very low concentrations for both components. 2. Effect of different surfactants and theoretical model.

    Science.gov (United States)

    Fainerman, V B; Lotfi, M; Javadi, A; Aksenenko, E V; Tarasevich, Yu I; Bastani, D; Miller, R

    2014-11-04

    The influence of the addition of the nonionic surfactants dodecyl dimethyl phosphine oxide (C12DMPO), tetradecyl dimethyl phosphine oxide (C14DMPO), decyl alcohol (C10OH), and C10EO5 at concentrations between 10(-5) and 10(-1) mmol/L to solutions of β-casein (BCS) and β-lactoglobulin (BLG) at a fixed concentration of 10(-5) mmol/L on the surface tension is studied. It is shown that a significant decrease of the water/air surface tension occurs for all the surfactants studied at very low concentrations (10(-5)-10(-3) mmol/L). All measurements were performed with the buoyant bubble profile method. The dynamics of the surface tension was simulated using the Fick and Ward-Tordai equations. The calculation results agree well with the experimental data, indicating that the equilibration times in the system studied do not exceed 30 000 s, while the time required to attain the equilibrium on a plane surface is by one order of magnitude higher. To achieve agreement between theory and experiment for the mixtures, a supposition was made about the influence of the concentration of nonionic surfactant on the adsorption activity of the protein. The adsorption isotherm equation of the protein was modified accordingly, and this corrected model agrees well with all experimental data.

  13. Simple one step synthesis of nonionic dithiol surfactants and their self-assembling with silver nanoparticles: Characterization, surface properties, biological activity

    Energy Technology Data Exchange (ETDEWEB)

    Abd-Elaal, Ali A., E-mail: ali_ashour5@yahoo.com; Tawfik, Salah M.; Shaban, Samy M.

    2015-07-01

    Graphical abstract: - Highlights: • Nonionic dithiol surfactants were synthesized by simple one step esterification. • The surface activity of the synthesized dithiol surfactants showed high tendency toward adsorption and micellization. • The nanostructure of the synthesized nonionic dithiol surfactants with silver nanoparticles was prepared. • The silver nanoparticles enhanced the biological activity of the synthesized dithiol surfactants. - Abstract: Simple esterification of 2-mercaptoacetic acid and polyethylene glycol with different molecular weights was done to form the desired nonionic dithiol surfactants. The chemical structures of synthesized thiol surfactants were confirmed using FT-IR and {sup 1}H NMR spectra. The surface activity of the synthesized surfactants was determined by measurement of the surface tension at different temperatures. The surface activity measurements showed their high tendency towards adsorption and micellization. The thermodynamic parameters of micellization (ΔG{sub mic}, ΔH{sub mic} and ΔS{sub mic}) and adsorption (ΔG{sub ads}, ΔG{sub ads} and ΔS{sub ads}) showed their tendency toward adsorption at the interfaces and also micellization in the bulk of their solutions. The nanostructure of the synthesized nonionic dithiol surfactants with silver nanoparticles was prepared and investigated using UV and TEM techniques. Screening tests of the synthesized dithiol surfactants and their nanostructure with silver nanoparticles, against gram positive bacteria (Bacillus subtilis and Microccus luteus), gram negative bacteria (Escherichia coli and Bordatella pertussis) and fungi (Aspergillus niger and Candida albicans) showed that they are highly active biocides. The presence of silver nanoparticles enhancement the biological activities of the individual synthesized nonionic dithiol surfactants.

  14. Simple one step synthesis of nonionic dithiol surfactants and their self-assembling with silver nanoparticles: Characterization, surface properties, biological activity

    International Nuclear Information System (INIS)

    Abd-Elaal, Ali A.; Tawfik, Salah M.; Shaban, Samy M.

    2015-01-01

    Graphical abstract: - Highlights: • Nonionic dithiol surfactants were synthesized by simple one step esterification. • The surface activity of the synthesized dithiol surfactants showed high tendency toward adsorption and micellization. • The nanostructure of the synthesized nonionic dithiol surfactants with silver nanoparticles was prepared. • The silver nanoparticles enhanced the biological activity of the synthesized dithiol surfactants. - Abstract: Simple esterification of 2-mercaptoacetic acid and polyethylene glycol with different molecular weights was done to form the desired nonionic dithiol surfactants. The chemical structures of synthesized thiol surfactants were confirmed using FT-IR and 1 H NMR spectra. The surface activity of the synthesized surfactants was determined by measurement of the surface tension at different temperatures. The surface activity measurements showed their high tendency towards adsorption and micellization. The thermodynamic parameters of micellization (ΔG mic , ΔH mic and ΔS mic ) and adsorption (ΔG ads , ΔG ads and ΔS ads ) showed their tendency toward adsorption at the interfaces and also micellization in the bulk of their solutions. The nanostructure of the synthesized nonionic dithiol surfactants with silver nanoparticles was prepared and investigated using UV and TEM techniques. Screening tests of the synthesized dithiol surfactants and their nanostructure with silver nanoparticles, against gram positive bacteria (Bacillus subtilis and Microccus luteus), gram negative bacteria (Escherichia coli and Bordatella pertussis) and fungi (Aspergillus niger and Candida albicans) showed that they are highly active biocides. The presence of silver nanoparticles enhancement the biological activities of the individual synthesized nonionic dithiol surfactants

  15. Preparation of stable tea seed oil nano-particle emulsions by a low energy method with non-ionic surfactants

    Directory of Open Access Journals (Sweden)

    M. Kanlayavattanakul

    2017-06-01

    Full Text Available Tea seed oil nano-particle emulsions were prepared. Non-ionic surfactants containing Tween 80 and Span 80 (1:1, w/w were mixed with propanol (3-9:1, w/w to give Smix, which was thereafter mixed with tea seed oil. The mixture was titrated with water at 150 rpm to give clear or bluish and bluish-white emulsions. Twelve nano-particle emulsions with 64.64 to 72.73% Smix, 16.66 to 27.27% oil and 9.09 to 16.67% water with particle sizes between 207.00 to 430.10 nm, PDI of 0 to 0.4, ζ-potential of -42.00 to -49.63 mV, pH of 7.04 to 7.32 and 151.33 to 241.93 cps, were stable following an accelerated stability test and long term storage at room temperature and 4 and 45 ºC for 90 days, although one system (16.66% oil and 66.67% Smix was separated. This nano-particle emulsion formulation is concise and feasible for an industrial development of topical products containing tea seed oil.

  16. Preparation of stable tea seed oil nano-particle emulsions by a low energy method with non-ionic surfactants

    International Nuclear Information System (INIS)

    Kanlayavattanakul, M.; Lourith, N.

    2017-01-01

    Tea seed oil nano-particle emulsions were prepared. Non-ionic surfactants containing Tween 80 and Span 80 (1:1, w/w) were mixed with propanol (3-9:1, w/w) to give Smix, which was thereafter mixed with tea seed oil. The mixture was titrated with water at 150 rpm to give clear or bluish and bluish-white emulsions. Twelve nano-particle emulsions with 64.64 to 72.73% Smix, 16.66 to 27.27% oil and 9.09 to 16.67% water with particle sizes between 207.00 to 430.10 nm, PDI of 0 to 0.4, ζ-potential of -42.00 to -49.63 mV, pH of 7.04 to 7.32 and 151.33 to 241.93 cps, were stable following an accelerated stability test and long term storage at room temperature and 4 and 45 ºC for 90 days, although one system (16.66% oil and 66.67% Smix) was separated. This nano-particle emulsion formulation is concise and feasible for an industrial development of topical products containing tea seed oil. [es

  17. Nonionic Fluorinated Surfactant Removal from Mesoporous Film Using sc-CO2.

    Science.gov (United States)

    Chavez Panduro, Elvia A; Assaker, Karine; Beuvier, Thomas; Blin, Jean-Luc; Stébé, Marie-José; Konovalov, Oleg; Gibaud, Alain

    2017-01-25

    Surfactant templated silica thin films were self-assembled on solid substrates by dip-coating using a partially fluorinated surfactant R 8 F (EO) 9 as the liquid crystal template. The aim was 2-fold: first we checked which composition in the phase diagram was corresponding to a 2D rectangular highly ordered crystalline phase and second we exposed the films to sc-CO 2 to foster the removal of the surfactant. The films were characterized by in situ X-ray reflectivity (XRR) and grazing incidence small angle X-ray scattering (GISAXS) under CO 2 pressure from 0 to 100 bar at 34 °C. GISAXS patterns reveal the formation of a 2-D rectangular structure at a molar ratio R 8 F (EO) 9 /Si equal to 0.1. R 8 F (EO) 9 micelles have a cylindrical shape, which have a core/shell structure ordered in a hexagonal system. The core contains the R 8 F part and the shell is a mixture of (EO) 9 embedded in the silica matrix. We further evidence that the extraction of the template using supercritical carbon dioxide can be successfully achieved. This can be attributed to both the low solubility parameter of the surfactants and the fluorine and ethylene oxide CO 2 -philic groups. The initial 2D rectangular structure was well preserved after depressurization of the cell and removal of the surfactant. We attribute the very high stability of the rinsed film to the large value of the wall thickness relatively to the small pore size.

  18. Investigation of surfactant/cosurfactant synergism impact on ibuprofen solubilization capacity and drug release characteristics of nonionic microemulsions.

    Science.gov (United States)

    Djekic, Ljiljana; Primorac, Marija; Filipic, Slavica; Agbaba, Danica

    2012-08-20

    The current study investigates the performances of the multicomponent mixtures of nonionic surfactants regarding the microemulsion stabilisation, drug solubilization and in vitro drug release kinetic. The primary surfactant was PEG-8 caprylic/capric glycerides (Labrasol). The cosurfactants were commercially available mixtures of octoxynol-12 and polysorbate 20 without or with the addition of PEG-40 hydrogenated castor oil (Solubilisant gamma 2421 and Solubilisant gamma 2429, respectively). The oil phase of microemulsions was isopropyl myristate. Phase behaviour study of the pseudo-ternary systems Labrasol/cosurfactant/oil/water at surfactant-to-cosurfactant weight ratios (K(m)) 40:60, 50:50 and 60:40, revealed a strong synergism in the investigated tensides mixtures for stabilisation of microemulsions containing up to 80% (w/w) of water phase at surfactant +cosurfactant-to-oil weight ratio (SCoS/O) 90:10. Solubilization of a model drug ibuprofen in concentration common for topical application (5%, w/w) was achieved at the water contents below 50% (w/w). Drug free and ibuprofen-loaded microemulsions M1-M6, containing 45% (w/w) of water phase, were prepared and characterized by polarized light microscopy, conductivity, pH, rheological and droplet size measurements. In vitro ibuprofen release kinetics from the microemulsions was investigated using paddle-over-enhancer cell method and compared with the commercial 5% (w/w) ibuprofen hydrogel product (Deep Relief, Mentholatum Company Ltd., USA). The investigated microemulsions were isotropic, low viscous Bingham-type liquids with the pH value (4.70-6.61) suitable for topical application. The different efficiency of the tensides mixtures for microemulsion stabilisation was observed, depending on the cosurfactant type and K(m) value. Solubilisant gamma 2429 as well as higher K(m) (i.e., lower relative content of the cosurfactant) provided higher surfactant/cosurfactant synergism. The drug molecules were predominantly

  19. Micelle formation of nonionic surfactants in a room temperature ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate: surfactant chain length dependence of the critical micelle concentration.

    Science.gov (United States)

    Inoue, Tohru; Yamakawa, Haruka

    2011-04-15

    Micellization behavior was investigated for polyoxyethylene-type nonionic surfactants with varying chain length (C(n)E(m)) in a room temperature ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF(4)). Critical micelle concentration (cmc) was determined from the variation of (1)H NMR chemical shift with the surfactant concentration. The logarithmic value of cmc decreased linearly with the number of carbon atoms in the surfactant hydrocarbon chain, similarly to the case observed in aqueous surfactant solutions. However, the slope of the straight line is much smaller in bmimBF(4) than in aqueous solution. Thermodynamic parameters for micelle formation estimated from the temperature dependence of cmc showed that the micellization in bmimBF(4) is an entropy-driven process around room temperature. This behavior is also similar to the case in aqueous solution. However, the magnitude of the entropic contribution to the overall micellization free energy in bmimBF(4) is much smaller compared with that in aqueous solution. These results suggest that the micellization in bmimBF(4) proceeds through a mechanism similar to the hydrophobic interaction in aqueous surfactant solutions, although the solvophobic effect in bmimBF(4) is much weaker than the hydrophobic effect. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Occurrence, distribution and partitioning of nonionic surfactants and pharmaceuticals in the urbanized Long Island Sound Estuary (NY)

    International Nuclear Information System (INIS)

    Lara-Martín, Pablo A.; González-Mazo, Eduardo; Petrovic, Mira; Barceló, Damià; Brownawell, Bruce J.

    2014-01-01

    Highlights: • Surfactant levels were one order of magnitude higher than those for pharmaceuticals. • Concentrations of analytes in seawater were influenced by tides and sampling depth. • Surfactants were found in all suspended solids samples at more than 1 μg g −1 . • Presence of pharmaceuticals in sewage impacted surface sediments was minimal. • Among all analytes, polyethylene glycols show highest concentrations in sediments. - Abstract: This work deals with the environmental distribution of nonionic surfactants (nonylphenol and alcohol ethoxylates), their metabolites (NP, nonylphenol; NPEC, nonylphenol ethoxycarboxylates; and PEG, polyethylene glycols) and a selection of 64 pharmaceuticals in the Long Island Sound (LIS) Estuary which receives important sewage discharges from New York City (NYC). Most target compounds were efficiently removed (>95%) in one wastewater treatment plant monitored, with the exception of NPEC and some specific drugs (e.g., hydrochlorothiazide). Concentrations of surfactants (1.4–4.5 μg L −1 ) and pharmaceuticals (0.1–0.3 μg L −1 ) in seawater were influenced by tides and sampling depth, consistent with salinity differences. Surfactants levels in suspended solids samples were higher than 1 μg g −1 , whereas only most hydrophobic or positively charged pharmaceuticals could be found (e.g., tamoxifen, clarithromycin). Maximum levels of target compounds in LIS sediments (PEG at highest concentrations, 2.8 μg g −1 ) were measured nearest NYC, sharply decreasing with distance from major sewage inputs

  1. HPLC/ESI-quadrupole ion trap mass spectrometry for characterization and direct quantification of amphoteric and nonionic surfactants in aqueous samples

    Science.gov (United States)

    Levine, Lanfang H.; Garland, Jay L.; Johnson, Jodie V.

    2002-01-01

    An amphoteric (cocamidopropylbetaine, CAPB) and a nonionic (alcohol polyethoxylate, AE) surfactant were characterized by electrospray ionization quadrupole ion trap mass spectrometry (ESI-MS) as to their homologue distribution and ionization/fragmentation chemistry. Quantitative methods involving reversed-phase gradient HPLC and (+)ESI-MSn were developed to directly determine these surfactants in hydroponic plant growth medium that received simulated graywater. The predominant homologues, 12 C alkyl CAPB and 9 EO AE, were monitored to represent the total amount of the respective surfactants. The methods demonstrated dynamic linear ranges of 0.5-250 ng (r2 > 0.996) for CAPB and 8-560 ng (r2 > 0.998) for AE homologue mixture, corresponding to minimum quantification limits of 25 ppb CAPB and 0.4 ppm AE with 20-microL injections. This translated into an even lower limit for individual components due to the polydispersive nature of the surfactants. The procedure was successfully employed for the assessment of CAPB and AE biodegradation in a hydroponic plant growth system used as a graywater bioreactor.

  2. Acute toxicity of anionic and non-ionic surfactants to aquatic organisms.

    Science.gov (United States)

    Lechuga, M; Fernández-Serrano, M; Jurado, E; Núñez-Olea, J; Ríos, F

    2016-03-01

    The environmental risk of surfactants requires toxicity measurements. As different test organisms have different sensitivity to the toxics, it is necessary to establish the most appropriate organism to classify the surfactant as very toxic, toxic, harmful or safe, in order to establish the maximum permissible concentrations in aquatic ecosystems. We have determined the toxicity values of various anionic surfactants ether carboxylic derivatives using four test organisms: the freshwater crustacean Daphnia magna, the luminescent bacterium Vibrio fischeri, the microalgae Selenastrum capricornutum (freshwater algae) and Phaeodactylum tricornutum (seawater algae). In addition, in order to compare and classify the different families of surfactants, we have included a compilation of toxicity data of surfactants collected from literature. The results indicated that V. fischeri was more sensitive to the toxic effects of the surfactants than was D. magna or the microalgae, which was the least sensitive. This result shows that the most suitable toxicity assay for surfactants may be the one using V. fischeri. The toxicity data revealed considerable variation in toxicity responses with the structure of the surfactants regardless of the species tested. The toxicity data have been related to the structure of the surfactants, giving a mathematical relationship that helps to predict the toxic potential of a surfactant from its structure. Model-predicted toxicity agreed well with toxicity values reported in the literature for several surfactants previously studied. Predictive models of toxicity is a handy tool for providing a risk assessment that can be useful to establish the toxicity range for each surfactant and the different test organisms in order to select efficient surfactants with a lower impact on the aquatic environment. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Determination of the critical micelle concentration in simulations of surfactant systems.

    Science.gov (United States)

    Santos, Andrew P; Panagiotopoulos, Athanassios Z

    2016-01-28

    Alternative methods for determining the critical micelle concentration (cmc) are investigated using canonical and grand canonical Monte Carlo simulations of a lattice surfactant model. A common measure of the cmc is the "free" (unassociated) surfactant concentration in the presence of micellar aggregates. Many prior simulations of micellizing systems have observed a decrease in the free surfactant concentration with overall surfactant loading for both ionic and nonionic surfactants, contrary to theoretical expectations from mass-action models of aggregation. In the present study, we investigate a simple lattice nonionic surfactant model in implicit solvent, for which highly reproducible simulations are possible in both the canonical (NVT) and grand canonical (μVT) ensembles. We confirm the previously observed decrease of free surfactant concentration at higher overall loadings and propose an algorithm for the precise calculation of the excluded volume and effective concentration of unassociated surfactant molecules in the accessible volume of the solution. We find that the cmc can be obtained by correcting the free surfactant concentration for volume exclusion effects resulting from the presence of micellar aggregates. We also develop an improved method for determination of the cmc based on the maximum in curvature for the osmotic pressure curve determined from μVT simulations. Excellent agreement in cmc and other micellar properties between NVT and μVT simulations of different system sizes is observed. The methodological developments in this work are broadly applicable to simulations of aggregating systems using any type of surfactant model (atomistic/coarse grained) or solvent description (explicit/implicit).

  4. Electrodeposition of Pt-Ru nanoparticles on fibrous carbon substrates in the presence of nonionic surfactant: Application for methanol oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Alex; Gyenge, Elod L.; Oloman, Colin W. [Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, BC (Canada)

    2006-07-28

    Liquid crystalline and micellar aqueous solutions of the nonionic surfactant Triton X-100 were used to direct the electrodeposition of Pt-Ru nanoparticles onto graphite felts, which were investigated as novel anodes for the direct methanol fuel cell. The effects of surfactant concentration, current density and deposition time in the preparation of these three-dimensional electrodes were studied in a factorial experiment and the electrodes were characterized by SEM and ICP-AES. Cyclic voltammetry, chronoamperometry and chronopotentiometry were carried out to assess the activity of the catalyzed felts for methanol oxidation. The presence of Triton X-100 (40-60wt.%) coupled with an acidic plating solution were essential for the efficient co-electrodeposition of Ru in the presence of Pt to yield approximately a 1:1 Pt:Ru atomic ratio in the deposit. The highest mass specific activity, 24Ag{sup -1} at 298K (determined by chronoamperometry after 180s at 0V versus Hg/Hg{sub 2}SO{sub 4}, K{sub 2}SO{sub 4std}), was obtained for the Pt-Ru electrodeposited in the presence of 40wt.% Triton X-100 at 60Am{sup -2}, 298K for 90min. Surfactant mediated electrodeposition is a promising method for meso-scale (ca. 10-60nm diameter) catalyst particle preparation on three-dimensional electrodes. (author)

  5. Electrodeposition of Pt-Ru nanoparticles on fibrous carbon substrates in the presence of nonionic surfactant: Application for methanol oxidation

    International Nuclear Information System (INIS)

    Bauer, Alex; Gyenge, Elod L.; Oloman, Colin W.

    2006-01-01

    Liquid crystalline and micellar aqueous solutions of the nonionic surfactant Triton X-100 were used to direct the electrodeposition of Pt-Ru nanoparticles onto graphite felts, which were investigated as novel anodes for the direct methanol fuel cell. The effects of surfactant concentration, current density and deposition time in the preparation of these three-dimensional electrodes were studied in a factorial experiment and the electrodes were characterized by SEM and ICP-AES. Cyclic voltammetry, chronoamperometry and chronopotentiometry were carried out to assess the activity of the catalyzed felts for methanol oxidation. The presence of Triton X-100 (40-60 wt.%) coupled with an acidic plating solution were essential for the efficient co-electrodeposition of Ru in the presence of Pt to yield approximately a 1:1 Pt:Ru atomic ratio in the deposit. The highest mass specific activity, 24 A g -1 at 298 K (determined by chronoamperometry after 180 s at 0 V versus Hg/Hg 2 SO 4 , K 2 SO 4std ), was obtained for the Pt-Ru electrodeposited in the presence of 40 wt.% Triton X-100 at 60 A m -2 , 298 K for 90 min. Surfactant mediated electrodeposition is a promising method for meso-scale (ca. 10-60 nm diameter) catalyst particle preparation on three-dimensional electrodes

  6. Determination of carcinogenic herbicides in milk samples using green non-ionic silicone surfactant of cloud point extraction and spectrophotometry.

    Science.gov (United States)

    Mohd, N I; Zain, N N M; Raoov, M; Mohamad, S

    2018-04-01

    A new cloud point methodology was successfully used for the extraction of carcinogenic pesticides in milk samples as a prior step to their determination by spectrophotometry. In this work, non-ionic silicone surfactant, also known as 3-(3-hydroxypropyl-heptatrimethylxyloxane), was chosen as a green extraction solvent because of its structure and properties. The effect of different parameters, such as the type of surfactant, concentration and volume of surfactant, pH, salt, temperature, incubation time and water content on the cloud point extraction of carcinogenic pesticides such as atrazine and propazine, was studied in detail and a set of optimum conditions was established. A good correlation coefficient ( R 2 ) in the range of 0.991-0.997 for all calibration curves was obtained. The limit of detection was 1.06 µg l -1 (atrazine) and 1.22 µg l -1 (propazine), and the limit of quantitation was 3.54 µg l -1 (atrazine) and 4.07 µg l -1 (propazine). Satisfactory recoveries in the range of 81-108% were determined in milk samples at 5 and 1000 µg l -1 , respectively, with low relative standard deviation, n  = 3 of 0.301-7.45% in milk matrices. The proposed method is very convenient, rapid, cost-effective and environmentally friendly for food analysis.

  7. Comparison of the orogenic displacement of sodium caseinate with the caseins from the air-water interface by nonionic surfactants.

    Science.gov (United States)

    Woodward, N C; Gunning, A P; Mackie, A R; Wilde, P J; Morris, V J

    2009-06-16

    Displacement of sodium caseinate from the air-water interface by nonionic surfactants Tween 20 and Tween 60 was observed by atomic force microscopy (AFM). The interfacial structure was sampled by Langmuir-Blodgett deposition onto freshly cleaved mica substrates. Protein displacement occurred through an orogenic mechanism: it involved the nucleation and growth of surfactant domains within the protein network, followed by failure of the protein network. The surface pressure at which failure of the protein network occurred was essentially independent of the type of surfactant. The major component of sodium caseinate is beta-casein, and previous studies at the air-water interface have shown that beta-casein networks are weak, failing at surface pressures below that observed for sodium caseinate. The other components of sodium caseinate are alpha(s)- and kappa-caseins. Studies of the displacement of alpha(s)-caseins from air-water interfaces show that these proteins also form weak networks that fail at surface pressures below that observed for sodium caseinate. However, kappa-casein was found to form strong networks that resisted displacement and failed at surface pressures comparable to those observed for sodium caseinate. The AFM images of the displacement suggest that, despite kappa-casein being a minor component, it dominates the failure of sodium caseinate networks: alpha(s)-casein and beta-casein are preferentially desorbed at lower surface pressures, allowing the residual kappa-casein to control the breakdown of the sodium caseinate network at higher surface pressures.

  8. SALT-INDUCED TRANSITION FROM A MICELLAR TO A LAMELLAR LIQUID-CRYSTALLINE PHASE IN DILUTE MIXTURES OF ANIONIC AND NONIONIC SURFACTANTS IN AQUEOUS-SOLUTION

    NARCIS (Netherlands)

    SEIN, A; ENGBERTS, JBFN; VANDERLINDEN, E; VANDEPAS, JC

    In dilute mixtures of anionic surfactant, sodium dodecylbenzenesulfonate (NaDoBS), and nonionic poly(ethylene oxide) alkyl monoether (C13-15E(7)) a transition from a micellar to a lamellar phase is found at high salting-out electrolyte (NaCit) concentrations. With an increase of the salt

  9. Indication of critical micelle concentration of nonionic surfactants with large emission change using water-soluble conjugated polymer as molecular light switch

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Lilin, E-mail: sunlilin126@126.com [Anhui Key Laboratory of Chemo-Biosensing, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000 (China); Hao, Dan; Zhang, Ping; Qian, Zhangsheng; Shen, Weili [Anhui Key Laboratory of Chemo-Biosensing, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000 (China); Shao, Taili [Anhui Key Laboratory of Chemo-Biosensing, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000 (China); Department of Pharmacy, Wannan Medical College, Wuhu 241000 (China); Zhu, Changqing, E-mail: zhucq@mail.ahnu.edu.cn [Anhui Key Laboratory of Chemo-Biosensing, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000 (China)

    2013-02-15

    A new near-infrared water-soluble conjugated polymer, i.e. poly [2,5-di (propyloxysulfonate)-1,4-phenylene-ethynylene-9,10-anthrylene] (PPEASO3) was synthesized to investigate its interaction with surfactants. It was found that PPEASO3 has only a weak fluorescence emission at about 670 nm due to its self-aggregation in water and in aqueous solution containing a low concentration of nonionic surfactants, i.e. below their critical micelle concentration (CMC). However, a dramatic fluorescence enhancement with a large emission blue-shift (>40 nm) was found once the concentration of nonionic surfactants reached the CMC (especially for Triton X-100). An orange fluorescence could be observed even with naked-eyes under UV-lamp, which gave a direct indication for the micelle forming process and provided a simple method for the CMC determination of the nonionic surfactants. The CMC values determined by this method were in good agreement with those obtained by other techniques. The dramatic emission change observed could be ascribed to the intensive hydrophobic interaction between PPEASO3 and surfactants micelle, which greatly disrupts the aggregation of the polymer and increase the fluorescence efficiency of PPEASO3. Highlights: Black-Right-Pointing-Pointer Investigated the interaction of a new water-soluble conjugated polymer with surfactants. Black-Right-Pointing-Pointer The dramatic fluorescence enhancement and emission blue-shift were observed at the CMC. Black-Right-Pointing-Pointer The obvious emission color change could be observed with naked-eyes under UV-lamp. Black-Right-Pointing-Pointer Gave a direct indication for the micelle forming process. Black-Right-Pointing-Pointer Provided a simple method for the CMC determination of the nonionic surfactants.

  10. Modeling of the Critical Micelle Concentration (CMC) of Nonionic Surfactants with an Extended Group-Contribution Method

    DEFF Research Database (Denmark)

    Mattei, Michele; Kontogeorgis, Georgios; Gani, Rafiqul

    2013-01-01

    , those compounds that exhibit larger correlation errors (based only on first- and second-order groups) are assigned to more detailed molecular descriptions, so that better correlations of critical micelle concentrations are obtained. The group parameter estimation has been performed using a data set......A group-contribution (GC) property prediction model for estimating the critical micelle concentration (CMC) of nonionic surfactants in water at 25 °C is presented. The model is based on the Marrero and Gani GC method. A systematic analysis of the model performance against experimental data...... concentration, and in particular, the quantitative structure−property relationship models, the developed GC model provides an accurate correlation and allows for an easier and faster application in computer-aided molecular design techniques facilitating chemical process and product design....

  11. Cloud point extraction for the determination of heavy metals by nonionic surfactant Triton X-100 and PAN

    International Nuclear Information System (INIS)

    Cabrera Puig, I.; Perez Gramatges, A.

    2006-01-01

    A novel methodology for extraction and preconcentration of trace metals based on cloud point phenomenon was applied to the analysis of Co(II), Cu(II), Cd(II), Pb(II) y Ni(II) in a certified reference material (CRM), using Triton X-100 as nonionic surfactant, and AAS for the determination. Different parameters that can influence the extraction efficiency were studied, such as pH and ionic strength of the solution. The precision, accuracy and detection limits of the method were determined using a CRM from the Environmental Analysis Laboratory of InSTEC. We applied our methodology to the detection of the metals in naturals waters (Almendares river and tap water) . The data obtained presented in this work is part of the validation file of the proposed analytical procedure for the determination of heavy metals

  12. Cloud point extraction of vanadium in pharmaceutical formulations, dialysate and parenteral solutions using 8-hydroxyquinoline and nonionic surfactant

    International Nuclear Information System (INIS)

    Khan, Sumaira; Kazi, Tasneem G.; Baig, Jameel A.; Kolachi, Nida F.; Afridi, Hassan I.; Wadhwa, Sham Kumar; Shah, Abdul Q.; Kandhro, Ghulam A.; Shah, Faheem

    2010-01-01

    A cloud point extraction (CPE) method has been developed for the determination of trace quantity of vanadium ions in pharmaceutical formulations (PF), dialysate (DS) and parenteral solutions (PS). The CPE of vanadium (V) using 8-hydroxyquinoline (oxine) as complexing reagent and mediated by nonionic surfactant (Triton X-114) was investigated. The parameters that affect the extraction efficiency of CPE, such as pH of sample solution, concentration of oxine and Triton X-114, equilibration temperature and time period for shaking were investigated in detail. The validity of CPE of V was checked by standard addition method in real samples. The extracted surfactant-rich phase was diluted with nitric acid in ethanol, prior to subjecting electrothermal atomic absorption spectrometry. Under these conditions, the preconcentration of 50 mL sample solutions, allowed raising an enrichment factor of 125-fold. The lower limit of detection obtained under the optimal conditions was 42 ng/L. The proposed method has been successfully applied to the determination of trace quantity of V in various pharmaceutical preparations with satisfactory results. The concentration ranges of V in PF, DS and PS samples were found in the range of 10.5-15.2, 0.65-1.32 and 1.76-6.93 μg/L, respectively.

  13. Front-face fluorescence spectroscopy study of globular proteins in emulsions: displacement of BSA by a nonionic surfactant.

    Science.gov (United States)

    Rampon, V; Genot, C; Riaublanc, A; Anton, M; Axelos, M A V; McClements, D J

    2003-04-23

    The displacement of a globular protein (bovine serum albumin, BSA) from the surface of oil droplets in concentrated oil-in-water emulsions by a nonionic surfactant (polyoxyethylene sorbitan monolauarate, Tween 20) was studied using front-face fluorescence spectroscopy (FFFS). This method relies on measurement of the change in intensity (I(MAX)) and wavelength (lambda(MAX)) of the maximum in the tryptophan emission spectrum. A series of oil-in-water emulsions (21 wt % n-hexadecane, 0.22 wt % BSA, pH 7.0) containing different molar ratios of Tween 20 to BSA (R = 0-131) were prepared. As the surfactant concentration was increased, the protein was progressively displaced from the droplet surfaces. At R > or = 66, the protein was completely displaced from the droplet surfaces. There was an increase in both I(MAX) and lambda(MAX) with increasing Tween 20 concentration up to R = 66, which correlated with the increase in the ratio of nonadsorbed to adsorbed protein. In contrast, there was a decrease in I(MAX) and lambda(MAX) with Tween 20 concentration in protein solutions and for R > or = 66 in the emulsions, which was attributed to binding of the surfactant to the protein. This study shows that FFFS is a powerful technique for nondestructively providing information about the interfacial composition of droplets in concentrated protein-stabilized emulsions in situ. Nevertheless, in general the suitability of the technique may also depend on protein type and the nature of the physicochemical matrix surrounding the proteins.

  14. Nonionic emulsion-mediated synthesis of zeolite beta

    Indian Academy of Sciences (India)

    Zeolite beta synthesis was first carried out in a newly developed emulsion system containing nonionic polyoxyethylated alkylphenol surfactant, which showed interesting non-conventional features. Compared to the conventional hydrothermal synthesis of zeolite beta, the reported nonionic emulsion system showed a faster ...

  15. Sorption of a nonionic surfactant Tween 80 by minerals and soils

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Soyoung, E-mail: soyoung@pusan.ac.kr; Jeong, Hoon Young, E-mail: hjeong@pusan.ac.kr

    2015-03-02

    Highlights: • Tween 80 sorption varies significantly among soil minerals. • Sorption mechanisms and atomic compositions explain to mineral-specific sorption. • Clay minerals and SOM in soils are the key contributors to Tween 80 sorption. • Hysteresis suggests the potential difficulty in removing residual surfactants. - Abstract: Batch experiments were conducted to evaluate Tween 80 sorption by oxides, aluminosilicates, and soils. For oxides, the sorption by silica and alumina follow linear isotherms, and that by hematite follows a Langmuir isotherm. Considering isotherm type and surface coverage, Tween 80 may partition into the silica/alumina–water interface, whereas it may bind to hematite surface sites. Among aluminosilicates, montmorillonite shows the greatest sorption due to the absorption of Tween 80 into interlayers. For other aluminosilicates, it sorbs to surfaces, with the sorption increasing as plagioclase < vermiculite < kaolinite. This results from the relative reactivity among surface sites: ≡NaOH, ≡CaOH << ≡SiOH < ≡AlOH. Experiments using dry- and wet-sieved soils reveal that fine-grained clay minerals, difficult to separate by dry-sieving, contribute significantly to Tween 80 sorption. The greater sorption by untreated soils than H{sub 2}O{sub 2}-treated soils indicates that soil organic matter is a vital sorbent. The sorption hysteresis, contributed to by clay minerals and soil organic matter, is characterized by the greater sorption during the desorption than the sorption stages. This suggests the potential difficulty in removing surfactants from soils. Also, sorption of surfactants can adversely affect surfactant-enhanced remediation by decreasing the aquifer permeability and the availability of surfactants for micellar solubilization.

  16. Adsorption at air-water and oil-water interfaces and self-assembly in aqueous solution of ethoxylated polysorbate nonionic surfactants.

    Science.gov (United States)

    Penfold, Jeffrey; Thomas, Robert K; Li, Peixun X; Petkov, Jordan T; Tucker, Ian; Webster, John R P; Terry, Ann E

    2015-03-17

    The Tween nonionic surfactants are ethoxylated sorbitan esters, which have 20 ethylene oxide groups attached to the sorbitan headgroup and a single alkyl chain, lauryl, palmityl, stearyl, or oleyl. They are an important class of surfactants that are extensively used in emulsion and foam stabilization and in applications associated with foods, cosmetics and pharmaceuticals. A range of ethoxylated polysorbate surfactants, with differing degrees of ethoxylation from 3 to 50 ethylene oxide groups, have been synthesized and characterized by neutron reflection, small-angle neutron scattering, and surface tension. In conjunction with different alkyl chain groups, this provides the opportunity to modify their surface properties, their self-assembly in solution, and their interaction with macromolecules, such as proteins. Adsorption at the air-water and oil-water interfaces and solution self-assembly of the range of ethoxylated polysorbate surfactants synthesized are presented and discussed.

  17. Mixtures of nonionic and anionic surfactants: interactions with low-molecular-mass homopeptides

    Czech Academy of Sciences Publication Activity Database

    Forgács, E.; Cserháti, T.; Deyl, Zdeněk; Mikšík, Ivan; Eckhardt, Adam

    2001-01-01

    Roč. 917, 1-2 (2001), s. 287-295 ISSN 0021-9673 R&D Projects: GA ČR GV203/96/K128; GA ČR GA203/99/0191; GA ČR GA203/00/D032 Institutional research plan: CEZ:AV0Z5011922 Keywords : molecular interactions * regression analysis * surfactants Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.793, year: 2001

  18. Communication: Salt-induced water orientation at a surface of non-ionic surfactant in relation to a mechanism of Hofmeister effect

    Energy Technology Data Exchange (ETDEWEB)

    Hishida, Mafumi; Kaneko, Yohei; Okuno, Masanari; Yamamura, Yasuhisa; Ishibashi, Taka-aki; Saito, Kazuya, E-mail: kazuya@chem.tsukuba.ac.jp [Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571 (Japan)

    2015-05-07

    The behavior of water molecules at the surface of nonionic surfactant (monomyristolein) and effects of monovalent ions on the behavior are investigated using the heterodyne-detected vibrational sum frequency generation spectroscopy. It is found that water molecules at the surface are oriented with their hydrogen atoms pointing to the bulk, and that the degree of orientation depends on the anion strongly but weakly on the cation. With measured surface potentials in those saline solutions, it is concluded that the heterogeneous distribution of anions and cations in combination with the nonionic surfactant causes the water orientation. This heterogeneous distribution well explains the contrasting order of anions and cations with respect to the ion size in the Hofmeister series.

  19. Communication: Salt-induced water orientation at a surface of non-ionic surfactant in relation to a mechanism of Hofmeister effect

    International Nuclear Information System (INIS)

    Hishida, Mafumi; Kaneko, Yohei; Okuno, Masanari; Yamamura, Yasuhisa; Ishibashi, Taka-aki; Saito, Kazuya

    2015-01-01

    The behavior of water molecules at the surface of nonionic surfactant (monomyristolein) and effects of monovalent ions on the behavior are investigated using the heterodyne-detected vibrational sum frequency generation spectroscopy. It is found that water molecules at the surface are oriented with their hydrogen atoms pointing to the bulk, and that the degree of orientation depends on the anion strongly but weakly on the cation. With measured surface potentials in those saline solutions, it is concluded that the heterogeneous distribution of anions and cations in combination with the nonionic surfactant causes the water orientation. This heterogeneous distribution well explains the contrasting order of anions and cations with respect to the ion size in the Hofmeister series

  20. Controlled synthesis of La1−xSrxCrO3 nanoparticles by hydrothermal method with nonionic surfactant and their ORR activity in alkaline medium

    International Nuclear Information System (INIS)

    Choi, Bo Hyun; Park, Shin-Ae; Park, Bong Kyu; Chun, Ho Hwan; Kim, Yong-Tae

    2013-01-01

    Graphical abstract: We demonstrate that Sr-doped LaCrO 3 nanoparticles were successfully prepared by the hydrothermal synthesis method using the nonionic surfactant Triton X-100 and the applicability of La 1−x Sr x CrO 3 to oxygen reduction reaction (ORR) electrocatalysis in an alkaline medium. Compared with the nanoparticles synthesized by the coprecipitation method, they showed enhanced ORR activity. - Highlights: • Sr-doped LaCrO 3 nanoparticles were successfully prepared by the hydrothermal method using the nonionic surfactant. • Homogeneously shaped and sized Sr-doped LaCrO 3 nanoparticles were readily obtained. • Compared with the nanoparticles synthesized by the coprecipitation method, they showed an enhanced ORR activity. • The main origin was revealed to be the decreased particle size due to the nonionic surfactant. - Abstract: Sr-doped LaCrO 3 nanoparticles were prepared by the hydrothermal method with the nonionic surfactant Triton X-100 followed by heat treatment at 1000 °C for 10 h. The obtained perovskite nanoparticles had smaller particle size (about 100 nm) and more uniform size distribution than those synthesized by the conventional coprecipitation method. On the other hand, it was identified with the material simulation that the electronic structure change by Sr doping was negligible, because the initially unfilled e g -band was not affected by the p-type doping. Finally, the perovskite nanoparticles synthesized by hydrothermal method showed much higher ORR activity by over 200% at 0.8 V vs. RHE than those by coprecipitation method

  1. The effect of ionic and non-ionic surfactants on the growth, nitrate reductase and nitrite reductase activities of Spirodela polyrrhiza (L. Schleiden

    Directory of Open Access Journals (Sweden)

    Józef Buczek

    2014-01-01

    Full Text Available Inclusion into the medium of 5 mg•dm-3 of non-ionic (ENF or ionic (DBST surfactant caused 50-60% inhibition of nitrite reductase MR activity in S. polyrrhiza. At the same time, increased accumulation of NO2- in the plant tissues and lowering of the total and soluble protein contents were found. DBST also lowered the nitrate reductase (NR activity and the dry mass of the plants.

  2. Performance evaluation of non-ionic surfactant based tazarotene encapsulated proniosomal gel for the treatment of psoriasis.

    Science.gov (United States)

    Prasad, Vure; Chaurasia, Sundeep

    2017-10-01

    The study aims to explore the potential of non-ionic surfactant based proniosomal gel (PNG) in improving the topical delivery of tazarotene by in vitro and in vivo studies. The PNG was prepared using coacervation phase separation method composed of span, stearylamine, cholesterol, and lecithin. The PNG demonstrated favorable vesicle size (3.26±0.22μm) and percent encapsulation efficiency (49.50±2.3%). The PNG was evaluated for viscosity which indicated that the ratio of span:cholesterol:stearylamine (64.5:30.5:5mM) demonstrated no any fluctuations in viscosity. The scanning electron micrographs exhibited spherical vesicles with sharp boundaries. The in vitro drug release through cellulose membrane and rat's skin were found to be in the following order of the formulation code A2>A4>A3>A5 and A4>A2>A3>A5, respectively, which showed the prolonged release of entrapped tazarotene. Further, in vitro drug permeation and retention studies revealed that formulations A2 and A4 showed the higher percent of drug permeation whereas formulations A3 and A5 showed the higher percent of drug retention through rat's skin. Moreover, PNG A2 and A4 formulations demonstrated good stability characteristics at different temperature conditions. The stability in the presence of detergent revealed that no any abrupt change in turbidity. The skin irritation studies performed with formulations A2 and A4 showed no erythema compared with the plain PNG. The male Albino NMRI mice tail model was used to performed in vivo skin histological examination which revealed that an increase in the orthokeratosis strengthened. Thus, all the results concluded that surfactant, Span 60 based PNG formulations have shown a good ability to increase drug accumulation in the various skin layers and more potential carrier for topical delivery of tazarotene for an effective therapy of psoriasis. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Confinement of a nonionic surfactant membrane within a montmorillonite as a new way to prepare organoclay materials

    Energy Technology Data Exchange (ETDEWEB)

    Guegan, Regis, E-mail: regis.guegan@univ-orleans.fr [Universite d' Orleans (France); Giovanela, Marcelo [Universidade de Caxias do Sul (UCS), RS (Brazil)

    2016-11-15

    The aim of this study was to prepare and characterize a hybrid layered material (organoclay) with a Na-montmorillonite and the triethylene glycol mono-n-decyl ether (C{sub 10}E{sub 3} ) nonionic surfactant which forms a lamellar phase at room temperature. The synthesized organoclay was characterized by complementary techniques (Fourier transform infrared spectroscopy and X-ray diffraction). Experiments in conjunction with electron density analysis showed that a bilayer or membrane of C{sub 10}E{sub 3} was intercalated within the interlayer space of a naturally exchanged Na-montmorillonite. The intercalation of a bilayer of C{sub 10}E{sub 3} in a clay mineral offers new perspectives for the manufacturing of nanomaterials. While showing a hydrophobic surface and a large interlayer space value, the resulting organoclay preserves the compensating cations within the interlayer space allowing one to perform ion exchanges, making easier the intercalation of further organic molecules of important size with functional properties or for environmental purposes. (author)

  4. Synthesis and Characterization of Encapsulated Nanosilica Particles with an Acrylic Copolymer by in Situ Emulsion Polymerization Using Thermoresponsive Nonionic Surfactant

    Directory of Open Access Journals (Sweden)

    Daryoosh Vashaee

    2013-08-01

    Full Text Available Nanocomposites of encapsulated silica nanoparticles were prepared by in situ emulsion polymerization of acrylate monomers. The synthesized material showed good uniformity and dispersion of the inorganic components in the base polymer, which enhances the properties of the nanocomposite material. A nonionic surfactant with lower critical solution temperature (LCST was used to encapsulate the silica nanoparticles in the acrylic copolymer matrix. This in situ method combined the surface modification and the encapsulation in a single pot, which greatly simplified the process compared with other conventional methods requiring separate processing steps. The morphology of the encapsulated nanosilica particles was investigated by dynamic light scattering (DLS and transmission electron microscopy (TEM, which confirmed the uniform distribution of the nanoparticles without any agglomerations. A neat copolymer was also prepared as a control sample. Both the neat copolymer and the prepared nanocomposite were characterized by Fourier transform infrared spectroscopy (FTIR, thermal gravimetric analyses (TGA, dynamic mechanical thermal analysis (DMTA and the flame resistance test. Due to the uniform dispersion of the non-agglomerated nanoparticles in the matrix of the polymer, TGA and flame resistance test results showed remarkably improved thermal stability. Furthermore, DMTA results demonstrated an enhanced storage modulus of the nanocomposite samples compared with that of the neat copolymer, indicating its superior mechanical properties.

  5. Environmentally evaluated HPLC-ELSD method to monitor enzymatic synthesis of a non-ionic surfactant.

    Science.gov (United States)

    Gaber, Yasser; Akerman, Cecilia Orellana; Hatti-Kaul, Rajni

    2014-01-01

    N-Lauroyl-N-methylglucamide is a biodegradable surfactant derived from renewable resources. In an earlier study, we presented an enzymatic solvent-free method for synthesis of this compound. In the present report, the HPLC method developed to follow the reaction between lauric acid/methyl laurate and N-methyl glucamine (MEG) and its environmental assessment are described. Use of ultraviolet (UV) absorption or refractive index (RI) detectors did not allow the detection of N-methyl glucamine (MEG). With Evaporative light scattering detector ELSD, it was possible to apply a gradient elution, and detect MEG with a limit of detection, LOD = 0.12 μg. A good separation of the peaks: MEG, lauric acid, product (amide) and by-product (amide-ester) was achieved with the gradient program with a run time of 40 min. The setting of ELSD detector was optimized using methyl laurate as the analyte. LC-MS/MS was used to confirm the amide and amide-ester peaks. We evaluated the greenness of the developed method using the freely available software HPLC-Environmental Assessment Tool (HPLC-EAT) and the method got a scoring of 73 HPLC-EAT units, implying that the analytical procedure was more environmentally benign compared to some other methods reported in literature whose HPLC-EAT values scored up to 182. Use of ELSD detector allowed the detection and quantification of the substrates and the reaction products of enzymatic synthesis of the surfactant, N-lauroyl-N-methylglucamide. The developed HPLC method has acceptable environmental profile based on HPLC-EAT evaluation.

  6. Inhibitory effect of non-ionic surfactants of the TRITON-X series on the corrosion of carbon steel in sulphuric acid

    International Nuclear Information System (INIS)

    Fuchs-Godec, R.

    2007-01-01

    The corrosion inhibition characteristics of non-ionic surfactants of the TRITON-X series, known as TRITON-X-100 and TRITON-X-405, on stainless steel (SS) type X4Cr13 in sulphuric acid were investigated by potentiodynamic polarisation measurements. It was found that these surfactants act as good inhibitors of the corrosion of stainless steel in 2 mol L -1 H 2 SO 4 solution, but the inhibition efficiency strongly depends on the electrode potential. The polarisation data showed that the non-ionic surfactants used in this study acted as mixed-type inhibitors and adsorb on the stainless steel surface, in agreement with the Flory-Huggins adsorption isotherm. Calculated ΔG ads values are -57.79 kJ mol -1 for TRITON-X-100, and -87.5 kJ mol -1 for TRITON-X-405. From the molecular structure it can be supposed that these surfactants adsorb on the metal surface through two lone pairs of electrons on the oxygen atoms of the hydrophilic head group, suggesting a chemisorption mechanism

  7. The application of density functional theory to the analysis of small-angle neutron scattering of concentrated microemulsion with nonionic surfactant

    International Nuclear Information System (INIS)

    Korneta, W.; Lopez Quintela, M.A.; Liz, L.

    1993-09-01

    The experimental results obtained by the static small-angle neutron scattering technique for the microemulsion consisting of 40% in volume of nonionic surfactant pentaethylene-glycol-4-octylphenylether, equal volumes of heavy water and decane, and additives (the salt KCl, the anionic surfactant SDS and butanol) are presented and discussed. The universal features of obtained scattering intensity plots are determined. The shape of the peak present in all scattering spectra was fitted by the universal function derived from the density functional theory. The persistence length of surfactant sheet used in many density functional theories of microemulsions is determined and the effect of different additives on this length is shown. (author). 10 refs, 2 figs

  8. Millimeter-wave sensor based on a λ/2-line resonator for identification and dielectric characterization of non-ionic surfactants.

    Science.gov (United States)

    Rodilla, H; Kim, A A; Jeffries, G D M; Vukusic, J; Jesorka, A; Stake, J

    2016-01-20

    Studies of biological and artificial membrane systems, such as niosomes, currently rely on the use of fluorescent tags, which can influence the system under investigation. For this reason, the development of label-free, non-invasive detection techniques is of great interest. We demonstrate an open-volume label-free millimeter-wave sensing platform based on a coplanar waveguide, developed for identification and characterization of niosome constituents. A design based on a λ/2-line resonator was used and on-wafer measurements of transmission and reflection parameters were performed up to 110 GHz. Our sensor was able to clearly distinguish between common niosome constituents, non-ionic surfactants Tween 20 and Span 80, measuring a resonance shift of 3 GHz between them. The complex permittivities of the molecular compounds have been extracted. Our results indicate insignificant frequency dependence in the investigated frequency range (3 GHz - 110 GHz). Values of permittivity around 3.0 + 0.7i and 2.2 + 0.4i were obtained for Tween 20 and Span 80, respectively.

  9. Preliminary studies of the toxic effects of non-ionic surfactants derived from lysine.

    Science.gov (United States)

    Macián, M; Seguer, J; Infante, M R; Selve, C; Vinardell, M P

    1996-01-08

    The toxic effects of new synthetic monodisperse non-ionic long-chain N alpha, N epsilon-diacyl lysine polyoxyethylene glycol amide compounds with a structural resemblance to natural lecithin phospholipids were studied by the haemolytic method and the test of the chorioallantoic membrane of the hen's egg (HET-CAM). The following compounds were tested: symmetrical N alpha,N epsilon-diacyl lysine homologues (N alpha,N epsilon-dihexanoyl, N alpha,N epsilon-dioctanoyl and N alpha,N epsilon-didecanoyl lysine) with one methyl ether polyoxyethylene glycol chain of different oxyethylene units (dioxyethylene glycol, tetraoxyethylene glycol and hexaoxyethylene glycol) as headgroup; symmetrical N alpha,N epsilon-diacyl lysine homologues with two methyl ether dioxyethylene glycol chains and the asymmetrical N alpha-butanoyl, N epsilon-dodecyl lysine with two hydrophilic methyl ether dioxyethylene glycol chains as headgroup. A commercial (polydisperse) oleoyl polyoxyethylene glycol diethanolamide with an average of eight units of ethylene oxide was used as control. All the synthesized tested compounds appeared to be less haemolytic and less irritant than the control. The synthesized products were studied with regard to their hydrophobic and hydrophilic chains in order to evaluate the influence of their structure on their haemolytic and irritative action. The results of this study show that the acyl chain distribution of these compounds greatly influence toxic effects: the asymmetrical compound N alpha-butanoyl,N epsilon-dodecyl lysine-bis[methyl ether diethylene glycol]amide was found to be the most haemolytic and irritating compound. Among the symmetrical homologues, the shortest-chain compounds N alpha,N epsilon-dihexanoyl lysine methyl ether polyoxyethylene glycol amides present the least haemolytic and irritating activity, independently of the number and length of the hydrophilic methyl ether polyoxyethylene glycol chains. Taking into account their surface activity

  10. Use of mixtures containing nonionic surfactants in the destabilization of petroleum emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Mansur, Claudia R.E.; Mauro, Aparecida C.; Aquino, Aline S.; Lechuga, Fernanda C.; Gonzalez, Gaspar; Lucas, Elizabete F. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Macromoleculas; Gonzalez, Gaspar [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2004-07-01

    During the petroleum dehydration process, it is necessary to used chemical demulsifiers in order to break the w/o emulsions that are formed in the oil field. These demulsifiers products are, in many cases, surfactants based poly(ethylene oxide-propylene oxide) block copolymers (PEO-PPO), with different EO/PO molar ratio. In this work were correlate the structure and the properties of PEO-PPO block copolymers with their performance as petroleum emulsion-destabilizing agent. Moreover, it was used an additive in the formulations, known as hydrotrope, in order to increase the solubility of these copolymers in aqueous solution. The results showed that the copolymer branched, whose hydrophilic segments (PEO and OH) are in an external adjacent position, present the higher solubility, in spite of to own EO/PO ratio similar to the others copolymers and the highest molar mass. Moreover, this copolymer presented the best efficiency in the emulsion destabilization. The addition of the hydrotrope NaBMGS to the PEO-PPO copolymers aqueous solutions caused the solubility increasing of these compounds in water. Such additive being used in the demulsifier formulation provoked an efficiency improving on the emulsion breaking process. (author)

  11. Determination of the critical micelle concentration in simulations of surfactant systems

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Andrew P.; Panagiotopoulos, Athanassios Z., E-mail: azp@princeton.edu [Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544 (United States)

    2016-01-28

    Alternative methods for determining the critical micelle concentration (cmc) are investigated using canonical and grand canonical Monte Carlo simulations of a lattice surfactant model. A common measure of the cmc is the “free” (unassociated) surfactant concentration in the presence of micellar aggregates. Many prior simulations of micellizing systems have observed a decrease in the free surfactant concentration with overall surfactant loading for both ionic and nonionic surfactants, contrary to theoretical expectations from mass-action models of aggregation. In the present study, we investigate a simple lattice nonionic surfactant model in implicit solvent, for which highly reproducible simulations are possible in both the canonical (NVT) and grand canonical (μVT) ensembles. We confirm the previously observed decrease of free surfactant concentration at higher overall loadings and propose an algorithm for the precise calculation of the excluded volume and effective concentration of unassociated surfactant molecules in the accessible volume of the solution. We find that the cmc can be obtained by correcting the free surfactant concentration for volume exclusion effects resulting from the presence of micellar aggregates. We also develop an improved method for determination of the cmc based on the maximum in curvature for the osmotic pressure curve determined from μVT simulations. Excellent agreement in cmc and other micellar properties between NVT and μVT simulations of different system sizes is observed. The methodological developments in this work are broadly applicable to simulations of aggregating systems using any type of surfactant model (atomistic/coarse grained) or solvent description (explicit/implicit)

  12. Determination of the critical micelle concentration in simulations of surfactant systems

    International Nuclear Information System (INIS)

    Santos, Andrew P.; Panagiotopoulos, Athanassios Z.

    2016-01-01

    Alternative methods for determining the critical micelle concentration (cmc) are investigated using canonical and grand canonical Monte Carlo simulations of a lattice surfactant model. A common measure of the cmc is the “free” (unassociated) surfactant concentration in the presence of micellar aggregates. Many prior simulations of micellizing systems have observed a decrease in the free surfactant concentration with overall surfactant loading for both ionic and nonionic surfactants, contrary to theoretical expectations from mass-action models of aggregation. In the present study, we investigate a simple lattice nonionic surfactant model in implicit solvent, for which highly reproducible simulations are possible in both the canonical (NVT) and grand canonical (μVT) ensembles. We confirm the previously observed decrease of free surfactant concentration at higher overall loadings and propose an algorithm for the precise calculation of the excluded volume and effective concentration of unassociated surfactant molecules in the accessible volume of the solution. We find that the cmc can be obtained by correcting the free surfactant concentration for volume exclusion effects resulting from the presence of micellar aggregates. We also develop an improved method for determination of the cmc based on the maximum in curvature for the osmotic pressure curve determined from μVT simulations. Excellent agreement in cmc and other micellar properties between NVT and μVT simulations of different system sizes is observed. The methodological developments in this work are broadly applicable to simulations of aggregating systems using any type of surfactant model (atomistic/coarse grained) or solvent description (explicit/implicit)

  13. Fragment-based approach to calculate hydrophobicity of anionic and nonionic surfactants derived from chromatographic retention on a C18 stationary phase.

    Science.gov (United States)

    Hammer, Jort; Haftka, Joris J-H; Scherpenisse, Peter; Hermens, Joop L M; de Voogt, Pim W P

    2017-02-01

    To predict the fate and potential effects of organic contaminants, information about their hydrophobicity is required. However, common parameters to describe the hydrophobicity of organic compounds (e.g., octanol-water partition constant [K OW ]) proved to be inadequate for ionic and nonionic surfactants because of their surface-active properties. As an alternative approach to determine their hydrophobicity, the aim of the present study was therefore to measure the retention of a wide range of surfactants on a C 18 stationary phase. Capacity factors in pure water (k' 0 ) increased linearly with increasing number of carbon atoms in the surfactant structure. Fragment contribution values were determined for each structural unit with multilinear regression, and the results were consistent with the expected influence of these fragments on the hydrophobicity of surfactants. Capacity factors of reference compounds and log K OW values from the literature were used to estimate log K OW values for surfactants (log KOWHPLC). These log KOWHPLC values were also compared to log K OW values calculated with 4 computational programs: KOWWIN, Marvin calculator, SPARC, and COSMOThermX. In conclusion, capacity factors from a C 18 stationary phase are found to better reflect hydrophobicity of surfactants than their K OW values. Environ Toxicol Chem 2017;36:329-336. © 2016 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC. © 2016 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC.

  14. Effect of a non-ionic surfactant added to the soil structure on the biodegradation of aromatic hydrocarbons within the soil

    Energy Technology Data Exchange (ETDEWEB)

    Aronstein, B N [Lab. of Soil Microbiology, Dept. of Soil, Crop, and Atmospheric Sciences, Cornell Univ., Ithaca, NY (United States); Alexander, M [Lab. of Soil Microbiology, Dept. of Soil, Crop, and Atmospheric Sciences, Cornell Univ., Ithaca, NY (United States)

    1993-06-01

    A study was conducted to determine whether a non-ionic surfactant (Novel II 1412-56) added to the surface of Lima silt loam would enhance the biodegradation of penanthrene and biphenyl present within the soil. Water containing the surfactant at concentrations of 10 and 100 [mu]g/ml was pumped through the soil. At 10 [mu]g/ml, Novel II 1412-56 markedly enhanced the rate and extent of phenanthrene mineralization and the extent but not the initial rate of biphenyl mineralization. The stimulation was less if the water added to the soil surface contained 100 [mu]g surfactant/ml. Addition of the surfactant at the two concentrations did not result in leaching of either phenanthrene or biphenyl, but products of the degradation were found in the soil leachate with or without the surfactant. We suggest that surfactants at low concentrations may be useful for in-situ bioremediation of sites contaminated with hydrophobic pollutants without causing movement of the parent compounds to ground-waters. (orig.)

  15. Tensiometric, fluorescence and 1H NMR study of mixed micellization of non-steroidal anti-inflammatory drug sodium salt of ibuprofen in the presence of non-ionic surfactant in aqueous/urea solutions

    International Nuclear Information System (INIS)

    Rub, Malik Abdul; Khan, Farah; Sheikh, Mohmad Shafi; Azum, Naved; Asiri, Abdullah M.

    2016-01-01

    Highlights: • Interaction between (IBF + TX-100) mixtures has been investigated. • (IBF + TX-100) mixtures exhibit synergistic behavior. • Urea increases the surface charge of the micelles resulting halt of the micelles formation. • N agg , K sv and dielectric constant of mixed systems have also been evaluated. • 1 H NMR data suggested that IBF and TX-100 interacts through hydrophobic as well as hydrophillic interaction. - Abstract: The desirable surface/bulk properties for specific applications of drug sodium salt of ibuprofen (IBF) and Triton X-100 (TX-100) can be achieved by adjusting mainly the composition of these systems. The interactions of anionic drug IBF with non-ionic surfactant TX-100 micelles have been investigated using tensiometry, fluorometry and 1 H NMR in aqueous as well in 250 mmol⋅kg −1 urea solutions. Different theoretical models like Clint, Rubingh, and Rosen, etc. were utilized to get information about the nature of interaction between these two in bulk and at the interface. These models disclose that the non-ideal behavior with attractive interaction in bulk and at the interface exists. The steady-state fluorescence quenching study was employed to evaluate micelle aggregation numbers (N agg ), which signify the involvement of surfactant was forever higher compared to IBF. Stern–Volmer binding constants (K sv ), micropolarity (I 1 /I 3 ) and dielectric constant (D exp ) of the mixtures are also obtained using fluorescence method. By the addition of urea raise in the surface charge of the micelles was observed followed by halt of the micellization of drug and surfactant as well as their mixture, therefore cmc values increases followed by decrease in aggregation number. The 1 H NMR resonance intensity variations were paralleled by upfield shifts in the resonance frequencies, due to an increased shielding of IBF happening from closeness of the non-ionic TX-100 surfactant.

  16. Non-ionic Surfactants and Non-Catalytic Protein Treatment on Enzymatic Hydrolysis of Pretreated Creeping Wild Ryegrass

    Science.gov (United States)

    Zheng, Yi; Pan, Zhongli; Zhang, Ruihong; Wang, Donghai; Jenkins, Bryan

    Our previous research has shown that saline Creeping Wild Ryegrass (CWR), Leymus triticoides, has a great potential to be used for bioethanol production because of its high fermentable sugar yield, up to 85% cellulose conversion of pretreated CWR. However, the high cost of enzyme is still one of the obstacles making large-scale lignocellulosic bioethanol production economically difficult. It is desirable to use reduced enzyme loading to produce fermentable sugars with high yield and low cost. To reduce the enzyme loading, the effect of addition of non-ionic surfactants and non-catalytic protein on the enzymatic hydrolysis of pretreated CWR was investigated in this study. Tween 20, Tween 80, and bovine serum albumin (BSA) were used as additives to improve the enzymatic hydrolysis of dilute sulfuric-acid-pretreated CWR. Under the loading of 0.1 g additives/g dry solid, Tween 20 was the most effective additive, followed by Tween 80 and BSA. With the addition of Tween 20 mixed with cellulase loading of 15 FPU/g cellulose, the cellulose conversion increased 14% (from 75 to 89%), which was similar to that with cellulase loading of 30 FPU/g cellulose and without additive addition. The results of cellulase and BSA adsorption on the Avicel PH101, pretreated CWR, and lignaceous residue of pretreated CWR support the theory that the primary mechanism behind the additives is prevention of non-productive adsorption of enzymes on lignaceous material of pretreated CWR. The addition of additives could be a promising technology to improve the enzymatic hydrolysis by reducing the enzyme activity loss caused by non-productive adsorption.

  17. Enhanced photocatalytic degradation of norfloxacin in aqueous Bi2WO6 dispersions containing nonionic surfactant under visible light irradiation

    International Nuclear Information System (INIS)

    Tang, Lin; Wang, Jiajia; Zeng, Guangming; Liu, Yani; Deng, Yaocheng; Zhou, Yaoyu; Tang, Jing; Wang, Jingjing; Guo, Zhi

    2016-01-01

    Highlights: • TX100 strongly enhanced the adsorption and photodegradation of NOF in Bi 2 WO 6 dispersions under visible light irradiation (400–750 nm). • Cu 2+ (10 mM) significantly suppressed the photocatalytic degradation of NOF. • FT-IR demonstrated that the NOF adsorbed on Bi 2 WO 6 was completely degraded. • Three possible photocatalytic degradation pathways of NOF were proposed, according to the HPLC/MS/MS analysis. - Abstract: Photocatalytic degradation is an alternative method to remove pharmaceutical compounds in water, however it is hard to achieve efficient rate because of the poor solubility of pharmaceutical compounds in water. This study investigated the photodegradation of norfloxacin in a nonionic surfactant Triton-X100 (TX100)/Bi 2 WO 6 dispersion under visible light irradiation (400–750 nm). It was found that the degradation of poorly soluble NOF can be strongly enhanced with the addition of TX100. TX100 was adsorbed strongly on Bi 2 WO 6 surface and accelerated NOF photodegradation at the critical micelle concentration (CMC = 0.25 mM). Higher TX100 concentration (>0.25 mM) lowered the degradation rate. In the presence of TX100, the degradation rate reached the maximum value when the pH value was 8.06. FTIR analyses demonstrated that the adsorbed NOF on the catalyst was completely degraded after 2 h irradiation. According to the intermediates identified by HPLC/MS/MS, three possible degradation pathways were proposed to include addition of hydroxyl radical to quinolone ring, elimination of piperazynilic ring in fluoroquinolone molecules, and replacement of F atoms on the aromatic ring by hydroxyl radicals.

  18. Masking of endotoxin in surfactant samples: Effects on Limulus-based detection systems.

    Science.gov (United States)

    Reich, Johannes; Lang, Pierre; Grallert, Holger; Motschmann, Hubert

    2016-09-01

    Over the last few decades Limulus Amebocyte Lysate (LAL) has been the most sensitive method for the detection of endotoxins (Lipopolysaccharides) and is well accepted in a broad field of applications. Recently, Low Endotoxin Recovery (LER) in biopharmaceutical drug products has been noticed, whereby the detection of potential endotoxin contaminations is not ensured. Notably, most of these drug products contain surfactants, which can have crucial effects on the detectability of endotoxin. In order to analyze the driving forces of LER, endotoxin detection in samples containing nonionic surfactants in various buffer systems was investigated. The results show that the process of LER is kinetically controlled and temperature-dependent. Furthermore, only the simultaneous presence of nonionic surfactants and components capable of forming metal complexes resulted in LER. In addition, capacity experiments show that even hazardous amounts of endotoxin can remain undetectable within such formulation compositions. In conclusion, the LER phenomenon is caused by endotoxin masking and not by test interference. In this process, the supramolecular structure of endotoxin is altered and exhibits only a limited susceptibility in binding to the Factor C of Limulus-based detection systems. We propose a two-step mechanism of endotoxin masking by complex forming agents and nonionic surfactants. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  19. DDT uptake by arbuscular mycorrhizal alfalfa and depletion in soil as influenced by soil application of a non-ionic surfactant

    International Nuclear Information System (INIS)

    Wu Naiying; Zhang Shuzhen; Huang Honglin; Shan Xiaoquan; Christie, Peter; Wang Youshan

    2008-01-01

    A greenhouse pot experiment was conducted to investigate the colonization of alfalfa roots by the arbuscular mycorrhizal (AM) fungus Glomus etunicatum and application of the non-ionic surfactant Triton X-100 on DDT uptake by alfalfa and depletion in soil. Mycorrhizal colonization led to an increase in the accumulation of DDT in roots but a decrease in shoots. The combination of AM inoculation and Triton X-100 application enhanced DDT uptake by both the roots and shoots. Application of Triton X-100 gave much lower residual concentrations of DDT in the bulk soil than in the rhizosphere soil or in the bulk soil without Triton X-100. AM colonization significantly increased bacterial and fungal counts and dehydrogenase activity in the rhizosphere soil. The combined AM inoculation of plants and soil application of surfactant may have potential as a biotechnological approach for the decontamination of soil polluted with DDT. - Combined colonization of alfalfa roots by an arbuscular mycorrhizal fungus and addition of non-ionic surfactant to the soil promoted root and shoot uptake and soil dissipation of DDT

  20. DDT uptake by arbuscular mycorrhizal alfalfa and depletion in soil as influenced by soil application of a non-ionic surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Wu Naiying [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Zhang Shuzhen [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China)], E-mail: szzhang@rcees.ac.cn; Huang Honglin; Shan Xiaoquan [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Christie, Peter [Agricultural and Environmental Science Department, Queen' s University Belfast, Newforge Lane, Belfast BT9 5PX (United Kingdom); Wang Youshan [Municipal Academy of Agriculture and Forestry, Institute of Plant Nutrition and Resources, Beijing 100097 (China)

    2008-02-15

    A greenhouse pot experiment was conducted to investigate the colonization of alfalfa roots by the arbuscular mycorrhizal (AM) fungus Glomus etunicatum and application of the non-ionic surfactant Triton X-100 on DDT uptake by alfalfa and depletion in soil. Mycorrhizal colonization led to an increase in the accumulation of DDT in roots but a decrease in shoots. The combination of AM inoculation and Triton X-100 application enhanced DDT uptake by both the roots and shoots. Application of Triton X-100 gave much lower residual concentrations of DDT in the bulk soil than in the rhizosphere soil or in the bulk soil without Triton X-100. AM colonization significantly increased bacterial and fungal counts and dehydrogenase activity in the rhizosphere soil. The combined AM inoculation of plants and soil application of surfactant may have potential as a biotechnological approach for the decontamination of soil polluted with DDT. - Combined colonization of alfalfa roots by an arbuscular mycorrhizal fungus and addition of non-ionic surfactant to the soil promoted root and shoot uptake and soil dissipation of DDT.

  1. Novel non-ionic surfactant proniosomes for transdermal delivery of lacidipine: optimization using 2(3) factorial design and in vivo evaluation in rabbits.

    Science.gov (United States)

    Soliman, Sara M; Abdelmalak, Nevine S; El-Gazayerly, Omaima N; Abdelaziz, Nabaweya

    2016-06-01

    Proniosomes offer a versatile vesicle drug delivery concept with potential for delivery of drugs via transdermal route. To develop proniosomal gel using cremophor RH 40 as non-ionic surfactant containing the antihypertensive drug lacidipine for transdermal delivery so as to avoid its extensive first pass metabolism and to improve its permeation through the skin. Proniosomes containing 1% lacidipine were prepared by the coacervation phase separation method, characterized, and optimized using a 2(3) full factorial design to define the optimum conditions to produce proniosomes with high entrapment efficiency, minimal vesicle size, and high-percentage release efficiency. The amount of cholesterol (X1), the amount of soya lecithin (X2), and the amount of cremophor RH 40 (X3) were selected as three independent variables. The system F4 was found to fulfill the maximum requisite of an optimum system because it had minimum vesicle size, maximum EE, maximum release efficiency, and maximum desirability. The optimized system (F4) was then converted to proniosomal gel using carbopol 940 (1% w/w). In vitro permeation through excised rabbit skin study revealed higher flux (6.48 ± 0.45) for lacidipine from the optimized proniosomal gel when compared with the corresponding emulgel (3.04 ± 0.13) mg/cm(2)/h. The optimized formulation was evaluated for its bioavailability compared with commercial product. Statistical analysis revealed significant increase in AUC (0 - α) 464.17 ± 113.15 ng h/ml compared with 209.02 ± 47.35 ng h/ml for commercial tablet. Skin irritancy and histopathological investigation of rat skin revealed its safety. Cremophor RH 40 proniosomal gel could be considered as very promising nanocarriers for transdermal delivery of lacidipine.

  2. EVALUATION OF THE USEFULNESS OF CONTINUOUS FLOW ANALYSIS FOR THE STUDY OF ANIONIC SURFACTANTS AND NONIONIC SURFACTANTS IN WATER AND SEWAGE SAMPLES

    Directory of Open Access Journals (Sweden)

    Aleksandra Strugała-Wilczek

    2014-10-01

    Established methods show low limit of detection, good precision and good correctness. The described full automatic method takes effect in short-time analysis, small sample volume required for testing and waste restriction. Proposed flow injection system comply with requirements and may be successfully applied in monitoring studies as well as in the routine laboratory analysis. Rapid determination of water and waste water quality by the SFA for the content of surfactants allows an adequate response in case of exceeding the permissible concentrations, even according to the most restricted requirements.

  3. Sequential injection chemiluminescence immunoassay for nonionic surfactants by using magnetic microbeads

    International Nuclear Information System (INIS)

    Zhang Ruiq; Nakajima, Hizuru; Soh, Nobuaki; Nakano, Koji; Masadome, Takashi; Nagata, Kazumi; Sakamoto, Kazuhira; Imato, Toshihiko

    2007-01-01

    A rapid and sensitive immunoassay based on a sequential injection analysis (SIA) using magnetic microbeads for the determination of alkylphenol polyethoxylates (APnEOs) is described. An SIA system was constructed from a syringe pump, a switching valve, a flow-through type immunoreaction cell equipped with a photon counting unit and a neodymium magnet. Magnetic beads, to which an anti-APnEOs monoclonal antibody was immobilized, were used as a solid support in an immunoassay. The introduction, trapping and release of the magnetic beads in and from the immunoreaction cell were controlled by means of a neodymium magnet and adjusting the flow of a carrier solution. The immunoassay was based on an indirect competitive immunoreaction of an anti-APnEOs monoclonal antibody immobilized on the magnetic beads with a sample APnEOs and a horseradish peroxidase (HRP)-labeled APnEOs in the same sample solution, and was based on the subsequent chemiluminscence reaction of HRP on the magnetic microbeads with a luminol solution containing hydrogen peroxide and p-iodophenol. The anti-APnEOs antibody was immobilized on the magnetic microbeads by coupling the antibody with the magnetic beads after activation of a carboxylate moiety on the surface of the magnetic beads that had been coated with a polylactic acid film. The antibody immobilized magnetic beads were introduced in the immunoreaction cell and trapped in it by the neodymium magnet, which was equipped beneath the immunoreaction cell. An APnEOs sample solution containing the HRP-labeled APnEOs at a constant concentration, and a luminol solution containing hydrogen peroxide and p-iodophenol were sequentially introduced into the immunoreaction cell, according to an SIA programmed sequence. Chemiluminescence emission was monitored by means of a photon counting unit located at the upper side of the immunoreaction cell by collecting the emitted light with a lens. A typical sigmoidal calibration curve was obtained, when the logarithm

  4. Adsorption of proteins at the solution/air interface influenced by added nonionic surfactants at very low concentrations for both components. 3. Dilational surface rheology.

    Science.gov (United States)

    Fainerman, V B; Aksenenko, E V; Lylyk, S V; Lotfi, M; Miller, R

    2015-03-05

    The influence of the addition of the nonionic surfactants C12DMPO, C14DMPO, C10OH, and C10EO5 at concentrations between 10(-5) and 10(-1) mmol/L to solutions of β-casein (BCS) and β-lactoglobulin (BLG) at a fixed concentration of 10(-5) mmol/L on the dilational surface rheology is studied. A maximum in the viscoelasticity modulus |E| occurs at very low surfactant concentrations (10(-4) to 10(-3) mmol/L) for mixtures of BCS with C12DMPO and C14DMPO and for mixtures of BLG with C10EO5, while for mixture of BCS with C10EO5 the value of |E| only slightly increased. The |E| values calculated with a recently developed model, which assumes changes in the interfacial molar area of the protein molecules due to the interaction with the surfactants, are in satisfactory agreement with experimental data. A linear dependence exists between the ratio of the maximum modulus for the mixture to the modulus of the single protein solution and the coefficient reflecting the influence of the surfactants on the adsorption activity of the protein.

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

    Science.gov (United States)

    Tanuja, Kosuri; Hemalatha, K; Karuna, Rupula; Sashidhar Rao, B

    2010-08-01

    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 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 12 days) 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.

  6. Effect of chemical structure on the cloud point of some new non-ionic surfactants based on bisphenol in relation to their surface active properties

    Directory of Open Access Journals (Sweden)

    A.M. Al-Sabagh

    2011-06-01

    Full Text Available A series of non-ionic surfactants were prepared from bisphenol derived from acetone (A, acetophenone (AC and cyclohexanone (CH. The prepared bisphenols were ethoxylated at different degrees of ethylene oxide (27, 35, 43. The ethoxylated bisphenols were non-esterified by fatty acids; decanoic, lauric, myristic, palmitic, stearic, oleic, linoloic and linolinic. Some surface active properties for these surfactants were measured and calculated such as, surface tension [γ], critical micelle concentration [CMC], minimum area per molecule [Amin], surface excess [Cmax], free energy of micellization and adsorption [ΔGmic] and [ΔGads]. At a certain temperature, the cloud point was measured for these surfactants. From the obtained data it was found that; the cloud point is very sensitive to the increase of the alkyl chain length, content of ethylene oxide and degree of unsaturation. The core of bisphenol affected the cloud point sharply and they are ranked regarding bisphenol structure as BA > BCH > BAC. By inspection of the surface active properties of these surfactants, a good relation was obtained with their cloud points. The data were discussed on the light of their chemical structures.

  7. A novel nonionic surfactant- and solvent-stable alkaline serine protease from Serratia sp. SYBC H with duckweed as nitrogen source: production, purification, characteristics and application.

    Science.gov (United States)

    Li, G Y; Cai, Y J; Liao, X R; Yin, J

    2011-07-01

    A novel nonionic surfactant- and hydrophilic solvent-stable alkaline serine protease was purified from the culture supernatant of Serratia sp. SYBC H with duckweed as nitrogen source. The molecular mass of the purified protease is about 59 kDa as assayed via SDS-PAGE. The protease is highly active over the pH range between 5.0 and 11.0, with the maximum activity at pH 8.0. It is also fairly active over the temperature range between 30 and 80°C, with the maximum activity at 40°C. The protease activity was substantially stimulated by Mn(2+) and Na(+) (5 mM), up to 837.9 and 134.5% at 40°C, respectively. In addition, Mn(2+) enhanced the thermostability of the protease significantly at 60°C. Over 90% of its initial activity remained even after incubating for 60 min at 40°C in 50% (v/v) hydrophilic organic solvents such as DMF, DMSO, acetone and MeOH. The protease retained 81.7, 83.6 and 76.2% of its initial activity in the presence of nonionic surfactants 20% (v/v) Tween 80, 25% (v/v) glycerol and Triton X-100, respectively. The protease is strongly inhibited by PMSF, suggesting that it is a serine protease. Washing experiments revealed that the protease has an excellent ability to remove blood stains.

  8. Preparation of graphene/TiO2 composites by nonionic surfactant strategy and their simulated sunlight and visible light photocatalytic activity towards representative aqueous POPs degradation

    International Nuclear Information System (INIS)

    Li, Kexin; Xiong, Jingjing; Chen, Tong; Yan, Liushui; Dai, Yuhua; Song, Dongyang; Lv, Ying; Zeng, Zhenxing

    2013-01-01

    Highlights: ► A series of graphene/TiO 2 composites were developed by nonionic surfactant strategy. ► The textural property, optical property, and composition were well characterized. ► Aqueous POPs were degraded under simulated sunlight and visible light irradiation. ► The degradation mechanism and kinetics of aqueous POPs were studied in detail. ► Mineralization of aqueous POPs and recyclability of the composites were also tested. -- Abstract: A series of graphene/TiO 2 composites were fabricated using a single-step nonionic surfactant strategy combined with the solvothermal treatment technique. Their phase structure, morphology, porosity, optical absorption property, as well as composition and structure, were characterized. The as-prepared composites were successfully applied to degrade aqueous persistent organic pollutants (POPs) such as rhodamine B, aldicarb, and norfloxacin in simulated sunlight (λ > 320 nm) and visible light (λ > 400 nm) irradiation. The degradation mechanism and kinetics of aqueous POPs were studied in detail. The mineralization of aqueous POPs and the recyclability of the composites were also tested in the same condition

  9. Electron beam irradiation of textile effluents and non-ionic ethoxylated surfactant for toxicity and color removal

    International Nuclear Information System (INIS)

    Sole, Stephanie V. Del; Garcia, Vanessa S.G.; Boiani, Nathalia F.; Rosa, Jorge M.; Andrade e Silva, Leonardo G. de; Borrely, Sueli I.

    2017-01-01

    Textile industry has an expressive scenario in the world economy and Brazil is the 5"t"h in the textile production. By 2015, Brazilian textile production represented US $ 39.3 billion, accounting for more than 1.8 million tons of fabric (ABIT, 2017). The effluents from textile industry are highlighted by quantity of wastewater discharged and variety of substances (dyes, bleaching agents, surfactants, salts, acids, among others). Such compounds often prove to be toxic to aquatic biota. This present study aims to assess toxicity of whole effluents, before and after irradiation (by electron beam accelerator, EBI). In addition, the reduction of the effluent color after irradiation is also very important. Daphnia similis and Vibrio fischeri were the biological systems applied for toxicity evaluations. Previous results demonstrated the surfactant as the main toxic compound, in the untreated and irradiated forms, EC 50 = 0.44 ppm ± 0.02 (untreated); EC 50 = 0.46 % ± 0.07 (irradiated). The irradiation was effective in reducing the color of the effluent, starting from 0.5 kGy. EB radiation may be proposed as an alternative treatment for the final effluent from textile processing, mainly for reuse purposes. (author)

  10. Electron beam irradiation of textile effluents and non-ionic ethoxylated surfactant for toxicity and color removal

    Energy Technology Data Exchange (ETDEWEB)

    Sole, Stephanie V. Del; Garcia, Vanessa S.G.; Boiani, Nathalia F.; Rosa, Jorge M.; Andrade e Silva, Leonardo G. de; Borrely, Sueli I., E-mail: vanessagranadeiro@gmail.com, E-mail: steh.vdsole@gmail.com, E-mail: jotarosa@hotmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); SENAI, Faculdade de Tecnologia Antoine Skaf, Sao Paulo, SP (Brazil)

    2017-11-01

    Textile industry has an expressive scenario in the world economy and Brazil is the 5{sup th} in the textile production. By 2015, Brazilian textile production represented US $ 39.3 billion, accounting for more than 1.8 million tons of fabric (ABIT, 2017). The effluents from textile industry are highlighted by quantity of wastewater discharged and variety of substances (dyes, bleaching agents, surfactants, salts, acids, among others). Such compounds often prove to be toxic to aquatic biota. This present study aims to assess toxicity of whole effluents, before and after irradiation (by electron beam accelerator, EBI). In addition, the reduction of the effluent color after irradiation is also very important. Daphnia similis and Vibrio fischeri were the biological systems applied for toxicity evaluations. Previous results demonstrated the surfactant as the main toxic compound, in the untreated and irradiated forms, EC 50 = 0.44 ppm ± 0.02 (untreated); EC 50 = 0.46 % ± 0.07 (irradiated). The irradiation was effective in reducing the color of the effluent, starting from 0.5 kGy. EB radiation may be proposed as an alternative treatment for the final effluent from textile processing, mainly for reuse purposes. (author)

  11. High-resolution Kendrick Mass Defect Analysis of Poly(ethylene oxide)-based Non-ionic Surfactants and Their Degradation Products.

    Science.gov (United States)

    Fouquet, Thierry; Shimada, Haruo; Maeno, Katsuyuki; Ito, Kanako; Ozeki, Yuka; Kitagawa, Shinya; Ohtani, Hajime; Sato, Hiroaki

    2017-09-01

    Matrix assisted laser desorption ionization (MALDI) high-resolution mass spectrometry (HRMS) and the recently introduced high-resolution Kendrick mass defect (HRKMD) analysis are combined to thoroughly characterize non-ionic surfactants made of a poly(ethylene oxide) (PEO) core capped by esters of fatty acids. A PEO monostearate surfactant is first analyzed as a proof of principle of the HRKMD analysis conducted with a fraction of EO as the base unit (EO/X with X being an integer) in lieu of EO for a regular KMD analysis. Data visualization is greatly enhanced and the distributions detected in the MALDI mass spectrum are assigned to a pristine (H, OH)-PEO as well as mono- and di-esterified PEO chains with palmitate and stearate end-groups in HRKMD plots computed with EO/45. The MALDI-HRMS/HRKMD analysis is then successfully applied to the more complex case of ethoxylated hydrogenated castor oil (EHCO) found to contain a large number of hydrogenated ricinoleate moieties (up to 14) in its HRKMD plot computed with EO/43, departing from the expected triglyceride structure. The exhaustiveness of the MALDI-HRMS/HRKMD strategy is validated by comparing the so-obtained fingerprints with results from alternative techniques (electrospray ionization MS, size exclusion and liquid adsorption chromatography, ion mobility spectrometry). Finally, aged non-ionic surfactants formed upon hydrolytic degradation are analyzed by MALDI-HRMS/HRKMD to easily assign the degradation products and infer the associated degradation routes. In addition to the hydrolysis of the ester groups observed for EHCO, chain scissions and new polar end-groups are observed in the HRKMD plot of PEO monostearate arising from a competitive oxidative ageing.

  12. Synthesis and characterization of anionic/nonionic surfactant-interceded iron-doped TiO{sub 2} to enhance sorbent/photo-catalytic properties

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Ajit; Lee, Byeong-Kyu, E-mail: bklee@ulsan.ac.kr

    2015-09-15

    We investigated the synthesis, characterization, and application of surfactant-interceded Fe nanoparticle-doped TiO{sub 2} (TiO{sub 2}/Fe-S1 and TiO{sub 2}/Fe-S2) that were used as adsorbents and photo-catalysts for the removal of As(V) ions from aqueous media. Two types of surfactant (anionic (sodium dodecyl sulfate), S1 and non-ionic (Triton X-100), S2) were used to obtain the separation and mono-dispersion of Fe(III) ions in the reaction solution. The nanocomposites were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), UV–vis, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX) and elemental mapping analysis before and after As(V) removal. The Langmuir capacities (q{sub e}, mg/g) of the sodium dodecyl sulfate (SDS) and Triton X-100 interceded nanocomposites (TiO{sub 2}/Fe-S1 and TiO{sub 2}/Fe-S2, respectively) for arsenic removal were determined to be 65.79 and 50.76 mg/g, respectively, in aqueous media with As(V) concentration ranges of 0–10 mg/L at pH 6.5. - Highlights: • Fe(III) doped TiO{sub 2} nanocomposite was prepared with surfactant. • Anionic surfactant SDS enhanced the transfer of Fe(III) ions to TiO{sub 2}. • Surfactant-interceded nanocomposite enhanced As(V) removal. • Arsenic removal efficiency was as follows: dark phase>visible phase>UV region.

  13. Atrazine and Diuron partitioning within a soil-water-surfactant system

    Science.gov (United States)

    Wang, P.; Keller, A.

    2006-12-01

    The interaction between pesticide and soil and water is even more complex in the presence of surfactants. In this study, batch equilibrium was employed to study the sorption of surfactants and the partitioning behaviors of Atrazine and Diuron within a soil-water-surfactant system. Five soils and four surfactants (nonionic Triton- 100, cationic Benzalkonium Chloride (BC), anionic Linear Alkylbenzenesulfonate (LAS), and anionic Sodium Dodecyl Sulfate (SDS)) were used. All surfactant sorption isotherms exhibited an initial linear increase at low surfactant concentrations but reached an asymptotic value as the surfactant concentrations increased. Among the surfactants, BC had the highest sorption onto all soils, followed by Triton-100 and then by LAS and SDS, implying that the nature of the charge significantly influences surfactant sorption. Sorption of either Triton-100 or BC was highly correlated with soil Cation Exchange Capacity (CEC) while that of LAS and SDS was complicated by the presence of Ca2+ and Mg2+ in the aqueous phase and the CEC sites. Both LAS and SDS formed complexes with Ca2+ and Mg2+, resulting in a significant decrease in the detergency of the surfactants. At high surfactant concentrations and with micelles present in the aqueous phase, the micelles formed a more competitive partitioning site for the pesticides, resulting in less pesticide sorbed to the soil. At low Triton-100 and BC concentration, the sorption of the surfactants first resulted in less Atrazine sorption but more Diuron sorption, implying competition between the surfactants and Atrazine, which serves as an indirect evidence that there is a different sorption mechanism for Atrazine. Atrazine is a weak base and it protonates and becomes positively charged near particle surfaces where the pH is much lower than in the bulk solution. The protonated Atrazine may then be held on the CEC sites via electrostatic attraction. Triton-100, LAS and SDS sorbed on the soil showed similar

  14. Effect of temperature on the (liquid + liquid) equilibrium for aqueous solution of nonionic surfactant and salt: Experimental and modeling

    Energy Technology Data Exchange (ETDEWEB)

    Foroutan, Masumeh [Physical Chemistry Department, School of Chemistry, College of Science, University of Tehran, 14155-6455 Enghelab Avenue, Tehran (Iran, Islamic Republic of)], E-mail: foroutan@khayam.ut.ac.ir; Heidari, Nosrat; Mohammadlou, Maryam [Chemistry Department, Faculty of Science, Uremia University, Uremia (Iran, Islamic Republic of); Sojahrood, Amin Jafari [Physics Department, Faculty of Science, Uremia University, Uremia (Iran, Islamic Republic of)

    2008-07-15

    The effect of temperature on the (liquid + liquid) equilibrium of the aqueous solution of surfactant polyoxyethylene cetylether (with abbreviation name Brij 58) and diammonium hydrogen phosphate has been investigated at T = (303.15, 313.15, 323.15, and 333.15) K. The Flory-Huggins equation with two electrostatic terms (Debye-Huckle and Pitzer-Debye-Huckle equations) was used to correlate the phase behavior of this system. Good agreement has been found between experimental and calculated data from both models. The results indicated that the enlargement of the two-phase region upon increasing the temperature. Additionally temperature dependency of the parameters of the Flory-Huggins model has been calculated.

  15. Nonionic surfactant-assisted hydrothermal synthesis of YVO4:Eu3+ powders in a wide pH range and their luminescent properties

    International Nuclear Information System (INIS)

    Wang Juan; Hojamberdiev, Mirabbos; Xu Yunhua; Peng Jianhong

    2011-01-01

    YVO 4 :Eu 3+ powders with different morphologies were fabricated by a simple hydrothermal method at 180 deg. C for 24 h in a wide pH range with the assistance of polyvinylpyrrolidone (PVP) as a nonionic surfactant. The as-synthesized samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence spectroscopy (PL). The obtained results showed that the pH value of synthesis solution played a key role in the formation of final products with different morphologies, such as, microspheres, irregular microspheres with grain-like nanoparticles, stone-like structures with regular short nanorods, and smooth rhombohedrons. The PL measurements revealed that the emission intensity of the samples was first decreased, and then increased with increasing the pH value due mainly to the increase in crystallinity and decrease in surface defects.

  16. Simultaneous quantification of poly-dispersed anionic, amphoteric and nonionic surfactants in simulated wastewater samples using C18 high-performance liquid chromatography-quadrupole ion-trap mass spectrometry

    Science.gov (United States)

    Levine, Lanfang H.; Garland, Jay L.; Johnson, Jodie V.

    2005-01-01

    This paper describes the development of a guantitative method for direct and simultaneous determination of three frequently encountered surfactants, amphoteric (cocoamphoacetate, CAA), anionic (sodium laureth sulfate, SLES), and nonionic (alcohol ethoxylate, AE) using a reversed-phase C18 HPLC coupled with an ESI ion-trap mass spectrometer (MS). Chemical composition, ionization characteristics and fragmentation pathways of the surfactants are presented. Positive ESI was effective for all three surfactants in agueous methanol buffered with ammonium acetate. The method enables rapid determinations in small sample volumes containing inorganic salts (up to 3.5 g L(-1)) and multiple classes of surfactants with high specificity by applying surfactant specific tandem mass spectrometric strategies. It has dynamic linear ranges of 2-60, 1.5-40, 0.8-56 mg L(-1) with R2 egual or greater than 0.999, 0.98 and 0.999 (10 microL injection) for CAA, SLES, and AE, respectively.

  17. Physico-chemical study of new non-ionic surfactants. Influence of ions on aggregation properties; Etude physico-chimique de nouveaux tensioactifs complexants thermoreversibles. Influence d'ions reconnus et non reconnus sur les proprietes d'agregation

    Energy Technology Data Exchange (ETDEWEB)

    Coulombeau, H

    2003-01-01

    New di-block thermo-sensitive metal chelating surfactants have been synthesised. They are based on polyethoxylated non-ionic surfactants (CiEj). A lysine block is linked either to the extremity of a CiEj (surfactant 2) or in a branched position (surfactant 1). These molecules retain the cloud point and the surface-active properties exhibited by the CiEj surfactants. Moreover they possess good complexing properties towards certain ions, which allows them to be successfully applied to cloud point extraction. In both cases, the cloud point and the area per headgroup at the air-water interface are higher than those of the analogous CiEj, which shows the hydrophilic contribution of the lysine block. Macroscopic properties (phase diagrams) and microscopic properties (shape of the aggregates and interactions between them) of the water-surfactant systems have been studied at ambient temperature. Small angle X-Rays scattering (SAXS) and small angle neutrons scattering (SANS) have shown that the new di-block surfactants form spherical micelles at low concentrations. The influence of non complexed salts on the new surfactants is the same as on classical CiEj: salting-in and salting-out phenomena occur according to the Hofmeister series. The effect of a complexed ion, uranyl cation, is however unusual: it leads to a sphere to rod transition, in turn lowering significantly the cloud point, which goes against the expectations on basis of the Hofmeister series. Finally, a preliminary study of ternary mixtures, water-surfactant 1-oil, is presented. It revealed the formation of microemulsions and pointed out that the surfactant film is then a lot more rigid than that formed with classical CiEj. (author)

  18. Lipid nanocapsules containing the non-ionic surfactant Solutol HS15 inhibit the transport of calcium through hyperforin-activated channels in neuronal cells.

    Science.gov (United States)

    Chauvet, Sylvain; Barras, Alexandre; Boukherroub, Rabah; Bouron, Alexandre

    2015-12-01

    Hyperforin is described as a natural antidepressant inhibiting the reuptake of neurotransmitters and also activating cation channels. However the blood-brain barrier limits the access to the brain of this biomolecule. To circumvent this problem it was envisaged to encapsulate hyperforin into biomimetic lipid nano-carriers like lipid nanocapsules (LNCs). When testing the safety of 25 nm LNCs it appeared that they strongly blocked hyperforin-activated Ca2+ channels of cultured cortical neurons. This inhibition was due to one of their main component: solutol HS15 (polyoxyethylene-660-12-hydroxy stearate), a non-ionic soluble surfactant. Solutol HS15 rapidly depresses in a concentration-dependent manner the entry of Ca2+ through hyperforin-activated channels without influencing store-operated channels. This effect is mimicked by Brij58 but not by PEG600, indicating that the lipid chain of Solutol HS15 is important in determining its effects on the channels. The inhibition of the Ca2+ fluxes depends on the cellular cholesterol content; it is stronger after depleting cholesterol with methyl-β-cyclodextrin and is nearly absent on cells cultured in a cholesterol-rich medium. When chronically applied for 24 h, Solutol HS15 slightly up-regulates the entry of Ca2+ through hyperforin-activated channels. Similar observations were made when testing 25 nm lipid nanocapsules containing the surfactant Solutol HS15. Altogether, this study shows that Solutol HS15 perturbs in a cholesterol-dependent manner the activity of some neuronal channels. This is the first demonstration that LNCs containing this surfactant can influence cellular calcium signaling in the brain, a finding that can have important clinical implications. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Self-assembly thermodynamics of pH-responsive amino-acid-based polymers with a nonionic surfactant

    Czech Academy of Sciences Publication Activity Database

    Bogomolova, Anna; Keller, S.; Klingler, J.; Sedlak, M.; Rak, D.; Šturcová, Adriana; Hrubý, Martin; Štěpánek, Petr; Filippov, Sergey K.

    2014-01-01

    Roč. 30, č. 38 (2014), s. 11307-11318 ISSN 0743-7463 R&D Projects: GA MŠk(CZ) LH14292 Grant - others:AV ČR(CZ) M200501201 Program:M Institutional support: RVO:61389013 Keywords : polymer * surfactant * thermodynamics Subject RIV: CC - Organic Chemistry Impact factor: 4.457, year: 2014

  20. Controlled synthesis of La{sub 1−x}Sr{sub x}CrO{sub 3} nanoparticles by hydrothermal method with nonionic surfactant and their ORR activity in alkaline medium

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Bo Hyun; Park, Shin-Ae [Energy System Major, School of Mechanical Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Park, Bong Kyu [GIFT Center, Pusan National University, Busan, 609-735 (Korea, Republic of); Chun, Ho Hwan, E-mail: chunahh@pusan.ac.kr [Global Core Research Center for Ships and Offshore Plants(GCRC-SOP), Pusan National University, Busan, 609-735 (Korea, Republic of); Kim, Yong-Tae, E-mail: yongtae@pusan.ac.kr [Energy System Major, School of Mechanical Engineering, Pusan National University, Busan 609-735 (Korea, Republic of)

    2013-10-15

    Graphical abstract: We demonstrate that Sr-doped LaCrO{sub 3} nanoparticles were successfully prepared by the hydrothermal synthesis method using the nonionic surfactant Triton X-100 and the applicability of La{sub 1−x}Sr{sub x}CrO{sub 3} to oxygen reduction reaction (ORR) electrocatalysis in an alkaline medium. Compared with the nanoparticles synthesized by the coprecipitation method, they showed enhanced ORR activity. - Highlights: • Sr-doped LaCrO{sub 3} nanoparticles were successfully prepared by the hydrothermal method using the nonionic surfactant. • Homogeneously shaped and sized Sr-doped LaCrO{sub 3} nanoparticles were readily obtained. • Compared with the nanoparticles synthesized by the coprecipitation method, they showed an enhanced ORR activity. • The main origin was revealed to be the decreased particle size due to the nonionic surfactant. - Abstract: Sr-doped LaCrO{sub 3} nanoparticles were prepared by the hydrothermal method with the nonionic surfactant Triton X-100 followed by heat treatment at 1000 °C for 10 h. The obtained perovskite nanoparticles had smaller particle size (about 100 nm) and more uniform size distribution than those synthesized by the conventional coprecipitation method. On the other hand, it was identified with the material simulation that the electronic structure change by Sr doping was negligible, because the initially unfilled e{sub g}-band was not affected by the p-type doping. Finally, the perovskite nanoparticles synthesized by hydrothermal method showed much higher ORR activity by over 200% at 0.8 V vs. RHE than those by coprecipitation method.

  1. Monitoring corrosion and corrosion control of iron in HCl by non-ionic surfactants of the TRITON-X series - Part III. Immersion time effects and theoretical studies

    International Nuclear Information System (INIS)

    Amin, Mohammed A.; Ahmed, M.A.; Arida, H.A.; Kandemirli, Fatma; Saracoglu, Murat; Arslan, Taner; Basaran, Murat A.

    2011-01-01

    Graphical abstract: . Display Omitted Research highlights: → The inhibition effect of TX-100, TX-165 and TX-305 on iron corrosion in 1.0 M HCl was studied. → TX-305 inhibited iron corrosion more effectively than TX-100 and TX-165. → In most cases, inhibition efficiency increased with time during the first 60 min of immersion, then decreased. → Calculated quantum chemical parameters confirmed the experimental inhibition efficiencies of the tested surfactants. - Abstract: The inhibition performance of three selected non-ionic surfactants of the TRITON-X series, namely TRITONX-100 (TX-100), TRITON-X-165 (TX-165) and TRITON-X-305 (TX-305), on the corrosion of iron was studied in 1.0 M HCl solutions as a function of inhibitor concentration (0.01-0.20 g L -1 ) and immersion time (0.0-8 h) at 298 K. Measurements were conducted based on Tafel polarization, LPR and impedance studies. At high frequencies, the impedance spectrum showed a depressed capacitive loop in the complex impedance plane, whose diameter is a function of the immersion time and the type and concentration of the introduced surfactant. In all cases, an inductive loop was observed in the low frequency and this could be attributed to the adsorption behavior. The inhibition efficiency increased with immersion time, reached a maximum and then decreased. This was attributed to the orientation change of adsorbed surfactant molecules. TX-305 inhibited iron corrosion more effectively than TX-100 and TX-165. The frontier orbital energies, the energy gap between frontier orbitals, dipole moments (μ), charges on the C and O atoms, the polarizabilities, and the quantum chemical descriptors were calculated. The quantum chemical calculation results inferred that for the HOMO representing the condensed Fukui function for an electrophilic attack (f k + ), the contributions belong to the phenyl group and the oxygen atom attached to the phenyl group for each tested surfactant. Quantitative structure

  2. Application of non-ionic surfactant as a developed method for the enhancement of two-phase solvent bar microextraction for the simultaneous determination of three phthalate esters from water samples.

    Science.gov (United States)

    Bandforuzi, Samereh Ranjbar; Hadjmohammadi, Mohammad Reza

    2018-08-03

    The extraction of phthalate esters (PEs) from aqueous matrices using two-phase solvent bar microextraction by organic micellar phase was investigated. A short hollow fiber immobilized with reverse micelles of Brij 35 surfactant in 1-octanol was served as the solvent bar for microextraction. Experimental results show that the extraction efficiency were much higher using two-phase solvent bar microextraction based on non-ionic surfactant than conventional two-phase solvent bar microextraction because of a positive effect of surfactant-containing extraction phase in promoting the partition process by non-ionic intermolecular forces such as polar and hydrophobicity interactions. The nature of the extraction solvent, type and concentration of non-ionic surfactant, extraction time, sample pH, temperature, stirring rate and ionic strength were the effecting parameters which optimized to obtain the highest extraction recovery. Analysis of recovered analytes was carried out with high performance liquid chromatography coupled with ultraviolet detection (HPLC-UV). Under the optimum conditions, linearity was observed in the range of 1-800 ng mL -1 for dimethylphthalate (DMP) and 0.5-800 ng mL -1 for diethylphthalate (DEP) and di-n-butyl phthalate (DBP) with correlation determination values above 0.99 for them. The limits of detection and quantification were ranged from 0.012 to 0.03 ng mL -1 and 0.04-0.1 ng mL -1 , respectively. The ranges of intra-day and inter-day RSD (n = 3) at 20 ng mL -1 of PEs were 1.8-2.1% and 2.1-2.6%, respectively. Results showed that developed method can be a very powerful, innovative and promising sample preparation technique in PEs analysis from environmental and drinking water samples. Copyright © 2018. Published by Elsevier B.V.

  3. Enhanced photocatalytic degradation of norfloxacin in aqueous Bi{sub 2}WO{sub 6} dispersions containing nonionic surfactant under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Lin, E-mail: tanglin@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Wang, Jiajia [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Zeng, Guangming, E-mail: zgming@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Liu, Yani; Deng, Yaocheng; Zhou, Yaoyu; Tang, Jing; Wang, Jingjing; Guo, Zhi [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China)

    2016-04-05

    Highlights: • TX100 strongly enhanced the adsorption and photodegradation of NOF in Bi{sub 2}WO{sub 6} dispersions under visible light irradiation (400–750 nm). • Cu{sup 2+} (10 mM) significantly suppressed the photocatalytic degradation of NOF. • FT-IR demonstrated that the NOF adsorbed on Bi{sub 2}WO{sub 6} was completely degraded. • Three possible photocatalytic degradation pathways of NOF were proposed, according to the HPLC/MS/MS analysis. - Abstract: Photocatalytic degradation is an alternative method to remove pharmaceutical compounds in water, however it is hard to achieve efficient rate because of the poor solubility of pharmaceutical compounds in water. This study investigated the photodegradation of norfloxacin in a nonionic surfactant Triton-X100 (TX100)/Bi{sub 2}WO{sub 6} dispersion under visible light irradiation (400–750 nm). It was found that the degradation of poorly soluble NOF can be strongly enhanced with the addition of TX100. TX100 was adsorbed strongly on Bi{sub 2}WO{sub 6} surface and accelerated NOF photodegradation at the critical micelle concentration (CMC = 0.25 mM). Higher TX100 concentration (>0.25 mM) lowered the degradation rate. In the presence of TX100, the degradation rate reached the maximum value when the pH value was 8.06. FTIR analyses demonstrated that the adsorbed NOF on the catalyst was completely degraded after 2 h irradiation. According to the intermediates identified by HPLC/MS/MS, three possible degradation pathways were proposed to include addition of hydroxyl radical to quinolone ring, elimination of piperazynilic ring in fluoroquinolone molecules, and replacement of F atoms on the aromatic ring by hydroxyl radicals.

  4. Influence of salts on the coexistence curve and protein partitioning in nonionic aqueous two-phase micellar systems

    Directory of Open Access Journals (Sweden)

    A. M. Lopes

    2014-12-01

    Full Text Available Aqueous two-phase micellar systems (ATPMS can be exploited in separation science for the extraction/purification of desired biomolecules. Prior to phase separation the surfactant solution reaches a cloud point temperature, which is influenced by the presence of electrolytes. In this work, we provide an investigation on the cloud point behavior of the nonionic surfactant C10E4 in the presence of NaCl, Li2SO4 and KI. We also investigated the salts' influence on a model protein partitioning. NaCl and Li2SO4 promoted a depression of the cloud point. The order of salts and the concentration that decreased the cloud point was: Li2SO4 0.5 M > NaCl 0.5 M ≈ Li2SO4 0.2 M. On the other hand, 0.5 M KI dislocated the curve to higher cloud point values. For our model protein, glucose-6-phosphate dehydrogenase (G6PD, partitioning experiments with 0.5 M NaCl or 0.2 M Li2SO4 at 13.85 ºC showed similar results, with K G6PD ~ 0.46. The lowest partition coefficient was obtained in the presence of 0.5 M KI (K G6PD = 0.12, with major recovery of the enzyme in the micelle-dilute phase (%Recovery = 90%. Our results show that choosing the correct salt to add to ATPMS may be useful to attain the desired partitioning conditions at more extreme temperatures. Furthermore, this system can be effective to separate a target biomolecule from fermented broth contaminants.

  5. Structural study of surfactant-dependent interaction with protein

    Energy Technology Data Exchange (ETDEWEB)

    Mehan, Sumit; Aswal, Vinod K., E-mail: vkaswal@barc.gov.in [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kohlbrecher, Joachim [Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 PSI Villigen (Switzerland)

    2015-06-24

    Small-angle neutron scattering (SANS) has been used to study the complex structure of anionic BSA protein with three different (cationic DTAB, anionic SDS and non-ionic C12E10) surfactants. These systems form very different surfactant-dependent complexes. We show that the structure of protein-surfactant complex is initiated by the site-specific electrostatic interaction between the components, followed by the hydrophobic interaction at high surfactant concentrations. It is also found that hydrophobic interaction is preferred over the electrostatic interaction in deciding the resultant structure of protein-surfactant complexes.

  6. Cloud point extraction of copper, lead, cadmium, and iron using 2,6-diamino-4-phenyl-1,3,5-triazine and nonionic surfactant, and their flame atomic absorption spectrometric determination in water and canned food samples.

    Science.gov (United States)

    Citak, Demirhan; Tuzen, Mustafa

    2012-01-01

    A cloud point extraction procedure was optimized for the separation and preconcentration of lead(II), cadmium(II), copper(II), and iron(III) ions in various water and canned food samples. The metal ions formed complexes with 2,6-diamino-4-phenyl-1,3,5-triazine that were extracted by surfactant-rich phases in the nonionic surfactant Triton X-114. The surfactant-rich phase was diluted with 1 M HNO3 in methanol prior to its analysis by flame atomic absorption spectrometry. The parameters affecting the extraction efficiency of the proposed method, such as sample pH, complexing agent concentration, surfactant concentration, temperature, and incubation time, were optimized. LOD values based on three times the SD of the blank (3Sb) were 0.38, 0.48, 1.33, and 1.85 microg/L for cadmium(II), copper(II), lead(II), and iron(III) ions, respectively. The precision (RSD) of the method was in the 1.86-3.06% range (n=7). Validation of the procedure was carried out by analysis of National Institute of Standards and Technology Standard Reference Material (NIST-SRM) 1568a Rice Flour and GBW 07605 Tea. The method was applied to water and canned food samples for determination of metal ions.

  7. FORMULASI MIKROEMULSI MINYAK DALAM AIR (O/W YANG STABIL MENGGUNAKAN KOMBINASI TIGA SURFAKTAN NON IONIK DENGAN NILAI HLB RENDAH, TINGGI DAN SEDANG Stable O/W Microemulsion Formulation Using Combination of Three Nonionic Surfactants with Low, High and Med

    Directory of Open Access Journals (Sweden)

    Sih Yuwanti

    2012-05-01

    Full Text Available The aim of this research was to determine the proportion of oil, surfactant and water which could produce a stable O/W microemulsion using combination of three nonionic surfactants with low, high and medium HLB values; and to determine the role of surfactant with a medium HLB value in O/W microemulsion formulation. The first group of microemulsions were prepared using combination of Tween 80, Span 80 and Span 40 (80 %:10 %:10 % with dif- ferent proportions of VCO:surfactant (1:3, 1:3.5 dan 1:4.  The second goups of microemulsion were prepared using combination of Tween 80, Span 80 and Span 40 (90 %:5 %:5 % with different proportions of VCO:surfactant 1:4,1:4.5 dan 1:5.  The stability of microemulsion was determined during storage at room temperature and after being ovened at 105 0C 5 hours and centrifuged at 2300 g 15 minutes. Microemulsion stability was determined by measur- ing absorbance of the microemulsion at 502 nm and then converted to turbidity (%.  In order to determine the role of surfactant with a medium HLB value in the formulation of O/W microemulsion, one set microemulsions were made without surfactant with a medium HLB value, and another set of microemulsions were prepared with different ratios of low and medium HLB surfactant (1:1, 2:1 and 1:2. The most stable microemulsion was achieved when the proportion of VCO:surfactant:water was 4:20:76 and combination of Tween 80:Span 80:Span 40 with the ratio of 90:3.33:6.67. A more stable O/W microemulsion could be obtained when surfactant with a medium HLB value was added to O/W microemulsion formulation. Surfactant with a medium HLB value would link the oil phase and water phase with sur- factant layer, interaction of surfactant-oil and surfactant-water increased. It provided a smooth transition between oil phase and water phase, and the microemulsion became more stable. ABSTRAK Tujuan dari penelitian ini adalah untuk menentukan proporsi minyak, surfaktan dan air yang dapat

  8. Fragment-based approach to calculate hydrophobicity of anionic and nonionic surfactants from chromatographic retention on a C18 stationary phase

    NARCIS (Netherlands)

    Hammer, J.; Haftka, J.J.-H.; Scherpenisse, P.; Hermens, J.L.M.; de Voogt, P.W.P.

    To predict the fate and potential effects of organic contaminants, information about their hydrophobicity is required. However, common parameters to describe the hydrophobicity of organic compounds (e.g., octanol–water partition constant [KOW]) proved to be inadequate for ionic and nonionic

  9. Fragment-based approach to calculate hydrophobicity of anionic and nonionic surfactants derived from chromatographic retention on a C18 stationary phase

    NARCIS (Netherlands)

    Hammer, Jort; Haftka, Joris J-H; Scherpenisse, Peter; Hermens, Joop L M; de Voogt, Pim W P

    To predict the fate and potential effects of organic contaminants, information about their hydrophobicity is required. However, common parameters to describe the hydrophobicity of organic compounds (e.g., octanol-water partition constant [KOW ]) proved to be inadequate for ionic and nonionic

  10. Use of organoclays obtained with nonionic surfactants for drilling fluids base organic; O uso de argilas organofilicas obtidas com tensoativo nao-ionico para fluidos de perfuracao base organica

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, F.K.A. [Universidade Federal de Campina Grande (UATEC/UFCG), PB (Brazil). Unidade Academica de Tecnologia do Desenvolvimento], e-mail: kegealves@ufcg.edu.br; Neves, G.A.; Ferreira, H.C.; Silva, A.L. [Universidade Federal de Campina Grande (UFCG/UAEMa), PB (Brazil). Unidade Academica de Engenharia de Materiais; Campos, L.F.A. [Departamento de Engenharia de Materiais, DEMat/CCT/UFPB, PB (Brazil)

    2010-07-01

    This paper aims to use the compositions of organo clays obtained with nonionic surfactant for drilling fluids organic base containing additives, emulsifiers, brine, activator, reducer filtered, adensante and evaluate their rheological, filtration and electrical stability. Were studied through the mixture delineament, ten compositions of organo clays, and its performance is evaluated by means of the rheological behavior (flow curves, GI, GF, VA, VP and LE) and the tests recommended by API (PE, EE and VF). The results were compared with the standard PETROBRAS and showed that among the developed compositions, two compositions showed promising that met most of the properties and use the clay of inferior quality (Bofe and Verde-lodo) in greater quantity and minimum clay Chocolate UBM, considered the best clay in the region mines Boa Vista, PB. (author)

  11. Surfactant modified clays’ consistency limits and contact angles

    Directory of Open Access Journals (Sweden)

    S Akbulut

    2012-07-01

    Full Text Available This study was aimed at preparing a surfactant modified clay (SMC and researching the effect of surfactants on clays' contact angles and consistency limits; clay was thus modified by surfactants formodifying their engineering properties. Seven surfactants (trimethylglycine, hydroxyethylcellulose  octyl phenol ethoxylate, linear alkylbenzene sulfonic acid, sodium lauryl ether sulfate, cetyl trimethylammonium chloride and quaternised ethoxylated fatty amine were used as surfactants in this study. The experimental results indicated that SMC consistency limits (liquid and plastic limits changedsignificantly compared to those of natural clay. Plasticity index and liquid limit (PI-LL values representing soil class approached the A-line when zwitterion, nonionic, and anionic surfactant percentageincreased. However, cationic SMC became transformed from CH (high plasticity clay to MH (high plasticity silt class soils, according to the unified soil classification system (USCS. Clay modifiedwith cationic and anionic surfactants gave higher and lower contact angles than natural clay, respectively.

  12. Monitoring corrosion and corrosion control of iron in HCl by non-ionic surfactants of the TRITON-X series - Part II. Temperature effect, activation energies and thermodynamics of adsorption

    International Nuclear Information System (INIS)

    Amin, Mohammed A.; Ahmed, M.A.; Arida, H.A.; Arslan, Taner; Saracoglu, Murat; Kandemirli, Fatma

    2011-01-01

    Research highlights: → TX-305 exhibits inhibiting properties for iron corrosion more than TX-165 and TX 100. → Inhibition efficiency increases with temperature, suggesting chemical adsorption. → The three tested surfactants act as mixed-type inhibitors with cathodic predominance. → Validation of corrosion rates measured by Tafel extrapolation method is confirmed. - Abstract: The inhibition characteristics of non-ionic surfactants of the TRITON-X series, namely TRITON-X-100 (TX-100), TRITON-X-165 (TX-165) and TRITON-X-305 (TX-305), on the corrosion of iron was studied in 1.0 M HCl solutions as a function of inhibitor concentration (0.005-0.075 g L -1 ) and solution temperature (278-338 K). Measurements were conducted based on Tafel extrapolation method. Electrochemical frequency modulation (EFM), a non-destructive corrosion measurement technique that can directly give values of corrosion current without prior knowledge of Tafel constants, is also presented. Experimental corrosion rates determined by the Tafel extrapolation method were compared with corrosion rates obtained by the EFM technique and an independent method of chemical analysis. The chemical method of confirmation of the corrosion rates involved determination of the dissolved cation, using ICP-AES (inductively coupled plasma atomic emission spectrometry). The aim was to confirm validation of corrosion rates measured by the Tafel extrapolation method. Results obtained showed that, in all cases, the inhibition efficiency increased with increase in temperature, suggesting that chemical adsorption occurs. The adsorptive behaviour of the three surfactants followed Temkin-type isotherm. The standard free energies of adsorption decreased with temperature, reflecting better inhibition performance. These findings confirm chemisorption of the tested inhibitors. Thermodynamic activation functions of the dissolution process were also calculated as a function of each inhibitor concentration. All the results

  13. An investigation of bubble coalescence and post-rupture oscillation in non-ionic surfactant solutions using high-speed cinematography.

    Science.gov (United States)

    Bournival, G; Ata, S; Karakashev, S I; Jameson, G J

    2014-01-15

    Most processes involving bubbling in a liquid require small bubbles to maximise mass/energy transfer. A common method to prevent bubbles from coalescing is by the addition of surfactants. In order to get an insight into the coalescence process, capillary bubbles were observed using a high speed cinematography. Experiments were performed in solutions of 1-pentanol, 4-methyl-2-pentanol, tri(propylene glycol) methyl ether, and poly(propylene glycol) for which information such as the coalescence time and the deformation of the resultant bubble upon coalescence was extracted. It is shown in this study that the coalescence time increases with surfactant concentration until the appearance of a plateau. The increase in coalescence time with surfactant concentration could not be attributed only to surface elasticity. The oscillation of the resultant bubble was characterised by the damping of the oscillation. The results suggested that a minimum elasticity is required to achieve an increased damping and considerable diffusion has a detrimental effect on the dynamic response of the bubble, thereby reducing the damping. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Growth Mechanism of Gold Nanorods in Binary Surfactant System

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bo-Mi; Seo, Sun-Hwa; Joe, Ara; Shim, Kyu-Dong; Jang, Eue-Soon [Kumoh National Institute of Technology, Gumi (Korea, Republic of)

    2016-06-15

    In order to reveal the growth mechanism of gold nanorods (GNRs) in a binary surfactant system, we synthesized various GNRs by changing the concentration of the surfactants, AgNO{sub 3}, and HBr in the growth solution. We found that the benzyldime thylhexadecylammoniumchloride surfactant had weak interaction with the gold ions, but it could reduce the membrane fluidity. In addition, we could dramatically decrease the cetyltrimethylammonium bromide concentration required for GNR growth by adding an HBr solution. Notably, Ag{sup +} ions were necessary to break the symmetry of the seed crystals for GNR growth, but increasing the concentration of Ag{sup +} and Br{sup -} ions caused a decrease in the template size.

  15. Structural studies of lamellar surfactant systems under shear

    DEFF Research Database (Denmark)

    Mortensen, K.

    2001-01-01

    Recent experimental studies on concentrated surfactant systems are reviewed. Particular attention is focused on the transformation from planar lamellar sheets to multilamellar vesicles. It is discussed whether both of these states are thermodynamic stable, or if the MLV is an artifact of shear in...

  16. Circulating surfactant protein D is decreased in systemic lupus erythematosus

    DEFF Research Database (Denmark)

    Hoegh, Silje Vermedal; Voss, Anne; Sorensen, Grith Lykke

    2009-01-01

    Objective. Deficiencies of innate immune molecules like mannan binding lectin (MBL) have been implicated in the pathogenesis of systemic lupus erythematosus (SLE). Surfactant protein D (SP-D) and MBL belong to the same family of innate immune molecules - the collectins, which share important...

  17. Viscosity of the oil-in-water Pickering emulsion stabilized by surfactant-polymer and nanoparticle-surfactant-polymer system

    Science.gov (United States)

    Sharma, Tushar; Kumar, G. Suresh; Chon, Bo Hyun; Sangwai, Jitendra S.

    2014-11-01

    Information on the viscosity of Pickering emulsion is required for their successful application in upstream oil and gas industry to understand their stability at extreme environment. In this work, a novel formulation of oil-in-water (o/w) Pickering emulsion stabilized using nanoparticle-surfactant-polymer (polyacrylamide) system as formulated in our earlier work (Sharma et al., Journal of Industrial and Engineering Chemistry, 2014) is investigated for rheological stability at high pressure and high temperature (HPHT) conditions using a controlled-strain rheometer. The nanoparticle (SiO2 and clay) concentration is varied from 1.0 to 5.0 wt%. The results are compared with the rheological behavior of simple o/w emulsion stabilized by surfactant-polymer system. Both the emulsions exhibit non-Newtonian shear thinning behavior. A positive shift in this behavior is observed for surfactant-polymer stabilized emulsion at high pressure conditions. Yield stress is observed to increase with pressure for surfactant-polymer emulsion. In addition, increase in temperature has an adverse effect on the viscosity of emulsion stabilized by surfactant-polymer system. In case of nanoparticle-surfactant-polymer stabilized o/w emulsion system, the viscosity and yield stress are predominantly constant for varying pressure and temperature conditions. The viscosity data for both o/w emulsion systems are fitted by the Herschel-Bulkley model and found to be satisfactory. In general, the study indicates that the Pickering emulsion stabilized by nanoparticle-surfactant-polymer system shows improved and stable rheological properties as compared to conventional emulsion stabilized by surfactant-polymer system indicating their successful application for HPHT environment in upstream oil and gas industry.

  18. Effect of chemical and biological surfactants on activated sludge of MBR system: microscopic analysis and foam test.

    Science.gov (United States)

    Capodici, Marco; Di Bella, Gaetano; Nicosia, Salvatore; Torregrossa, Michele

    2015-02-01

    A bench-scale MBR unit was operated, under stressing condition, with the aim of stimulating the onset of foaming in the activated sludge. Possible synergies between synthetic surfactants in the wastewater and biological surfactants (Extra-Cellular Polymeric Substances, EPSs) were investigated by changing C/N ratio. The growth of filamentous bacteria was also discussed. The MBR unit provided satisfactory overall carbon removal overall efficiencies: in particular, synthetic surfactants were removed with efficiency higher than 90% and 95% for non-ionic and ionic surfactants, respectively. Lab investigation suggested also the importance to reduce synthetic surfactants presence entering into mixed liquor: otherwise, their presence can significantly worsen the natural foaming caused by biological surfactants (EPSs) produced by bacteria. Finally, a new analytic method based on "ink test" has been proposed as a useful tool to achieve a valuation of EPSs bound fraction. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Structure and Conformational Dynamics of DMPC/Dicationic Surfactant and DMPC/Dicationic Surfactant/DNA Systems

    Directory of Open Access Journals (Sweden)

    Maciej Kozak

    2013-04-01

    Full Text Available Amphiphilic dicationic surfactants, known as gemini surfactants, are currently studied for gene delivery purposes. The gemini surfactant molecule is composed of two hydrophilic “head” groups attached to hydrophobic chains and connected via molecular linker between them. The influence of different concentrations of 1,5-bis (1-imidazolilo-3-decyloxymethyl pentane chloride (gemini surfactant on the thermotropic phase behaviour of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC bilayers with and without the presence of DNA was investigated using Fourier transformed infrared (FTIR and circular dichroism (CD spectroscopies, small angle scattering of synchrotron radiation and differential scanning calorimetry. With increasing concentration of surfactant in DMPC/DNA systems, a disappearance of pretransition and a decrease in the main phase transition enthalpy and temperature were observed. The increasing intensity of diffraction peaks as a function of surfactant concentration also clearly shows the ability of the surfactant to promote the organisation of lipid bilayers in the multilayer lamellar phase.

  20. Use of surfactants for the remediation of contaminated soils: a review.

    Science.gov (United States)

    Mao, Xuhui; Jiang, Rui; Xiao, Wei; Yu, Jiaguo

    2015-03-21

    Due to the great harm caused by soil contamination, there is an increasing interest to apply surfactants to the remediation of a variety of contaminated soils worldwide. This review article summarizes the findings of recent literatures regarding remediation of contaminated soils/sites using surfactants as an enhancing agent. For the surfactant-based remedial technologies, the adsorption behaviors of surfactants onto soil, the solubilizing capability of surfactants, and the toxicity and biocompatibility of surfactants are important considerations. Surfactants can enhance desorption of pollutants from soil, and promote bioremediation of organics by increasing bioavailability of pollutants. The removal of heavy metals and radionuclides from soils involves the mechanisms of dissolution, surfactant-associated complexation, and ionic exchange. In addition to the conventional ionic and nonionic surfactants, gemini surfactants and biosurfactants are also applied to soil remediation due to their benign features like lower critical micelle concentration (CMC) values and better biocompatibility. Mixed surfactant systems and combined use of surfactants with other additives are often adopted to improve the overall performance of soil washing solution for decontamination. Worldwide the field studies and full-scale remediation using surfactant-based technologies are yet limited, however, the already known cases reveal the good prospect of applying surfactant-based technologies to soil remediation. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Dilational viscoelastic properties of fluid interfaces - III mixed surfactant systems

    Energy Technology Data Exchange (ETDEWEB)

    Djabbarah, N.F.; Wasan, D.T.

    1982-01-01

    The surface viscosity and elasticity of solutions of mixed surfactants were determined using the longitudinal wave technique combined with tracer particle measurements. The recent analysis of Maru et al., which was restricted to insoluble monolayers and to monolayers adsorbed from a single surfactant solution, has now been extended to multicomponent solutions. This analysis can be used not only to estimate the ''net'' viscoelastic properties at gas-liquid interfaces but also to estimate the composition as well as the intrinsic viscoelastic properties. Furthermore, when accompanied by separate measurements of shear viscoelastic properties, the above analysis can be used for the determination of dilational viscosity and elasticity. Surface viscoelasticity measurements were conducted on aqueous solutions of sodium lauryl sulfate and sodium lauryl sulfate-lauryl alcohol. Net surface viscosity and elasticity of sodium lauryl sulfate solutions increased with bulk concentration and reached a maximum at a concentration in the neighborhood of the critical micelle concentration. The presence of small amount of lauryl alcohol caused almost an order of magnitude increase in intrinsic surface viscosity and a similar increase in compositional surface elasticity. A comparison between the values of intrinsic surface viscosity and those of surface shear viscosity indicated that surface dilational viscosity exceeds surface shear viscosity by at least two orders of magnitude. These appear to be the first set of data presented hitherto for the surface dilational properties in addition to surface shear properties for the same mixed surfactant systems.

  2. Occurrence of multi-class surfactants in urban wastewater: contribution of a healthcare facility to the pollution transported into the sewerage system.

    Science.gov (United States)

    Bergé, Alexandre; Wiest, Laure; Baudot, Robert; Giroud, Barbara; Vulliet, Emmanuelle

    2018-04-01

    Healthcare facility discharges, by their nature, are often considered as non-domestic effluent, which can provide significant pollution comparatively to other domestic sources. In this context, a total of 12 monthly sampling campaigns were collected from a healthcare facility as well as the output of a sewerage system of Site Pilote de Bellecombe (SIPIBEL) observatory. This study focuses more specifically on 12 surfactants and biocides: four anionics, four cationic, two non-ionic, one zwitterionic, and one dispersive agent, among the most commonly used commercial surfactants. Particular attention was also provided to routine wastewater quality parameters. Both effluents were heavily contaminated by most anionic surfactants; they displayed median concentrations up to 1 to 2 mg/L for linear alkylbenzene sulfonates and between 10 and 100 μg/L for other sodium sulfate congeners (lauryl and laureth). Overall, for the majority of surfactants, the healthcare facility contribution to the total flux reaching the wastewater treatment plant ranges between 5 and 9%.

  3. The effect of pressure on the phase behavior of surfactant systems: An experimental study

    DEFF Research Database (Denmark)

    Sandersen, Sara Bülow; Stenby, Erling Halfdan; von Solms, Nicolas

    2012-01-01

    Enhanced oil recovery is employed in many mature oil reservoirs to maintain or increase the reservoir recovery factor. In this context, surfactant flooding has recently gained interest again. Surfactant flooding is the injection of surfactants (and co-surfactants) into the reservoir, in order...... to create microemulsions at the interface between crude oil and water, thus obtaining very low interfacial tension, which consequently helps mobilize the trapped oil.In this work a surfactant system, which has been thoroughly described at atmospheric pressure, is examined at elevated pressure. The effect...

  4. Use of surfactants for the remediation of contaminated soils: A review

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Xuhui, E-mail: clab@whu.edu.cn [School of Resource and Environmental Science, Wuhan University, Wuhan 430072 (China); Jiang, Rui; Xiao, Wei [School of Resource and Environmental Science, Wuhan University, Wuhan 430072 (China); Yu, Jiaguo, E-mail: jiaguoyu@yahoo.com [State Key Laboratory of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

    2015-03-21

    Highlights: • The recent advances in use of surfactant for soil remediation are reviewed. • The mechanisms of surfactant-based soil remediation are discussed. • A review on the application of different types of surfactants is made. • The future research direction of surfactant-based technologies is suggested. - Abstract: Due to the great harm caused by soil contamination, there is an increasing interest to apply surfactants to the remediation of a variety of contaminated soils worldwide. This review article summarizes the findings of recent literatures regarding remediation of contaminated soils/sites using surfactants as an enhancing agent. For the surfactant-based remedial technologies, the adsorption behaviors of surfactants onto soil, the solubilizing capability of surfactants, and the toxicity and biocompatibility of surfactants are important considerations. Surfactants can enhance desorption of pollutants from soil, and promote bioremediation of organics by increasing bioavailability of pollutants. The removal of heavy metals and radionuclides from soils involves the mechanisms of dissolution, surfactant-associated complexation, and ionic exchange. In addition to the conventional ionic and nonionic surfactants, gemini surfactants and biosurfactants are also applied to soil remediation due to their benign features like lower critical micelle concentration (CMC) values and better biocompatibility. Mixed surfactant systems and combined use of surfactants with other additives are often adopted to improve the overall performance of soil washing solution for decontamination. Worldwide the field studies and full-scale remediation using surfactant-based technologies are yet limited, however, the already known cases reveal the good prospect of applying surfactant-based technologies to soil remediation.

  5. Use of surfactants for the remediation of contaminated soils: A review

    International Nuclear Information System (INIS)

    Mao, Xuhui; Jiang, Rui; Xiao, Wei; Yu, Jiaguo

    2015-01-01

    Highlights: • The recent advances in use of surfactant for soil remediation are reviewed. • The mechanisms of surfactant-based soil remediation are discussed. • A review on the application of different types of surfactants is made. • The future research direction of surfactant-based technologies is suggested. - Abstract: Due to the great harm caused by soil contamination, there is an increasing interest to apply surfactants to the remediation of a variety of contaminated soils worldwide. This review article summarizes the findings of recent literatures regarding remediation of contaminated soils/sites using surfactants as an enhancing agent. For the surfactant-based remedial technologies, the adsorption behaviors of surfactants onto soil, the solubilizing capability of surfactants, and the toxicity and biocompatibility of surfactants are important considerations. Surfactants can enhance desorption of pollutants from soil, and promote bioremediation of organics by increasing bioavailability of pollutants. The removal of heavy metals and radionuclides from soils involves the mechanisms of dissolution, surfactant-associated complexation, and ionic exchange. In addition to the conventional ionic and nonionic surfactants, gemini surfactants and biosurfactants are also applied to soil remediation due to their benign features like lower critical micelle concentration (CMC) values and better biocompatibility. Mixed surfactant systems and combined use of surfactants with other additives are often adopted to improve the overall performance of soil washing solution for decontamination. Worldwide the field studies and full-scale remediation using surfactant-based technologies are yet limited, however, the already known cases reveal the good prospect of applying surfactant-based technologies to soil remediation

  6. Surfactants from petroleum paraffin wax

    Energy Technology Data Exchange (ETDEWEB)

    Kassem, T.M.; Hussein, M.H.; El Sayed, A.S.

    Paraffin wax from Egyptian petroleum was purified and then oxidized to fatty acids which were esterified to form their methyl esters, fractionated and then hydrolysed. The obtained fatty acids were converted into the corresponding primary amines which were converted with ethylene oxide to form nonionic surfactants. The prepared primary amines were also converted into tertiary amines and then converted into cationic surfactants through condensation with benzyl chloride or 1-chloromethylnaphthalene. Also, amine oxide surfactants were prepared by oxidation of the tertiary amines with hydrogen peroxide. The surface active properties of all the prepared surfactants were determined, and the effect of their chemical structure on the surfactant properties are discussed in this paper.

  7. Micellar solubilization in strongly interacting binary surfactant systems. [Binary surfactant systems of: dodecyltrimethylammonium chloride + sodium dodecyl sulfate; benzyldimethyltetradecylammonium chloride + tetradecyltrimethylammonium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Treiner, C. (Universite Pierre et Marie Curie, Paris (France)); Nortz, M.; Vaution, C. (Faculte de Pharmacie de Paris-sud, Chatenay-Malabry (France))

    1990-07-01

    The apparent partition coefficient P of barbituric acids between micelles and water has been determined in mixed binary surfactant solutions from solubility measurements in the whole micellar composition range. The binary systems chosen ranged from the strongly interacting system dodecyltrimethylammonium chloride + sodium dodecyl sulfate to weakly interacting systems such as benzyldimethyltetradecylammonium chloride + tetradecyltrimethyammonium chloride. In all cases studied, mixed micelle formation is unfavorable to micellar solubilization. A correlation is found between the unlike surfactants interaction energy, as measured by the regular solution parameter {beta} and the solute partition coefficient change upon surfactant mixing. By use of literature data on micellar solubilization in binary surfactant solutions, it is shown that the change of P for solutes which are solubilized by surface adsorption is generally governed by the sign and amplitude of the interaction parameter {beta}.

  8. A novel lignin-based surfactant system for the Salem Unit

    International Nuclear Information System (INIS)

    DeBons, F.E.; Whittington, L.E.

    1991-01-01

    Texaco conducted a successful surfactant/polymer flood in a 60-acre [24 ha] portion of the Salem Benoist reservoir in Salem, Illinois, in 1981. This pilot used a brine-tolerant petroleum sulfonate surfactant system blended in injection brine followed by a xanthan mobility control polymer in fresher water. The oil recovery over the seven year life of the flood was 487,050 bbl [77 435 m 3 ]. This represents 45% of the oil remaining in the total thickness of 73% of that from the more permeable lower interval where most of the surfactant flowed. Since this successful project, Texaco has continued to improve enhanced oil recovery surfactant systems. We have developed novel, brine tolerant surfactants based on the renewable resources lignin and tallow amine. This paper describes the laboratory work leading to a surfactant system which has been recommended for field testing. The laboratory work includes blending, interfacial tension measurements, and core floods in Berea and reservoir cores. The type of lignin based surfactant system described in this report has applicability in all fields where conventional petroleum-based surfactants have been used. Their much lower cost means that they can be used economically at lower crude oil prices

  9. Analysis of polyethoxylated surfactants in microemulsion-oil-water systems III. Fractionation and partitioning of polyethoxylated alcohol surfactants

    International Nuclear Information System (INIS)

    Marquez, N.; Bravo, B.; Ysambertt, F.; Chavez, G.; Subero, N.; Salager, J.L.

    2002-01-01

    Oligomer distribution of polyethoxylated alcohol and polyethoxylated nonylphenol surfactants is studied by normal and reverse-phase high performance liquid chromatography (HPLC). A RP8 column is able to efficiently separate these surfactants according to their alkyl chain (lipophilic) group, while silica and amino columns separate them according to their polyether chain length (hydrophilic group). Polyethoxylated alcohol and polyethoxylated nonylphenol oligomers selectively partition between the microemulsion-oil-water phases of a Winsor III system. Partitioning of these oligomers was analyzed by HPLC with RI detection. The logarithm of the partition coefficient between the water and oil linearly increases with the number of ethylene oxide groups per molecule of oligomer. For a same ethoxylation degree, the partition coefficient of a polyethoxylated tridecanol is found to be higher than the one of the corresponding nonylphenol specie. On the other hand, a polyethoxylated nonylphenol exhibits a higher solubilization than the matching polyethoxylated alcohol

  10. Systems of mechanized and reactive droplets powered by multi-responsive surfactants

    Science.gov (United States)

    Yang, Zhijie; Wei, Jingjing; Sobolev, Yaroslav I.; Grzybowski, Bartosz A.

    2018-01-01

    Although ‘active’ surfactants, which are responsive to individual external stimuli such as temperature, electric or magnetic fields, light, redox processes or chemical agents, are well known, it would be interesting to combine several of these properties within one surfactant species. Such multi-responsive surfactants could provide ways of manipulating individual droplets and possibly assembling them into larger systems of dynamic reactors. Here we describe surfactants based on functionalized nanoparticle dimers that combine all of these and several other characteristics. These surfactants and therefore the droplets that they cover are simultaneously addressable by magnetic, optical and electric fields. As a result, the surfactant-covered droplets can be assembled into various hierarchical structures, including dynamic ones, in which light powers the rapid rotation of the droplets. Such rotating droplets can transfer mechanical torques to their non-nearest neighbours, thus acting like systems of mechanical gears. Furthermore, droplets of different types can be merged by applying electric fields and, owing to interfacial jamming, can form complex, non-spherical, ‘patchy’ structures with different surface regions covered with different surfactants. In systems of droplets that carry different chemicals, combinations of multiple stimuli can be used to control the orientations of the droplets, inter-droplet transport, mixing of contents and, ultimately, sequences of chemical reactions. Overall, the multi-responsive active surfactants that we describe provide an unprecedented level of flexibility with which liquid droplets can be manipulated, assembled and reacted.

  11. Evaluation of a common commercial surfactant in a water recycle system

    International Nuclear Information System (INIS)

    Rector, T.; Jackson, A.; Rainwater, K.; Pickering, S.

    2002-01-01

    The fate of a common commercial surfactant was investigated in the biological reactors of a water recycle system. A NO 2 - reducing packed-bed bioreactor was employed to evaluate degradation of surfactant present in a typical greywater stream. The research was conducted to determine if an alternative commercial surfactant could be used in a biological water recycle system proposed for space travel in place of the current surfactant. The commercial soap used in the research was Pert Plus for Kids (PPK), which contains sodium laureth sulfate (SLES) as the active surfactant. Experiments included a combination of microcosm studies as well as a continuous-flow packed-bed bioreactor. The hydraulic retention time of the packed-bed bioreactor was varied through changes in flow rate to yield different steady-state values for NO 2 -N, TOC, and COD. Steady-state values will allow the determination of the bacterial kinetic parameters. Initial results suggest that the commercial surfactant may be difficult to treat in the time frame of typical biological systems. NO 2 - reduction was favorable in the packed-bed reactor, but TOC removal rates did not correspond to the NO 2 - removal. It is theorized that, due to its high K oc value (1200), SLES has an affinity to absorb to the media contained in the bed, which in turn allows for adsorption of the surfactant. Future research will include development of an isotherm model to characterize the adsorption rates and correlate them to surfactant removal. (author)

  12. Effect of Exposure to Non-ionizing Radiation (Electromagnetic Fields on Human System: A Literature Review

    Directory of Open Access Journals (Sweden)

    Paula Rubya Souza C and acirc;mara

    2014-08-01

    Full Text Available The indiscriminate presence of radio base stations, which emit non-ionizing radiation (NIR, as well as the frequent use of mobile phones, can cause increased susceptibility of populations to the emergence of diseases such as cancers of the head and neck, biochemical, hematopoietic and hepatic changes, among others. Exposure to physical contamination, including NIR, has been implicated in numerous diseases, raising concerns about the widespread sources of exposure to this type of radiation. This paper reviews studies that have assessed associations between likely exposure to electromagnetic fields, such as radiofrequency transmissions, and many kinds of human diseases including cancer, as well as alerts to the current knowledge on the association between environmental exposure to NIR and the risk of development of adverse human health effects. This way, there appears to be an urgent need to reconsider exposure limits for low frequency and static magnetic fields, based on combined experimental and epidemiological research. [J Interdiscipl Histopathol 2014; 2(4.000: 187-190

  13. ATR-FTIR Based Pre and Post Formulation Compatibility Studies for the Design of Niosomal Drug Delivery System Containing Nonionic Amphiphiles and Chondroprotective Drug

    International Nuclear Information System (INIS)

    Khan, M.I.; Madni, A.; Ahmad, S.; Rehmanand, M.; Mahmood, M.A.; Khan, A.

    2015-01-01

    Pharmaceutical compatibility studies are considered as the most important and first screening stage during development of pharmaceutical drug product. Attenuated total reflectance/fourier transform infrared (ATR-FTIR) is one of the techniques currently available to pharmaceutical scientists for investigating the compatibilities between active drug and inactive pharmaceutical ingredients. The present study was designed to assess the interaction among different niosomes forming components i.e nonionic amphiphiles and chondroprotective/antiinflamatory drug Diacerein by ATR-FTIR method. Physical mixtures and niosomes were prepared by physical mixing and thin film hydration method, respectively. The individual niosomal components, physical mixtures as well as niosomal formulations were analyzed. The spectra of Diacerein showed characteristic peaks at 3300 cm/sup -1/(-COOH) and 760 cm/sup -1/(msubstituted benzene), Span 60 at 2916 cm/sup -1/(-OH), Span 80 at 1740 cm/sup -1/(5- membered ring), Span 85 at 1643 cm/sup -1/(ketone with 5-membered ring), Tween 20 at 1734 cm/sup 1/ (5-membered ring) and Tween 80 at 3488 cm/sup -1/(-OH). The characteristic peaks of Diacerein were present in niosomal formulations with slight shift at 3355-3379 cm/sup -1/(-COOH) and 760-770 cm/sup -1/(m-substituted benzene). This work suggested no significant interaction in characteristic peaks of Diacerein after combining with nonionic surfactants as physical mixtures and niosomal formulations which proposed potential for niosomes to encapsulate diacerein in their micro vicinity. (author)

  14. Some aspects of surfactant action mechanism in the organic reagents - metal ions systems

    Energy Technology Data Exchange (ETDEWEB)

    Chernova, R K; Shtykov, S N; Beloliptseva, G M; Sukhova, L K; Amelin, V G; Kulapina, E G [Saratovskij Gosudarstvennyj Univ. (USSR)

    1984-06-01

    Results are reviewed of investigations into the interaction of ions of Mo(6), W, Zr, Be, Sc, Nb, Ta, J, rare earths, a. o. with organic reagents of triphenylmethane class in the 8M H/sub 2/SO/sub 4/-pH14 acidity range and the 1x10/sup -3/-5x10/sup -6/ M concentration range both in the presence and absence of different surfactant type (cetylpyridine, methyltrimethylammonium, synthanols, etc). Three types of effects, determining enhancement of the sensitivity and selectivity of reactions jn the Me-R-surfactant systems, were determined: an increase in the number of coordinated ligands, the activating effect of cation surfactants resulting in a potential complexing in acid media, multicenter interaction of polydentate ligands both via chelating groups and auxochrome groups in the presence of cation surfactants. Protolytic and flotation properties of ionic associates are considered. The observed effects are explained from the viewpoint of electrostatic and hydrophobic interactions in the R-surfactant systems, observed by the methods of NMR, polarography amperometry, conductometry. A possible use of the investigated M-R-surfactant systems as complexonometric indicators was evaluated. A possibility was shown of using them for direct titrimetric determination of hundredth milligram portions of Cu, Ga, In and Sc at a titrant concentratjon of less than 0.01 M. It follows from the estimation of basic optical parameters of the Me-R-surfactant systems that detection.

  15. Some aspects of surfactant action mechanism in the organic reagents - metal ions systems

    International Nuclear Information System (INIS)

    Chernova, R.K.; Shtykov, S.N.; Beloliptseva, G.M.; Sukhova, L.K.; Amelin, V.G.; Kulapina, E.G.

    1984-01-01

    Results are reviewed of investigations into the interaction of ions of Mo(6), W, Zr, Be, Sc, Nb, Ta, J, rare earths, a. o. with organic reagents of triphenylmethane class in the 8M H 2 SO 4 -pH14 acidity range and the 1x10 -3 -5x10 -6 M concentration range both in the presence and absence of different surfactant type (cetylpyridine, methyltrimethylammonium, synthanols, etc). Three types of effects, determining enhancement of the sensitivity and selectivity of reactions jn the Me-R-surfactant systems, were determined: an increase in the number of coordinated ligands, the activating effect of cation surfactants resulting in a potential complexing in acid media, multicenter interaction of polydentate ligands both via chelating groups and auxochrome groups in the presence of cation surfactants. Protolytic and flotation properties of ionic associates are considered. The observed effects are explained from the viewpoint of electrostatic and hydrophobic interactions in the R-surfactant systems, observed by the methods of NMR, polarography amperometry, conductometry. A possible use of the investigated M-R-surfactant systems as complexonometric indicators was evaluated. A possibility was shown of using them for direct titrimetric determination of hundredth milligram portions of Cu, Ga, In and Sc at a titrant concentratjon of less than 0.01 M. It follows from the estimation of basic optical parameters of the Me-R-surfactant systems that detection

  16. Partitioning of hydrophobic pesticides within a soil-water-anionic surfactant system.

    Science.gov (United States)

    Wang, Peng; Keller, Arturo A

    2009-02-01

    Surfactants can be added to pesticide-contaminated soils to enhance the treatment efficiency of soil washing. Our results showed that pesticide (atrazine and diuron) partitioning and desorbability within a soil-water-anionic surfactant system is soil particle-size dependent and is significantly influenced by the presence of anionic surfactant. Anionic surfactant (linear alkylbenzene sulphonate, LAS) sorption was influenced by its complexation with both the soluble and exchangeable divalent cations in soils (e.g. Ca2+, Mg2+). In this study, we propose a new concept: soil system hardness which defines the total amount of soluble and exchangeable divalent cations associated with a soil. Our results showed that anionic surfactant works better with soils having lower soil system hardness. It was also found that the hydrophobic organic compounds (HOCs) sorbed onto the LAS-divalent cation precipitate, resulting in a significant decrease in the aqueous concentration of HOC. Our results showed that the effect of exchangeable cations and sorption of HOC onto the surfactant precipitates needs to be considered to accurately predict HOC behavior within soil-water-anionic surfactant systems.

  17. Nanofiltration: ion exchange system for effective surfactant removal from water solutions

    Directory of Open Access Journals (Sweden)

    I. Kowalska

    2014-12-01

    Full Text Available A system combining nanofiltration and ion exchange for highly effective separation of anionic surfactant from water solutions was proposed. The subjects of the study were nanofiltration polyethersulfone membranes and ion-exchange resins differing in type and structure. The quality of the treated solution was affected by numerous parameters, such as quality of the feed solution, membrane cut-off, resin type, dose and the solution contact time with the resin. A properly designed purification system made it possible to reduce the concentration of anionic surfactant below 1 mg L-1 from feed solutions containing surfactant in concentrations above the CMC value.

  18. Organofilização de argilas bentoníticas com tensoativos não- iônicos visando seu uso em fluidos de perfuração base óleo Nonionic surfactants organophilization bentonite clays aiming their use in oil base drilling fluids

    Directory of Open Access Journals (Sweden)

    I. A. Silva

    2012-09-01

    Full Text Available O uso de tensoativos não iônicos vem substituindo os tradicionais tensoativos iônicos dentre outros motivos pelo seu elevado potencial de resistência a degradação térmica. Assim, este trabalho tem por objetivo o desenvolvimento de argilas organofílicas através da incorporação de tensoativos não iônicos visando seu uso em fluidos de perfuração de poços de petróleo base óleo. Argilas bentoníticas natural, industrializadas e organofilizadas foram caracterizadas por análise química, difração de raios X e análises térmicas. Após a organofilização foi realizado o inchamento de Foster, visando a escolha dos tensoativos mais adequados aos meios líquidos orgânicos dispersantes: éster, diesel e parafina. Com as dispersões obtidas foram determinadas as propriedades reológicas através de viscosidades aparente e plástica. Os resultados evidenciaram que as argilas organofilicas apresentaram um aumento do espaçamento interlamelar e que as dispersões apresentaram propriedades reológicas dentro das especificações da Petrobrás, para uso como argilas organofílicas em fluidos de perfuração em base óleo.The nonionic surfactants use is replacing the traditional ionic surfactants among other reasons because of its high resistance to thermal degradation potential. This work aims the organoclays development through the nonionic surfactants incorporation in order to oil base drilling fluids use. The natural bentonite clay, and industrialized organophilizated were characterized by chemical analysis, X-ray diffraction and thermal analysis. After, the clay organophilization was performed by Foster swelling, seeking the most appropriate choice of surfactants to the liquid media organic dispersants, ester, paraffin and diesel. With the obtained dispersions were determined by plastic and apparent viscosities the rheological properties. The results showed that organoclays increase in the interlayer spacing and that the dispersions

  19. Thermodynamic aspects of polymer–surfactant interactions: Gemini (16-5-16-PVP-water system

    Directory of Open Access Journals (Sweden)

    Naved Azum

    2016-11-01

    Full Text Available The interaction between polyvinylpyrrolidone (PVP and gemini surfactant (16-5-16 in aqueous solution has been analyzed using conductometry. From conductivity data the critical aggregation concentration (cac, critical micelle concentration (cmc, the effective degree of counter-ion binding (β at different temperatures were obtained. The thermodynamic parameters, i.e., Gibbs energy of aggregation and micellization, standard enthalpy of aggregation, and standard entropy of aggregation of surfactant/polymer system were estimated, employing pseudophase separation model. The negative values of Gibbs energy and standard enthalpy suggest that the surfactant/polymer aggregation process is spontaneous and exothermic respectively.

  20. Effect of surfactants on the spectrofluorimetric properties of zearalenone

    International Nuclear Information System (INIS)

    Appell, Michael; Bosma, Wayne B.

    2011-01-01

    The chemiluminescent properties of the estrogenic mycotoxin zearalenone in the presence of aqueous micellar media were investigated using steady state fluorescence techniques. Micelles of surfactants sodium dodecyl sulfate (SDS), hexadecyltrimethylammonium bromide (CTAB), and non-ionic Triton X-100 enhanced the fluorescence intensity of zearalenone in aqueous solutions. The binding constants have been determined and indicate zearalenone has the highest affinity for Triton X-100, followed by CTAB, and then by SDS. The encapsulation of zearalenone by the micelles studied is spontaneous and exothermic. The selective microenvironments provided by organized micellar systems offer an attractive medium to modulate fluorescence detection of zearalenone. - Highlights: → Surfactants can selectively modulate the fluorescence detection of zearalenone. → Binding studies provide information on the zearalenone-surfactant interactions. → Fluorescence intensity of zearalenone is related to the micelle microenvironment.

  1. Silica micro- and nanoparticles reduce the toxicity of surfactant solutions.

    Science.gov (United States)

    Ríos, Francisco; Fernández-Arteaga, Alejandro; Fernández-Serrano, Mercedes; Jurado, Encarnación; Lechuga, Manuela

    2018-04-20

    In this work, the toxicity of hydrophilic fumed silica micro- and nanoparticles of various sizes (7 nm, 12 nm, and 50 μm) was evaluated using the luminescent bacteria Vibrio fischeri. In addition, the toxicity of an anionic surfactant solution (ether carboxylic acid), a nonionic surfactant solution (alkyl polyglucoside), and a binary (1:1) mixture of these solutions all containing these silica particles was evaluated. Furthermore, this work discusses the adsorption of surfactants onto particle surfaces and evaluates the effects of silica particles on the surface tension and critical micellar concentration (CMC) of these anionic and nonionic surfactants. It was determined that silica particles can be considered as non-toxic and that silica particles reduce the toxicity of surfactant solutions. Nevertheless, the toxicity reduction depends on the ionic character of the surfactants. Differences can be explained by the different adsorption behavior of surfactants onto the particle surface, which is weaker for nonionic surfactants than for anionic surfactants. Regarding the effects on surface tension, it was found that silica particles increased the surface activity of anionic surfactants and considerably reduced their CMC, whereas in the case of nonionic surfactants, the effects were reversed. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Effect of surfactant and surfactant blends on pseudoternary phase diagram behavior of newly synthesized palm kernel oil esters

    Directory of Open Access Journals (Sweden)

    Mahdi ES

    2011-06-01

    Full Text Available Elrashid Saleh Mahdi1, Mohamed HF Sakeena1, Muthanna F Abdulkarim1, Ghassan Z Abdullah1,3, Munavvar Abdul Sattar2, Azmin Mohd Noor11Department of Pharmaceutical Technology, 2Department of Physiology, School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden, Penang, Malaysia; 3Department of Pharmaceutical Technology, International Medical University, Bukit Jalil, Kuala Lumpur, MalaysiaBackground: The purpose of this study was to select appropriate surfactants or blends of surfactants to study the ternary phase diagram behavior of newly introduced palm kernel oil esters.Methods: Nonionic surfactant blends of Tween® and Tween®/Span® series were screened based on their solubilization capacity with water for palm kernel oil esters. Tween® 80 and five blends of Tween® 80/Span® 80 and Tween® 80/Span® 85 in the hydrophilic-lipophilic balance (HLB value range of 10.7–14.0 were selected to study the phase diagram behavior of palm kernel oil esters using the water titration method at room temperature.Results: High solubilization capacity was obtained by Tween® 80 compared with other surfactants of Tween® series. High HLB blends of Tween® 80/Span® 85 and Tween® 80/Span® 80 at HLB 13.7 and 13.9, respectively, have better solubilization capacity compared with the lower HLB values of Tween® 80/Span® 80. All the selected blends of surfactants were formed as water-in-oil microemulsions, and other dispersion systems varied in size and geometrical layout in the triangles. The high solubilization capacity and larger areas of the water-in-oil microemulsion systems were due to the structural similarity between the lipophilic tail of Tween® 80 and the oleyl group of the palm kernel oil esters.Conclusion: This study suggests that the phase diagram behavior of palm kernel oil esters, water, and nonionic surfactants is not only affected by the HLB value, but also by the structural similarity between palm kernel oil esters and the surfactant

  3. NMR studies of electrophoretic mobility in surfactant systems

    International Nuclear Information System (INIS)

    Conveney, F.M.; Strange, J.H.; Smith, A.L.; Smith, E.G.

    1989-01-01

    An experimental technique is described in which the flow of electrically charged micelles is measured in the presence of an applied electric field using an NMR technique. The method is used to determine the electrophoretic mobility at ambient temperature of a 5% aqueous solution of sodium dodecyl sulphate and is shown to provide a new technique for the study of electrophoresis in surfactant solutions. (author). 8 refs.; 4 figs

  4. Antinociceptive activity of Delta9-tetrahydrocannabinol non-ionic microemulsions.

    Science.gov (United States)

    Lazzari, P; Fadda, P; Marchese, G; Casu, G L; Pani, L

    2010-06-30

    Delta(9)-Tetrahydrocannabinol (Delta(9)-THC), the major psychoactive constituent of Cannabis sativa L., has been widely studied for its potential pharmaceutical application in the treatment of various diseases and disturbs. This sparingly soluble terpeno-phenolic compound is not easy to handle and to be formulated in pharmaceutical preparations. The aim of this work was to develop a stable aqueous Delta(9)-THC formulation acceptable for different ways of administration, and to evaluate the therapeutic properties of the new Delta(9)-THC based preparation for pain treatment. Due to the thermodynamic stability and advantages of microemulsion based systems, the study was focused on the identification of aqueous microemulsion based systems containing Delta(9)-THC. Oil in water Delta(9)-THC microemulsions were individuated through phase diagrams construction, using the non-ionic surfactant Solutol HS15, being this surfactant acceptable for parenteral administration in human. A selected microemulsion samples containing 0.2 wt% of Delta(9)-THC, stable up to 52 degrees C, was successfully assayed on animal models of pain. Significant antinociceptive activity has been detected by both intraperitoneal and intragastric administration of the new Delta(9)-THC pharmaceutical preparation. The effect has been highlighted in shorter time if compared to a preparation of the same active principle based on previously reported conventional preparation. 2010 Elsevier B.V. All rights reserved.

  5. The possibility of the dose limitation system application non-ionizing radiation protection

    International Nuclear Information System (INIS)

    Ranisavljevic, M., Markovic, S.

    1997-01-01

    Modern conception of the ionizing radiation protection is based on Dose Limitation System. In the base of every human decision lies compromise. Balance between positive and negative factors, benefit and detriment, profit and expense includes the decision about possibilities for realization any defined radiation practice. The optimal option for the given value of the varying parameter gives the maximum benefit and the minimum detriment. In radiation protection field, detriment is related with human health or expenses, and varying parameter is level of radiation protection (for example dimensions of the installed shielding). The problem lies in fact that for the given value of the varying shielding parameter the maximum benefit and the minimum detriment are not achievable simultaneously because the greater benefit includes the greater expense. The problems which have to be solved because of introducing Dose Limitation System, in regard to create Modified Dose Limitation System, are presented. (author)

  6. Immobilization of enzymes using non-ionic colloidal liquid aphrons (CLAs): Surface and enzyme effects.

    Science.gov (United States)

    Ward, Keeran; Xi, Jingshu; Stuckey, David C

    2015-12-01

    The use of non-ionic colloidal liquid aphrons (CLAs) as a support for enzyme immobilisation was investigated. Formulation required the mixing of an aqueous-surfactant solution with a relatively non-polar solvent-surfactant solution, forming a solvent droplet surrounded by a thin stabilised aqueous film (soapy shell). Studies utilising anionic surfactants have showed increased retention, however, very little have been understood about the forces governing immobilisation. This study seeks to determine the effects of enzyme properties on CLA immobilisation by examining a non-ionic/non-polar solvent system comprised of two non-ionic surfactants, Tween 20 and 80, mineral oil and the enzymes lipase, aprotinin and α-chymotrypsin. From these results it was deduced that hydrophobic interactions strongly governed immobilisation. Confocal Scanning Laser Microscopy (CSLM) revealed that immobilisation was predominantly achieved by surface adsorption attributed to hydrophobic interactions between the enzyme and the CLA surface. Enzyme surface affinity was found to increase when added directly to the formulation (pre-manufacture addition), as opposed to the bulk continuous phase (post-manufacture addition), with α-chymotrypsin and aprotinin being the most perturbed, while lipase was relatively unaffected. The effect of zeta potential on immobilisation showed that enzymes adsorbed better closer to their pI, indicating that charge minimisation was necessary for immobilisation. Finally, the effect of increasing enzyme concentration in the aqueous phase resulted in an increase in adsorption for all enzymes due to cooperativity between protein molecules, with saturation occurring faster at higher adsorption rates. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Influence of surfactants on the sorption of two chloroacetanilide in an Romanian chernozem soil.

    Science.gov (United States)

    Coroi, I G; De Wilde, T; Cara, M S; Jitareanu, G; Steurbaut, W

    2011-01-01

    Pesticides have been extensively used in modern agriculture. Due to the prevalent use, there have been serious problems generated by pesticides wastes which could eventually endanger water resources and human health. The development of technologies for the decontamination of soils and waters polluted by hydrophobic organic compounds has encouraged research into the use of non-ionic surfactants as potential agents for the enhanced solubilization and removal of contaminants from soils and sediments. Sorption of two chloroacetanilide herbicides, acetochlor and metolachlor was studied on a representative chernozem soil of the Main Agricultural Research Station Ezareni belonging to the "Ion Ionescu de la Brad" University of Agriculture and Veterinary Medicine lasi, Romania, in the presence and absence of surfactants. Three different non-ionic surfactants were selected: Tween-20, Synperonic 91/5 and Silwet L-77, to verify the influence of their presence on herbicide sorption at different concentrations. Our results showed that the sorption of the studied herbicides within the soil-water-non-ionic surfactant system was influenced by the presence of non-ionic surfactants. The n values obtained were lower than 1 for all pesticide-surfactant combinations, which indicates that the amount of acetochor and metolachlor sorbed decreased with an increase in pesticide concentration. The sorption of acetochlor increased in the following order: Acetochlor+Synperonic 91/5 < Acetochlor < Acetochlor+Tween-20 < Acetochlor+Silwet L-77. In the case of metolachlor+Synperonic and metolachlor+Silwet L-77, the Kf values were significantly higher than the Kf value of metolachlor+Tween-20 on soil, where a lower Kf value could be observed with however a higher n value which indicate a higher sorption capacity at higher concentrations.

  8. Competition between a lamellar and a microemulsion phase in an ionic surfactant system

    NARCIS (Netherlands)

    Kegel, W.K.; Lekkerkerker, H.N.W.

    1993-01-01

    An experimental study of a microemulsion system consisting of equal volumes of brine (water plus salt) and oil (cyclohexane), sodium dodecyl sulfate (SDS) as surfactant, and a mixture of hexanol and pentanol as cosurfactant is presented. Increasing the hexanol fraction in the cosurfactant mixture

  9. Nonionizing radiation and health

    International Nuclear Information System (INIS)

    Suess, M.J.

    1985-01-01

    While a great deal of work has been done by international bodies to establish permissible levels for ionizing radiation, much less attention has been paid to the nonionizing forms of radiation and their possible health effects. Taking into account that equipment producing such radiation is now widely used both in the house and in industry, the paper presents the possible health effects of ultraviolet, visible, laser, infrared and microwave radiation, of electric and magnetic fields and of the ultrasound waves

  10. Solubilization of Hydrophobic Dyes in Surfactant Solutions

    Directory of Open Access Journals (Sweden)

    Ali Reza Tehrani-Bagha

    2013-02-01

    Full Text Available In this paper, the use of surfactants for solubilization of hydrophobic organic dyes (mainly solvent and disperse dyes has been reviewed. The effect of parameters such as the chemical structures of the surfactant and the dye, addition of salt and of polyelectrolytes, pH, and temperature on dye solubilization has been discussed. Surfactant self-assemble into micelles in aqueous solution and below the concentration where this occurs—the critical micelle concentration (CMC—there is no solubilization. Above the CMC, the amount of solubilized dye increases linearly with the increase in surfactant concentration. It is demonstrated that different surfactants work best for different dyes. In general, nonionic surfactants have higher solubilization power than anionic and cationic surfactants. It is likely that the reason for the good performance of nonionic surfactants is that they allow dyes to be accommodated not only in the inner, hydrocarbon part of the micelle but also in the headgroup shell. It is demonstrated that the location of a dye in a surfactant micelle can be assessed from the absorption spectrum of the dye-containing micellar solution.

  11. Non-ionizing radiation

    International Nuclear Information System (INIS)

    Fischer, P.G.

    1983-01-01

    The still growing use of non-ionizing radiation such as ultraviolet radiation laser light, ultrasound and infrasound, has induced growing interest in the effects of these types of radiation on the human organism, and in probable hazards emanating from their application. As there are up to now no generally approved regulations or standards governing the use of non-ionizing radiation and the prevention of damage, it is up to the manufacturers of the relevant equipment to provide for safety in the use of their apparatus. This situation has led to a feeling of incertainty among manufacturers, as to how which kind of damage should be avoided. Practice has shown that there is a demand for guidelines stating limiting values, for measuring techniques clearly indicating safety thresholds, and for safety rules providing for safe handling. The task group 'Non-ionizing radiation' of the Radiation Protection Association started a programme to fulfill this task. Experts interested in this work have been invited to exchange their knowledge and experience in this field, and a collection of loose leaves will soon be published giving information and recommendations. (orig./HP) [de

  12. Preparation of stable tea seed oil nano-particle emulsions by a low energy method with non-ionic surfactants; Preparación de emulsiones estables de nanopartículas de aceite de semilla de té mediante un método de baja energía con tensioactivos no iónicos

    Energy Technology Data Exchange (ETDEWEB)

    Kanlayavattanakul, M.; Lourith, N.

    2017-07-01

    Tea seed oil nano-particle emulsions were prepared. Non-ionic surfactants containing Tween 80 and Span 80 (1:1, w/w) were mixed with propanol (3-9:1, w/w) to give Smix, which was thereafter mixed with tea seed oil. The mixture was titrated with water at 150 rpm to give clear or bluish and bluish-white emulsions. Twelve nano-particle emulsions with 64.64 to 72.73% Smix, 16.66 to 27.27% oil and 9.09 to 16.67% water with particle sizes between 207.00 to 430.10 nm, PDI of 0 to 0.4, ζ-potential of -42.00 to -49.63 mV, pH of 7.04 to 7.32 and 151.33 to 241.93 cps, were stable following an accelerated stability test and long term storage at room temperature and 4 and 45 ºC for 90 days, although one system (16.66% oil and 66.67% Smix) was separated. This nano-particle emulsion formulation is concise and feasible for an industrial development of topical products containing tea seed oil. [Spanish] Se prepararon emulsiones de nanopartículas de aceite de semilla de té. Se mezclaron tensioactivos no iónicos que contenían Tween 80 y Span 80 (1:1, p/p) con propanol (3-9: 1, p/p) para dar Smix que después se mezcló con aceite de semilla de té. La mezcla se valoró con agua a 150 rpm para dar emulsiones claras o azuladas y blanco azulado. Doce emulsiones de nanopartículas con 64,64 a 72,73% de Smix, 16,66 a 27,27% de aceite y 9,09 a 16,67% de agua con tamaños de partícula entre 207,00 y 430,10 nm, PDI de 0 a 0,4, potencial ζ de -42,00 a -49,63 mV, PH de 7,04 a 7,32 y 151,33 a 241,93 cps, se mantuvieron estables tras el ensayo de estabilidad acelerada y almacenamiento a largo plazo a temperatura ambiente y 4 y 45 ºC durante 90 días, aunque uno de los sistemas (16,66% de aceite y 66,67% de Smix) se desvió. Esta formulación de emulsión de nanopartículas es concisa y factible para un desarrollo industrial de productos tópicos que contienen aceite de semilla de té.

  13. Radioactive slurry waste treatment (2) - surfactants dose effects on filtration

    International Nuclear Information System (INIS)

    Jung, K. H.; Park, S. K.; Jung, W. S.; Baek, S. T.; Jung, K. J.

    1999-01-01

    The influence of anionic flocculants on the dewatering of radioactive slurries has been investigated in a laboratory-scale vacuum filtration unit. Simultaneously the influence of certain surfactants has also been investigated. Test results show that the flocculated filter cake generally contains higher residual water than the unflocculated cake. The non-ionic surfactant was effective in reducing the moisture content of the cake

  14. Effect of Surfactants on Plasmid DNA Stability and Release from ...

    African Journals Online (AJOL)

    Purpose: To evaluate the effect of surfactants on plasmid DNA during preparation and release from polylactic glycolide (PLGA) microspheres. Methods: Various surfactants, both ionic and non-ionic (Span, Tween, Triton X100, cetyltrimethylammonium bromide and sodium dodecyl sulphate), were added during the ...

  15. Behavior of microemulsion systems of virgin coconut oil (VCO) using igepal CO-520 and tween 80 surfactant

    Science.gov (United States)

    Safuan, A.; Hamdan, S.; Laili, C. R.

    2017-09-01

    Virgin Coconut Oil (VCO) has been applied in many application and products. Formation of microemulsion region with surfactant was investigated by using phase diagram. The surfactants used are igepal CO-520 and tween 80. The studies showed that formation of microemulsion region were dependent on the behaviour of the surfactant toward VCO. The result showed that microemulsion regions were present in igepal CO-520 system formed a larger water-in-oil microemulsion region compared to tween 80 system. Certain weight ratios of VCO to surfactants were studied by using evaporation test in order to study the water loss of the microemulsion in ambient condition. The evaporation rate of samples was varies depending their compositon of VCO, surfactant and water.

  16. COMBINED MICROBIAL SURFACTANT-POLYMER SYSTEM FOR IMPROVED OIL MOBILITY AND CONFORMANCE CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Jorge Gabitto; Maria Barrufet

    2004-08-01

    Many domestic oil fields are facing abandonment even though they still contain two-thirds of their original oil. A significant number of these fields can yield additional oil using advanced oil recovery (AOR) technologies. To maintain domestic oil production at current levels, AOR technologies are needed that are affordable and can be implemented by independent oil producers of the future. Microbial enhanced oil recovery (MEOR) technologies have become established as cost-effective solutions for declining oil production. MEOR technologies are affordable for independent producers operating stripper wells and can be used to extend the life of marginal fields. The demonstrated versatility of microorganisms can be used to design advanced microbial systems to treat multiple production problems in complex, heterogeneous reservoirs. The proposed research presents the concept of a combined microbial surfactant-polymer system for advanced oil recovery. The surfactant-polymer system utilizes bacteria that are capable of both biosurfactant production and metabolically-controlled biopolymer production. This novel technology combines complementary mechanisms to extend the life of marginal fields and is applicable to a large number of domestic reservoirs. The research project described in this report is performed jointly by, Bio-Engineering Inc., a woman owned small business, Texas A&M University and Prairie View A&M University, a Historically Black College and University. This report describes the results of our laboratory work to grow microbial cultures and the work done on recovery experiments on core rocks. We have selected two bacterial strains capable of producing both surfactant and polymers. We have conducted laboratory experiments to determine under what conditions surfactants and polymers can be produced from one single strain. We have conduct recovery experiments to determine the performance of these strains under different conditions. Our results do not show a

  17. The application of a mulch biofilm barrier for surfactant enhanced polycyclic aromatic hydrocarbon bioremediation

    International Nuclear Information System (INIS)

    Seo, Youngwoo; Lee, Woo-Hyung; Sorial, George; Bishop, Paul L.

    2009-01-01

    Lab scale mulch biofilm barriers were constructed and tested to evaluate their performance for preventing the migration of aqueous and surfactant solubilized PAHs. The spatial distribution of viable PAH degrader populations and resultant biofilm formation were also monitored to evaluate the performance of the biobarrier and the prolonged surfactant effect on the PAH degrading microorganism consortia in the biobarrier. Sorption and biodegradation of PAHs resulted in stable operation of the system for dissolved phenanthrene and pyrene during 150 days of experimentation. The nonionic surfactant could increase the solubility of phenanthrene and pyrene significantly. However, the biobarrier itself couldn't totally prevent the migration of micellar solubilized phenanthrene and pyrene. The presence of surfactant and the resultant highly increased phenanthrene or pyrene concentration didn't appear to cause toxic effects on the attached biofilm in the biobarrier. However, the presence of surfactant did change the structural composition of the biofilm. - Mulch biofilm barrier showed potential for surfactant enhanced bioremediation, and the presence of surfactant changed the structural composition of the biofilm

  18. Pulmonary haptoglobin (pHp) is part of the surfactant system in the human lung.

    Science.gov (United States)

    Abdullah, Mahdi; Goldmann, Torsten

    2012-11-20

    Since the existence of pHp was demonstrated, it has been shown that this molecule and its receptor CD163 are regulated by different stimuli. Furthermore, a comparably fast secretion of pHp was described as well as the immuno-stimulatory effects. The intention of this study was to elucidate the role of pHp in the human lungs further. Here we show, by means of confocal microscopy and immune-electron-microscopy, a clear co-localization of pHp with surfactant protein-B in lamellar bodies of alveolar epithelial cells type II. These results are underlined by immunohistochemical stainings in differently fixed human lung tissues, which show pHp in vesicular and released form. The images of the released form resemble the intended position of surfactant in the human alveolus. pHp is secreted by Alveolar epithelial cells type II as previously shown. Moreover, pHp is co-localized with Surfactant protein-B. We conclude that the presented data shows that pHp is a native part of the surfactant system in the human lung. http://www.diagnosticpathology.diagnomx.eu/vs/2563584738239912.

  19. Surfactant-assisted sol–gel synthesis of forsterite nanoparticles as a novel drug delivery system

    Energy Technology Data Exchange (ETDEWEB)

    Hassanzadeh-Tabrizi, S.A., E-mail: tabrizi1980@gmail.com [Young Researchers and Elite Club, Najafabad Branch, Islamic Azad University, Najafabad, Isfahan (Iran, Islamic Republic of); Bigham, Ashkan [Advanced Materials Research Center, Materials Engineering Department, Najafabad Branch, Islamic Azad University, Najafabad, Isfahan (Iran, Islamic Republic of); Rafienia, Mohammad [Biosensor Research Center, Isfahan University of Medical Sciences, Isfahan (Iran, Islamic Republic of)

    2016-01-01

    In the present study, forsterite nanoparticles were synthesized via surfactant-assisted sol–gel method using cetyltrimethyl ammonium bromide (CTAB) as a surfactant. The effects of CTAB contents and heat treatment on the textural properties and drug release from nanoparticles were investigated. The synthesized powders were studied by X-ray diffraction, Fourier transform infrared spectra, Brunauer–Emmett–Teller surface area analysis and transmission electron microscope images. Mg{sub 2}SiO{sub 4} materials demonstrated mesoporous characteristics and large specific surface area ranging from 159 to 30 m{sup 2}/g. The TEM results showed that forsterite nanorods had diameters about 4 nm and lengths ranging from 10 to 60 nm. It was found that the samples with 6 g CTAB show slower drug release rate than the other specimens, which is due to smaller pore size. This study revealed that the drug delivery of forsterite can be tailored by changing the amount of surfactant. - Highlights: • Forsterite nanoparticles were synthesized via surfactant-assisted sol–gel method. • Nanoparticles were loaded with ibuprofen as a novel drug delivery system. • Synthesized nanoparticles had a rod-like morphology. • CTAB concentration strongly affected the textural properties and drug release of the nanoparticles.

  20. Estimation hydrophilic-lipophilic balance number of surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Pawignya, Harsa, E-mail: harsa-paw@yahoo.co.id [Chemical Engineering Department Diponegoro University (Indonesia); Chemical Engineering Departement University of Pembangunan Nasional Yogyakarta (Indonesia); Prasetyaningrum, Aji, E-mail: ajiprasetyaningrum@gmail.com; Kusworo, Tutuk D.; Pramudono, Bambang, E-mail: Pramudono2004@yahoo.com [Chemical Engineering Department Diponegoro University (Indonesia); Dyartanti, Endah R. [Chemical Engineering Department Diponegoro University (Indonesia); Chemical Enginering Departement Sebelas Maret University (Indonesia)

    2016-02-08

    Any type of surfactant has a hydrophilic-lipophilic balance number (HLB number) of different. There are several methods for determining the HLB number, with ohysical properties of surfactant (solubility cloud point and interfacial tension), CMC methods and by thermodynamics properties (Free energy Gibbs). This paper proposes to determined HLB numbers from interfelation methods. The result of study indicated that the CMC method described by Hair and Moulik espesially for nonionic surfactant. The application of exess Gibbs free energy and by implication activity coefficient provides the ability to predict the behavior of surfactants in multi component mixtures of different concentration. Determination of HLB number by solubility and cloud point parameter is spesific for anionic and nonionic surfactant but this methods not available for cationic surfactants.

  1. Polymer⁻Surfactant System Based Amorphous Solid Dispersion: Precipitation Inhibition and Bioavailability Enhancement of Itraconazole.

    Science.gov (United States)

    Feng, Disang; Peng, Tingting; Huang, Zhengwei; Singh, Vikramjeet; Shi, Yin; Wen, Ting; Lu, Ming; Quan, Guilan; Pan, Xin; Wu, Chuanbin

    2018-04-24

    The rapid release of poorly water-soluble drugs from amorphous solid dispersion (ASD) is often associated with the generation of supersaturated solution, which provides a strong driving force for precipitation and results in reduced absorption. Precipitation inhibitors, such as polymers and surfactants, are usually used to stabilize the supersaturated solution by blocking the way of kinetic or thermodynamic crystal growth. To evaluate the combined effect of polymers and surfactants on maintaining the supersaturated state of itraconazole (ITZ), various surfactants were integrated with enteric polymer hydroxypropyl methylcellulose acetate succinate (HPMC AS) to develop polymer⁻surfactant based solid dispersion. The supersaturation stability was investigated by in vitro supersaturation dissolution test and nucleation induction time measurement. Compared to the ASD prepared with HPMC AS alone, the addition of d-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) exhibited a synergistic effect on precipitation inhibition. The results indicated that the TPGS not only significantly reduced the degree of supersaturation which is the driving force for precipitation, but also provided steric hindrance to delay crystal growth by absorbing onto the surface of small particles. Subsequently, the formulations were evaluated in vivo in beagle dogs. Compared with commercial product Sporanox ® , the formulation prepared with HPMC AS/TPGS exhibited a 1.8-fold increase in the AUC (0⁻24 h) of ITZ and a 1.43-fold increase of hydroxyitraconazole (OH-ITZ) in the plasma. Similarly, the extent of absorption was increased by more than 40% when compared to the formulation prepared with HPMC AS alone. The results of this study demonstrated that the ASD based on polymer⁻surfactant system could obviously inhibit drug precipitation in vitro and in vivo, which provides a new access for the development of ASD for poorly water-soluble drug.

  2. Surfactant-aided size exclusion chromatography

    NARCIS (Netherlands)

    Horneman, D.A.; Wolbers, M.; Zomerdijk, M.; Ottens, M.; Keurentjes, J.T.F.; Wielen, van der L.A.M.

    2004-01-01

    The flexibility and selectivity of size exclusion chromatog. (SEC) for protein purifn. can be modified by adding non-ionic micelle-forming surfactants to the mobile phase. The micelles exclude proteins from a liq. phase similar to the exclusion effect of the polymer fibers of the size exclusion

  3. Comprehensive study of tartrazine/cationic surfactant interaction.

    Science.gov (United States)

    Shahir, Afshin Asadzadeh; Javadian, Soheila; Razavizadeh, Bi Bi Marzieh; Gharibi, Hussein

    2011-12-15

    Interaction of a food dye, tartrazine, with some cationic conventional and gemini surfactants, tetradecyltrimethylammonium bromide (TTAB), N,N'-ditetradecyl-N,N,N',N'-tetramethyl-N,N'-butanediyl-diammonium dibromide (14,4,14), and N,N'-didodecyl-N,N,N',N'-tetramethyl-N,N'-butanediyl-diammonium dibromide (12,4,12), were first investigated comprehensively employing conductometry, tensiometry, and UV-visible spectroscopy. Tartrazine was found to behave in the same manner as aromatic counterions. The formation of ion pairs reflected as a considerable increase of the surfactant efficiency in tensiometry plots and their stoichiometry were determined by Job's method of continuous variations. For the tartrazine/TTAB system, nonionic DS(3), ionic DS(2-), and/or DS(2)(-) ion pairs, their small premicelles, and tartrazine-rich micelles were constituted as well as dye-containing TTAB-rich micelles. Insoluble J-aggregates of DS(-) ion pairs and cylindrical surfactant-rich micelles were also formed in tartrazine/gemini surfactant systems and recognized by transmission electron microscopy. The zeta potential and the size of the aggregates were determined using dynamic light scattering and confirmed the suggested models for the processes happening in each system. Cyclic voltammetry was applied successfully to track all of these species using tartrazine's own reduction peak current for the first time.

  4. COMBINED MICROBIAL SURFACTANT-POLYMER SYSTEM FOR IMPROVED OIL MOBILITY AND CONFORMANCE CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Jorge Gabitto; Maria Barrufet

    2005-08-01

    Many domestic oil fields are facing abandonment even though they still contain two-thirds of their original oil. A significant number of these fields can yield additional oil using advanced oil recovery (AOR) technologies. To maintain domestic oil production at current levels, AOR technologies are needed that are affordable and can be implemented by the independent oil producers of the future. Microbial enhanced oil recovery (MEOR) technologies have become established as cost-effective solutions for declining oil production. MEOR technologies are affordable for independent producers operating stripper wells and can be used to extend the life of marginal fields. The demonstrated versatility of microorganisms can be used to design advanced microbial systems to treat multiple production problems in complex, heterogeneous reservoirs. The proposed research presents the concept of a combined microbial surfactant-polymer system for advanced oil recovery. The surfactant-polymer system utilizes bacteria that are capable of both biosurfactant production and metabolically-controlled biopolymer production. This novel technology combines complementary mechanisms to extend the life of marginal fields and is applicable to a large number of domestic reservoirs. The research project described in this report was performed by Bio-Engineering Inc., a woman owned small business, Texas A&M University and Prairie View A&M University, a Historically Black College and University. This report describes the results of our laboratory work to grow microbial cultures, the work done on recovery experiments on core rocks, and computer simulations. We have selected two bacterial strains capable of producing both surfactant and polymers. We have conducted laboratory experiments to determine under what conditions surfactants and polymers can be produced from one single strain. We have conduct recovery experiments to determine the performance of these strains under different conditions. Our results

  5. Determination of anionic surfactants during wastewater recycling process by ion pair chromatography with suppressed conductivity detection

    Science.gov (United States)

    Levine, L. H.; Judkins, J. E.; Garland, J. L.; Sager, J. C. (Principal Investigator)

    2000-01-01

    A direct approach utilizing ion pairing reversed-phase chromatography coupled with suppressed conductivity detection was developed to monitor biodegradation of anionic surfactants during wastewater recycling through hydroponic plant growth systems and fixed-film bioreactors. Samples of hydroponic nutrient solution and bioreactor effluent with high concentrations (up to 120 mS electrical conductance) of inorganic ions can be analyzed without pretreatment or interference. The presence of non-ionic surfactants did not significantly affect the analysis. Dynamic linear ranges for tested surfactants [Igepon TC-42, ammonium lauryl sulfate, sodium laureth sulfate and sodium alkyl (C10-C16) ether sulfate] were 2 to approximately 500, 1 to approximately 500, 2.5 to approximately 550 and 3.0 to approximately 630 microg/ml, respectively.

  6. Superamphiphilic nanocontainers based on the resorcinarene - Cationic surfactant system: Synergetic self-assembling behavior

    Science.gov (United States)

    Gaynanova, Gulnara A.; Bekmukhametova, Alina M.; Kashapov, Ruslan R.; Ziganshina, Albina Yu.; Zakharova, Lucia Ya.

    2016-05-01

    Self-organization in the mixed system based on water-soluble aminomethylated calix[4]arene with sulfonatoethyl groups at the lower rim and classical cationic surfactant cetyltrimethylammonium bromide has been studied by the methods of tensiometry, conductometry, spectrophotometry, dynamic and electrophoretic light scattering. The values of the critical association concentration, the size and zeta potential values, and the solubilization capacity of mixed aggregates toward the hydrophobic probe (Sudan I) were determined.

  7. Preliminary Testing For Anionic, Cationic and Non-ionic

    Directory of Open Access Journals (Sweden)

    Bokic, Lj.

    2007-11-01

    Full Text Available Detergents present a major environmental problem due to large quantities of surfactants released from laundries. For this reason, it is important to apply an appropriate analytical method for their determination. In this work, we propose two simple, fast and inexpensive analytical methods for anionic, cationic and non-ionic surfactant determination: thin layer chromatography (TLC separation for qualitative screening and quantitative potentiometric determination with ion-selective electrodes. These methods have been chosen because of their many advantages: rapidity, ease of operation, low cost of analysis and a wide variety of TLC application possibilities. The advantage of potentiometric titration is its very high degree of automation and very low detection limits obtained with different ion-selective electrodes applied for different surfactants.

  8. Role of the thickening agent concentration and surfactant additions in the system's soap-oil

    Energy Technology Data Exchange (ETDEWEB)

    Shchegolev, G.G.; Trapeznikov, A.A.; Taranenko, V.G.

    1973-03-01

    The effect of the thickening agent concentration, surfactant additions and mechanical treatment on the microstructure and structural-mechanical properties of the system's lithium stearate-oil has been studied. The rate of cooling of the soap-oil system has been shown also to be of importance. The surfactants are less effective when introduced into a finished pseudogel, than when added during crystallization.

  9. Cationic surfactants for control of fresh- and saltwater mollusks in nuclear cooling systems

    International Nuclear Information System (INIS)

    Post, R.M.; Mallen, E.; Lehmann, F.

    1991-01-01

    One result of the release of the US Nuclear Regulatory Commission's Generic Letter 89-13, Service Water Problems Affecting Safety-Related Equipment, was the heightened awareness of the nuclear industry to the problems of macrofouling in heat exchange systems. The principal mollusk species that contribute to freshwater macrofouling problems are Asiatic Clam (southern United States) and Zebra Mussel (Great Lakes). The predominant saltwater fouling mollusks are the Blue Mussel (Pacific, northern Atlantic), Ribbed Mussel (southern Atlantic, Gulf Coast), and American Oyster (Atlantic, Gulf Coast). The nuclear community's awareness of macrofouling problems and the ineffectiveness of intermittent chlorination programs have led to the development of several chemical control technologies for eliminating macrofouling organism infestation. One technology that has proven effective for the control of macrofouling organisms is the periodic addition of a combination of two cationic charged surfactants, specifically, alkyldimethylbenzylammonium chloride (QUAT) and dodecyl guanidine hydrochloride (DGH). Experience with the cationic surfactants at several nuclear power plants is reported

  10. The origin and evolution of the surfactant system in fish: insights into the evolution of lungs and swim bladders.

    Science.gov (United States)

    Daniels, Christopher B; Orgeig, Sandra; Sullivan, Lucy C; Ling, Nicholas; Bennett, Michael B; Schürch, Samuel; Val, Adalberto Luis; Brauner, Colin J

    2004-01-01

    Several times throughout their radiation fish have evolved either lungs or swim bladders as gas-holding structures. Lungs and swim bladders have different ontogenetic origins and can be used either for buoyancy or as an accessory respiratory organ. Therefore, the presence of air-filled bladders or lungs in different groups of fishes is an example of convergent evolution. We propose that air breathing could not occur without the presence of a surfactant system and suggest that this system may have originated in epithelial cells lining the pharynx. Here we present new data on the surfactant system in swim bladders of three teleost fish (the air-breathing pirarucu Arapaima gigas and tarpon Megalops cyprinoides and the non-air-breathing New Zealand snapper Pagrus auratus). We determined the presence of surfactant using biochemical, biophysical, and morphological analyses and determined homology using immunohistochemical analysis of the surfactant proteins (SPs). We relate the presence and structure of the surfactant system to those previously described in the swim bladders of another teleost, the goldfish, and those of the air-breathing organs of the other members of the Osteichthyes, the more primitive air-breathing Actinopterygii and the Sarcopterygii. Snapper and tarpon swim bladders are lined with squamous and cuboidal epithelial cells, respectively, containing membrane-bound lamellar bodies. Phosphatidylcholine dominates the phospholipid (PL) profile of lavage material from all fish analyzed to date. The presence of the characteristic surfactant lipids in pirarucu and tarpon, lamellar bodies in tarpon and snapper, SP-B in tarpon and pirarucu lavage, and SPs (A, B, and D) in swim bladder tissue of the tarpon provide strong evidence that the surfactant system of teleosts is homologous with that of other fish and of tetrapods. This study is the first demonstration of the presence of SP-D in the air-breathing organs of nonmammalian species and SP-B in actinopterygian

  11. Tunable, antibacterial activity of silicone polyether surfactants.

    Science.gov (United States)

    Khan, Madiha F; Zepeda-Velazquez, Laura; Brook, Michael A

    2015-08-01

    Silicone surfactants are used in a variety of applications, however, limited data is available on the relationship between surfactant structure and biological activity. A series of seven nonionic, silicone polyether surfactants with known structures was tested for in vitro antibacterial activity against Escherichia coli BL21. The compounds varied in their hydrophobic head, comprised of branched silicone structures with 3-10 siloxane linkages and, in two cases, phenyl substitution, and hydrophilic tail of 8-44 poly(ethylene glycol) units. The surfactants were tested at three concentrations: below, at, and above their Critical Micelle Concentrations (CMC) against 5 concentrations of E. coli BL21 in a three-step assay comprised of a 14-24h turbidometric screen, a live-dead stain and viable colony counts. The bacterial concentration had little effect on antibacterial activity. For most of the surfactants, antibacterial activity was higher at concentrations above the CMC. Surfactants with smaller silicone head groups had as much as 4 times the bioactivity of surfactants with larger groups, with the smallest hydrophobe exhibiting potency equivalent to sodium dodecyl sulfate (SDS). Smaller PEG chains were similarly associated with higher potency. These data link lower micelle stability and enhanced permeability of smaller silicone head groups to antibacterial activity. The results demonstrate that simple manipulation of nonionic silicone polyether structure leads to significant changes in antibacterial activity. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Extraction and Characterization of Surfactants from Atmospheric Aerosols.

    Science.gov (United States)

    Nozière, Barbara; Gérard, Violaine; Baduel, Christine; Ferronato, Corinne

    2017-04-21

    Surface-active compounds, or surfactants, present in atmospheric aerosols are expected to play important roles in the formation of liquid water clouds in the Earth's atmosphere, a central process in meteorology, hydrology, and for the climate system. But because specific extraction and characterization of these compounds have been lacking for decades, very little is known on their identity, properties, mode of action and origins, thus preventing the full understanding of cloud formation and its potential links with the Earth's ecosystems. In this paper we present recently developed methods for 1) the targeted extraction of all the surfactants from atmospheric aerosol samples and for the determination of 2) their absolute concentrations in the aerosol phase and 3) their static surface tension curves in water, including their Critical Micelle Concentration (CMC). These methods have been validated with 9 references surfactants, including anionic, cationic and non-ionic ones. Examples of results are presented for surfactants found in fine aerosol particles (diameter <1 μm) collected at a coastal site in Croatia and suggestions for future improvements and other characterizations than those presented are discussed.

  13. Thermodynamic and Interfacial Properties of DTABr/CTABr Mixed Surfactant Systems in Ethanolamine/Water Mixtures: A Conductometry Study

    OpenAIRE

    Esan, Olaseni Segun; Osundiya, Medinat Olubunmi; Aboluwoye, Christopher Olumuyiwa; Olanrewaju, Owoyomi; Ige, Jide

    2013-01-01

    Mixed-micelle formation in the binary mixtures of dodecyltrimethylammonium bromide (DTABr) and cetyltrimethylammonium bromide (CTABr) surfactants in water-ethanolamine mixed solvent systems has been studied by conductometric method in the temperature range of 298.1 to 313.1 K at 5 K intervals. It was observed that the presence of ethanolamine forced the formation of mixed micelle to lower total surfactant concentration than in water only. The synergistic interaction was quantitatively investi...

  14. Study of adjuvant effect of model surfactants from the groups of alkyl sulfates, alkylbenzene sulfonates, alcohol ethoxylates and soaps

    DEFF Research Database (Denmark)

    Clausen, S K; Sobhani, S; Poulsen, O M

    2000-01-01

    The sodium salts of representatives of anionic surfactants, dodecylbenzene sulfonate (SDBS), dodecyl sulfate (SDS) and coconut oil fatty acids, and a nonionic surfactant, dodecyl alcohol ethoxylate, were studied for adjuvant effect on the production of specific IgE antibodies in mice. The surfact......The sodium salts of representatives of anionic surfactants, dodecylbenzene sulfonate (SDBS), dodecyl sulfate (SDS) and coconut oil fatty acids, and a nonionic surfactant, dodecyl alcohol ethoxylate, were studied for adjuvant effect on the production of specific IgE antibodies in mice...

  15. Interfacial behaviour between oil/water systems using ionic surfactants from regional vegetable industry and animal pet

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Francisco Klebson G.; Alves, Juan V.A.; Dantas, Tereza N. Castro; Dutra Junior, Tarcilio V.; Barros Neto, Eduardo L. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    Interfacial tension (IFT) is one of the most important physical properties in the study of fluid-fluid interfaces. In this research the surfactants - saponified coconut oil, saponified castor oil, saponified soybean oil, saponified sunflower oil and basis soap - were synthesized in laboratory, using carboxylic acids from regional industry and animal fat (bovine fat). This study focuses on the search of a high-efficient, low-cost, and safe for the environment flooding system to be applied in enhanced oil recovery. The principal aim of this work is the obtaining of interfacial tensions between oil/water systems, using the developed ionic surfactants. Results showed that the studied surfactants are able to reduce the IFT between oil and brine. The surfactant that was more effective in reducing the IFT value was the one from animal fat. The composition, as well as the kind of the bond, as saturated or unsaturated, of the surfactants has influence in the IFT value. The ionic surfactants from regional industry and animal fat besides presenting low cost propitiate very low interfacial tensions between oil and brine, favoring the interactions with residual oil and thus increasing oil recovery. (author)

  16. Adsorption of β-casein-surfactant mixed layers at the air-water interface evaluated by interfacial rheology.

    Science.gov (United States)

    Maestro, Armando; Kotsmar, Csaba; Javadi, Aliyar; Miller, Reinhard; Ortega, Francisco; Rubio, Ramón G

    2012-04-26

    This work presents a detailed study of the dilational viscoelastic moduli of the adsorption layers of the milk protein β-casein (BCS) and a surfactant at the liquid/air interface, over a broad frequency range. Two complementary techniques have been used: a drop profile tensiometry technique and an excited capillary wave method, ECW. Two different surfactants were studied: the nonionic dodecyldimethylphosphine oxide (C12DMPO) and the cationic dodecyltrimethylammonium bromide (DoTAB). The interfacial dilational elasticity and viscosity are very sensitive to the composition of protein-surfactant mixed adsorption layers at the air/water interface. Two different dynamic processes have been observed for the two systems studied, whose characteristic frequencies are close to 0.01 and 100 Hz. In both systems, the surface elasticity was found to show a maximum when plotted versus the surfactant concentration. However, at frequencies above 50 Hz the surface elasticity of BCS + C12DMPO is higher than the one of the aqueous BCS solution over most of the surfactant concentration range, whereas for the BCS + DoTAB it is smaller for high surfactant concentrations and higher at low concentrations. The BCS-surfactant interaction modifies the BCS random coil structure via electrostatic and/or hydrophobic interactions, leading to a competitive adsorption of the BCS-surfactant complexes with the free, unbound surfactant molecules. Increasing the surfactant concentration decreases the adsorbed proteins. However, the BCS molecules are rather strongly bound to the interface due to their large adsorption energy. The results have been fitted to the model proposed by C. Kotsmar et al. ( J. Phys. Chem. B 2009 , 113 , 103 ). Even though the model describes well the concentration dependence of the limiting elasticity, it does not properly describe its frequency dependence.

  17. Dynamic covalent surfactants

    NARCIS (Netherlands)

    Minkenberg, C.B.

    2012-01-01

    In this thesis the development of surfactant aggregates with fast exchange dynamics between the aggregated and non-aggregated state is described. Dynamic surfactant exchange plays an important role in natural systems, for instance in cell signaling, cell division, and uptake and release of cargo.

  18. A study on the interaction of horse heart cytochrome c with some conventional and ionic liquid surfactants probed by ultraviolet-visible and fluorescence spectroscopic techniques.

    Science.gov (United States)

    Mondal, Satyajit; Das, Bijan

    2018-06-05

    The interactions of a protein cytochrome c with some selected conventional and ionic liquid surfactants have been investigated at pH7.4 using ultraviolet-visible and fluorescence spectroscopic techniques. We used four conventional surfactants - cetyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium bromide (DTAB), sodium N-dodecanoylsarcosinate (SDDS), and N-decanoyl-N-methylglucamine (Mega 10), and a surface active ionic liquid 1-hexadecyl-3-methylimidazolium chloride (C 16 MeImCl). All the investigated surfactants were found to induce an unfolding of the protein cytochrome c. In presence of CTAB, SDDS and C 16 MeImCl, the heme iron atom was found to loose methionine from its axial position. Differential binding of the surfactant monomers and their micelles to the protein molecules was inferred. The ionic surfactants were found to be more effective than the nonionic one in unfolding the investigated protein. However, the extent of binding of CTAB/C 16 MeImCl to cytochrome c reaches a plateau past the critical micellization concentration (cmc) of the surfactant. For each of the cytochrome c-DTAB, cytochrome c-SDDS and cytochrome c-Mega 10 system, although there exists an inflection in the surfactant-binding, saturation point could not be detected. It has been demonstrated from the ultraviolet-visible spectral studies that the oxidation state of iron in cytochrome c does not change when the protein binds with the investigated surfactants. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. A study on the interaction of horse heart cytochrome c with some conventional and ionic liquid surfactants probed by ultraviolet-visible and fluorescence spectroscopic techniques

    Science.gov (United States)

    Mondal, Satyajit; Das, Bijan

    2018-06-01

    The interactions of a protein cytochrome c with some selected conventional and ionic liquid surfactants have been investigated at pH 7.4 using ultraviolet-visible and fluorescence spectroscopic techniques. We used four conventional surfactants - cetyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium bromide (DTAB), sodium N-dodecanoylsarcosinate (SDDS), and N-decanoyl-N-methylglucamine (Mega 10), and a surface active ionic liquid 1-hexadecyl-3-methylimidazolium chloride (C16MeImCl). All the investigated surfactants were found to induce an unfolding of the protein cytochrome c. In presence of CTAB, SDDS and C16MeImCl, the heme iron atom was found to loose methionine from its axial position. Differential binding of the surfactant monomers and their micelles to the protein molecules was inferred. The ionic surfactants were found to be more effective than the nonionic one in unfolding the investigated protein. However, the extent of binding of CTAB/C16MeImCl to cytochrome c reaches a plateau past the critical micellization concentration (cmc) of the surfactant. For each of the cytochrome c-DTAB, cytochrome c-SDDS and cytochrome c-Mega 10 system, although there exists an inflection in the surfactant-binding, saturation point could not be detected. It has been demonstrated from the ultraviolet-visible spectral studies that the oxidation state of iron in cytochrome c does not change when the protein binds with the investigated surfactants.

  20. Size influences the effect of hydrophobic nanoparticles on lung surfactant model systems.

    Science.gov (United States)

    Dwivedi, Mridula V; Harishchandra, Rakesh Kumar; Koshkina, Olga; Maskos, Michael; Galla, Hans-Joachim

    2014-01-07

    The alveolar lung surfactant (LS) is a complex lipid protein mixture that forms an interfacial monolayer reducing the surface tension to near zero values and thus preventing the lungs from collapse. Due to the expanding field of nanotechnology and the corresponding unavoidable exposure of human beings from the air, it is crucial to study the potential effects of nanoparticles (NPs) on the structural organization of the lung surfactant system. In the present study, we investigated both, the domain structure in pure DPPC monolayers as well as in lung surfactant model systems. In the pure lipid system we found that two different sized hydrophobic polymeric nanoparticles with diameter of ~12 nm and ~136 nm have contrasting effect on the functional and structural behavior. The small nanoparticles inserted into fluid domains at the LE-LC phase transition are not visibly disturbing the phase transition but disrupting the domain morphology of the LE phase. The large nanoparticles led to an expanded isotherm and to a significant decrease in the line tension and thus to a drastic disruption of the domain structures at a much lower number of nanoparticles with respect to the lipid. The surface activity of the model LS films again showed drastic variations due to presence of different sized NPs illustrated by the film balance isotherms and the atomic force microscopy. AFM revealed laterally profuse multilayer protrusion formation on compression but only in the presence of 136 nm sized nanoparticles. Moreover we investigated the vesicle insertion process into a preformed monolayer. A severe inhibition was observed only in the presence of ~136 nm NPs compared to minor effects in the presence of ~12 nm NPs. Our study clearly shows that the size of the nanoparticles made of the same material determines the interaction with biological membranes. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  1. The effect of the head group on branched-alkyl chain surfactants in glycolipid/n-octane/water ternary system.

    Science.gov (United States)

    Nainggolan, Irwana; Radiman, Shahidan; Hamzah, Ahmad Sazali; Hashim, Rauzah

    2009-10-01

    Two novel glycolipids have been synthesized and their phase behaviour studied. They have been characterized using FT-IR, FAB and 13C NMR and 1H NMR to ensure the purity of novel glycolipids. The two glycolipids are distinguished based on the head group of glycolipids (monosaccharide/glucose and disaccharide/maltose). These two novel glycolipids have been used as surfactant to perform two phase diagrams. Phase behaviours that have been investigated are 2-hexyldecyl-beta-D-glucopyranoside (2-HDG)/n-octane/water ternary system and 2-hexyldecyl-beta-D-maltoside (2-HDM)/n-octane/water ternary system. SAXS and polarizing optical microscope have been used to study the phase behaviours of these two surfactants in ternary phase diagram. Study of effect of the head group on branched-alkyl chain surfactants in ternary system is a strategy to derive the structure-property relationship. For comparison, 2-HDM and 2-HDG have been used as surfactant in the same ternary system. The phase diagram of 2-hexyldecyl-beta-D-maltoside/n-octane/water ternary system exhibited a Lalpha phase at a higher concentration regime, followed with two phases and a micellar solution region in a lower concentration regime. The phase diagram of 2-HDG/water/n-octane ternary system shows hexagonal phase, cubic phase, rectangular ribbon phase, lamellar phase, cubic phase as the surfactant concentration increase.

  2. Triblock Copolymers with Grafted Fluorine-Free Amphiphilic Non-Ionic Side Chains for Antifouling and Fouling-Release Applications

    Energy Technology Data Exchange (ETDEWEB)

    Y Cho; H Sundaram; C Weinman; M Paik; M Dimitriou; J Finlay; M Callow; J Callow; E Kramer; C Ober

    2011-12-31

    Fluorine-free, amphiphilic, nonionic surface active block copolymers (SABCs) were synthesized through chemical modification of a polystyrene-block-poly(ethylene-ran-butylene)-block-polyisoprene triblock copolymer precursor with selected amphiphilic nonionic Brij and other surfactants. Amphiphilicity was imparted by a hydrophobic aliphatic group combined with a hydrophilic poly(ethylene glycol) (PEG) group-containing moiety. The surfaces were characterized by dynamic water contact angle, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and near edge X-ray absorption fine structure (NEXAFS) analysis. In biofouling assays, settlement (attachment) of both spores of the green alga Ulva and cells of the diatom Navicula on SABCs modified with Brij nonionic side chains was significantly reduced relative to a PDMS standard, with a nonionic surfactant combining a PEG group and an aliphatic moiety demonstrating the best performance. Additionally, a fouling-release assay using sporelings (young plants) of Ulva and Navicula suggested that the SABC derived from nonionic Brij side chains also out-performed PDMS as a fouling-release material. Good antifouling and fouling-release properties were not demonstrated for the other two amphiphilic surfaces derived from silicone and aromatic group containing nonionic surfactants included in this study. The results suggest that small differences in chemical surface functionality impart more significant changes with respect to the antifouling settlement and fouling-release performance of materials than overall wettability behavior.

  3. Self-assembled systems of water soluble metal 8-hydroxyquinolates with surfactants and conjugated polyelectrolytes

    DEFF Research Database (Denmark)

    Burrows, Hugh D.; Costa, Telma; Luisa Ramos, M.

    2016-01-01

    We have studied the interaction of 8-hydroxyquinoline-5-sulfonate (8-HQS) with the metal ions Al(III) and Zn(II) in aqueous solution in the presence of tetraalkylammonium surfactants using UV/vis absorption, fluorescence, NMR spectroscopy and electrical conductivity measurements, complemented by ...... assembly between the conjugated polyelectrolyte and the metal/8-HQS complex, as demonstrated by electronic energy transfer. The potential of these systems in sensing, light harvesting, and electron injection/transport layers in organic semiconductor devices is discussed....

  4. Molecular interactions in a surfactant-water-polyacrylamide system, according to densimetry, viscometry, conductometry, and spectroscopy data

    Science.gov (United States)

    Harutyunyan, R. S.

    2013-08-01

    Molecular interactions in a surfactant-polyacrylamide-water system are investigated. It is established that the interactions affect such physicochemical parameters of the system as viscosity, density, surface tension, conductivity, and critical micelle concentration. It is shown that in a polyacrylamide-water system, raising the polyacrylamide concentration to 0.02% causes conformational changes in its macromolecule.

  5. Application of surfactant enhanced permanganate oxidation and bidegradation of trichloroethylene in groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, T.T.; Kao, C.M. [Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Yeh, T.Y. [Department of Civil and Environmental Engineering, National University of Kaohsiung, Kaohsiung, Taiwan (China)], E-mail: tyyeh@nuk.edu.tw; Liang, S.H.; Chien, H.Y. [Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan (China)

    2009-01-15

    The industrial solvent trichloroethylene (TCE) is among the most ubiquitous chlorinated solvents found in groundwater contamination. The main objectives of this study were to evaluate the feasibility of using non-ionic surfactant Simple Green{sup TM} (SG) to enhance the oxidative dechlorination of TCE by potassium permanganate (KMnO{sub 4}) employing a continuous stir batch reactor system (CSBR) and column experiments. The effect of using surfactant SG to enhance the biodegradation of TCE via aerobic cometabolism was also examined. Results from CSBR experiments revealed that combination of KMnO{sub 4} with surfactant SG significantly enhanced contaminant removal, particularly when the surfactant SG concentrated at its CMC. TCE degradation rates ranged from 74.1% to 85.7% without addition of surfactant SG while TCE degradation rates increased to ranging from 83.8% to 96.3% with presence of 0.1 wt% SG. Furthermore, results from column experiments showed that TCE was degraded from 38.1 {mu}M to 6.2 {mu}M in equivalent to 83.7% of TCE oxidation during first 560 min reaction. This study has also demonstrated that the addition of surfactant SG is a feasible method to enhance bioremediation efficiency for TCE contaminated groundwater. The complete TCE degradation was detected after 75 days of incubation with both 0.01 and 0.1 wt% of surfactant SG addition. Results revealed that surfactant enhanced chemical oxidation and bioremediation technology is one of feasible approaches to clean up TCE contaminated groundwater.

  6. Critical micelle concentration of surfactants in aqueous buffered and unbuffered systems

    International Nuclear Information System (INIS)

    Fuguet, Elisabet; Rafols, Clara; Roses, Marti; Bosch, Elisabeth

    2005-01-01

    Critical micelle concentration (CMC) of sodium dodecyl sulphate (SDS), lithium perfluorooctanesulfonate (LPFOS), hexadecyltrimethylammonium bromide (HTAB), tetradecyltrimethylammonium bromide (TTAB), and sodium cholate (SC), surfactants commonly used as pseudostationary phases in micellar electrokinetic chromatography (MEKC), have been determined by means of three different methods: MEKC, spectrophotometry, and conductometry. Determinations have been performed in water, and also in different concentrations of phosphate buffer at pH 7.0. CMC values ranging from 8.08 (water) to 1.99 (50 mM phosphate buffer) mM for SDS, from 7.16 (water) to 2,81 (30 mM phosphate buffer) mM for LPFOS, from 3.77 (water) to 1.93 (20 mM phosphate buffer) mM for TTAB, from 0.91 (water) to ∼0.34 (20 mM phosphate buffer) for HTAB, and around 13 mM (20 mM phosphate buffer) for SC, are obtained. The effect of the electrolyte concentration on the CMC, as well as the linear relationship between the electrolyte counter-ion concentration and the CMC are discussed. This linear relationship provides an easy way for users to estimate the CMC of a MEKC system, at a given electrolyte concentration. A comparison between experimental methods, as well as a discussion about the suitability of a given method for the determination of the CMC for a given surfactant system is also provided

  7. Selectivity and stoichiometry boosting of beta-cyclodextrin in cationic/anionic surfactant systems: when host-guest equilibrium meets biased aggregation equilibrium.

    Science.gov (United States)

    Jiang, Lingxiang; Yu, Caifang; Deng, Manli; Jin, Changwen; Wang, Yilin; Yan, Yun; Huang, Jianbin

    2010-02-18

    Cationic surfactant/anionic surfactant/beta-CD ternary aqueous systems provide a platform for the coexistence of the host-guest (beta-CD/surfactant) equilibrium and the biased aggregation (monomeric/aggregated surfactants) equilibrium. We report here that the interplay between the two equilibria dominates the systems as follows. (1) The biased aggregation equilibrium imposes an apparent selectivity on the host-guest equilibrium, namely, beta-CD has to always selectively bind the major surfactant (molar fraction > 0.5) even if binding constants of beta-CD to the pair of surfactants are quite similar. (2) In return, the host-guest equilibrium amplifies the bias of the aggregation equilibrium, that is, the selective binding partly removes the major surfactant from the aggregates and leaves the aggregate composition approaching the electroneutral mixing stoichiometry. (3) This composition variation enhances electrostatic attractions between oppositely charged surfactant head groups, thus resulting in less-curved aggregates. In particular, the present apparent host-guest selectivity is of remarkably high values, and the selectivity stems from the bias of the aggregation equilibrium rather than the difference in binding constants. Moreover, beta-CD is defined as a "stoichiometry booster" for the whole class of cationic/anionic surfactant systems, which provides an additional degree of freedom to directly adjust aggregate compositions of the systems. The stoichiometry boosting of the compositions can in turn affect or even determine microstructures and macroproperties of the systems.

  8. (Surfactant + polymer) interaction parameter studied by (liquid + liquid) equilibrium data of quaternary aqueous solution containing surfactant, polymer, and salt

    Energy Technology Data Exchange (ETDEWEB)

    Foroutan, Masumeh [Physical Chemistry Department, School of Chemistry, College of Science, University of Tehran, 14155-6455 Tehran (Iran, Islamic Republic of)], E-mail: foroutan@khayam.ut.ac.ir; Heidari, Nosrat; Mohammadlou, Maryam [Chemistry Department, Faculty of Science, Uremia University, Uremia (Iran, Islamic Republic of); Sojahrood, Amin Jafari [Physics Department, Faculty of Science, Uremia University, Uremia (Iran, Islamic Republic of)

    2009-02-15

    (Liquid + liquid) equilibrium (LLE) data of quaternary aqueous system containing polyoxyethylene (20) cetyl ether (with abbreviation name Brij 58, non-ionic surfactant), diammonium hydrogen phosphate, and poly ethylene glycol (PEG) with three molar masses {l_brace}M{sub W} = (1000, 6000, and 35,000) g . mol{sup -1}{r_brace} have been determined experimentally at T = 313.15 K. Furthermore, the Flory-Huggins theory with two electrostatic terms (Debye-Hueckel and Pitzer-Debye-Hueckel equations) have been used to calculate the phase behavior of the quaternary systems and (surfactant + polymer) interaction parameter as well as interaction parameters between other species. Temperature dependency of the parameters of the Flory-Huggins theory has been obtained. Also an effort have been done to show that addition of PEG as well as increasing the temperature can shift the binodal curves of the ternary aqueous system containing surfactant and salt to lower mole fraction of salt. Also the effect of polymer molar mass on the binodal diagram displacement has been discussed.

  9. Potential application of surfactant systems in formulation of dosage forms with slightly soluble substances

    Directory of Open Access Journals (Sweden)

    Ibrić Svetlana R.

    2012-01-01

    Full Text Available In order to achieve fast release of ibuprofen, slightly soluble model substance (0.52104 mol/l, surfactant systems for oral use with different PEG-40 hydrogenated castor oil (C/diethylene glycol monoethyl ether (T ratios were investigated. Comparison between dissolution profiles for ibuprofen from formulated systems and from two commercial products, film tablets and soft capsules, is presented in this paper. Photon correlation spectroscopy has shown that after high dilution with water, surfactant systems were able to form micellar solutions. The size of micelles varies from 14.8 ± 0,075 nm to 16.2 ± 0,021 nm with increasing C/T ratio from 1:2 to 2:1. Although with increasing content of PEG-40 hydrogenated castor oil larger micelles have formed, lower values of polydispersity index indicated that more homogeneous distribution of micelles size was gained. Conductometric analysis has demonstrated that system composing of C/T ratio 2:1, has shown most pronounced interaction between droplets, which can be seen as high rise of electrical conductivity with increasing water content (% (wwater/wtotal in the sample. No significant difference in percolation threshold between formulations with different C/T ratios was observed. Different surfactant systems were adsorbed on magnesium aluminometasilicate, as adsorbent with high specific active surface (≈300 m2/g, in order to investigate potential influence of adsorbent on ibuprofen dissolution rate. Formulated systems, with or without adsorbent were filled in hard gelatin capsules. The dissolution profiles of ibuprofen from different formulations were obtained in 30 minutes by dissolution apparatus with rotating baskets and compared with dissolution profiles of ibuprofen from commercial products. For formulations without adsorbent faster release of ibuprofen in first minutes of dissolution test, showed formulations with C/T ratio 2:1 and 1:1. Magnesium aluminometasilicate, as adsorbent with high specific

  10. Theoretical and Simulations-Based Modeling of Micellization in Linear and Branched Surfactant Systems

    Science.gov (United States)

    Mendenhall, Jonathan D.

    Surfactants are chemically-heterogeneous molecules possessing hydrophilic (head) and hydrophobic (tail) moieties. This dual nature of surfactants leads to interesting phase behavior in aqueous solution as a function of surfactant concentration, including: (i) formation of surfactant monolayers at surfaces and interfaces, and (ii) self-assembly into finite aggregates (micelles) in the bulk solution beyond the critical micelle concentration (cmc). This concentration-dependent phase behavior induces changes in solution properties. For example, the surface activity of surfactants can decrease the surface tension, and self-assembly in bulk solution can lead to changes in viscosity, equivalent conductivity, solubilization capacity, and other bulk properties. These effects make surfactants quite attractive and unique for use in product formulations, where they are utilized as detergents, dispersants, emulsifiers, solubilizers, surface and interfacial tension modifiers, and in other contexts. The specific chemical structure of the surfactant head and tail is essential in determining the overall performance properties of a surfactant in aqueous media. The surfactant tail drives the self-assembly process through the hydrophobic effect, while the surfactant head imparts a certain extent of solubility to the surfactant in aqueous solution through preferential interactions with the hydrogen-bonding network of water. The interplay between these two effects gives rise to the particular phase diagram of a surfactant, including the specific cmc at which micelles begin to form. In addition to serving as a quantitative indicator of micelle formation, the cmc represents a limit to surface monolayer formation, and hence to surface and interfacial tension reduction, because surfactant adsorption at interfaces remains approximately constant beyond the cmc. In addition, the cmc represents the onset of changes in bulk solution properties. This Thesis is concerned with the prediction of cmc

  11. Solubilization and mineralization of polycyclic aromatic hydrocarbons by Pseudomonas putida in the presence of surfactant

    International Nuclear Information System (INIS)

    Doong Rueyan; Lei Wengang

    2003-01-01

    The solubilization and mineralization of polycyclic aromatic hydrocarbons (PAHs) in a soil system amended with different surfactants was examined. Mineralization experiments were conducted with the addition of [ 14 C]pyrene. An inoculum of the PAH-degrading microorganism, Pseudomonas putida, was investigated for its sensitivity towards four non-ionic and one anionic surfactants with different polyoxyethylene (POE) chain lengths. The addition of surfactant was found to enhance the bioavailability of naphthalene, phenanthrene and pyrene with efficiencies ranging from 21.1 to 60.6%, 33.3 to 62.8% and 26.8 to 70.9%, respectively. The enhanced efficiency followed the order of Brij 30, Triton X-100, Tween 80, and Brij 35, which is correlated with the polyoxyethylene chain of the surfactants. Brij 35 and Tween 80 inhibited the growth of P. putida. However, microorganisms can utilize Triton X-100 and Brij 30 as the sole carbon and energy sources at concentrations above CMC values. In the aqueous system without the addition of surfactants, microorganisms could mineralize [ 14 C]pyrene to 14 CO 2 which corresponds to 28% of mineralization. The addition of surfactants decreased the mineralization rate of pyrene. Also, the fraction of the micellar-phase pyrene that can be directly biodegraded decreased as the concentration of micelle increases. However, the mineralization rate can be enhanced by the amendment of Brij 30 when soil was applied to the cultures. This suggests that biodegradable surfactants can be applicable for increasing the bioavailability and mineralization of PAHs in soil systems

  12. Partitioning of hexachlorobenzene in a kaolin/humic acid/surfactant/water system: Combined effect of surfactant and soil organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Jinzhong; Wang, Lingling [Environmental Science Research Institute, Huazhong University of Science and Technology, Wuhan 430074 (China); Lu, Xiaohua, E-mail: hust-esri2009@hotmail.com [Environmental Science Research Institute, Huazhong University of Science and Technology, Wuhan 430074 (China); Lin, Yusuo; Zhang, Shengtian [Nanjing Institute of Environmental Science, Ministry of Environmental Protection of China, Nanjing 210042 (China)

    2011-11-30

    Highlights: Black-Right-Pointing-Pointer We study HCB partitioning in a kaolin/humic acid/TX100/water system. Black-Right-Pointing-Pointer We reveal influence of TX100-HA interaction on TX100 and HA sorption to kaolin. Black-Right-Pointing-Pointer We verify combined effect of TX100 and HA on HCB desorption from clay. - Abstract: Understanding the combined effect of soil organic matter (SOM) and surfactants on the partitioning of hydrophobic organic compounds in soil/water systems is important to predict the effectiveness of surfactant-enhanced remediation (SER). In the present study we investigate the partitioning of hexachlorobenzene (HCB) within a humic acid (HA)-coated kaolin/Triton X-100 (TX100)/water system, with special emphasis on the interaction between TX100 and HA, and their combined effect on HCB sorption. HA firstly enhanced then suppressed TX100 sorption to kaolin as the amounts of HA increased, while the addition of TX100 led to a consistent reduction in HA sorption. In the HA-coated kaolin/TX100/water system, TX100 played a primary role in enhancing desorption of HCB, while the role could be suppressed and then enhanced as HA coating amounts increased. Only at HA coating above 2.4%, dissolved HA outcompeted clay-bound HA for HCB partitioning, resulting in dissolved HA enhanced desorption. The presence of dissolved HA at these conditions further promoted the effectiveness of TX100 enhanced desorption. Despite a reduced TX100 sorption to clay was achieved due to the presence of dissolved HA, the effect on HCB desorption was comparatively slight. A reliable cumulative influence of HA and TX100 on HCB desorption was observed, although HCB desorption by HA/TX100 mixed was less than the sum of HA and TX100 individually. Our study suggests that for soils of high organic contents, the combined effect of SOM and surfactants on HOCs desorption can be applied to improve the performance of SER.

  13. Critical micelle concentration values for different surfactants measured with solid-phase microextraction fibers

    NARCIS (Netherlands)

    Haftka, Joris J H; Scherpenisse, Peter; Oetter, G??nter; Hodges, Geoff; Eadsforth, Charles V.; Kotthoff, Matthias; Hermens, Joop L M

    The amphiphilic nature of surfactants drives the formation of micelles at the critical micelle concentration (CMC). Solid-phase microextraction (SPME) fibres were used in the present study to measure CMC values of twelve nonionic, anionic, cationic and zwitterionic surfactants. The SPME derived CMC

  14. Persistence length of wormlike micelles composed of ionic surfactants: self-consistent-field predictions

    NARCIS (Netherlands)

    Lauw, Y.; Leermakers, F.A.M.; Cohen Stuart, M.A.

    2007-01-01

    The persistence length of a wormlike micelle composed of ionic surfactants CnEmXk in an aqueous solvent is predicted by means of the self-consistent-field theory where CnEm is the conventional nonionic surfactant and X-k is an additional sequence of k weakly charged (pH-dependent) segments. By

  15. The Systematic Screening Methodology for Surfactant Flooding Chemicals in Enhanced Oil Recovery

    DEFF Research Database (Denmark)

    Cholpraves, Cholathis; Rattanaudom, Pattamas; Suriyapraphadilok, Uthaiporn

    2017-01-01

    for non-ionic surfactants is found to be qualitatively correct and so it can be used for surfactant screening-selection. Other properties like melting point, cloud-point, etc., are also used for the screening-selection step. Application of the model-based method is highlighted through two case studies...

  16. Ionizing and non-ionizing radiations

    International Nuclear Information System (INIS)

    1994-01-01

    The monograph is a small manual to get a knowledge of ionizing and non-ionizing radiations. The main chapters are: - Electromagnetic radiations - Ionizing and non-ionizing radiations - Non-ionizing electromagnetic radiations - Ionizing electromagnetic radiation - Other ionizing radiations - Ionizing radiation effects - The Nuclear Safety Conseil

  17. The use of Nile Red to monitor the aggregation behavior in ternary surfactant-water-organic solvent systems

    NARCIS (Netherlands)

    Stuart, MCA; van de Pas, JC; Engberts, JBFN; Pas, John C. van de

    Ternary systems of surfactants, water and organic solvents were studied by monitoring the steady-state fluorescence of the versatile solvatochromic probe Nile Red. We found not only that Nile Red can be used throughout the whole isotropic regions in the phase diagram, but also that subtle changes in

  18. Molecular organization and dynamics of micellar phase of polyelectrolyte-surfactant complexes: ESR spin probe study

    Science.gov (United States)

    Wasserman, A. M.; Kasaikin, V. A.; Zakharova, Yu. A.; Aliev, I. I.; Baranovsky, V. Yu.; Doseva, V.; Yasina, L. L.

    2002-04-01

    Molecular dynamics and organization of the micellar phase of complexes of linear polyelectrolytes with ionogenic and non-ionogenic surfactants was studied by the ESR spin probe method. Complexes of polyacrylic acid (PAA) and sodium polystyrenesulfonate (PSS) with alkyltrimethylammonium bromides (ATAB), as well as complexes of poly- N, N'-dimethyldiallylammonium chloride (PDACL) with sodium dodecylsulfate (SDS) were studied. The micellar phase of such complexes is highly organized molecular system, molecular ordering of which near the polymeric chain is much higher than in the 'center' of the micelle, it depends on the polymer-detergent interaction, flexibility of polymeric chain and length of carbonic part of the detergent molecule. Complexes of polymethacrylic acid (PMAA) with non-ionic detergent (dodecyl-substituted polyethyleneglycol), show that the local mobility of surfactant in such complexes is significantly lower than in 'free' micelles and depends on the number of micellar particles participating in formation of complexes.

  19. Respiratory and Systemic Effects of LASSBio596 Plus Surfactant in Experimental Acute Respiratory Distress Syndrome

    Directory of Open Access Journals (Sweden)

    Johnatas Dutra Silva

    2016-02-01

    Full Text Available Background/Aims: Exogenous surfactant has been proposed as adjunctive therapy for acute respiratory distress syndrome (ARDS, but it is inactivated by different factors present in the alveolar space. We hypothesized that co-administration of LASSBio596, a molecule with significant anti-inflammatory properties, and exogenous surfactant could reduce lung inflammation, thus enabling the surfactant to reduce edema and improve lung function, in experimental ARDS. Methods: ARDS was induced by cecal ligation and puncture surgery in BALB/c mice. A sham-operated group was used as control (CTRL. After surgery (6 hours, CTRL and ARDS animals were assigned to receive: (1 sterile saline solution; (2 LASSBio596; (3 exogenous surfactant or (4 LASSBio596 plus exogenous surfactant (n = 22/group. Results: Regardless of exogenous surfactant administration, LASSBio596 improved survival rate and reduced collagen fiber content, total number of cells and neutrophils in PLF and blood, cell apoptosis, protein content in BALF, and urea and creatinine levels. LASSBio596 plus surfactant yielded all of the aforementioned beneficial effects, as well as increased BALF lipid content and reduced surface tension. Conclusion: LASSBio596 exhibited major anti-inflammatory and anti-fibrogenic effects in experimental sepsis-induced ARDS. Its association with surfactant may provide further advantages, potentially by reducing surface tension.

  20. Influence of sediment on the fate and toxicity of a polyethoxylated tallowamine surfactant system (MON 0818) in aquatic microcosms

    Science.gov (United States)

    Wang, N.; Besser, J.M.; Buckler, D.R.; Honegger, J.L.; Ingersoll, C.G.; Johnson, B. Thomas; Kurtzweil, M.L.; MacGregor, J.; McKee, M.J.

    2005-01-01

    The fate and toxicity of a polyethoxylated tallowamine (POEA) surfactant system, MON 0818, was evaluated in water–sediment microcosms during a 4-d laboratory study. A surfactant solution of 8 mg l−1 nominal concentration was added to each of nine 72-l aquaria with or without a 3-cm layer of one of two natural sediments (total organic carbon (TOC) 1.5% or 3.0%). Control well water was added to each of nine additional 72-l aquaria with or without sediment. Water samples were collected from the microcosms after 2, 6, 24, 48, 72, and 96 h of aging to conduct 48-h toxicity tests with Daphnia magna and to determine surfactant concentrations. Elevated mortality of D. magna (43–83%) was observed in overlying water sampled from water-only microcosms throughout the 96-h aging period, whereas elevated mortality (23–97%) was only observed in overlying water sampled from water–sediment microcosms during the first 24 h of aging. Measured concentrations of MON 0818 in water-only microcosms remained relatively constant (4–6 mg l−1) during the 96-h period, whereas the concentrations in overlying water from microcosms containing either of the two types of sediment dissipated rapidly, with half-lives of 13 h in the 3.0% TOC sediment and 18 h in the 1.5% TOC sediment. Both toxicity and the concentration of MON 0818 in overlying water decreased more rapidly in microcosms containing sediment with the higher percent TOC and clay and with a higher microbial biomass. Mortality of D. magna was significantly correlated with surfactant concentrations in the overlying water. These results indicate that the toxicity of the POEA surfactant in water rapidly declines in the presence of sediment due to a reduction in the surfactant concentration in the overlying water above the sediment.

  1. Influence of metacide - surfactant complexes on agricultural crops

    Directory of Open Access Journals (Sweden)

    Orynkul Esimova

    2014-12-01

    Full Text Available The complexes based on surfactants and polyhexamethyleneguanidine hydrochloride (metacide are important for agriculture. This paper considers compositions of known bactericidal metacide with different surfactants: anionic surfactant sodium dodecylsulphate (DDSNa and nonionic surfactant Tween 80 (monooleate of oxyethylenated anhydrosorbitols. The effect of individual components and associates of metacide and surfactants on productivity and infection of cereals was studied. According to the study, the highest productivity and infection rate were shown by the associate of metacide and Tween-80. At concentration of Tween-80 in aqueous solution equal to 0.001% in combination with metacide, efficiency was 98% at 0% infection. The surface tension and the wetting of metacide, DDSNa, Tween-80, and associates of metacide with surfactants were studied. In comparison with individual components, metacide-DDSNa and metacide-Tween-80 associates have higher surface activity.

  2. The effect of nanoparticle aggregation on surfactant foam stability.

    Science.gov (United States)

    AlYousef, Zuhair A; Almobarky, Mohammed A; Schechter, David S

    2018-02-01

    The combination of nanoparticles (NPs) and surfactant may offer a novel technique of generating stronger foams for gas mobility control. This study evaluates the potential of silica NPs to enhance the foam stability of three nonionic surfactants. Results showed that the concentration of surfactant and NPs is a crucial parameter for foam stability and that there is certain concentrations for strong foam generation. A balance in concentration between the nonionic surfactants and the NPs can enhance the foam stability as a result of forming flocs in solutions. At fixed surfactant concentration, the addition of NPs at low to intermediate concentrations can produce a more stable foam compared to the surfactant. The production of small population of flocs as a result of mixing the surfactant and NPs can enhance the foam stability by providing a barrier between the gas bubbles and delaying the coalescence of bubbles. Moreover, these flocs can increase the solution viscosity and, therefore, slow the drainage rate of thin aqueous film (lamellae). The measurements of foam half-life, bubble size, and mobility tests confirmed this conclusion. However, the addition of more solid particles or surfactant might have a negative impact on foam stability and reduce the maximum capillary pressure of coalescence as a result of forming extensive aggregates. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. NMR study of the dynamics of cationic gemini surfactant 14-2-14 in mixed solutions with conventional surfactants.

    Science.gov (United States)

    Jiang, Yan; Lu, Xing-Yu; Chen, Hong; Mao, Shi-Zhen; Liu, Mai-Li; Luo, Ping-Ya; Du, You-Ru

    2009-06-18

    Three kinds of conventional surfactants, namely, two nonionic surfactants [polyethylene glycol (23) lauryl ether (Brij-35) and Triton X-100 (TX-100)], one cationic surfactant [n-tetradecyltrimethyl ammonium bromide (TTAB)], and an anionic surfactant [sodium n-dodecyl sulfate (SDS)}, were mixed into the quaternary ammonium gemini surfactant [C(14)H(29)N(+)(CH(3))(2)](2)(CH(2))(2).2Br(-) (14-2-14) in aqueous solution. The exchange rate constants between 14-2-14 molecules in the mixed micelles and those in the bulk solution were detected using two nuclear magnetic resonance (NMR) methods: one-dimensional (1D) line shape analysis and two-dimensional (2D) exchange spectroscopy (EXSY). The results obtained from these two methods were consistent. Both showed that mixing a nonionic conventional surfactant, either Brij-35 or TX-100, enhanced the exchange process between the 14-2-14 molecules in the mixed micelles and those in the bulk solution. In contrast, the anionic surfactant SDS and the cationic surfactant TTAB slowed the process slightly.

  4. Respiratory failure following anti-lung serum: study on mechanisms associated with surfactant system damage

    International Nuclear Information System (INIS)

    Lachmann, B.; Hallman, M.; Bergmann, K.C.

    1987-01-01

    Within 2 minutes intravenous anti-lung serum (ALS) into guinea pig induces a respiratory failure that is fatal within 30 min. The relationship between surfactant, alveolar-capillary permeability and respiratory failure was studied. Within two minutes ALS induced a leak in the alveolar-capillary barrier. Within 30 minutes 28.3% (controls, given normal rabbit serum: 0.7%) of iv 131 I-albumin, and 0.5% (controls 0.02%) of iv surfactant phospholipid tracer were recovered in bronchoalveolar lavage. Furthermore, 57% (controls 32%) of the endotracheally administered surfactant phospholipid became associated with lung tissue and only less than 0.5% left the lung. The distribution of proteins and phospholipids between the in vivo small volume bronchoalveolar lavages and the ex vivo bronchoalveolar lavages were dissimilar: 84% (controls 20%) of intravenously injected, lavageable 131 I-albumin and 23% (controls 18%) of total lavageable phospholipid were recovered in the in vivo small volume bronchoalveolar lavages. ALS also decreased lavageable surfactant phospholipid by 41%. After ALS the minimum surface tension increased. The supernatant of the lavage increased the minimum surface tension of normal surfactant. In addition, the sediment fraction of the lavage had slow surface adsorption, and a marked reduction in 35,000 and 10,000 MW peptides. Exogenous surfactant ameliorated the ALS-induced respiratory failure. We propose that inhibition, altered intrapulmonary distribution, and dissociation of protein and phospholipid components of surfactant are important in early pathogenesis of acute respiratory failure

  5. The study of the influence of surfactant charge on alkaline hydrolysis reactions of acetylsalicylic acid (ASA) and triflusal (TFL) using spectrophotometric methods.

    Science.gov (United States)

    Ferrit, Mónica; del Valle, Carmen; Martínez, Fernando

    2007-07-01

    In this research, the effects of micellar systems on alkaline hydrolysis reactions of acetylsalicylic acid (ASA) and triflusal (TFL) were found to be dependant upon the surfactant charge within the micelle. In cationic micelles, there is a catalytic effect at low concentrations of surfactant. However, this reaction is inhibited at higher surfactant concentrations. In anionic micelles, a catalytic effect occurs, while in zwitterionic and non-ionic micelles there is an inhibitory effect. Such reactions are attributable to changes in reactants on the micellar surface, or to the fact that both reactants are found in different microenvironments. The pseudophase (PS) and ion-exchange (PPIE) models were found to be consistent with the experimental result. Furthermore, the association constants for both drugs could be determined together with micellar rate constants in heterogeneous media.

  6. Point force singularities outside a drop covered with an incompressible surfactant: Image systems and their applications

    Science.gov (United States)

    Shaik, Vaseem A.; Ardekani, Arezoo M.

    2017-11-01

    In this work we derive the image flow fields for point force singularities placed outside a stationary drop covered with an insoluble, nondiffusing, and incompressible surfactant. We assume the interface to be Newtonian and use the Boussinesq-Scriven constitutive law for the interfacial stress tensor. We use this analytical solution to investigate two different problems. First, we derive the mobility matrix for two drops of arbitrary sizes covered with an incompressible surfactant. In the second example, we calculate the velocity of a swimming microorganism (modeled as a Stokes dipole) outside a drop covered with an incompressible surfactant.

  7. Mixed Micelle System Produced by Interaction Between Transglycosylated Stevia and an Ionic Surfactant Improves Dissolution Profile of Mefenamic Acid.

    Science.gov (United States)

    Fujimori, Miki; Kadota, Kazunori; Tozuka, Yuichi

    2017-04-01

    Transglycosylated stevia (stevia-G) can effectively improve the dissolution and bioavailability of poorly water-soluble drugs. Furthermore, addition of an ionic surfactant to stevia-G solution has been shown to enhance the dissolution effect of stevia-G on flurbiprofen. Herein, 4 surfactants, namely sodium dodecyl sulfate, sodium N-dodecanoylsarcosinate, sodium monododecyl phosphate, and lauryltrimethylammonium chloride (LTAC) were screened to investigate their synergistic effect with stevia-G in enhancing the solubility of mefenamic acid (MFA). The ternary formulation containing LTAC produced the highest increase in solubility, whereas the binary MFA/LTAC formulation did not increase the solubility of MFA. Surface tension was evaluated to analyze the interaction between stevia-G and each ionic surfactant, wherein the Rubingh model was applied to predict mixed micelle formation between stevia-G and LTAC. Interaction parameters calculated by the Rubingh model reflected mixed micelle formation between stevia-G and LTAC relative to the self-interactions of the 2 individual surfactants. All interaction parameters in this system showed negative values, indicating a favorable interaction (e.g., hydrogen bond or electrostatic and dipole) between binary components in the mixed micelles. Spray-dried particles of ternary formulations (MFA/stevia-G/LTAC) were prepared to evaluate the dissolution profile and physicochemical properties. Dissolution profiling showed that the concentration of MFA released from spray-dried particles was significantly higher than untreated MFA. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  8. SOME PHYSICOCHEMICAL PROPERTIES OF OCTYLPHENOL ETHOXYLATE NONIONICS (TRITON X-100, TRITON X-114 AND TRITON X-405 AND THE TEMPERATURE EFFECT ON THIS PROPERTIES

    Directory of Open Access Journals (Sweden)

    Taliha Sidim

    2016-11-01

    Full Text Available Surface tensions and condutvities of aqueous solutions of nonionic surfactants at various concentrations were measured at diffferent temperatures.The critical micelle concentration (CMC of aqueous solutions of three different octylphenol ethoxylate nonionics(Triton X-114, Triton X-100 and Triton X-405 are determined at different temperatures.The effect of the ethylene oxide chain length and temperature on the CMC is also determined.

  9. Interactions of Proline in Non-aqueous Anionic, Cationic and Nonionic Surfactants at Different Temperatures%不同温度下脯氨酸在非水阴离子、阳离子及非离子型表面活性剂中的作用

    Institute of Scientific and Technical Information of China (English)

    ALI Anwar; SHAHJAHAN

    2008-01-01

    Density and viscosity data of proline (Pro) in sodium dodecyl sulfate/cetyltrimethylammonium bromide/poly (oxyethylene) isooctyl phenyl ether in formamide were measured at 298.15, 303.15, 308.15, and 313.15K and 0.1MPa. The density data were utilized to evaluate standard partial molar volumes (φ0V) and partial molar isobaric expansibility (φ0E). The viscosity data were used to evaluate A-and B-coefficients, free energy of activation of viscous flow (⊿μ0*1) and (⊿μ0*2), per mole of solvent and solute respectively, enthalpy (⊿H*) and entropy (⊿S*) of activation of viscous flow. The results obtained were utilized in the qualitative elucidation of the Pro-surfactant/formamide and Pro-Pro interactions in the present systems.

  10. Ionic versus nonionic contrast media

    International Nuclear Information System (INIS)

    Zylak, C.J.; Gafni, A.

    1988-01-01

    The efficacy and effectiveness of the nonionic contrast media have been established. Widespread usage has been hampered because of the approximate tenfold increase in cost compared with the ionic media. An economic evaluation considering costs and consequences of both interventions (ionic vs nonionic contrast media) was performed; it is a cost effectiveness (CEA) and a cost-benefit analysis (CBA) for the Canadian experience. The results of the CEA demonstrate a value per life-year saved within an acceptable range when compared with value for quality-adjusted life years for programs such as treatment of severe (diastolic≥ 105 mm Hg) and mild (diastolic 95-104 mm Hg) hypertension in men aged 40. The CBA showed a net cost to society when benefits were measured as future treatment costs saved plus productivity gained. However, if people are willing to pay a small amount for the comfort of the new intervention, this will result in a break-even situation

  11. Formation mechanism of CdS nanoparticles with tunable luminescence via a non-ionic microemulsion route

    International Nuclear Information System (INIS)

    Angelescu, Daniel G.; Munteanu, Gabriel; Anghel, Dan F.; Peretz, Sandu; Maraloiu, Adrian V.; Teodorescu, Valentin S.

    2013-01-01

    We investigated the synthesis of CdS nanoparticles via an optimized water-in-oil microemulsion route that used the non-ionic surfactant-based system H 2 O–n-octane–Brij30/1-octanol. For that purpose, a microemulsion that contained Cd(II) ions (μe1) and another microemulsion that contained S 2− ions (μe2) were combined. To investigate the ways in which the non-ionic microemulsion characteristics controlled the size and emission properties of colloidal CdS quantum dots, μe1 and μe2 with tunable and robust similar structure were prepared. This requirement was fulfilled by matching the water emulsification failure boundary (wefb) of the two microemulsions and carrying out synthesis along this boundary. Dynamic light scattering and fluorescence probe techniques were used to investigate the size and interfacial organization of the microemulsion water droplets, and the CdS nanoparticles were characterized by UV–Vis and static fluorescence spectrometry, TEM and HRTEM. Nanoparticles of diameter 4.5–5.5 nm exhibiting enhanced band edge emission were produced by increasing the water content of the precursor microemulsions. The experimental results were combined with a Monte Carlo simulation approach to demonstrate that growth via coagulation of seed nuclei represented the driving mechanism for the CdS nanoparticle formation in the water-in-oil microemulsion.

  12. Formation mechanism of CdS nanoparticles with tunable luminescence via a non-ionic microemulsion route

    Energy Technology Data Exchange (ETDEWEB)

    Angelescu, Daniel G., E-mail: dangelescu@hotmail.com; Munteanu, Gabriel [Quantum Chemistry and Molecular Structure Laboratory, Romanian Academy, ' Ilie Murgulescu' Institute of Physical Chemistry (Romania); Anghel, Dan F.; Peretz, Sandu [Romanian Academy, ' Ilie Murgulescu' Institute of Physical Chemistry, Colloidal Laboratory (Romania); Maraloiu, Adrian V.; Teodorescu, Valentin S. [National Institute of Materials Physics, Institute of Atomic Physics (Romania)

    2013-01-15

    We investigated the synthesis of CdS nanoparticles via an optimized water-in-oil microemulsion route that used the non-ionic surfactant-based system H{sub 2}O-n-octane-Brij30/1-octanol. For that purpose, a microemulsion that contained Cd(II) ions ({mu}e1) and another microemulsion that contained S{sup 2-} ions ({mu}e2) were combined. To investigate the ways in which the non-ionic microemulsion characteristics controlled the size and emission properties of colloidal CdS quantum dots, {mu}e1 and {mu}e2 with tunable and robust similar structure were prepared. This requirement was fulfilled by matching the water emulsification failure boundary (wefb) of the two microemulsions and carrying out synthesis along this boundary. Dynamic light scattering and fluorescence probe techniques were used to investigate the size and interfacial organization of the microemulsion water droplets, and the CdS nanoparticles were characterized by UV-Vis and static fluorescence spectrometry, TEM and HRTEM. Nanoparticles of diameter 4.5-5.5 nm exhibiting enhanced band edge emission were produced by increasing the water content of the precursor microemulsions. The experimental results were combined with a Monte Carlo simulation approach to demonstrate that growth via coagulation of seed nuclei represented the driving mechanism for the CdS nanoparticle formation in the water-in-oil microemulsion.

  13. A study of surfactant interaction in cement-based systems and the role of the surfactant in frost protection

    Science.gov (United States)

    Tunstall, Lori Elizabeth

    Air voids are deliberately introduced into concrete to provide resistance against frost damage. However, our ability to control air distribution in both traditional and nontraditional concrete is hindered by the limited amount of research available on air-entraining agent (AEA) interaction with both the solid and solution components of these systems. This thesis seeks to contribute to the information gap in several ways. Using tensiometry, we are able to quantify the adsorption capacity of cement, fly ash, and fly ash carbon for four commercial AEAs. These results indicate that fly ash interference with air entrainment is due to adsorption onto the glassy particles tucked inside carbon, rather than adsorption onto the carbon itself. Again using tensiometry, we show that two of the AEA show a stronger tendency to micellize and to interact with calcium ions than the others, which seems to be linked to the freezing behavior in mortars, since mortars made with these AEA require smaller dosages to achieve similar levels of protection. We evaluate the frost resistance of cement and cement/fly ash mortars by measuring the strain in the body as it is cooled and reheated. All of the mortars show some expansion at temperatures ≥ -42 °C. Many of the cement mortars are able to maintain net compression during this expansion, but none of the fly ash mortars maintain net compression once expansion begins. Frost resistance improves with an increase in AEA dosage, but no correlation is seen between frost resistance and the air void system. Thus, another factor must contribute to frost resistance, which we propose is the microstructure of the shell around the air void. The strain behavior is attributed to ice growth surrounding the void, which can plug the pores in the shell and reduce or eliminate the negative pore pressure induced by the ice inside the air void; the expansion would then result from the unopposed crystallization pressure, but this must be verified by future work

  14. Alcohol--Induced Polyelectrolyte-Surfactant Complex Coacervate Systems: Characterization and Applications in Enzyme and Protein Extraction

    Science.gov (United States)

    Nejati Moshtaghin, Mahboubeh

    The focus of this thesis is to achieve a better understanding of the newly discovered surfactant-polyelectrolyte complex coacervate (SPCC) systems induced by fluoroalcohol/acid as well as short chain aliphatic alcohol; and to elucidate their applications in extraction and enrichment of proteins and enzyme. We have discovered that fluoroalcohols and --acids induce complex coacervation and phase separation in the aqueous mixtures of oppositely charged anionic polyelectrolytes; specifically, sodium salts of polyacrylic acid and polymethacrylic acid and cationic surfactant (cetyltrimethylammonium bromide, CTAB) over a broad range of concentrations of mole fractions of the oppositely charged amphiphiles. Accordingly, these new classes of coacervators will significantly broaden the scope and facilitate engineering of new coacervate phases. Toward these goals, we have inspected the formation of surfactant-polyelectrolyte complex coacervates in the presence of fluoroalcohols namely hexafluoroisopropanol (HFIP) and Trifluoroethanol (TFE). Furthermore, the extent of coacervation as a function of concentrations the system components, and charge ratios of the oppositely charged amphiphiles has been investigated. Polyelectrolytes are considered to be milder reagents, as compared to surfactants, regarding proteins denaturation. This highlights the importance of a detailed investigation of the efficiency of our coacervate systems for extraction and preconcentration of proteins and enzymes, especially, when the biological activity of the extracted proteins needs to be maintained based on the objectives mentioned above, the results of the investigations have been organized in four chapters. In Chapter II, the phase behavior of the FA-SPCC will be investigated. The objective is to examine the phase behavior and phase properties with respect to the extent of coacervation in different solution conditions. In particular, the effects of different solution variables such as concentration

  15. Oleate coating of iron oxide nanoparticles in aqueous systems: the role of temperature and surfactant concentration

    Energy Technology Data Exchange (ETDEWEB)

    Roth, Hans-Christian; Schwaminger, Sebastian; Fraga García, Paula; Ritscher, Jonathan; Berensmeier, Sonja, E-mail: s.berensmeier@tum.de [Technische Universität München, Bioseparation Engineering Group (Germany)

    2016-04-15

    Coating magnetic nanoparticles (MNPs) with sodium oleate (SO) is known to be an excellent method to create biocompatible, stable colloids with a narrow size distribution. However, the mechanism of oleate adsorption on the MNP surface in aqueous systems, as well as its influence on colloidal stability, is not yet fully understood. In this context, we present here a physico-chemical study to provide a deeper understanding of surfactant interaction mechanisms with nanoparticles. We examined the effect of temperature and the SO/MNP ratio (w/w) on the adsorption process in water and observed the existence of a maximum for the adsorbed oleate amount at lower temperatures, whereas at higher temperatures, the isotherm can be adapted to the Langmuir model with constant capacity after saturation. The oleate load on the MNP surface was quantified using reversed-phase high-performance liquid chromatography measurements of samples in solution. The thermogravimetric analyses of the solid residues together with infrared spectroscopy analyses indicate a bilayer-similar structure at the MNP/water interface even for low oleate loads. The oleate interacts with the iron oxide surface through a bidentate coordination of the carboxyl group. Zeta potential measurements demonstrate the high stability of the coated system. The maximal oleate load per unit mass of MNPs reaches approximately 0.35 g{sub oleate} g{sub MNP}{sup −1}.Graphical abstract.

  16. Probing dynamics and mechanism of exchange process of quaternary ammonium dimeric surfactants, 14-s-14, in the presence of conventional surfactants.

    Science.gov (United States)

    Liu, Jun; Jiang, Yan; Chen, Hong; Mao, Shi Zhen; Du, You Ru; Liu, Mai Li

    2012-12-27

    In this Article, we investigated effects of different types of conventional surfactants on exchange dynamics of quaternary ammonium dimeric surfactants, with chemical formula C(14)H(29)N(+)(CH(3))(2)- (CH(2))(s)-N(+)(CH(3))(2)C(14)H(29)·2Br(-), or 14-s-14 for short. Two nonionic surfactants, TritonX-100 (TX-100) and polyethylene glycol (23) laurylether (Brij-35), and one cationic surfactant, n-tetradecyltrimethyl ammonium bromide (TTAB), and one ionic surfactant, sodium dodecyl sulfate (SDS) were chosen as typical conventional surfactants. Exchange rates of 14-s-14 (s = 2, 3, and 4) between the micelle form and monomer in solution were detected by two NMR methods: one-dimensional (1D) line shape analysis and two-dimensional (2D) exchange spectroscopy (EXSY). Results show that the nonionic surfactants (TX-100 and Brij-35), the cationic surfactant (TTAB), and the ionic surfactant (SDS) respectively accelerated, barely influenced, and slowed the exchange rate of 14-s-14. The effect mechanism was investigated by the self-diffusion experiment, relaxation time measurements (T(2)/T(1)), the fluorescence experiment (I(1)/I(3)) and observed chemical shift variations. Results reveal that, nonionic conventional surfactants (TX-100 and Brij-35) loosened the molecule arrangement and decreased hydrophobic interactions in the micelle, and thus accelerated the exchange rate of 14-s-14. The cationic conventional surfactant (TTAB) barely changed the molecule arrangement and thus barely influenced the exchange rate of 14-s-14. The ionic conventional surfactant (SDS) introduced the electrostatic attraction effect, tightened the molecule arrangement, and increased hydrophobic interactions in the micelle, and thus slowed down the exchange rate of 14-s-14. Additionally, the two-step exchange mechanism of 14-s-14 in the mixed solution was revealed through interesting variation tendencies of exchange rates of 14-s-14.

  17. The selective partitioning of the oligomers of polyethoxylated surfactant mixtures between interface and oil and water bulk phases.

    Science.gov (United States)

    Graciaa, Alain; Andérez, José; Bracho, Carlos; Lachaise, Jean; Salager, Jean-Louis; Tolosa, Laura; Ysambertt, Fredy

    2006-11-16

    Because their affinities for the oil and water phases vary considerably with the number of ethylene oxide units in their hydrophilic group, the ethoxylated nonionic species occurring in commercial products tend to behave in a non-collective way, with the low ethoxylation oligomers partitioning mostly in the oil phase. This results in a surfactant mixture at the interface which is more hydrophilic than the one which was introduced in the system in the first place. The pseudophase model is used to study the partitioning in Winsor III type systems, and to estimate the deviation of the interfacial mixture composition from the overall one. New results indicate that the selective partitioning into the oil phase increases when the oil phase becomes aromatic, when the total surfactant concentration decreases and when the water-to-oil ratio decreases.

  18. Effect of reaction systems and surfactant additives on the morphology evolution of hydroxyapatite nanorods obtained via a hydrothermal route

    Energy Technology Data Exchange (ETDEWEB)

    Ma Tianyuan; Xia Zhiguo [School of Materials Sciences and Technology, China University of Geosciences, Beijing 100083 (China); Liao Libing, E-mail: lbliao@cugb.edu.cn [School of Materials Sciences and Technology, China University of Geosciences, Beijing 100083 (China)

    2011-02-15

    Well-dispersed hydroxyapatite (HA) nanorods with different morphologies were synthesized by a hydrothermal method in oleic acid, ethanol and water reaction system, and the surfactant assisted modifications effect was also comparatively studied. The structure and morphology of samples were characterized using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and transmission electron microscopy (TEM), respectively. The effect of reaction systems and surfactant additives on the morphology evolution of HA nanorods were discussed in detail. The results showed that the controlled experimental conditions in the systems, such as the content ratio of oleic acid/ethanol, pH value and the content ratio of Ca/P source had an significant effect on the morphology evolution of as-prepared HA nanorods. Further, the selected surfactant additives, such as cetyltriethylammnonium bromide (CTAB), sodium dodecyl sulfate (K12) also play an important role in the formation of the uniform morphology of HA nanorods. Some possible formation mechanisms of the HA nanorods in the present reaction systems is proposed.

  19. Controlling nonspecific protein adsorption in a plug-based microfluidic system by controlling interfacial chemistry using fluorous-phase surfactants.

    Science.gov (United States)

    Roach, L Spencer; Song, Helen; Ismagilov, Rustem F

    2005-02-01

    Control of surface chemistry and protein adsorption is important for using microfluidic devices for biochemical analysis and high-throughput screening assays. This paper describes the control of protein adsorption at the liquid-liquid interface in a plug-based microfluidic system. The microfluidic system uses multiphase flows of immiscible fluorous and aqueous fluids to form plugs, which are aqueous droplets that are completely surrounded by fluorocarbon oil and do not come into direct contact with the hydrophobic surface of the microchannel. Protein adsorption at the aqueous-fluorous interface was controlled by using surfactants that were soluble in fluorocarbon oil but insoluble in aqueous solutions. Three perfluorinated alkane surfactants capped with different functional groups were used: a carboxylic acid, an alcohol, and a triethylene glycol group that was synthesized from commercially available materials. Using complementary methods of analysis, adsorption was characterized for several proteins (bovine serum albumin (BSA) and fibrinogen), including enzymes (ribonuclease A (RNase A) and alkaline phosphatase). These complementary methods involved characterizing adsorption in microliter-sized droplets by drop tensiometry and in nanoliter plugs by fluorescence microscopy and kinetic measurements of enzyme catalysis. The oligoethylene glycol-capped surfactant prevented protein adsorption in all cases. Adsorption of proteins to the carboxylic acid-capped surfactant in nanoliter plugs could be described by using the Langmuir model and tensiometry results for microliter drops. The microfluidic system was fabricated using rapid prototyping in poly(dimethylsiloxane) (PDMS). Black PDMS microfluidic devices, fabricated by curing a suspension of charcoal in PDMS, were used to measure the changes in fluorescence intensity more sensitively. This system will be useful for microfluidic bioassays, enzymatic kinetics, and protein crystallization, because it does not require

  20. Mixed micelles of polyethylene glycol (23) lauryl ether with ionic surfactants studied by proton 1D and 2D NMR.

    Science.gov (United States)

    Gao, Hong-Chang; Zhao, Sui; Mao, Shi-Zhen; Yuan, Han-Zhen; Yu, Jia-Yong; Shen, Lian-Fang; Du, You-Ru

    2002-05-01

    (1)H NMR chemical shift, spin-lattice relaxation time, spin-spin relaxation time, self-diffusion coefficient, and two-dimensional nuclear Overhauser enhancement (2D NOESY) measurements have been used to study the nonionic-ionic surfactant mixed micelles. Cetyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) were used as the ionic surfactants and polyethylene glycol (23) lauryl ether (Brij-35) as the nonionic surfactant. The two systems are both with varying molar ratios of CTAB/Brij-35 (C/B) and SDS/Brij-35 (S/B) ranging from 0.5 to 2, respectively, at a constant concentration of 6 mM for Brij-35 in aqueous solutions. Results give information about the relative arrangement of the surfactant molecules in the mixed micelles. In the former system, the trimethyl groups attached to the polar heads of the CTAB molecules are located between the first oxy-ethylene groups next to the hydrophobic chains of Brij-35 molecules. These oxy-ethylene groups gradually move outward from the hydrophobic core of the mixed micelle with an increase in C/B in the mixed solution. In contrast to the case of the CTAB/Triton X-100 system, the long flexible hydrophilic poly oxy-ethylene chains, which are in the exterior part of the mixed micelles, remain coiled, but looser, surrounding the hydrophobic core. There is almost no variation in conformation of the hydrophilic chains of Brij-35 molecules in the mixed micelles of the SDS/Brij-35 system as the S/B increases. The hydrophobic chains of both CTAB and SDS are co-aggregated with Brij-35, respectively, in their mixed micellar cores.

  1. Extracting Aggregation Free Energies of Mixed Clusters from Simulations of Small Systems: Application to Ionic Surfactant Micelles.

    Science.gov (United States)

    Zhang, X; Patel, L A; Beckwith, O; Schneider, R; Weeden, C J; Kindt, J T

    2017-11-14

    Micelle cluster distributions from molecular dynamics simulations of a solvent-free coarse-grained model of sodium octyl sulfate (SOS) were analyzed using an improved method to extract equilibrium association constants from small-system simulations containing one or two micelle clusters at equilibrium with free surfactants and counterions. The statistical-thermodynamic and mathematical foundations of this partition-enabled analysis of cluster histograms (PEACH) approach are presented. A dramatic reduction in computational time for analysis was achieved through a strategy similar to the selector variable method to circumvent the need for exhaustive enumeration of the possible partitions of surfactants and counterions into clusters. Using statistics from a set of small-system (up to 60 SOS molecules) simulations as input, equilibrium association constants for micelle clusters were obtained as a function of both number of surfactants and number of associated counterions through a global fitting procedure. The resulting free energies were able to accurately predict micelle size and charge distributions in a large (560 molecule) system. The evolution of micelle size and charge with SOS concentration as predicted by the PEACH-derived free energies and by a phenomenological four-parameter model fit, along with the sensitivity of these predictions to variations in cluster definitions, are analyzed and discussed.

  2. Influence of surfactants in forced dynamic dewetting.

    Science.gov (United States)

    Henrich, Franziska; Fell, Daniela; Truszkowska, Dorota; Weirich, Marcel; Anyfantakis, Manos; Nguyen, Thi-Huong; Wagner, Manfred; Auernhammer, Günter K; Butt, Hans-Jürgen

    2016-09-20

    In this work we show that the forced dynamic dewetting of surfactant solutions depends sensitively on the surfactant concentration. To measure this effect, a hydrophobic rotating cylinder was horizontally half immersed in aqueous surfactant solutions. Dynamic contact angles were measured optically by extrapolating the contour of the meniscus to the contact line. Anionic (sodium 1-decanesulfonate, S-1DeS), cationic (cetyl trimethylammonium bromide, CTAB) and nonionic surfactants (C 4 E 1 , C 8 E 3 and C 12 E 5 ) with critical micelle concentrations (CMCs) spanning four orders of magnitude were used. The receding contact angle in water decreased with increasing velocity. This decrease was strongly enhanced when adding surfactant, even at surfactant concentrations of 10% of the critical micelle concentration. Plots of the receding contact angle-versus-velocity almost superimpose when being plotted at the same relative concentration (concentration/CMC). Thus the rescaled concentration is the dominating property for dynamic dewetting. The charge of the surfactants did not play a role, thus excluding electrostatic effects. The change in contact angle can be interpreted by local surface tension gradients, i.e. Marangoni stresses, close to the three-phase contact line. The decrease of dynamic contact angles with velocity follows two regimes. Despite the existence of Marangoni stresses close to the contact line, for a dewetting velocity above 1-10 mm s -1 the hydrodynamic theory is able to describe the experimental results for all surfactant concentrations. At slower velocities an additional steep decrease of the contact angle with velocity was observed. Particle tracking velocimetry showed that the flow profiles do not differ with and without surfactant on a scales >100 μm.

  3. Clinical, biological, and skin histopathologic effects of ionic macrocyclic and nonionic linear gadolinium chelates in a rat model of nephrogenic systemic fibrosis.

    Science.gov (United States)

    Fretellier, Nathalie; Idée, Jean-Marc; Guerret, Sylviane; Hollenbeck, Claire; Hartmann, Daniel; González, Walter; Robic, Caroline; Port, Marc; Corot, Claire

    2011-02-01

    the purpose of this study was to compare the clinical, pathologic, and biochemical effects of repeated administrations of ionic macrocyclic or nonionic linear gadolinium chelates (GC) in rats with impaired renal function. rats submitted to subtotal nephrectomy were allocated to single injections of 2.5 mmol/kg of gadodiamide (nonionic linear chelate), nonformulated gadodiamide (ie, without the free ligand caldiamide), gadoterate (ionic macrocyclic chelate), or saline for 5 consecutive days. Blinded semi-quantitative histopathologic and immunohistochemical examinations of the skin were performed, as well as clinical, hematological, and biochemical follow-up. Rats were killed at day 11. Long-term (up to day 32) follow-up of rats was also performed in an auxiliary study. epidermal lesions (ulcerations and scabs) were found in 4 of the 10 rats treated with nonformulated gadodiamide. Two rats survived the study period. Inflammatory signs were observed in this group. No clinical, hematological, or biochemical signs were observed in the saline and gadoterate- or gadodiamide-treated groups. Plasma fibroblast growth factor-23 levels were significantly higher in the gadodiamide group than in the gadoterate group (day 11). Decreased plasma transferrin-bound iron levels were measured in the nonformulated gadodiamide group. Histologic lesions were in the range: nonformulated gadodiamide (superficial epidermal lesions, inflammation, necrosis, and increased cellularity in papillary dermis) > gadodiamide (small superficial epidermal lesions and signs of degradation of collagen fibers in the dermis) > gadoterate (very few pathologic lesions, similar to control rats). repeated administration of the nonionic linear GC gadodiamide to renally impaired rats is associated with more severe histologic lesions and higher FGF-23 plasma levels than the macrocyclic GC gadoterate.

  4. Treatment of Produced Waters Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System

    Energy Technology Data Exchange (ETDEWEB)

    Lynn E. Katz; Kerry A. Kinney; R. S. Bowman; E. J. Sullivan

    2004-03-11

    This report summarizes work of this project from October 2003 through March 2004. The major focus of the research was to further investigate BTEX removal from produced water, to quantify metal ion removal from produced water, and to evaluate a lab-scale vapor phase bioreactor (VPB) for BTEX destruction in off-gases produced during SMZ regeneration. Batch equilibrium sorption studies were conducted to evaluate the effect of semi-volatile organic compounds commonly found in produced water on the sorption of benzene, toluene, ethylbenzene, and xylene (BTEX) onto surfactant-modified zeolite (SMZ) and to examine selected metal ion sorption onto SMZ. The sorption of polar semi-volatile organic compounds and metals commonly found in produced water onto SMZ was also investigated. Batch experiments were performed in a synthetic saline solution that mimicked water from a produced water collection facility in Wyoming. Results indicated that increasing concentrations of semi-volatile organic compounds increased BTEX sorption. The sorption of phenol compounds could be described by linear isotherms, but the linear partitioning coefficients decreased with increasing pH, especially above the pKa's of the compounds. Linear correlations relating partitioning coefficients of phenol compounds with their respective solubilities and octanol-water partitioning coefficients were developed for data collected at pH 7.2. The sorption of chromate, selenate, and barium in synthetic produced water were also described by Langmuir isotherms. Experiments conducted with a lab-scale vapor phase bioreactor (VPB) packed with foam indicated that this system could achieve high BTEX removal efficiencies once the nutrient delivery system was optimized. The xylene isomers and benzene were found to require the greatest biofilter bed depth for removal. This result suggested that these VOCs would ultimately control the size of the biofilter required for the produced water application. The biofilter

  5. Non-ionizing radiation

    International Nuclear Information System (INIS)

    Tyrrell, R.M.; Pourzand, C.; Zhong, J.L.

    2003-01-01

    induced oxidative stress in human photocarcinogenesis. Certain phenolic antioxidants (notably from green tea) have been shown to protect against UV carcinogenesis in rodent models after both topical and systemic application. Interestingly our recent studies have shown that several flavonoids and their metabolites (e.g. epicatechin and its methylated derivatives) protect human skin cells against UVA induced cytotoxic membrane damage. The protection takes several hours to develop and requires de novo protein synthesis consistent with existing evidence that these compounds are not acting as classical antioxidants but trigger the expression of a specific gene or genes whose protein product is involved in an adaptive response that leads to protection

  6. Non-Ionizing Radiation Used in Microwave Ovens

    Science.gov (United States)

    ... Non-Ionizing Radiation Used in Microwave Ovens Non-Ionizing Radiation Used in Microwave Ovens Explore the interactive, virtual ... can do Where to learn more About Non-Ionizing Radiation Used in Microwave Ovens Microwave Oven. Microwave ovens ...

  7. Surfactant media for constant-current coulometry. Application for the determination of antioxidants in pharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Ziyatdinova, Guzel, E-mail: Ziyatdinovag@mail.ru [Analytical Chemistry Department, A.M. Butlerov Institute of Chemistry, Kazan (Volga Region) Federal University, Kremlyevskaya, 18, Kazan 420008 (Russian Federation); Ziganshina, Endzhe; Budnikov, Herman [Analytical Chemistry Department, A.M. Butlerov Institute of Chemistry, Kazan (Volga Region) Federal University, Kremlyevskaya, 18, Kazan 420008 (Russian Federation)

    2012-09-26

    Highlights: Black-Right-Pointing-Pointer Applicability of surfactants in constant-current coulometry is shown for the first time. Black-Right-Pointing-Pointer Reactions of antioxidants with electrogenerated titrants in surfactant media are investigated. Black-Right-Pointing-Pointer Water insoluble antioxidants can be determined in water media with addition of surfactants. Black-Right-Pointing-Pointer Coulometric determination of antioxidants in pharmaceutical dosage forms using surfactants media is developed. - Abstract: Effect of surfactant presence on electrochemical generation of titrants has been evaluated and discussed for the first time. Cationic (1-dodecylpyridinium and cetylpyridinium bromide), anionic (sodium dodecyl sulfate) and nonionic (Triton X100 and Brij{sup Registered-Sign} 35) surfactants as well as nonionic high molecular weight polymer (PEG 4000) do not react with the electrogenerated bromine, iodine and hexacyanoferrate(III) ions. The electrogenerated chlorine chemically interact with Triton X100 and Brij{sup Registered-Sign} 35. The allowable range of surfactants concentrations providing 100% current yield has been found. Chain-breaking low molecular weight antioxidants (ascorbic acid, rutin, {alpha}-tocopherol and retinol) were determined by reaction with the electrogenerated titrants in surfactant media. Nonionic and cationic surfactants can be used for the determination of antioxidants by reaction with the electrogenerated halogens. On contrary, cationic surfactants gives significantly overstated results of antioxidants determination with electrogenerated hexacyanoferrate(III) ions. The use of surfactants in coulometry of {alpha}-tocopherol and retinol provides their solubilization and allows to perform titration in water media. Simple, express and reliable coulometric approach for determination of {alpha}-tocopherol, rutin and ascorbic acid in pharmaceuticals using surfactant media has been developed. The relative standard deviation of the

  8. BEHAVIOR OF SURFACTANT MIXTURE AT SOLID/LIQUID AND OIL/LIQUID INTERFACE IN CHEMICAL FLOODING SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Prof. P. Somasundaran

    2002-03-01

    The aim of the project is to develop and evaluate efficient novel surfactant mixtures for enhanced oil recovery. Preliminary ultra-filtration tests suggest that two kinds of micelles may exist in binary surfactant mixtures at different concentrations. Due to the important role played in interfacial processes by micelles as determined by their structures, focus of the current work is on the delineation of the relationship between such aggregate structures and chemical compositions of the surfactants. A novel analytical centrifuge application is explored to generate information on structures of different surfactants aggregates. In this report, optical systems, typical output of the analytical ultracentrifuge results and four basic experiments are discussed. Initial sedimentation velocity investigations were conducted using nonyl phenol ethoxylated decyl ether (NP-10) to choose the best analytical protocol, calculate the partial specific volume and obtain information on sedimentation coefficient, aggregation mass of micelles. The partial specific volume was calculated to be 0.920. Four softwares: Optima{trademark} XL-A/XL-I data analysis software, DCDT+, Svedberg and SEDFIT, were compared for the analysis of sedimentation velocity experimental data. The sedimentation coefficient and aggregation number of NP-10 micelles obtained using the first three softwares at 25 C are 209, 127, and 111, respectively. The last one is closest to the result from Light Scattering. The reason for the differences in numbers obtained using the three softwares is discussed. Based on these tests, Svedberg and SEDFIT analysis are chosen for further studies. This approach using the analytical ultracentrifugation offers an unprecedented opportunity now to obtain important information on mixed micelles and their role in interfacial processes.

  9. Co-assembly in chitosan-surfactant mixtures: thermodynamics, structures, interfacial properties and applications.

    Science.gov (United States)

    Chiappisi, Leonardo; Gradzielski, Michael

    2015-06-01

    In this review, different aspects characterizing chitosan-surfactant mixtures are summarized and compared. Chitosan is a bioderived cationic polysaccharide that finds wide-ranged applications in various field, e.g., medical or food industry, in which synergistic effects with surfactant can play a fundamental role. In particular, the behavior of chitosan interacting with strong and weak anionic, nonionic as well as cationic surfactants is reviewed. We put a focus on oppositely charged systems, as they exhibit the most interesting features. In that context, we discuss the thermodynamic description of the interaction and in particular the structural changes as they occur as a function of the mixed systems and external parameters. Moreover, peculiar properties of chitosan coated phospholipid vesicles are summarized. Finally, their co-assembly at interfaces is briefly reviewed. Despite the behavior of the mentioned systems might strongly differ, resulting in a high variety of properties, few general rules can be pointed out which improve the understanding of such complex systems. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Nanoparticle-enabled delivery of surfactants in porous media.

    Science.gov (United States)

    Nourafkan, Ehsan; Hu, Zhongliang; Wen, Dongsheng

    2018-06-01

    The adsorption of surfactants on the reservoir rocks surface is a serious issue in many energy and environment related areas. Learning from the concept of drug delivery in the nano-medicine field, this work proposes and validates the concept of using nanoparticles to deliver a mixture of surfactants into a porous medium. TiO 2 nanoparticles (NPs) are used as carriers for a blend of surfactants mixtures including anionic alkyl aryl sulfonic acid (AAS) and nonionic alcohol ethoxylated (EA) at the optimum salinity and composition conditions. The transport of NPs through a core sample of crushed sandstone grains and the adsorption of surfactants are evaluated. By using TiO 2 NPs, the adsorption of surfactant molecules can be significantly reduced, i.e. half of the initial adsorption value. The level of surfactant adsorption reduction is related to the NPs transport capability through the porous medium. An application study shows that comparing to surfactant flooding alone, the total oil recovery can be increased by 7.81% of original oil in place (OOIP) by using nanoparticle bonded surfactants. Such work shows the promise of NP as an effective surfactant carrier for sandstone reservoirs, which could have many potential applications in enhanced oil recovery (EOR) and environmental remediation. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. New thermo-sensitive chelating surfactants for selective solvent-free extraction of uranyl nitrate

    International Nuclear Information System (INIS)

    Prevost, S.; Larpent, C.; Testard, F.; Coulombeau, H.; Baczko, K.; Berthon, L.; Desvaux, H.; Madic, C.; Zemb, T.

    2004-01-01

    Functional surfactants were synthesised by grafting a chelating group (amino-acid residue) to the tip of a poly-ethoxylated nonionic surfactant chain (C i E j : C i H 2i +1(OCH 2 CH 2 ) j OH)) or in a branched position. C i E j nonionic surfactants are known to be thermo-reversible and to exhibit a clouding phenomenon associated to phase separation of micelles. The functional surfactants retain both surface-active properties, characteristic thermo-reversible behaviour and have efficient complexing properties toward uranyl. In the presence of uranyl nitrate, small micelles are formed at ambient temperature and the de-mixing leads to a separation of the target ion trapped by the functional surfactant (cloud point extraction). Those surfactants are more efficient than mixture of classical C i E j and complexing agent solubilized in the micelles. This reveals a synergistic effect of the covalent bond between the chelating group and the nonionic surfactant C i E j . This paper presents a systematic study of the extraction and aggregation properties and the influence of the nature of the ions. (authors)

  12. Insertion of anisotropic particles in lamellar surfactant phases

    International Nuclear Information System (INIS)

    Grillo, Isabelle

    1998-01-01

    We search for the interactions governing the possibility to mix organic and inorganic colloids. We use laponite, a synthetic anionic clay, made of 30 nm diameter and 1 nm thickness anisotropic disks. Three surfactant Systems, an anionic one (AOT), a cationic one (DDAB) and a nonionic one (C_1_2E_5) investigate three different cases of interaction forces. We establish experimentally the equilibrium phase diagrams and characterise the structure of these ternary Systems by SANS and SAXS experiments. We quantify the adsorption. An AOT bilayer surround the particle edges; an almost complete bilayer of DDAB and C_1_2E_5 is formed on the basal faces. SANS contrast variation experiments under controlled conditions along the adsorption isotherm of C_1_2E_5 allow to determine the average thickness of the adsorbed surfactant layer. In the monophasic lamellar domain, the particles stay between the membranes, when the spacing is larger than the particle thickness. In the biphasic domain, dense clay aggregates are in equilibrium with a lamellar phase, containing few amount of particles. They enter in the AOT bilayers when the space between the bilayers are smaller than 8 A. From the phase diagram and interaction forces study, three conditions of stability emerge: - an osmotic one: the osmotic lamellar pressure is higher or equal to the colloidal one. - an energetic one: the interaction energy between a particle and the surfactant bilayer is close to the particle energy in aqueous suspension. - an entropic one: particles should not inhibit the stabilising fluctuations of the lamellar phase. (author) [fr

  13. Surfactant loss control in chemical flooding spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Annual report, September 30, 1993--September 30, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Somasundaran, P.

    1995-06-01

    The aim of this project is to elucidate the mechanisms underlying adsorption and surface precipitation of flooding surfactants on reservoir minerals. Effect of surfactant structure, surfactant combinations, other inorganic and polymeric species is being studied. A multi-pronged approach consisting of micro and nano spectroscopy, microcalorimetry, electrokinetics, surface tension and wettability is used to achieve the goals. The results of this study should help in controlling surfactant loss in chemical flooding and also in developing optimum structures and conditions for efficient chemical flooding processes. During the second year of this three year contract, adsorption/desorption of single surfactants and select surfactant mixtures on alumina and silica was studied. Surfactants studied include the anionic sodium dodecyl sulfate (SDS), cationic tetradecyl trimethyl ammonium chloride (TTAC), nonionic pentadecylethoxylated nonyl phenol (NP-15) and the nonionic octaethylene glycol n-dodecyl ether (C{sub 12}EO{sub 8}) of varying hydrocarbon chain length. The microstructure of the adsorbed layer in terms of micropolarity and aggregation numbers was probed using fluorescence spectroscopy. Changes of microstructure upon dilution (desorption) were also studied. Presence of the nonionic surfactant in the mixed aggregate led to shielding of the charge of the ionic surfactant which in-turn promoted aggregation but reduced electrostatic attraction between the charged surfactant and the mineral surface. Strong consequences of surfactant interactions in solution upon adsorption as well as correlations between monomer concentrations in mixtures and adsorption were revealed.

  14. Environmental assessment of surfactant using aquatic microcosm system; Konuma no suiken seitaikei ni oyobosu kaimen kasseizai no microcosm system wo mochiita hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Takamatsu, Y.; Matsumura, M. [University of Tsukuba, Tsukuba (Japan); Inamori, Y. [National Institute for Environmental Studies, Tsukuba (Japan); Sudo, R. [Tohoku University, Sendai (Japan). Faculty of Engineering

    1995-10-10

    Microcosm system was applied to assess effect of surfactants on aquatic ecosystem. Surfactants such as LAS and Soap were added to an aquatic flask-size microcosm consisting of four species of bacteria as decomposer, one species of ciliate protozoa (Cyclidium glaucoma), two rotifers (Philodina sp. and Lepadella sp.) and one aquatic oligochaete (Aeolosoma hemprichi) as predator, and a green alga (Chlorella sp.) and a filamentous blue-green alga (Tolypothrix sp.) as producer. In the system, NOEC (no observed effect concentration) of LAS was below 1.5mg{center_dot}l{sup -1}, whereas soap was below 30mg{center_dot}l{sup -1}. Microcosm test is a pertinent tool to assess the effect of surfactant on ecosystem because microcosm test makes it possible to evaluate the effect of surfactant from a viewpoint of the interaction of microorganisms, material cycle and energy flow. With these respects, microcosm test is useful environmental assessment method which can reflect aquatic ecosystem. 10 refs., 6 figs., 1 tab.

  15. Surfactant use with nitrate-based bioremediation

    International Nuclear Information System (INIS)

    Wilson, B.H.; Hutchins, S.R.; West, C.C.

    1995-01-01

    This study presents results of an initial survey on the effect of six surfactants on the biodegradation of petroleum hydrocarbons in bioremediation applications using nitrate as the electron acceptor. Aquifer material from Park City, Kansas, was used for the study. The three atomic surfactants chosen were Steol CS-330, Dowfax 8390 and sodium dodecylbenzene sulfonate (SDBS); the three nonionic surfactants were T-MAZ-60, Triton X-100, and Igepal CO-660. Both Steol CS-330 and T-MAZ-60 biodegraded under denitrifying conditions. The Steol inhibited biodegradation of benzene, toluene, ethylbenzene, xylenes, and trimethylbenzenes (BTEXTMB). Only toluene was rapidly degraded in the presence of T-MAZ-60. Biodegradation of all compounds, including toluene, appears to be inhibited by Dowfax 8390 and SDBS. No biodegradation of Dowfax 8390 or SDBS was observed. SDBS inhibited denitrification, but Dowfax 8390 did not. For the microcosms containing Triton X-100 or Igepal CO-660, removal of toluene, ethylbenzene, m-xylene, 1,3,5-TMB, and 1,2,4-TMB were similar to their removals in the no-surfactant treatment. These two surfactants did not biodegrade, did not inhibit biodegradation of the alkylbenzenes, and did not inhibit denitrification. Further studies are continuing with aquifer material from Eglin Air Force Base

  16. Foaming behaviour of polymer-surfactant solutions

    International Nuclear Information System (INIS)

    Cervantes-MartInez, Alfredo; Maldonado, Amir

    2007-01-01

    We study the effect of a non-ionic amphiphilic polymer (PEG-100 stearate also called Myrj 59) on the foaming behaviour of aqueous solutions of an anionic surfactant (sodium dodecyl sulfate or SDS). The SDS concentration was kept fixed while the Myrj 59 concentration was varied. Measurements of foamability, surface tension and electrical conductivity were carried out. The results show two opposite effects depending on the polymer concentration: foamability is higher when the Myrj 59 concentration is low; however, it decreases considerably when the polymer concentration is increased. This behaviour is due to the polymer adsorption at the air/liquid interface at lower polymer concentrations, and to the formation of a polymer-surfactant complex in the bulk at higher concentrations. The results are confirmed by surface tension and electrical conductivity measurements, which are interpreted in terms of the microstructure of the polymer-surfactant solutions. The observed behaviour is due to the amphiphilic nature of the studied polymer. The increased hydrophobicity of Myrj 59, compared to that of water-soluble polymers like PEG or PEO, increases its 'reactivity' towards SDS, i.e. the strength of its interaction with this anionic surfactant. Our results show that hydrophobically modified polymers have potential applications as additives in order to control the foaming properties of surfactant solutions

  17. Detergent extraction of herpes simplex virus type 1 glycoprotein D by zwitterionic and non-ionic detergents and purification by ion-exchange high-performance liquid chromatography

    NARCIS (Netherlands)

    Welling-Wester, S; Feijlbrief, M; Koedijk, DGAM; Welling, GW

    1998-01-01

    Detergents (surfactants) are the key reagents in the extraction and purification of integral membrane proteins. Zwitterionic and non-ionic detergents were used for the extraction of recombinant glycoprotein D (gD-1) of herpes simplex virus type 1 (HSV-1) from insect cells infected with recombinant

  18. Treatment of Produced Water Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System

    Energy Technology Data Exchange (ETDEWEB)

    Lynn E. Katz; Kerry A. Kinney; Robert S. Bowman; Enid J. Sullivan; Soondong Kwon; Elaine B. Darby; Li-Jung Chen; Craig R. Altare

    2006-01-31

    Co-produced water from the oil and gas industry accounts for a significant waste stream in the United States. Produced waters typically contain a high total dissolved solids content, dissolved organic constituents such as benzene and toluene, an oil and grease component as well as chemicals added during the oil-production process. It has been estimated that a total of 14 billion barrels of produced water were generated in 2002 from onshore operations (Veil, 2004). Although much of this produced water is disposed via reinjection, environmental and cost considerations can make surface discharge of this water a more practical means of disposal. In addition, reinjection is not always a feasible option because of geographic, economic, or regulatory considerations. In these situations, it may be desirable, and often necessary from a regulatory viewpoint, to treat produced water before discharge. It may also be feasible to treat waters that slightly exceed regulatory limits for re-use in arid or drought-prone areas, rather than losing them to reinjection. A previous project conducted under DOE Contract DE-AC26-99BC15221 demonstrated that surfactant modified zeolite (SMZ) represents a potential treatment technology for produced water containing BTEX. Laboratory and field experiments suggest that: (1) sorption of benzene, toluene, ethylbenzene and xylenes (BTEX) to SMZ follows linear isotherms in which sorption increases with increasing solute hydrophobicity; (2) the presence of high salt concentrations substantially increases the capacity of the SMZ for BTEX; (3) competitive sorption among the BTEX compounds is negligible; and, (4) complete recovery of the SMZ sorption capacity for BTEX can be achieved by air sparging the SMZ. This report summarizes research for a follow on project to optimize the regeneration process for multiple sorption/regeneration cycles, and to develop and incorporate a vapor phase bioreactor (VPB) system for treatment of the off-gas generated during

  19. Influence of synthetic surfactants on the uptake of Pd, Cd and Pb by the marine macroalga, Ulva lactuca

    International Nuclear Information System (INIS)

    Masakorala, Kanaji; Turner, Andrew; Brown, Murray T.

    2008-01-01

    Uptake of Pd, Cd and Pb by the marine macroalga, Ulva lactuca, has been studied in the presence of an anionic (sodium dodecyl sulphate, SDS), cationic (hexadecyltrimethylammonium bromide; HDTMA) and non-ionic (Triton X-100; TX) surfactant. Compared with the surfactant-free system, metal sorption was reduced in the presence of SDS or TX. Neither surfactant, however, had any measurable impact on cell membrane permeability, determined by leakage of dissolved free amino acids (DFAA), or on metal internalisation. We attribute these observations to the stabilisation of aqueous Cd and Pb by SDS and the shielding of otherwise amenable sorption sites by TX. Presence of HDTMA resulted in a reduction in the extent of both sorption and internalisation of all metals and a significant increase in the leakage of DFAA. Thus, by enhancing membrane permeability, HDTMA exerts the greatest influence on metal behaviour in the presence of U. lactuca. - Synthetic surfactants exert a significant impact on the uptake and internalisation of metals by a marine macroalga

  20. Influence of synthetic surfactants on the uptake of Pd, Cd and Pb by the marine macroalga, Ulva lactuca

    Energy Technology Data Exchange (ETDEWEB)

    Masakorala, Kanaji [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Turner, Andrew [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)], E-mail: aturner@plymouth.ac.uk; Brown, Murray T. [School of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)

    2008-12-15

    Uptake of Pd, Cd and Pb by the marine macroalga, Ulva lactuca, has been studied in the presence of an anionic (sodium dodecyl sulphate, SDS), cationic (hexadecyltrimethylammonium bromide; HDTMA) and non-ionic (Triton X-100; TX) surfactant. Compared with the surfactant-free system, metal sorption was reduced in the presence of SDS or TX. Neither surfactant, however, had any measurable impact on cell membrane permeability, determined by leakage of dissolved free amino acids (DFAA), or on metal internalisation. We attribute these observations to the stabilisation of aqueous Cd and Pb by SDS and the shielding of otherwise amenable sorption sites by TX. Presence of HDTMA resulted in a reduction in the extent of both sorption and internalisation of all metals and a significant increase in the leakage of DFAA. Thus, by enhancing membrane permeability, HDTMA exerts the greatest influence on metal behaviour in the presence of U. lactuca. - Synthetic surfactants exert a significant impact on the uptake and internalisation of metals by a marine macroalga.

  1. Effect of different surfactants in biorelevant medium on the secretion of a lipophilic compound in lipoproteins using Caco-2 cell culture

    DEFF Research Database (Denmark)

    Karpf, Ditte M; Holm, René; Garafalo, Carole

    2006-01-01

    The impact of a pharmaceutical relevant metabolizable, ionic surfactant or two synthetic, nonionic surfactants on the absorption and lipoprotein incorporation of a lipophilic drug, retinol, was studied in the Caco-2 cell culture. Filter-grown monolayers of Caco-2 cells were incubated for 20 h...

  2. Correlation and prediction of environmental properties of alcohol ethoxylate surfactants using the UNIFAC method

    DEFF Research Database (Denmark)

    Cheng, Hongyuan; Kontogeorgis, Georgios; Stenby, Erling Halfdan

    2005-01-01

    ), the bioconcentration factor (BCF), and the toxicity. Kow values of alcohol ethoxylates are difficult to measure. Existing methods such as those in commercial software like ACD,ClogP and KowWin have not been applied to surfactants, and they fail for heavy alcohol ethoxylates (alkyl carbon numbers above 12). Thus...... and toxicity of alcohol ethoxylates are correlated with their Kow. The proposed approach can be extended to other families of nonionic surfactants....

  3. Are the nonionic contrast media really safe

    International Nuclear Information System (INIS)

    Seyferth, W.; Zeitler, E.

    1987-01-01

    The authors used a wide variety of ionic and nonionic contrast media in 11,203 patient examinations (angiography, phlebography, CT). Data have been collected in prospective studies since 1982. The rate of mild side effects was reduced by a factor of 2 to 3 for all examinations when nonionic contrast media were used. Angiography may not be suitable for evaluating the safety of contrast media. Because of statistical requirements, the influence of nonionic media on the rate of severe side effects will not be known for some time. The side effects of nonionic contrast media were somewhat delayed, and differed from times reported in the literature: 29% of wide effects were noticed within 15 minutes and 71% between 25 minutes to 72 hours after the study. The final results of the study will have numerous consequences for patient treatment protocols

  4. Effect of Surfactants on Mechanical, Thermal, and Photostability of a Monoclonal Antibody.

    Science.gov (United States)

    Agarkhed, Meera; O'Dell, Courtney; Hsieh, Ming-Ching; Zhang, Jingming; Goldstein, Joel; Srivastava, Arvind

    2018-01-01

    The purpose of this work was to evaluate the effect of commonly used surfactants (at 0.01% w/v concentration) on mechanical, thermal, and photostability of a monoclonal antibody (MAb1) of IgG1 sub-class and to evaluate the minimum concentration of surfactant (Polysorbate 80) required in protecting MAb1 from mechanical stress. Surfactants evaluated were non-ionic surfactants, Polysorbate 80, Polysorbate 20, Pluronic F-68 (polyoxyethylene-polyoxypropylene block polymer), Brij 35 (polyoxyethylene lauryl ether), Triton X-100, and an anionic surfactant, Caprylic acid (1-Heptanecarboxylic acid). After evaluating effect of surfactants and determining stabilizing effect of Polysorbate 80 against mechanical stress without compromising thermal and photostability of MAb1, the minimum concentration of Polysorbate 80 required for mechanical stability was further examined. Polysorbate 80 concentration was varied from 0 to 0.02%. Mechanical stability was evaluated by agitation of MAb1 at 300 rotations per minute at room temperature for 72 h. Samples were analyzed for purity by SEC-HPLC, turbidity by absorbance at 350 nm, visible particles by visual inspection, and sub-visible particles by light obscuration technique on a particle analyzer. All non-ionic surfactants tested showed a similar effect in protecting against mechanical stress and did not exhibit any significant negative effect on thermal and photostability. However, Caprylic acid had a slightly negative effect on mechanical and photostability when compared to the non-ionic surfactants or sample without surfactant. This work demonstrated that polysorbate 80 is better than other surfactants tested and that a concentration of at least 0.005% (w/v) Polysorbate 80 is needed to protect MAb1 against mechanical stress.

  5. Surfactant -- Where Are We in 2003?

    Directory of Open Access Journals (Sweden)

    JF Lewis

    2004-01-01

    Full Text Available Surfactant research has progressed over the past several years to the extent that exogenous surfactant administration in patients with the acute respiratory distress syndrome (ARDS is now being evaluated. Unfortunately, clinical responses have been variable, and we now need to take a look at how surfactant is altered in this disease so that more effective treatment strategies can be developed. This review briefly discusses the biophysical and host defense properties of surfactant, the impact of mechanical ventilation (MV on the endogenous surfactant system and the most recent clinical data involving exogenous surfactant administration in patients with ARDS. Discussions regarding future directions of surfactant research both in ARDS and diseases other than acute lung injury are included.

  6. Design, characterization, and biological evaluation of curcumin-loaded surfactant-based systems for topical drug delivery

    Directory of Open Access Journals (Sweden)

    Fonseca-Santos B

    2016-09-01

    Full Text Available Bruno Fonseca-Santos, Aline Martins dos Santos, Camila Fernanda Rodero, Maria Palmira Daflon Gremião, Marlus Chorilli School of Pharmaceutical Sciences, UNESP – São Paulo State University, Araraquara, São Paulo Brazil Abstract: From previous studies, it has been found that curcumin exhibits an anti-inflammatory activity and is being used for the treatment of skin disorders; however, it is hydrophobic and has weak penetrating ability, resulting in poor drug transport through the stratum corneum. The aim of this study was to develop liquid crystalline systems for topical administration of curcumin for the treatment of inflammation. These liquid crystalline systems were developed from oleic acid, polyoxypropylene (5 polyoxyethylene (20 cetyl alcohol, and water as the surfactant, oil phase, and aqueous phase, respectively. These systems were characterized, and polarized light microscopy showed anisotropy with lamellar mesophases (Formulation 1 and hexagonal mesophases (Formulations 2 and 3, which were confirmed by the peak ratio measured using small-angle X-ray scattering. In addition, rheological tests revealed that the formulations exhibited gel-like behavior (G'>G'', as evidenced by the increased G' values that indicate structured systems. Texture profile analysis showed that hexagonal mesophases have high values of hardness, adhesiveness, and compressibility, which indicate structured systems. In vitro studies on bioadhesion revealed that the hexagonal mesophases increased the bioadhesiveness of the systems to the skin of the pig ear. An in vivo inflammation experiment showed that the curcumin-loaded hexagonal mesophase exhibited an anti-inflammatory activity as compared to the positive control (dexamethasone. The results suggest that this system has a potential to be used as a bioadhesive vehicle for the topical administration of curcumin. Therefore, it is possible to conclude that these systems can be used for the optimization of drug

  7. Degradation of Triton X-100 surfactant/lipid regulator systems by ionizing radiation in water

    International Nuclear Information System (INIS)

    Racz, Gergely; Obuda-University, Budapest; Csay, Tamas; Takacs, Erzsebet; Wojnarovits, Laszlo

    2017-01-01

    The radiolytic degradation of Triton X-100 surfactant was investigated at concentrations below and above the critical micelle concentration (CMC, ∼ 0.23 mmol dm -3 ) in air saturated aqueous solutions. At low concentrations the degradation took place both on the aromatic head and on the polyethoxylates chain, while above CMC it was shifted towards the chain. The CMC was higher in irradiated solutions at 10 Gy by a factor of 2, at 20 kGy by a factor of 3 than in the un-irradiated solution. The degradation of clofibric acid in the presence of TX-100 was more effective outside the micelles than inside them. (author)

  8. Cost Effective Surfactant Formulations for Improved Oil Recovery in Carbonate Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    William A. Goddard; Yongchun Tang; Patrick Shuler; Mario Blanco; Yongfu Wu

    2007-09-30

    their ability to recover oil by imbibition. Results demonstrate several types of promising candidates, and that within a given series of nonionic surfactants the oil recovery appears to be related to the HLB of each surfactant. For the McElroy brine and crude oil system, higher HLB (more water soluble) surfactants perform better than in earlier imbibition tests performed with the model oil and a fresh water or low salinity brine. We speculate that this difference mostly is because a more water soluble surfactant is required to be compatible with higher salinity of the McElroy brine (over 3 wt% salt).

  9. Streak artifacts on Kidney CT: Ionic vs nonionic contrast media

    International Nuclear Information System (INIS)

    Cho, Eun Ok; Kim, Won Hong; Jung, Myung Suk; Kim, Yong Hoon; Hur, Gham

    1993-01-01

    The authors reviewed findings of enhanced abdominal computed tomography (CT) scans to know the difference between a higher dose of conventional ionic contrast media(iothalamate meglumine) and a lower dose of a new, nonionic contrast material(ioversol). One hundred adult patients were divided into two groups. Each group consisted of 50 patients. Iothalamate meglumine and ioversol were intravenously administered in each group. The radio of the male to female in the former was 28:22, and the latter 29:21. We examine the degree of renal streak artifact and measure the Hounsfield number of urine in renal collecting system. There were significant differences of the degree of the streak artifact depending upon the osmolality of contrast media used and that was related with urine CT number(P value<0.005). We authors conclude that nonionic low osmolar contrast media is prone to cause streak artifacts and distortions of renal image than conventional ionic high osmolar contrast media

  10. Surfactant Membrane Phases Containing Mixtures of Hydrocarbon and Fluorocarbon Surfactants

    International Nuclear Information System (INIS)

    de Campo, Liliana; Warr, G.G.

    2005-01-01

    Full text: We describe the structure and stability of sponge and lamellar phases comprising mixtures of hydrocarbon and fluorocarbon surfactants. Such mixtures can show limited miscibility with each other, forming for example coexisting populations of hydrocarbon rich and fluorocarbon rich micelles under some circumstances. Our system is based on the well-characterised lamellar and sponge phases of cetylpyridinium chloride, hexanol and 0.2M brine, into which the partially fluorinated surfactant N-1H,1H,2H,2H-tridecafluorooctylpyridinium chloride is incorporated. By probing the structures with SAXS (small angle x-ray scattering) and SANS (small angle neutron scattering) using contrast variation, and by characterizing the dynamic properties with dynamic light scattering, we will describe the effect of incorporating the fluorinated surfactant on the phase equilibria and properties of the surfactant membrane structures. (authors)

  11. Marine toxicity and persistence of surfactants used in the petroleum producing industry

    International Nuclear Information System (INIS)

    Maddin, C.M.

    1991-01-01

    This paper presents a survey of marine toxicity and biodegradability data for surfactants used in the petroleum industry. Surfactants are key chemicals in the formulation of products such as emulsifiers, demulsifiers, dispersants and inhibitors. They are also used directly as foaming and defoaming agents. Because they function at low concentrations, below 1%, and have a tendency to adsorb on solid surfaces, their long-term environmental effects are minimal. In applications such as cementing, surfactants cannot migrate into the environment and, thus, have no bioavailability. The possibility of environmental contamination has caused well operators and regulatory agencies to require fish toxicity and persistence data for products used in servicing wells. This data has been organized for nonionic, anionic, cationic and amphoteric surfactants. Nonionic surfactants are toxic to fish at concentrations below 10 mg/L to over 2500 mg/L depending on their chemical compositions. Anionic surfactants are toxic to fish at concentrations under 1 mg/L to several hundred mg/L depending on their chemical compositions. cationic and amphoteric surfactants are generally toxic to fish at concentrations below 50 mg/L. Overall efforts are aimed at low toxicity and high biodegradability with the least compromise in product efficiency. This requires the continual testing and environmental evaluation of surfactants summarized herein

  12. Fouling behavior of silica nanoparticle-surfactant mixtures during constant flux dead-end ultrafiltration

    NARCIS (Netherlands)

    Trzaskus, Krzystof; Lee, Sooi Li; de Vos, Wiebe Matthijs; Kemperman, Antonius J.B.; Nijmeijer, Kitty

    2017-01-01

    The increasing use of engineered nanoparticles in customer products results in their accumulation in water sources. In this experimental study, we investigated the role of surfactant type (cationic, anionic and non-ionic) and concentration on fouling development, nanoparticle rejection and fouling

  13. Cellobiohydrolase and endoglucanase respond differently to surfactants during the hydrolysis of cellulose

    DEFF Research Database (Denmark)

    Hsieh, Chia-wen C.; Cannella, David; Jørgensen, Henning

    2015-01-01

    Background: Non-ionic surfactants such as polyethylene glycol (PEG) can increase the glucose yield obtained from enzymatic saccharification of lignocellulosic substrates. Various explanations behind this effect include the ability of PEG to increase the stability of the cellulases, decrease non-p...

  14. Preparation and tumor cell model based biobehavioral evaluation of the nanocarrier system using partially reduced graphene oxide functionalized by surfactant

    Directory of Open Access Journals (Sweden)

    Wang Y

    2015-07-01

    Full Text Available Yimin Wang,1 Kunping Liu,1,2 Zewei Luo,1 Yixiang Duan1 1Research Center of Analytical Instrumentation, Key Laboratory of Bio-resource and Eco-environment, Ministry of Education, College of Life Science, Sichuan University, 2Faculty of Biotechnology Industry, Chengdu University, Chengdu, People’s Republic of China Background: Currently, surfactant-functionalized nanomaterials are tending toward development of novel tumor-targeted drug carriers to overcome multidrug resistance in cancer therapy. Now, investigating the biocompatibility and uptake mechanism of specific drug delivery systems is a growing trend, but usually a troublesome issue, in simple pharmaceutical research.Methods: We first reported the partially reduced graphene oxide modified with poly(sodium 4-styrenesulfonate (PSS as a nanocarrier system. Then, the nanocarrier was characterized by atomic force microscope, scanning electron microscope, high-resolution transmission electron microscope, ultraviolet–visible (UV-vis spectroscopy, Fourier transform infrared spectroscopy, X-Ray powder diffraction, and Raman spectroscopy. Epirubicin (EPI was attached to PSSG via π–π stacking, hydrogen bonding, and physical absorption to form conjugates of PSSG–EPI. The adsorption and desorption profiles, cytotoxicity coupled with drug accumulation, and uptake of PSSG and PSSG–EPI were evaluated. Finally, the subcellular behaviors, distribution, and biological fate of the drug delivery system were explored by confocal laser scanning microscope using direct fluorescence colocalization imaging and transmission electron microscopy.Results: The partially reduced graphene oxide sheets functionalized by surfactant exhibit good dispersibility. Moreover, due to much less carboxyl groups retained on the edge of PSSG sheets, the nanocarriers exhibit biocompatibility in vitro. The obtained PSSG shows a high drug-loading capacity of 2.22 mg/mg. The complexes of PSSG–EPI can be transferred to

  15. Adsorption of surfactants on sand surface in enhanced oil recovery: Isotherms, kinetics and thermodynamic studies

    Energy Technology Data Exchange (ETDEWEB)

    Bera, Achinta; Kumar, T.; Ojha, Keka; Mandal, Ajay, E-mail: mandal_ajay@hotmail.com

    2013-11-01

    Adsorption of surfactants onto reservoir rock surface may result in the loss and reduction of their concentrations in surfactant flooding, which may render them less efficient or ineffective in practical applications of enhanced oil recovery (EOR) techniques. Surfactant flooding for EOR received attraction due to its ability to increase the displacement efficiency by lowering the interfacial tension between oil and water and mobilizing the residual oil. This article highlights the adsorption of surfactants onto sand surface with variation of different influencing factors. It has been experimentally found that adsorption of cationic surfactant on sand surface is more and less for anionic surfactant, while non-ionic surfactant shows intermediate behaviour. X-ray diffraction (XRD) study of clean sand particles has been made to determine the main component present in the sand particles. The interaction between sand particles and surfactant has been studied by Fourier Transform Infrared (FTIR) Spectroscopy of the sand particles before and after aging with surfactant. Salinity plays an important role in adsorption of anionic surfactant. Batch experiments were also performed to understand the effects of pH and adsorbent dose on the sorption efficiency. The sand particles exhibited high adsorption efficiency at low pH for anionic and nonionic surfactants. But opposite trend was found for cationic surfactant. Adsorption data were analyzed by fitting with Langmuir, Freundlich, Redlich-Peterson, and Sips isotherm models. Results show that the Langmuir isotherm and pseudo-second order kinetics models suit the equilibrium and kinetics of adsorption on sand surface. Thermodynamics feasibility of the adsorption process was also studied to verify the spontaneity of the process.

  16. Evolvement of soft templates in surfactant/cosurfactant system for shape control of ZnSe nanocrystals

    International Nuclear Information System (INIS)

    Hou Bo; Liu Yongjun; Li Yanjuan; Yuan Bo; Jia Mingfen; Jiang Fengzhi

    2012-01-01

    Highlights: ► Soft templates were found in the shape control synthesis of ZnSe nanocrystals. ► Micelle formation model in the soft templates system was proposed and proved. ► Different shapes of ZnSe nanocrystals were prepared and explained by proposed model. - Abstract: The evolution of soft templates in the synthesis of ZnSe nanocrystals realized through a surfactant/cosurfactant system was investigated and a micelle formation process model was proposed. Through freeze-fracture electron microscopy, it was proven that template micelles were formed in the zinc precursors. Furthermore, it was found that a long stirring period was essential for achieving the lowest energy state of the soft templates which were used for synthesizing monodisperse ZnSe quantum dots.

  17. Evolvement of soft templates in surfactant/cosurfactant system for shape control of ZnSe nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Hou Bo [Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091 (China); Liu Yongjun [Advanced Analysis and Measurement Center, Yunnan University, Kunming 650091 (China); Li Yanjuan [Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091 (China); Yuan Bo [Advanced Analysis and Measurement Center, Yunnan University, Kunming 650091 (China); Jia Mingfen [Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091 (China); Jiang Fengzhi, E-mail: fengzhij@ynu.edu.cn [Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091 (China); Advanced Analysis and Measurement Center, Yunnan University, Kunming 650091 (China)

    2012-03-25

    Highlights: Black-Right-Pointing-Pointer Soft templates were found in the shape control synthesis of ZnSe nanocrystals. Black-Right-Pointing-Pointer Micelle formation model in the soft templates system was proposed and proved. Black-Right-Pointing-Pointer Different shapes of ZnSe nanocrystals were prepared and explained by proposed model. - Abstract: The evolution of soft templates in the synthesis of ZnSe nanocrystals realized through a surfactant/cosurfactant system was investigated and a micelle formation process model was proposed. Through freeze-fracture electron microscopy, it was proven that template micelles were formed in the zinc precursors. Furthermore, it was found that a long stirring period was essential for achieving the lowest energy state of the soft templates which were used for synthesizing monodisperse ZnSe quantum dots.

  18. Adsorption of dimeric surfactants in lamellar silicates

    Energy Technology Data Exchange (ETDEWEB)

    Balcerzak, Mateusz; Pietralik, Zuzanna [Department of Macromolecular Physics, Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Domka, Ludwik [Department of Metalorganic Chemistry, Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, 60-780 Poznań (Poland); Skrzypczak, Andrzej [Institute of Chemical Technology, Poznań University of Technology, Berdychowo 4, 60-965 Poznań (Poland); Kozak, Maciej, E-mail: mkozak@amu.edu.pl [Department of Macromolecular Physics, Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland)

    2015-12-01

    Highlights: • The intercalation of dimeric surfactants changed the morphology of MMT samples. • XRD indicated structures formed by surfactant molecules in interlayer space. • The four-step thermal decomposition of dimeric surfactant, confirms intercalation. - Abstract: The adsorption of different types of cationic surfactants in lamellar silicates changes their surface character from hydrophilic to hydrophobic. This study was undertaken to obtain lamellar silicates modified by a series of novel dimeric (gemini) surfactants of different length alkyl chains and to characterise these organophilised materials. Synthetic sodium montmorillonite SOMASIF® ME 100 (M) and enriched bentonite of natural origin (Nanoclay – hydrophilic bentonite®) were organophilised with dimeric (gemini) surfactants (1,1′-(1,4-butanediyl)bis(alkoxymethyl)imidazolium dichlorides). As a result of surfactant molecule adsorption in interlamellar space, the d-spacing (d{sub 001}) increased from 0.97 nm (for the anhydrous structure) to 2.04 nm. A Fourier transform infrared spectroscopy (FTIR) analysis of the modified systems reveals bands assigned to the stretching vibrations of the CH{sub 2} and CH{sub 3} groups and the scissoring vibrations of the NH group from the structure of the dimeric surfactants. Thermogravimetric (TG) and derivative thermogravimetric (DTG) studies imply a four-stage process of surfactant decomposition. Scanning electron microscopy (SEM) images provide information on the influence of dimeric surfactant intercalation into the silicate structures. Particles of the modified systems show a tendency toward the formation of irregularly shaped agglomerates.

  19. Effects of various surfactants on the dispersion stability and electrical conductivity of surface modified graphene

    Energy Technology Data Exchange (ETDEWEB)

    Uddin, Md. Elias [WCU Program, Department of BIN Fusion Technology, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Kuila, Tapas [Surface Engineering and Tribology, CSIR – Central Mechanical Engineering Research Institute, Durgapur 721 302 (India); Nayak, Ganesh Chandra [Department of Applied Chemistry, ISM Dhanbad, Dhanbad 826 004, Jharkhand (India); Kim, Nam Hoon [Department of Hydrogen and Fuel Cell Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Ku, Bon-Cheol [Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Dunsan-ri, Bongdong-eup, Wanju-gun, Jeollabuk-do 864-9 (Korea, Republic of); Lee, Joong Hee, E-mail: jhl@chonbuk.ac.kr [WCU Program, Department of BIN Fusion Technology, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Department of Hydrogen and Fuel Cell Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of)

    2013-06-15

    Highlights: ► Water dispersible graphene has been prepared using ionic and non-ionic surfactants. ► XPS and FTIR spectra analysis confirm surface modification and reduction of GO. ► The highest water dispersibility is observed in the graphene modified with of SDBS. ► The best properties of modified graphene is achieved with GO/surfactant ratio of two. -- Abstract: Ionic and non-ionic surfactant functionalized, water dispersible graphene were prepared to investigate the effects on the dispersion stability and electrical conductivity of graphene. In this study, sodium dodecyl benzene sulfonate (SDBS), sodium dodecyl sulfate and 4-(1,1,3,3-tetramethylbutyl) phenyl-polyethylene glycol (Triton X-100) were used as ionic and non-ionic surfactants. The effects of surfactant concentrations on the dispersibility and electrical conductivity of the surface modified graphene were investigated. The dispersion stability of SDBS functionalized graphene (SDBS-G) was found to be best in water at 1.5 mg ml{sup −1}. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy analysis indicate that the presence of surfactants does not prevent the reduction of graphene oxide (GO). These measurements also demonstrated that the surfactants were present on the surface of graphene, resulting in the formation of functionalized graphene. The thickness of different functionalized graphene was measured by Atomic force microscopy and varied significantly with different surfactants. The thermal properties of the functionalized graphene were also found to be dependent on the nature of the surfactants. The electrical conductivity of SDBS-G (108 S m{sup −1}) was comparatively higher than SDS and Triton X-100 functionalized graphene.

  20. Adsorption of hydrophobic organic compounds onto a hydrophobic carbonaceous geosorbent in the presence of surfactants.

    Science.gov (United States)

    Wang, Peng; Keller, Arturo A

    2008-06-01

    The adsorption of hydrophobic organic compounds (HOCs; atrazine and diuron) onto lampblack was studied in the presence of nonionic, cationic, and anionic surfactants (Triton(R) X-100), benzalkonium chloride [BC], and linear alkylbenzene sulfonate [LAS]) to determine the effect of the surfactant on HOC adsorption onto a hydrophobic carbonaceous geosorbent. Linear alkylbenzene sulfonate showed an adsorption capacity higher than that of BC but similar to that of Triton X-100, implying the charge property of a surfactant is not a useful indicator for predicting the surfactant's adsorption onto a hydrophobic medium. The results also indicated that the octanol-water partition coefficient (K(OW)) of a surfactant is not a good predictor of that surfactant's sorption onto a hydrophobic medium. Under subsaturation adsorption conditions (i.e., before sorption saturation is reached), surfactant adsorption reduced HOC adsorption to a significant extent, with the reduction in HOC adsorption increasing monotonically with the amount of surfactant adsorbed. Among the three surfactants, Triton X-100 was the most effective in reducing HOC adsorption, whereas BC and LAS showed similar effectiveness in this regard. Under the same amount of the surfactant sorbed, the reduction in atrazine adsorption was consistently greater than that for diuron because of atrazine's lower hydrophobicity. No significant difference was observed in the amount of the HOC adsorbed under different adsorption sequences. Our results showed that the presence of surfactant can significantly decrease HOC adsorption onto hydrophobic environmental media and, thus, is important in predicting HOC fate and transport in the environment.

  1. Structure-activity relationship of surfactant for preparing DMFC anodic catalyst

    International Nuclear Information System (INIS)

    Su Yi; Xue Xinzhong; Xu Weilin; Liu Changpeng; Xing Wei; Zhou Xiaochun; Tian Tian; Lu Tianhong

    2006-01-01

    Three kinds of surfactants as stabilizer were applied to the preparation of electrocatalysts for direct methanol fuel cell (DMFC). The catalysts have been characterized by examining their catalytic activities, morphologies and particle sizes by means of cyclic voltammetry, chronoamperometry, X-ray diffraction and transmission electron microscopy (TEM). It is found that the surfactants with different structures have a significantly influence on the catalyst shape and activity. The catalysts prepared with non-ionic surfactants as the stabilizer show higher activity for direct oxidation of methanol. The structure-activity relationship (SAR) analysis has been explored and the effect of hydrophile-lipophile balance (HLB value) has also been discussed

  2. Modification of the activity of an alpha-amylase from Bacillus licheniformis by several surfactants

    OpenAIRE

    Bravo Rodríguez,Vicente; Jurado Alameda,Encarnación; Martínez Gallegos,Juan Francisco; Reyes Requena,Antonia; García López,Ana Isabel; Sampaio Cabral,Joaquim Manuel; Fernandes,Pedro; Pina da Fonseca,Luis Joaquim

    2006-01-01

    The influence of different commercial surfactants on the enzymatic activity of a commercial alpha-amylase from Bacillus licheniformis (Termamyl 300 L) has been studied. As non-ionic surfactants, alkyl polyglycosides (Glucopon® 215, Glucopon® 600 and Glucopon® 650) were studied, as were fatty alcohol ethoxylates (Findet 1214N/23 and Findet 10/15), and nonyl phenol ethoxylate (Findet 9Q/21.5NF). Also, an anionic surfactant, linear alkyl benzene sulfonate (LAS) was assayed. In general, none of t...

  3. Effects of Surfactant Contamination on the Next Generation Gas Trap for the ISS Internal Thermal Control System

    Science.gov (United States)

    Leimkuehler, Thomas O.; Lukens, Clark; Reeves, Daniel R.; Holt, James M.

    2004-01-01

    The current dual-membrane gas trap is designed to remove non-condensed gas bubbles from the Internal Thermal Control System (ITCS) coolant on board the International Space Station (ISS). To date it has successfully served its purpose of preventing gas bubbles from causing depriming, overspeed, and shutdown of the ITCS pump. However, contamination in the ITCS coolant has adversely affected the gas venting rate and lifetime of the gas trap, warranting a development effort for a next-generation gas trap. Previous testing has shown that a hydrophobic-only design is capable of performing even better than the current dual-membrane design for both steady-state gas removal and gas slug removal in clean deionized water. This paper presents results of testing to evaluate the effects of surfactant contamination on the steady-state performance of the hydrophobic-only design.

  4. The Molecular Era of Surfactant Biology

    OpenAIRE

    Whitsett, Jeffrey A.

    2014-01-01

    Advances in the physiology, biochemistry, molecular and cell biology of the pulmonary surfactant system transformed the clinical care and outcome of preterm infants with respiratory distress syndrome. The molecular era of surfactant biology provided genetic insights into the pathogenesis of pulmonary disorders, previously termed “idiopathic” that affect newborn infants, children and adults. Knowledge related to the structure and function of the surfactant proteins and their roles in alveolar ...

  5. Studies of bio-mimetic medium of ionic and non-ionic micelles by a simple charge transfer fluorescence probe N,N-dimethylaminonapthyl-(acrylo)-nitrile

    Science.gov (United States)

    Samanta, Anuva; Paul, Bijan Kumar; Guchhait, N.

    2011-05-01

    In this report we have studied micellization process of anionic, cationic and non-ionic surfactants using N,N-dimethylaminonapthyl-(acrylo)-nitrile (DMANAN) as an external fluorescence probe. Micropolarity, microviscosity, critical micellar concentration of these micelles based on steady state absorption and fluorescence and time resolved emission spectroscopy of the probe DMANAN show that the molecule resides in the micelle-water interface for ionic micelles and in the core for the non-ionic micelle. The effect of variation of pH of the micellar solution as well as fluorescence quenching measurements of DMANAN provide further support for the location of the probe in the micelles.

  6. Separation process for lanthanides based on solvation properties of non ionic surfactants

    International Nuclear Information System (INIS)

    Draye, M.; Favre-Reguillon, A.; Foos, J.; Cote, G.

    2004-01-01

    In the present study, cloud-point extraction is used with a lipophilic chelating agent (8-hydroxyquinoline) to extract and separate lanthanum (III) and gadolinium (III) from an aqueous solution. The methodology used is based on the formation of lanthanide (III) organic complexes that are soluble in a micellar phase of non-ionic surfactant. The lanthanide (III) complexes are then extracted into the surfactant-rich phase at a temperature above the cloud-point temperature. The cloud-point temperature, the structure of the lipophilic part of the nonionic surfactant and the chelating agent - metal molar ratio are identified as factors determining the extraction efficiency and selectivity. With Triton X-114, high selectivity and decontamination factor for Gd(III) is observed indicating that micelle mediated extraction involving cloud-point extraction is promising for the specific separation of actinide ions from nuclear waste solution. (authors)

  7. Effects of surfactant micelles on viscosity and conductivity of poly(ethylene glycol) solutions

    Science.gov (United States)

    Wang, Shun-Cheng; Wei, Tzu-Chien; Chen, Wun-Bin; Tsao, Heng-Kwong

    2004-03-01

    The neutral polymer-micelle interaction is investigated for various surfactants by viscometry and electrical conductometry. In order to exclude the well-known necklace scenario, we consider aqueous solutions of low molecular weight poly(ethylene glycol) (2-20)×103, whose radial size is comparable to or smaller than micelles. The single-tail surfactants consist of anionic, cationic, and nonionic head groups. It is found that the viscosity of the polymer solution may be increased several times by micelles if weak attraction between a polymer segment and a surfactant exists, ɛsurfactant concentration is therefore attributed to the considerable cross links among micelles and polymers (transient network). In addition to substantial alteration of the transport properties, this weak interaction also influences the onset point of thermodynamic instability associated with polymer-surfactant solutions. The examples include the decrease of critical aggregation concentration for ionic surfactant and clouding point for nonionic surfactant due to PEG addition.

  8. Improving Polycyclic Aromatic Hydrocarbon Biodegradation in Contaminated Soil Through Low-Level Surfactant Addition After Conventional Bioremediation.

    Science.gov (United States)

    Adrion, Alden C; Singleton, David R; Nakamura, Jun; Shea, Damian; Aitken, Michael D

    2016-09-01

    Efficacy of bioremediation for soil contaminated with polycyclic aromatic hydrocarbons (PAHs) may be limited by the fractions of soil-bound PAHs that are less accessible to PAH-degrading microorganisms. In previous test-tube-scale work, submicellar doses of nonionic surfactants were screened for their ability to enhance the desorption and biodegradation of residual PAHs in soil after conventional bioremediation in a laboratory-scale, slurry-phase bioreactor. Polyoxyethylene sorbitol hexaoleate (POESH) was the optimum surfactant for enhancing PAH removal, especially the high-molecular weight PAHs. This work extends that concept by treating the effluent from the slurry-phase bioreactor in a second-stage batch reactor, to which POESH was added, for an additional 7 or 12 days. Surfactant amendment removed substantial amounts of the PAHs and oxy-PAHs remaining after conventional slurry-phase bioremediation, including more than 80% of residual 4-ring PAHs. Surfactant-amended treatment decreased soil cytotoxicity, but often increased the genotoxicity of the soil as measured using the DT-40 chicken lymphocyte DNA damage response assay. Potential ecotoxicity, measured using a seed germination assay, was reduced by bioreactor treatment and was reduced further after second-stage treatment with POESH. Of bacteria previously implicated as potential PAH degraders under POESH-amended conditions in a prior study, members of the Terrimonas genus were associated with differences in high-molecular weight PAH removal in the current study. Research using submicellar doses of surfactant as a second-stage treatment step is limited and these findings can inform the design of bioremediation systems at field sites treating soil contaminated with PAHs and other hydrophobic contaminants that have low bioaccessibility.

  9. A Novel Aqueous Micellar Two-Phase System Composed of Surfactant and Sorbitol for Purification of Pectinase Enzyme from Psidium guajava and Recycling Phase Components

    Science.gov (United States)

    Murshid, Fara Syazana; Manap, Mohd Yazid; Hussin, Muhaini

    2015-01-01

    A novel aqueous two-phase system composed of a surfactant and sorbitol was employed for the first time to purify pectinase from Psidium guajava. The influences of different parameters, including the type and concentration of the surfactant and the concentration and composition of the surfactant/sorbitol ratio, on the partitioning behavior and recovery of pectinase were investigated. Moreover, the effects of system pH and the crude load on purification fold and the yield of purified pectinase were studied. The experimental results indicated that the pectinase was partitioned into surfactant-rich top phase, and the impurities were partitioned into the sorbitol-rich bottom phase with the novel method involving an ATPS composed of 26% (w/w) Triton X-100 and 23% (w/w) sorbitol at 54.2% of the TLL crude load of 20% (w/w) at pH 6.0. The enzyme was successfully recovered by this method with a high purification factor of 15.2 and a yield of 98.3%, whereas the phase components were also recovered and recycled at rates above 96%. This study demonstrated that this novel ATPS method can be used as an efficient and economical alternative to the traditional ATPS for the purification and recovery of the valuable enzyme. PMID:25756051

  10. A novel aqueous micellar two-phase system composed of surfactant and sorbitol for purification of pectinase enzyme from Psidium guajava and recycling phase components.

    Science.gov (United States)

    Amid, Mehrnoush; Murshid, Fara Syazana; Manap, Mohd Yazid; Hussin, Muhaini

    2015-01-01

    A novel aqueous two-phase system composed of a surfactant and sorbitol was employed for the first time to purify pectinase from Psidium guajava. The influences of different parameters, including the type and concentration of the surfactant and the concentration and composition of the surfactant/sorbitol ratio, on the partitioning behavior and recovery of pectinase were investigated. Moreover, the effects of system pH and the crude load on purification fold and the yield of purified pectinase were studied. The experimental results indicated that the pectinase was partitioned into surfactant-rich top phase, and the impurities were partitioned into the sorbitol-rich bottom phase with the novel method involving an ATPS composed of 26% (w/w) Triton X-100 and 23% (w/w) sorbitol at 54.2% of the TLL crude load of 20% (w/w) at pH 6.0. The enzyme was successfully recovered by this method with a high purification factor of 15.2 and a yield of 98.3%, whereas the phase components were also recovered and recycled at rates above 96%. This study demonstrated that this novel ATPS method can be used as an efficient and economical alternative to the traditional ATPS for the purification and recovery of the valuable enzyme.

  11. Non-ionic contrast media: are they obligatory?

    International Nuclear Information System (INIS)

    Halva, S.R.

    1993-01-01

    Author presents recommendations for nonionic contrast media application. They are more expensive but less toxic than ionic ones. In order to avoid side effects in many radiological examinations (phlebography, arteriography, coronarography, ventriculography) one should use nonionic contrast media. Another reason for application of nonionic contrast agents is young age of patient or his state of health

  12. Manipulating interfacial polymer structures through mixed surfactant adsorption and complexation.

    Science.gov (United States)

    Cattoz, Beatrice; de Vos, Wiebe M; Cosgrove, Terence; Crossman, Martin; Prescott, Stuart W

    2012-04-17

    The effects of a nonionic alcohol ethoxylate surfactant, C(13)E(7), on the interactions between PVP and SDS both in the bulk and at the silica nanoparticle interface are studied by photon correlation spectroscopy, solvent relaxation NMR, SANS, and optical reflectometry. Our results confirmed that, in the absence of SDS, C(13)E(7) and PVP are noninteracting, while SDS interacts strongly both with PVP and C(13)E(7) . Studying interfacial interactions showed that the interfacial interactions of PVP with silica can be manipulated by varying the amounts of SDS and C(13)E(7) present. Upon SDS addition, the adsorbed layer thickness of PVP on silica increases due to Coulombic repulsion between micelles in the polymer layer. When C(13)E(7) is progressively added to the system, it forms mixed micelles with the complexed SDS, reducing the total charge per micelle and thus reducing the repulsion between micelle and the silica surface that would otherwise cause the PVP to desorb. This causes the amount of adsorbed polymer to increase with C(13)E(7) addition for the systems containing SDS, demonstrating that addition of C(13)E(7) hinders the SDS-mediated desorption of an adsorbed PVP layer. © 2012 American Chemical Society

  13. Latex imaging by environmental STEM: application to the study of the surfactant outcome in hybrid alkyd/acrylate systems.

    Science.gov (United States)

    Faucheu, Jenny; Chazeau, Laurent; Gauthier, Catherine; Cavaillé, Jean-Yves; Goikoetxea, Monika; Minari, Roque; Asua, José M

    2009-09-01

    Among other uses, latexes are a successful alternative to solvent-borne binders for coatings. Efforts are made to produce hybrid nanostructured latexes containing an acrylic phase and an alkyd phase. However, after the film-forming process, the surfactant used to stabilize these latexes remains in the film, and its location can have a drastic effect on the application properties. Among the processing parameters, the alkyd hydrophobicity can strongly influence this location. This article aims at the imaging of these surfactant molecules in two hybrid latexes with different hydrophobicity level of the alkyd resin. A first part of this paper is dedicated to the understanding of the contrast provided by the surfactant in environmental STEM imaging of latexes. Then, the influence of surfactant-polymer affinity on the surfactant location after film-forming of those hybrid alkyd/acrylate latexes is studied by this technique. It is shown that in the hybrid latex with an alkyd shell (obtained with the most hydrophilic resin), the surfactant molecules tend to remain buried in the alkyd phase. Conversely, in the hybrid latex with an acrylate shell (in the case of the most hydrophobic resin), the surfactant molecules tend to gather into islands like in pure acrylate latex films.

  14. End Functionalized Nonionic Water-Dispersible Conjugated Polymers.

    Science.gov (United States)

    Zhan, Ruoyu; Liu, Bin

    2017-09-01

    2,7-Dibromofluorene monomers carrying two or four oligo(ethylene glycol) (OEG) side chains are synthesized. Heck coupling between the monomers and 1,4-divinylbenzene followed by end capping with [4-(4-bromophenoxy)butyl]carbamic acid tert-butyl ester leads to two nonionic water-dispersible poly(fluorene-alt-1,4-divinylenephenylene)s end-functionalized with amine groups after hydrolysis. In water, the polymer with a lower OEG density (P1) has poor water dispersibility with a quantum yield of 0.24, while the polymer with a higher OEG density (P2) possesses excellent water-dispersibility with a high quantum yield of 0.45. Both polymers show fluorescence enhancement and blue-shifted absorption and emission maxima in the presence of surfactant sodium dodecyl sulfate and dodecyltrimethylammonium bromide. The polymers are also resistant to ionic strength with minimal nonspecific interactions to bovine serum albumin. When biotin is incorporated into the end of the polymer backbones through N-hydroxysuccinimide/amine coupling reaction, the biotinylated polymers interact specifically with streptavidin on solid surface. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Effect of surfactants on the penetration of 14C-glyphosate in Cyperus rotundus in Pakistani agroclimatic conditions

    International Nuclear Information System (INIS)

    Jamil Qureshi, M.; Anwarul Haq; Uzma Maqbool

    1998-01-01

    The penetration of 14 C-glyphosate was studied in Cyperus rotundus with three nonionic surfactants. Among the three surfactants Synperonic A20 was more effective than A2 and A7 in enhancing penetration of glyphosate 24 hours after treatment both in dry and wet seasons. The addition of diesel oil to Synperonic A20 further increased penetration of glyphosate in both seasons. (author)

  16. Biomimicry of surfactant protein C.

    Science.gov (United States)

    Brown, Nathan J; Johansson, Jan; Barron, Annelise E

    2008-10-01

    Since the widespread use of exogenous lung surfactant to treat neonatal respiratory distress syndrome, premature infant survival and respiratory morbidity have dramatically improved. Despite the effectiveness of the animal-derived surfactant preparations, there still remain some concerns and difficulties associated with their use. This has prompted investigation into the creation of synthetic surfactant preparations. However, to date, no clinically used synthetic formulation is as effective as the natural material. This is largely because the previous synthetic formulations lacked analogues of the hydrophobic proteins of the lung surfactant system, SP-B and SP-C, which are critical functional constituents. As a result, recent investigation has turned toward the development of a new generation of synthetic, biomimetic surfactants that contain synthetic phospholipids along with a mimic of the hydrophobic protein portion of lung surfactant. In this Account, we detail our efforts in creating accurate mimics of SP-C for use in a synthetic surfactant replacement therapy. Despite SP-C's seemingly simple structure, the predominantly helical protein is extraordinarily challenging to work with given its extreme hydrophobicity and structural instability, which greatly complicates the creation of an effective SP-C analogue. Drawing inspiration from Nature, two promising biomimetic approaches have led to the creation of rationally designed biopolymers that recapitulate many of SP-C's molecular features. The first approach utilizes detailed SP-C structure-activity relationships and amino acid folding propensities to create a peptide-based analogue, SP-C33. In SP-C33, the problematic and metastable polyvaline helix is replaced with a structurally stable polyleucine helix and includes a well-placed positive charge to prevent aggregation. SP-C33 is structurally stable and eliminates the association propensity of the native protein. The second approach follows the same design

  17. Effects of concentration, head group, and structure of surfactants on the degradation of phenanthrene

    International Nuclear Information System (INIS)

    Jin Danyue; Jiang Xia; Jing Xin; Ou Ziqing

    2007-01-01

    The effects of concentration, polar/ionic head group, and structure of surfactants on the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in the aqueous phase, as well as their effects on the bacterial activity were investigated. The toxicity ranking of studied surfactants is: non-ionic surfactants (Tween 80, Brij30, 10LE and Brij35) -1 ) served the sole carbon and energy resource. However, the degradation of 14 C-phenanthrene showed either a decrease or no obvious change with the surfactants present at all tested concentrations (5-40 mg L -1 ). Thus, the surfactant addition is not beneficial to the removal of phenanthrene or other PAH contaminants due presumably to the preferential utilization of surfactants at low levels as the non-toxic nutrient resource and to the high toxicity of the surfactants at high levels to the microorganism activity. Biodegradation of phenanthrene was also influenced by the surfactant concentration, head group type, and structure. Much more research has yet to be completed on the use of surfactants for soil remediation due to the surfactant toxicity or biodegradation effect

  18. 29 CFR 1910.97 - Nonionizing radiation.

    Science.gov (United States)

    2010-07-01

    ... electromagnetic energy or in which the cross section of the body is smaller than the cross section of the incident... Warning Symbol (4) Scope. This section applies to all radiations originating from radio stations, radar... 29 Labor 5 2010-07-01 2010-07-01 false Nonionizing radiation. 1910.97 Section 1910.97 Labor...

  19. Surfactant selection for a liquid foam-bed photobioreactor.

    Science.gov (United States)

    Janoska, Agnes; Vázquez, María; Janssen, Marcel; Wijffels, René H; Cuaresma, María; Vílchez, Carlos

    2018-02-01

    A novel liquid foam-bed photobioreactor has been shown to hold potential as an innovative technology for microalgae production. In this study, a foam stabilizing agent has been selected which fits the requirements of use in a liquid foam-bed photobioreactor. Four criteria were used for an optimal surfactant: the surfactant should have good foaming properties, should not be rapidly biodegradable, should drag up microalgae in the foam formed, and it should not be toxic for microalgae. Ten different surfactants (nonionic, cationic, and anionic) and two microalgae genera (Chlorella and Scenedesmus) were compared on the above-mentioned criteria. The comparison showed the following facts. Firstly, poloxameric surfactants (Pluronic F68 and Pluronic P84) have acceptable foaming properties described by intermediate foam stability and liquid holdup and small bubble size. Secondly, the natural surfactants (BSA and Saponin) and Tween 20 were easily biodegraded by bacteria within 3 days. Thirdly, for all surfactants tested the microalgae concentration is reduced in the foam phase compared to the liquid phase with exception of the cationic surfactant CTAB. Lastly, only BSA, Saponin, Tween 20, and the two Pluronics were not toxic at concentrations of 10 CMC or higher. The findings of this study indicate that the Pluronics (F68 and P84) are the best surfactants regarding the above-mentioned criteria. Since Pluronic F68 performed slightly better, this surfactant is recommended for application in a liquid foam-bed photobioreactor. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018. © 2018 American Institute of Chemical Engineers.

  20. How Chain Length and Charge Affect Surfactant Denaturation of Acyl Coenzyme A Binding Protein (ACBP)

    DEFF Research Database (Denmark)

    Andersen, Kell Kleiner; Otzen, Daniel

    2009-01-01

    maltoside (DDM). The aim has been to determine how surfactant chain length and micellar charge affect the denaturation mechanism. ACBP denatures in two steps irrespective of surfactant chain length, but with increasing chain length, the potency of the denaturant rises more rapidly than the critical micelle......Using intrinsic tryptophan fluorescence, equilibria and kinetics of unfolding of acyl coenzyme A binding protein (ACBP) have been investigated in sodium alkyl sulfate surfactants of different chain length (8-16 carbon atoms) and with different proportions of the nonionic surfactant dodecyl...... constants increases linearly with denaturant concentration below the cmc but declines at higher concentrations. Both shortening chain length and decreasing micellar charge reduce the overall kinetics of unfolding and makes the dependence of unfolding rate constants on surfactant concentration more complex...

  1. Development, optimization and evaluation of surfactant-based pulmonary nanolipid carrier system of paclitaxel for the management of drug resistance lung cancer using Box-Behnken design.

    Science.gov (United States)

    Kaur, Prabhjot; Garg, Tarun; Rath, Goutam; Murthy, R S Rayasa; Goyal, Amit K

    2016-07-01

    In the present study, nanostructured lipid carriers (NLCs) along with various surfactants loaded with paclitaxel (PTX) were prepared by an emulsification technique using a Box-Behnken design. The Box-Behnken design indicated that the most effective factors on the size and PDI were at high surfactant concentration (1.5%), low lipids ratio (6:4) and medium homogenization speed (6000 rpm). Among all the formulations, Tween 20-loaded NLCs show least particle size compared to Tween 80 and Tween 60. Entrapment efficiency of Tween 20, Tween 80 and Tween 60-loaded formulations were 82.40, 85.60 and 79.78%, respectively. Drug release of Tween 80, Tween 20 and Tween 60-loaded NLCs is 64.9, 62.3 and 59.7%, respectively (within 72 h). Maximum cellular uptake was observed with Tween 20 formulation on Caco-2 cell lines. Furthermore, spray drying of resultant NLCs was showed good flow properties and was selected for drug delivery to deeper airways. In-vivo studies demonstrated the better localization of drug within the lungs using different surfactant-based pulmonary delivery systems. From this study, we have concluded that delivering drugs through pulmonary route is advantageous for local action in lungs as maximum amount of drug concentration was observed in lungs. The surfactants could prove to be beneficial in treating drug resistance lung cancer by inhibiting P-gp efflux in the form of nano lipidic carriers.

  2. Ferricyanide confined into the integrative system of pyrrolic surfactant and SWCNTs: The enhanced electrochemial sensing of paracetamol

    International Nuclear Information System (INIS)

    Wu, Xiao-Yan; Niu, Wen-Jun; Cosnier, Serge; Deng, Sheng-Yuan; Zhang, Xue-Ji; Shan, Dan

    2015-01-01

    Highlights: • Amphiphilic surfactant derived from pyrrole was used to construct a special microheterogeneous system incorporated with SWCNTs by electropolymerization. • Common redox probe, Fe(CN) 6 3−/4− , was captured into this microheterogeneous system due to the cooperation interactions of electrostatic and π-π stacking. • A dramatically negative shift in the half wave potential compared to Fe(CN) 6 3−/4− in aqueous solution can be obtained due to the unusual Fe(CN) 6 3−/4− partitioning. • The entrapped Fe(CN) 6 3−/4− was applied in the construction of the enhanced electrochemical sensor to paracetamol. - Abstract: An enhanced paracetamol sensor was developed based on the integrative system of single walled carbon nanotubes (SWCNTs) and the pyrrolic surfactant, (11-pyrrolyl-1-yl-undecyl)triethylammonium tetrafluoroborate (A 2 ), in which confined the redox probe, Fe(CN) 6 3−/4− . A well-defined redox peaks of the firmly confined Fe(CN) 6 3−/4− with dramatically negative shift in the half-wave potential compared to Fe(CN) 6 3−/4− in aqueous solution was observed at GCE/polyA 2 -Fe(CN) 6 3−/4− /SWCNTs. To understand the unusual Fe(CN) 6 3−/4− partitioning in this microheterogeneous system, the responses of the Fe(CN) 6 3−/4− at the electrodes modified by SWCNTs, polyA 2 , SWCNTs/polyA 2 , and polyA 2 /SWCNTs were investigated, respectively. The results of cyclic voltammetry (CV) and differential pulse voltammetry (DPV) indicated that the proposed electrode exhibiting efficient electrocatalytic capability towards the paracetamol oxidation. Thereafter, an amperometric assay for paracetamol at GCE/polyA 2 -Fe(CN) 6 3−/4− /SWCNTs was developed at 0.4 V with an enhanced linear range from 3.4×10 −7 ∼7.98 × 10 −4 M.

  3. Surfactant protein D in newborn infants

    DEFF Research Database (Denmark)

    Dahl, Marianne; Juvonen, Pekka Olavi; Holmskov, Uffe

    2005-01-01

    Surfactant protein D (SP-D) is a collectin that plays an important role in the innate immune system. The role of SP-D in the metabolism of surfactant is as yet quite unclear. The aims of this study were to establish normal values of SP-D in the umbilical cord blood and capillary blood of mature...

  4. Design, characterization, and biological evaluation of curcumin-loaded surfactant-based systems for topical drug delivery.

    Science.gov (United States)

    Fonseca-Santos, Bruno; Dos Santos, Aline Martins; Rodero, Camila Fernanda; Gremião, Maria Palmira Daflon; Chorilli, Marlus

    From previous studies, it has been found that curcumin exhibits an anti-inflammatory activity and is being used for the treatment of skin disorders; however, it is hydrophobic and has weak penetrating ability, resulting in poor drug transport through the stratum corneum. The aim of this study was to develop liquid crystalline systems for topical administration of curcumin for the treatment of inflammation. These liquid crystalline systems were developed from oleic acid, polyoxypropylene (5) polyoxyethylene (20) cetyl alcohol, and water as the surfactant, oil phase, and aqueous phase, respectively. These systems were characterized, and polarized light microscopy showed anisotropy with lamellar mesophases (Formulation 1) and hexagonal mesophases (Formulations 2 and 3), which were confirmed by the peak ratio measured using small-angle X-ray scattering. In addition, rheological tests revealed that the formulations exhibited gel-like behavior (G'>G″), as evidenced by the increased G' values that indicate structured systems. Texture profile analysis showed that hexagonal mesophases have high values of hardness, adhesiveness, and compressibility, which indicate structured systems. In vitro studies on bioadhesion revealed that the hexagonal mesophases increased the bioadhesiveness of the systems to the skin of the pig ear. An in vivo inflammation experiment showed that the curcumin-loaded hexagonal mesophase exhibited an anti-inflammatory activity as compared to the positive control (dexamethasone). The results suggest that this system has a potential to be used as a bioadhesive vehicle for the topical administration of curcumin. Therefore, it is possible to conclude that these systems can be used for the optimization of drug delivery systems to the skin.

  5. Application experience with ADBAC/DGH cationic surfactants for zebra mussel control in a nuclear service water system

    International Nuclear Information System (INIS)

    Jung, W.R.; Lacy, J.R.; Post, R.

    1992-01-01

    In response to the introduction and rapid growth of the zebra mussel population in the Great Lakes and the issuance of NRC Generic Letter 89-13 (Service Water Problems Affecting Safety-Related Equipment). A midwest nuclear station instituted a zebra mussel monitoring and control program. The nuclear station uses Lake Michigan as a cooling water source for two 1,100 MW Westinghouse 4-loop design, pressurized water reactors (PWR). Two years of monitoring indicated a growth in zebra mussel population from 0.5 organisms/m 2 in July 1990 to 100 organisms/m 2 by November 1990. This rapid increase indicated an urgent need for viable methods of zebra mussel control to protect the plant's essential service water (ESW) and non-essential service water (NESW) systems. In April 1991, the station formulated a plan that combined increased system inlet temperature with targeted application of a proprietary product containing two cationic surfactants, ADBAC/DGH. Sidestream biomonitoring boxes were seeded with zebra mussels and observed as a measure of the efficacy of the treatment. Where recommended dosages and duration were maintained, 100% control was achieved

  6. Survey of the pharmacology of non-ionic X-ray contrast media

    International Nuclear Information System (INIS)

    Turnheim, K.

    1986-01-01

    The non-ionic X-ray contrast media metrizamide, iopamidol, iohexol, and iopromide do not bind calcium and are less hyperosmolar than the conventional ionic contrast media, for instance amidotrizoate (diatrizoate), iothalamte, or ioglicate. Hence the use of non-ionic contrast media is associated with less undesirable side-effects that are attributable to hypertonicity such as an increase in circulating plasma volume, decreased deformability of red blood cells, damage of vascular endothelium with consequent activation of blood coagulation, the complement system and fibrinolysis, increased release of bradykinin and histamine, cardiac arrhythimas, diuresis, vasodilation and decreased blood pressure, pain and heat sensation. Because of less dilution the quality of imaging is also better. According to the intravenous LD 50 in experimental animals the acute toxicity of non-ionic contrast media is lower than that of ionic media. With respect to contrast quality and the rate of side-effects tha various non-ionic contrast media appear to be equivalent. Despite their higher price and higher viscosity it is probable that the non-ionic contrast media will replace the classical ionic media, especially in angio- and myelography. (Author)

  7. High Charge-Carrier Mobility of 2.5 cm(2) V(-1) s(-1) from a Water-Borne Colloid of a Polymeric Semiconductor via Smart Surfactant Engineering.

    Science.gov (United States)

    Cho, Jangwhan; Cheon, Kwang Hee; Ahn, Hyungju; Park, Kwang Hun; Kwon, Soon-Ki; Kim, Yun-Hi; Chung, Dae Sung

    2015-10-07

    Semiconducting polymer nanoparticles dispersed in water are synthesized by a novel method utilizing non-ionic surfactants. By developing a smart surfactant engineering technique involving a selective post-removal process of surfactants, an unprecedentedly high mobility of 2.51 cm(2) V(-1) s(-1) from a water-borne colloid is demonstrated for the first time. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. A Novel Aqueous Two Phase System Composed of Surfactant and Xylitol for the Purification of Lipase from Pumpkin (Cucurbita moschata) Seeds and Recycling of Phase Components.

    Science.gov (United States)

    Amid, Mehrnoush; Manap, Mohd Yazid; Hussin, Muhaini; Mustafa, Shuhaimi

    2015-06-17

    Lipase is one of the more important enzymes used in various industries such as the food, detergent, pharmaceutical, textile, and pulp and paper sectors. A novel aqueous two-phase system composed of surfactant and xylitol was employed for the first time to purify lipase from Cucurbita moschata. The influence of different parameters such as type and concentration of surfactants, and the composition of the surfactant/xylitol mixtures on the partitioning behavior and recovery of lipase was investigated. Moreover, the effect of system pH and crude load on the degree of purification and yield of the purified lipase were studied. The results indicated that the lipase was partitioned into the top surfactant rich phase while the impurities partitioned into the bottom xylitol-rich phase using an aqueous two phase system composed of 24% (w/w) Triton X-100 and 20% (w/w) xylitol, at 56.2% of tie line length (TLL), (TTL is one of the important parameters in this study and it is determined from a bimodal curve in which the tie-line connects two nodes on the bimodal, that represent concentration of phase components in the top and bottom phases) and a crude load of 25% (w/w) at pH 8.0. Recovery and recycling of components was also measured in each successive step process. The enzyme was successfully recovered by the proposed method with a high purification factor of 16.4 and yield of 97.4% while over 97% of the phase components were also recovered and recycled. This study demonstrated that the proposed novel aqueous two phase system method is more efficient and economical than the traditional aqueous two phase system method for the purification and recovery of the valuable enzyme lipase.

  9. A Novel Aqueous Two Phase System Composed of Surfactant and Xylitol for the Purification of Lipase from Pumpkin (Cucurbita moschata Seeds and Recycling of Phase Components

    Directory of Open Access Journals (Sweden)

    Mehrnoush Amid

    2015-06-01

    Full Text Available Lipase is one of the more important enzymes used in various industries such as the food, detergent, pharmaceutical, textile, and pulp and paper sectors. A novel aqueous two-phase system composed of surfactant and xylitol was employed for the first time to purify lipase from Cucurbita moschata. The influence of different parameters such as type and concentration of surfactants, and the composition of the surfactant/xylitol mixtures on the partitioning behavior and recovery of lipase was investigated. Moreover, the effect of system pH and crude load on the degree of purification and yield of the purified lipase were studied. The results indicated that the lipase was partitioned into the top surfactant rich phase while the impurities partitioned into the bottom xylitol-rich phase using an aqueous two phase system composed of 24% (w/w Triton X-100 and 20% (w/w xylitol, at 56.2% of tie line length (TLL, (TTL is one of the important parameters in this study and it is determined from a bimodal curve in which the tie-line connects two nodes on the bimodal, that represent concentration of phase components in the top and bottom phases and a crude load of 25% (w/w at pH 8.0. Recovery and recycling of components was also measured in each successive step process. The enzyme was successfully recovered by the proposed method with a high purification factor of 16.4 and yield of 97.4% while over 97% of the phase components were also recovered and recycled. This study demonstrated that the proposed novel aqueous two phase system method is more efficient and economical than the traditional aqueous two phase system method for the purification and recovery of the valuable enzyme lipase.

  10. Obtenção de argilas organofílicas purificadas através de tensoativos iônicos e não iônicos visando uso em fluidos de perfuração base óleo Getting purified organoclays by ionic and non-ionic surfactant aiming use in oil based drilling fluids

    Directory of Open Access Journals (Sweden)

    J. M. R. Costa

    2012-12-01

    Full Text Available Em perfurações de petróleo sensíveis ao contato com água, torna-se necessária a utilização de fluidos de perfuração base óleo. Nestes casos, utilizam-se argilas organofílicas, que são obtidas a partir de argilas bentoníticas purificadas e tratadas com a adição de tensoativos. A utilização do hidrociclone pode representar uma ferramenta eficiente e de custo acessível para purificar argilas naturais em escala industrial. Este trabalho tem por objetivo estudar a purificação de argilas bentoníticas utilizando-se um hidrociclone, visando o desenvolvimento de argilas organofílicas para uso em fluidos de perfuração base óleo. As caracterizações das amostras das argilas estudadas - Brasgel PA e Chocolate - foram efetuadas por meio das técnicas: análise granulométrica por difração de laser, difração de raios X (DRX e análise química por fluorescência de raios X. A caracterização das argilas organofílicas obtidas foi efetuada por meio dos seguintes métodos: DRX e por uma modificação do inchamento de Foster. Os resultados mostram que o processo de purificação foi eficiente na redução de impurezas presentes na bentonita e que a argila organofílica purificada tratada com Praepagen WB e Imidazolina Oléica Vegetal apresenta valores de inchamento de Foster em éster, óleo diesel e parafina superiores aos obtidos com argilas organofílicas sem purificação (natural, e evidenciando maior afinidade com o tensoativo Praepagen WB.Oil drilling in sensitive contact with water, becomes required the use of oil base drilling fluids. In these cases, organoclays are used, which are made from clay bentonite purified and treated with surfactants addition. The use of the hydrocyclone can be a effective tool and affordable for purifying clays in industrial scale. This work aims to study the purification of clays bentonite using a hydrocyclone, aiming to develop organoclays for use in oil base drilling fluids. The

  11. Pyrene removal from contaminated soil using electrokinetic process combined with surfactant

    Directory of Open Access Journals (Sweden)

    Seyed Enayat Hashemi

    2015-07-01

    Full Text Available Background: Pyrene is one of the stable polycyclic aromatic hydrocarbons that is considered as an important pollutants, because of extensive distribution in the environment and carcinogenic and mutagenic properties. Among the various treatment techniques, electrokinetic method is an environmental- friendly process for organic and mineral pollutants adsorbed to soil with fine pore size the same as clay and low hydraulic conductivity soils. For improving the efficiency of pyrene removal from soil, soulobilization of pyrene from soil could be used by surfactants. Materials and Methods : In this study, clay soil was selected as model because of the specific properties. Combined method using surfactant and electrokinetic was applied for pyrene removal from soil. Experiments were designed using response surface methodology (RSM, and effect of three variables includes surfactant concentration, voltage and surfactant type were evaluated for pyrene removal from contaminated soil. Results: Pyrene removal using anionic surfactants(SDS and nonionic surfactants(TX100 as a solubilizing agents has high removal efficiency. In the optimum condition with 95% confidence coefficient, utilizing mixed surfactants of sodium dodecyl sulfate and triton X-100 with the same volume, induced of 18.54 volt and 6.53 percent surfactant concentration have 94.6% pyrene removal efficiency. Conclusion:: Results of this study shows that electrokinetic process combined with surfactant as solubilizing agent could be applied as an efficient method for treating the pyrene-contaminated soils.

  12. Supramolecular "Big Bang" in a Single-Ionic Surfactant/Water System Driven by Electrostatic Repulsion: From Vesicles to Micelles.

    Science.gov (United States)

    Leclercq, Loïc; Bauduin, Pierre; Nardello-Rataj, Véronique

    2017-04-11

    In aqueous solution, dimethyldi-n-octylammonium chloride, [DiC 8 ][Cl], spontaneously forms dimers at low concentrations (1-10 mM) to decrease the strength of the hydrophobic-water contact. Dimers represent ideal building blocks for the abrupt edification of vesicles at 10 mM. These vesicles are fully characterized by dynamic and static light scattering, self-diffusion nuclear magnetic resonance, and freeze-fracture transmission electron microscopy. An increase in concentration leads to electrostatic repulsion between vesicles that explode into small micelles at 30 mM. These transitions are detected by means of surface tension, conductivity, and solubility of hydrophobic solutes as well as by isothermal titration microcalorimetry. These unusual supramolecular transitions emerge from the surfactant chemical structure that combines two contradictory features: (i) the double-chain structure tending to form low planar aggregates with low water solubility and (ii) the relatively short chains giving high hydrophilicity. The well-balanced hydrophilic-hydrophobic character of [DiC 8 ][Cl] is then believed to be at the origin of the unusual supramolecular sequence offering new opportunities for drug delivery systems.

  13. Study of polyacrylamide-surfactant system on the water–oil interface properties and rheological properties for EOR

    Directory of Open Access Journals (Sweden)

    S.Z. Mahdavi

    2017-12-01

    Full Text Available Nowadays, due to the remarkable oil reduction in oil fields, enhanced oil recovery (EOR techniques have been considered by a large number of scientists and company. Situ oil extraction is normally done by these techniques with high efficiency. In this particular study, five different surface active agents (surfactant, two kinds of oil with various API, two kinds of sulfonated polyacrylamide, two different electrolyte solutions with various TDS and two distinctive alcohols were tested and evaluated. An optimal formulation in terms of the properties and quantity of materials has to be used in order to enhance oil recovery, achieved by investigation of surface tension and the phase behavior of mentioned substances. Rheological behavior of polymer flooding and surfactant was studied. Employing this formulation, the maximum micro emulsion of oil in water occurred. Due to the synergy between surfactant and alcohol (as a co-surfactant, relatively lower amounts of surfactants were used which led to the dip in the cost of operation, and ultimately the efficiency of operation improved.

  14. A pH-responsive wormlike micellar system of a noncovalent interaction-based surfactant with a tunable molecular structure.

    Science.gov (United States)

    Kang, Wanli; Wang, Pengxiang; Fan, Haiming; Yang, Hongbin; Dai, Caili; Yin, Xia; Zhao, Yilu; Guo, Shujun

    2017-02-08

    Responsive wormlike micelles are very useful in a number of applications, whereas it is still challenging to create dramatic viscosity changes in wormlike micellar systems. Here we developed a pH-responsive wormlike micellar system based on a noncovalent constructed surfactant, which is formed by the complexation of N-erucamidopropyl-N,N-dimethylamine (UC 22 AMPM) and citric acid at the molar ratio of 3 : 1 (EACA). The phase behavior, aggregate microstructure and viscoelasticity of EACA solutions were investigated by macroscopic appearance observation, rheological and cryo-TEM measurements. It was found that the phase behavior of EACA solutions undergoes transition from transparent viscoelastic fluids to opalescent solutions and then phase separation with white floaters upon increasing the pH. Upon increasing the pH from 2.03 to 6.17, the viscosity of wormlike micelles in the transparent solutions continuously increased and reached ∼683 000 mPa s at pH 6.17. As the pH was adjusted to 7.31, the opalescent solution shows a water-like flowing behaviour and the η 0 rapidly declines to ∼1 mPa s. Thus, dramatic viscosity changes of about 6 magnitudes can be triggered by varying the pH values without any deterioration of the EACA system. This drastic variation in rheological behavior is attributed to the pH dependent interaction between UC 22 AMPM and citric acid. Furthermore, the dependence on concentration and temperature of the rheological behavior of EACA solutions was also studied to assist in obtaining the desired pH-responsive viscosity changes.

  15. Self-assembling surfactant-like peptide A6K as potential delivery system for hydrophobic drugs

    Directory of Open Access Journals (Sweden)

    Chen Y

    2015-01-01

    Full Text Available Yongzhu Chen,1 Chengkang Tang,2 Jie Zhang,2 Meng Gong,3 Bo Su,2 Feng Qiu4 1Periodical Press, 2Core Facility of West China Hospital, 3Laboratory of Endocrinology and Metabolism, West China Hospital, 4Laboratory of Anaesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, People’s Republic of China Background: Finding a suitable delivery system to improve the water solubility of hydrophobic drugs is a critical challenge in the development of effective formulations. In this study, we used A6K, a self-assembling surfactant-like peptide, as a carrier to encapsulate and deliver hydrophobic pyrene.Methods: Pyrene was mixed with A6K by magnetic stirring to form a suspension. Confocal laser scanning microscopy, transmission electron microscopy, dynamic light scattering, atomic force microscopy, fluorescence, and cell uptake measurements were carried out to study the features and stability of the nanostructures, the state and content of pyrene, as well as the pyrene release profile.Results: The suspension formed contained pyrene monomers trapped in the hydrophobic cores of the micellar nanofibers formed by A6K, as well as nanosized pyrene crystals wrapped up and stabilized by the nanofibers. The two different encapsulation methods greatly increased the concentration of pyrene in the suspension, and formation of pyrene crystals wrapped up by A6K nanofibers might be the major contributor to this effect. Furthermore, the suspension system could readily release and transfer pyrene into living cells.Conclusion: A6K could be further exploited as a promising delivery system for hydrophobic drugs. Keywords: pyrene, self-assembling peptide, micelles, nanofibers, drug delivery  

  16. Surfactant loss control in chemical flooding spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Annual report, September 30, 1992--September 30 1995

    Energy Technology Data Exchange (ETDEWEB)

    Casteel, J. [Bartlesville Project Office, OK (United States)

    1996-07-01

    The aim of this research project was to investigate mechanisms governing adsorption and surface precipitation of flooding surfactants on reservoir minerals. Effects of surfactant structure, surfactant combinations, various inorganic and polymeric species, and solids mineralogy have been determined. A multi-pronged approach consisting of micro & nano spectroscopy, electrokinetics, surface tension and wettability is used in this study. The results obtained should help in controlling surfactant loss in chemical flooding and in developing optimum structures and conditions for efficient chemical flooding processes. During the three years contract period, adsorption of single surfactants and select surfactant mixtures was studied at the solid-liquid and gas-liquid interfaces. Alkyl xylene sulfonates, polyethoxylated alkyl phenols, octaethylene glycol mono n-decyl ether, and tetradecyl trimethyl ammonium chloride were the surfactants studied. Adsorption of surfactant mixtures of varying composition was also investigated. The microstructure of the adsorbed layer was characterized using fluorescence spectroscopy. Changes in interfacial properties such as wettability, electrokinetics and stability of reservoir minerals were correlated with the amounts of reagent adsorbed. Strong effects of the structure of the surfactant and position of functional groups were revealed. Changes of microstructure upon dilution (desorption) were also studied. Presence of the nonionic surfactants in mixed aggregate leads to shielding of the charge of ionic surfactants which in turn promotes aggregation but reduced electrostatic attraction between the charged surfactant and the mineral surface. Strong consequences of surfactant interactions in solution on adsorption as well as correlations between monomer concentration in mixtures and adsorption were revealed.

  17. Lung surfactant levels are regulated by Ig-Hepta/GPR116 by monitoring surfactant protein D.

    Directory of Open Access Journals (Sweden)

    Taku Fukuzawa

    Full Text Available Lung surfactant is a complex mixture of lipids and proteins, which is secreted from the alveolar type II epithelial cell and coats the surface of alveoli as a thin layer. It plays a crucial role in the prevention of alveolar collapse through its ability to reduce surface tension. Under normal conditions, surfactant homeostasis is maintained by balancing its release and the uptake by the type II cell for recycling and the internalization by alveolar macrophages for degradation. Little is known about how the surfactant pool is monitored and regulated. Here we show, by an analysis of gene-targeted mice exhibiting massive accumulation of surfactant, that Ig-Hepta/GPR116, an orphan receptor, is expressed on the type II cell and sensing the amount of surfactant by monitoring one of its protein components, surfactant protein D, and its deletion results in a pulmonary alveolar proteinosis and emphysema-like pathology. By a coexpression experiment with Sp-D and the extracellular region of Ig-Hepta/GPR116 followed by immunoprecipitation, we identified Sp-D as the ligand of Ig-Hepta/GPR116. Analyses of surfactant metabolism in Ig-Hepta(+/+ and Ig-Hepta(-/- mice by using radioactive tracers indicated that the Ig-Hepta/GPR116 signaling system exerts attenuating effects on (i balanced synthesis of surfactant lipids and proteins and (ii surfactant secretion, and (iii a stimulating effect on recycling (uptake in response to elevated levels of Sp-D in alveolar space.

  18. Is surfactant a promising additive drug in ALI/ARDS-patients?

    NARCIS (Netherlands)

    Schultz, MJ; Kesecioglu, J

    The rationale for surfactant replacement therapy in patients with acute respiratory distress syndrome (ARDS) is to restore the normal composition of the surfactant system, as well as to overcome ongoing inactivation of present surfactant. Indeed, surfactant replacement therapy call normalize the

  19. Is surfactant a promising additive drug in ALI/ARDS-patients?

    NARCIS (Netherlands)

    Schultz, Marcus J.; Kesecioglu, Jozef

    2004-01-01

    The rationale for surfactant replacement therapy in patients with acute respiratory distress syndrome (ARDS) is to restore the normal composition of the surfactant system, as well as to overcome ongoing inactivation of present surfactant. Indeed, surfactant replacement therapy call normalize the

  20. Effects of surfactant and polymerization method on the synthesis of magnetic colloidal polymeric nanoparticles

    International Nuclear Information System (INIS)

    Puentes-Vara, Luis A.; Gregorio-Jauregui, Karla M.; Bolarín, Ana M.; Navarro-Clemente, Ma. E.; Dorantes, Héctor J.; Corea, Mónica

    2016-01-01

    The addition of superparamagnetic iron nanoparticles into polystyrene matrix allows for the modification of the physical properties as well as the implementation of new features in the hybrid nanomaterials. These materials have excellent potential for biomedical and bioengineering applications. Nevertheless, it is necessary to achieve a good dispersion of magnetic nanoparticles for its successful incorporation into polymer particles. This can be obtained through the use of a stabilizer, which provides stability against aggregation. In this work, magnetic nanoparticles were dispersed using different stabilizers. Subsequently, ferrofluids stabilized using the mixture of ABEX/IGEPAL and acrylic acid (AA) were used to synthesize PS-Fe 3 O 4 nanocomposites, through miniemulsion and emulsion polymerization conventional techniques. Semicontinuous and batch processes were compared, by varying surfactants and their concentrations. The PS-Fe 3 O 4 nanoparticles were characterized by dynamic light scattering, scanning electron microscopy, Raman spectroscopy, and vibrating sample magnetometer. Magnetic nanoparticle dispersions show better results when the anionic and nonionic surfactants are used as a mixture rather than when used alone. Results of DLS showed that the semicontinuous process allowed obtaining monodisperse materials, whereas polidisperse systems are generated in batch process. Raman spectroscopy confirmed the presence of magnetite and polystyrene in the nanocomposites. PS-Fe 3 O 4 nanoparticles showed superparamagnetic behavior with final magnetization of around 0.01 emu/g and low coercivity, properties that make them suitable for applications in wide fields of technology. Particle size (Dz), was lower than 300 nm in all cases. Moreover, the use of AA as stabilizer allows enhancing the PS-Fe 3 O 4 composite properties. These findings showed that particle size, morphology, and agglomeration are directly influenced by the concentration and the type of surfactant

  1. Novel sample preparation method for surfactant containing suppositories: effect of micelle formation on drug recovery.

    Science.gov (United States)

    Kalmár, Éva; Ueno, Konomi; Forgó, Péter; Szakonyi, Gerda; Dombi, György

    2013-09-01

    Rectal drug delivery is currently at the focus of attention. Surfactants promote drug release from the suppository bases and enhance the formulation properties. The aim of our work was to develop a sample preparation method for HPLC analysis for a suppository base containing 95% hard fat, 2.5% Tween 20 and 2.5% Tween 60. A conventional sample preparation method did not provide successful results as the recovery of the drug failed to fulfil the validation criterion 95-105%. This was caused by the non-ionic surfactants in the suppository base incorporating some of the drug, preventing its release. As guidance for the formulation from an analytical aspect, we suggest a well defined surfactant content based on the turbidimetric determination of the CMC (critical micelle formation concentration) in the applied methanol-water solvent. Our CMC data correlate well with the results of previous studies. As regards the sample preparation procedure, a study was performed of the effects of ionic strength and pH on the drug recovery with the avoidance of degradation of the drug during the procedure. Aminophenazone and paracetamol were used as model drugs. The optimum conditions for drug release from the molten suppository base were found to be 100 mM NaCl, 20-40 mM NaOH and a 30 min ultrasonic treatment of the final sample solution. As these conditions could cause the degradation of the drugs in the solution, this was followed by NMR spectroscopy, and the results indicated that degradation did not take place. The determined CMCs were 0.08 mM for Tween 20, 0.06 mM for Tween 60 and 0.04 mM for a combined Tween 20, Tween 60 system. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Effects of surfactant and polymerization method on the synthesis of magnetic colloidal polymeric nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Puentes-Vara, Luis A.; Gregorio-Jauregui, Karla M. [Instituto Politécnico Nacional, ESIQIE, UPALM (Mexico); Bolarín, Ana M. [Universidad Autónoma Del Estado de Hidalgo (Mexico); Navarro-Clemente, Ma. E.; Dorantes, Héctor J.; Corea, Mónica, E-mail: mcoreat@yahoo.com.mx, E-mail: mcorea@ipn.mx [Instituto Politécnico Nacional, ESIQIE, UPALM (Mexico)

    2016-07-15

    The addition of superparamagnetic iron nanoparticles into polystyrene matrix allows for the modification of the physical properties as well as the implementation of new features in the hybrid nanomaterials. These materials have excellent potential for biomedical and bioengineering applications. Nevertheless, it is necessary to achieve a good dispersion of magnetic nanoparticles for its successful incorporation into polymer particles. This can be obtained through the use of a stabilizer, which provides stability against aggregation. In this work, magnetic nanoparticles were dispersed using different stabilizers. Subsequently, ferrofluids stabilized using the mixture of ABEX/IGEPAL and acrylic acid (AA) were used to synthesize PS-Fe{sub 3}O{sub 4} nanocomposites, through miniemulsion and emulsion polymerization conventional techniques. Semicontinuous and batch processes were compared, by varying surfactants and their concentrations. The PS-Fe{sub 3}O{sub 4} nanoparticles were characterized by dynamic light scattering, scanning electron microscopy, Raman spectroscopy, and vibrating sample magnetometer. Magnetic nanoparticle dispersions show better results when the anionic and nonionic surfactants are used as a mixture rather than when used alone. Results of DLS showed that the semicontinuous process allowed obtaining monodisperse materials, whereas polidisperse systems are generated in batch process. Raman spectroscopy confirmed the presence of magnetite and polystyrene in the nanocomposites. PS-Fe{sub 3}O{sub 4} nanoparticles showed superparamagnetic behavior with final magnetization of around 0.01 emu/g and low coercivity, properties that make them suitable for applications in wide fields of technology. Particle size (Dz), was lower than 300 nm in all cases. Moreover, the use of AA as stabilizer allows enhancing the PS-Fe{sub 3}O{sub 4} composite properties. These findings showed that particle size, morphology, and agglomeration are directly influenced by the

  3. Surfactants in tribology

    CERN Document Server

    Biresaw, Girma

    2014-01-01

    Surface science and tribology play very critical roles in many industries. Manufacture and use of almost all consumer and industrial products rely on the application of advanced surface and tribological knowledge. The fourth in a series, Surfactants in Tribology, Volume 4 provides an update on research and development activities connecting surfactants and tribological phenomena. Written by renowned subject matter experts, the book demonstrates how improved design of surfactants can be harnessed to control tribological phenomena. Profusely illustrated and copiously referenced, the chapters also

  4. Sugar ester surfactants: enzymatic synthesis and applications in food industry.

    Science.gov (United States)

    Neta, Nair S; Teixeira, José A; Rodrigues, Lígia R

    2015-01-01

    Sugar esters are non-ionic surfactants that can be synthesized in a single enzymatic reaction step using lipases. The stability and efficiency of lipases under unusual conditions and using non-conventional media can be significantly improved through immobilization and protein engineering. Also, the development of de novo enzymes has seen a significant increase lately under the scope of the new field of synthetic biology. Depending on the esterification degree and the nature of fatty acid and/or sugar, a range of sugar esters can be synthesized. Due to their surface activity and emulsifying capacity, sugar esters are promising for applications in food industry.

  5. The system with zwitterionic lactose-based surfactant for complexation and delivery of small interfering ribonucleic acid—A structural and spectroscopic study

    International Nuclear Information System (INIS)

    Skupin, Michalina; Sobczak, Krzysztof; Zieliński, Ryszard; Kozak, Maciej

    2016-01-01

    Systems suitable for the effective preparation of complexes with siRNA (small interfering RNA) are at the center of interest in the area of research work on the delivery of the RNA-based drugs (RNA-therapeutics). This article presents results of a study on the structural effects associated with siRNA complexation by a surfactant comprising a lactose group (N-(3-propanesulfone)-N-dodecyl-amino-beta-D-lactose hydrochloride, LA12). The double stranded siRNA oligomer (21 base pairs) used in this study is responsible for silencing a gene that can be important in the therapy of myotonic dystrophy type 1. The obtained siRNA/LA12 lipoplexes were studied using the methods of small angle scattering of synchrotron radiation, circular dichroism spectroscopy, Fourier transform infrared spectroscopy, and electrophoretic mobility tests. Lipoplexes form in solution stable lamellar or cubic phases. The surfactant selected for the study shows much lower cytotoxicity and good complexation abilities of siRNA than dicationic or polycationic surfactants.

  6. The system with zwitterionic lactose-based surfactant for complexation and delivery of small interfering ribonucleic acid—A structural and spectroscopic study

    Science.gov (United States)

    Skupin, Michalina; Sobczak, Krzysztof; Zieliński, Ryszard; Kozak, Maciej

    2016-05-01

    Systems suitable for the effective preparation of complexes with siRNA (small interfering RNA) are at the center of interest in the area of research work on the delivery of the RNA-based drugs (RNA-therapeutics). This article presents results of a study on the structural effects associated with siRNA complexation by a surfactant comprising a lactose group (N-(3-propanesulfone)-N-dodecyl-amino-beta-D-lactose hydrochloride, LA12). The double stranded siRNA oligomer (21 base pairs) used in this study is responsible for silencing a gene that can be important in the therapy of myotonic dystrophy type 1. The obtained siRNA/LA12 lipoplexes were studied using the methods of small angle scattering of synchrotron radiation, circular dichroism spectroscopy, Fourier transform infrared spectroscopy, and electrophoretic mobility tests. Lipoplexes form in solution stable lamellar or cubic phases. The surfactant selected for the study shows much lower cytotoxicity and good complexation abilities of siRNA than dicationic or polycationic surfactants.

  7. The system with zwitterionic lactose-based surfactant for complexation and delivery of small interfering ribonucleic acid—A structural and spectroscopic study

    Energy Technology Data Exchange (ETDEWEB)

    Skupin, Michalina [Department of Macromolecular Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Sobczak, Krzysztof [Department of Gene Expression, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań (Poland); Zieliński, Ryszard [Department of Technology and Instrumental Analysis, Faculty of Commodity Science, Poznań University of Economics, al. Niepodległości 10, 61-875 Poznań (Poland); Kozak, Maciej, E-mail: mkozak@amu.edu.pl [Department of Macromolecular Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Joint SAXS Laboratory, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland)

    2016-05-23

    Systems suitable for the effective preparation of complexes with siRNA (small interfering RNA) are at the center of interest in the area of research work on the delivery of the RNA-based drugs (RNA-therapeutics). This article presents results of a study on the structural effects associated with siRNA complexation by a surfactant comprising a lactose group (N-(3-propanesulfone)-N-dodecyl-amino-beta-D-lactose hydrochloride, LA12). The double stranded siRNA oligomer (21 base pairs) used in this study is responsible for silencing a gene that can be important in the therapy of myotonic dystrophy type 1. The obtained siRNA/LA12 lipoplexes were studied using the methods of small angle scattering of synchrotron radiation, circular dichroism spectroscopy, Fourier transform infrared spectroscopy, and electrophoretic mobility tests. Lipoplexes form in solution stable lamellar or cubic phases. The surfactant selected for the study shows much lower cytotoxicity and good complexation abilities of siRNA than dicationic or polycationic surfactants.

  8. Physicochemical characteristics of PFC surfactants for dry decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Won Jin; Lee, Chi Woo [Korea University, Seoul (Korea)

    2001-04-01

    Even the trace amount of the used nuclear fuels of high radioactivity are hazardous to the earth and humans. Perfluorocarbons and perfluorocarbon surfactants are emerging to be efficient chemicals in the dry decontamination process of the used fuels of high radioactivity. The theme was undertaken to increase the knowledge on perfluorocarbon surfactants to develop the perfluorocarbon system in the dry decontamination process in Korea. Several cationic and anionic pfc surfactants were synthesized. Effects of pfc surfactants on electrochemical etching of silicon were investigated to form porous silicons. Forces were measured between silicon surfaces and AFM tip in the absence and presence of pfc surfactants. 7 refs., 10 figs. (Author)

  9. Preparation and characterization of insulin-surfactant complexes for loading into lipid-based drug delivery systems

    DEFF Research Database (Denmark)

    Li, Ping; Nielsen, Hanne Mørck; Fano, Mathias

    2013-01-01

    of surfactants, but also a nonnative secondary structure in the solid state. Finally, circular dichroism analysis of rehydrated complexes showed that the processing did not irreversibly alter the secondary structure of insulin. In short, the present study demonstrates changes in the secondary structure...

  10. Lipase activity in vesiclular systems: characterization of candida cylindracea lipase and its activity in polymerizable dialkylammonium surfactant vesicles

    NARCIS (Netherlands)

    Mosmuller, E.W.J.; Franssen, M.C.R.; Engbersen, Johannes F.J.

    1993-01-01

    Lipase from Candida cylindracea (CCL) was incorporated into polymerizable positively charged dialkylammonium bromide surfactant vesicles. The enzyme was incorporated by the use of the dehydration-rehydration method or by incubation. In the latter case, trapping efficiencies of up to 100% could be

  11. Semi-quantitative proteomics of mammalian cells upon short-term exposure to nonionizing electromagnetic fields

    NARCIS (Netherlands)

    Kuzniar, A. (Arnold); C. Laffeber; B. Eppink (Berina); K. Bezstarosti (Karel); D.H. Dekkers (Dick); H. Woelders (Henri); A.P.M. Zwamborn; J.A.A. Demmers (Jeroen); J.H.G. Lebbink (Joyce); R. Kanaar (Roland)

    2017-01-01

    textabstractThe potential effects of non-ionizing electromagnetic fields (EMFs), such as those emitted by power-lines (in extremely low frequency range), mobile cellular systems and wireless networking devices (in radio frequency range) on human health have been intensively researched and debated.

  12. Influence of clay and surfactant content in non-aqueous fluid rheology

    International Nuclear Information System (INIS)

    Guedes, I.C.; Gomes, N.L.; Menezes, R.R.; Campos, L.F.A.; Ferreira, H.S.

    2012-01-01

    The bentonite clay used as viscosity agent in the production of non-aqueous fluids cannot be used without organic treatment for their surfaces to become hydrophobic. These clays are called organophilic clays, and are generally obtained by adding, in an aqueous way, ionic or a nonionic surfactant. Recent studies of the variables involved in the dispersion of bentonite clays and in the process of organophilization, showed their lack of influence. This work aims to study the influence of clay content and surfactants on the rheology of nonaqueous fluids. To this end, the clays were treats and characterized, evidencing the incorporation of the surfactant, and then formulated non-aqueous fluids, following PETROBRAS standards, being possible to verify the influence of clay content and surfactant both from the point of view as the characterizing and rheological behavior. (author)

  13. ASSOCIATION OF BRANCHED POLYETHYLENE IMINE WITH SURFACTANTS IN AQUEOUS SOLUTION

    Directory of Open Access Journals (Sweden)

    Ismael C. Bellettini

    2015-07-01

    Full Text Available Three polymer-surfactant systems comprised of branched polyethylene imine (PEI with an anionic surfactant (sodium dodecylsulfate; SDS, a cationic surfactant (tetradecyltrimethylammonium bromide; TTAB, and a zwitterionic surfactant (N-tetradecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate; SB3-14 were studied based on the properties of surface tension, pyrene fluorescence emission, dynamic light scattering, pH, and zeta potential measurements. The critical aggregation concentration (cac and polymer saturation point (psp were determined for all three systems. The effect of these surfactants on the physico-chemical characteristics (diameter and surface charge of the complexes formed was determined. Polymer-surfactant interactions occurred in all of the systems studied, with the strongest interactions, electrostatic in nature, occurring in the SDS-PEI system. After the neutralization of the polymer charges with the addition of the surfactant, the hydrophobic effect started to control the interlacing of the polymer chains. For the PEI-TTAB system, a very dense film was formed at surfactant concentrations above 2.0 mmol L-1. In this case, the bromide counter-ion interacted with both the positively-charged PEI and the head of the surfactant, which is responsible for the formation of double layer coordination complexes. For the system composed of PEI and the zwitterionic surfactant, less cooperative associations occurred in comparison with the other systems.

  14. The extraction of uranium from wet process phosphoric acid using a liquid surfactant membrane system

    International Nuclear Information System (INIS)

    Dickens, N.; Davies, G.A.

    1984-01-01

    A liquid membrane extraction process is examined for the extraction of uranium from wet process phosphoric acid. Uranium is present in the acid in concentrations up to 100 ppm which in principle makes it ideal for treatment with a membrane process. The membrane system studied is based on extraction using DEHPA-TOPO reagents which are contained within the organic phase of a water in oil emulsion. Formulations of the emulsion membrane system have been studied, the limitations of acid temperature, P 2 O 5 concentration and solid dispersed impurities in the acid have been studied in laboratory batch experiments and in a continuous pilot plant unit capable of treating 5l of concentrated acid per minute. Data from the pilot plant work has been used to develop a flowsheet for a commercial unit based on this process. (author)

  15. Genetic effects of nonionizing electromagnetic fields

    International Nuclear Information System (INIS)

    Lai, Henry

    2001-01-01

    Due to the increased use of electricity and wireless communication devices, there is a concern on whether exposure to nonionizing electromagnetic fields (50/60 Hz fields and radiofrequency radiation) can lead to harmful health effects, particularly, genetic effects and cancer development. This presentation will review recent research on genetic effects of power line frequency and radiofrequency electromagnetic fields. Even though the mechanism of interaction is still unknown, there is increasing evidence that these electromagnetic fields at low intensities can cause genetic damage in cells. There is also evidence suggesting that the effects are caused by oxidative stress. (author)

  16. Medical uses non-ionizing radiation

    International Nuclear Information System (INIS)

    Ubeda Maeso, A.; Trillo Ruiz, M. A.

    2016-01-01

    This article reviews various clinical applications of non-ionizing radiation, focusing on the Hz-GHz frequency range. Depending on the signal characteristics, the applications cover several therapeutic areas, including osteology and traumatology, tissue regeneration, physiotherapy, chronic pain treatment, neurology, cardiology, urology and oncology. Electromagnetic therapies have proved simple, safe, low cost, devoid of side effects and able to treat the underlying pathology rather than simply alleviate the symptoms. Therefore, it is predictable that these therapies will have as serious impact on public health and associated costs. (Author)

  17. Treatment of Produced Waters Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System

    Energy Technology Data Exchange (ETDEWEB)

    Lynn E. Katz; Kerry A. Kinney; R. S. Bowman; E. J. Sullivan

    2004-09-11

    This report summarizes work performed on this project from April 2004 through September 2004. Our previous work demonstrated that a polyurethane foam biofilter could successfully biodegrade the BTEX contaminants found in the SMZ regeneration waste gas stream. However, establishing the biomass on the polyurethane foam packing was relatively time consuming and daily recirculation of a concentrated nutrient solution was required for efficient operation of the foam biofilter. To simplify the start up and operating requirements of the biofilter system, a simple, compost-based biofilter was investigated for its ability to treat the BTEX contaminants generated during the SMZ regeneration process. The investigation of the compost biofilter was divided into three experimental phases that spanned 180 days of biofilter operation. During Phase 1, the biofilter was continuously supplied a BTEX-contaminated waste gas stream. During Phase 2, a series of periodic shutdown tests were conducted to assess how the biofilter responded when the BTEX feed was discontinued for periods ranging from 1 day to 2.8 days. The Phase 3 experiments focused on determining how the biofilter would handle periodic spikes in inlet BTEX concentration as would be expected when it is coupled with an SMZ column. Results from the continuous feed (Phase 1) experiments demonstrated that the compost biofilter could maintain BTEX removals of greater than 98% within two weeks of startup. Results of the shutdown experiments indicated that benzene removal was the most sensitive to interruptions in the BTEX feed. Nevertheless, the BTEX removal efficiency exceeded 95% within 6 hours of reestablishing the BTEX feed to the biofilter. When the biofilter was subjected to periodic spikes in BTEX concentration (Phase 3), it was found that the total BTEX removal efficiency stabilized at approximately 75% despite the fact that the biofilter was only fed BTEX contaminants 8 hours per day. Finally, the effects of nutrient

  18. Non-ionic surfactant based vesicular drug delivery system for topical delivery of caffeine for treatment of cellulite: design, formulation, characterization, histological anti-cellulite activity, and pharmacokinetic evaluation.

    Science.gov (United States)

    Teaima, Mahmoud H; Abdelhalim, Sally A; El-Nabarawi, Mohamed A; Attia, Dalia A; Helal, Doaa A

    2018-01-01

    Cellulite is a common topographical alteration where skin acquires an orange peel or mattress appearance with alterations in adipose tissue and microcirculation. This work aims to develop and evaluate a topical niosomal gel formulae with good permeation to reach the subcutaneous fat layer. Several caffeine niosomal dispersions were prepared and incorporated into gel formulae using Carbopol 940 polymer, chemical penetration enhancers, and iontophoresis, then the prepared gels were applied onto the skin of rats and anticellulite activity of caffeine from the prepared gels compared to that of the commercial product Cellu Destock ® was evaluated by histological study of the skin and measurement of plasma level of caffeine passing through the skin using liquid chromatography (LC/MS-MS). Results of histology revealed reduction of size and thickness of fatty layer of rat skin in the following order: FVII > FXIV > Cellu Destock ®  > FVII + Iontophoresis > FXIV + Iontophoresis. Pharmacokinetic results of caffeine in plasma revealed that C max , T max , and AUC 0-12h decreased in the following order: FXIV > FVII > Cellu Destock ® . These results conclude that incorporation of caffeine niosomal dispersion into gel matrix with penetration enhancers and iontophoresis resulted in improvement in penetration of caffeine through the skin into the underlying fatty layer in treatment of cellulite.

  19. Micelle-induced depletion interaction and resultant structure in charged colloidal nanoparticle system

    Energy Technology Data Exchange (ETDEWEB)

    Ray, D.; Aswal, V. K., E-mail: vkaswal@barc.gov.in [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kohlbrecher, J. [Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 PSI Villigen (Switzerland)

    2015-04-28

    The evolution of the interaction and the resultant structure in the mixed system of anionic silica nanoparticles (Ludox LS30) and non-ionic surfactant decaethylene glycol monododecylether (C12E10), undergoing phase separation, have been studied using small-angle neutron scattering and dynamic light scattering. The measurements have been carried out for a fixed concentration of nanoparticle (1 wt. %) with varying concentration of surfactant (0 to 1 wt. %), in the absence and presence of an electrolyte. It is found that the micelles of non-ionic surfactant adsorb on the nanoparticle in the absence of electrolyte (form stable system), whereas these micelles become non-adsorbing in the presence of electrolyte (show phase separation). The phase separation arises because of C12E10 micelles, causing depletion interaction between nanoparticles and leading to their aggregation. The interaction is modeled by double Yukawa potential accounting for attractive depletion as well as repulsive electrostatic forces. Both the interactions (attraction and repulsion) are found to be of long-range. The nanoparticle aggregation (phase separation) is governed by the increase in the magnitude and the range of the depletion attraction with the increase in the surfactant concentration. The nanoparticle aggregates formed are quite large in size (order of micron) and are characterized by the surface fractal having simple cubic packing of nanoparticles within the aggregates.

  20. Synthesis and properties evaluation of sulfobetaine surfactant with double hydroxyl

    Science.gov (United States)

    Zhou, Ming; Luo, Gang; Zhang, Ze; Li, Sisi; Wang, Chengwen

    2017-09-01

    A series of sulfobetaine surfactants {N-[(3-alkoxy-2-hydroxyl)propoxy] ethyl-N,N-dimethyl-N-(2-hydroxyl)propyl sulfonate} ammonium chloride were synthesized with raw materials containing linear saturated alcohol, N,N-dimethylethanolamine, sodium 3-chloro-2-hydroxyl propane sulfonic acid and epichlorohydrin. The molecule structures of sulfobetaine surfactants were characterized by FTIR, 1HNMR and elemental analysis. Surface tension measurements can provide us information about the surface tension at the CMC (γCMC), pC20, Γmax and Amin. The pC20 values of sulfobetaine surfactants increase with the hydrophobic chain length increasing. Amin values of the surfactants decrease with increasing hydrophobic chain length from 10 to 14. The critical micelle concentration (CMC) and surface tension (γCMC) values of the sulfobetaine surfactants decrease with increasing hydrophobic chain length from 10 to 16. The lipophilicity of surfactant was enhanced with the increase of the carbon chain, however, the ability of anti-hard water was weakened. The minimum oil/water interfacial tension of four kinds of sulfobetaine surfactants is 10-2-10-3 mN/m magnitude, which indicates that the synthesized bis-hydroxy sulfobetaine surfactants have a great ability to reduce interfacial tension in the surfactant flooding system. The surface tension (γCMC) values of synthesized surfactants were lower compared with conventional anionic surfactant sodium dodecyl sulfonate.

  1. Should nonionic radiographic contrast media be given to all patients?

    International Nuclear Information System (INIS)

    Parfrey, P.S.; Cramer, B.C.; McManamon, P.J.

    1988-01-01

    In the 1970s about one patient of every 40,000 who underwent intravenous urography died. It has been suggested that lives can be saved by using only nonionic or low-osmolarity contrast agents. The authors suggest a multicentre double-blind randomized controlled trial of nonionic versus ionic contrast media

  2. Latex Imaging by Environmental STEM: Application to the Study of the Surfactant Outcome in Hybrid Alkyd/Acrylate Systems

    OpenAIRE

    Faucheu , Jenny; Chazeau , Laurent; Gauthier , Catherine; Cavaille , Jean-Yves; Goikoetxea , Monika; Minari , Roque; Asua , Jose M.

    2009-01-01

    International audience; Among other uses. latexes are a successful alternative to solvent-borne binders for coatings. Efforts are made to produce hybrid nanostructured latexes containing an acrylic phase and an alkyd phase, However, after the film-forming process, the surfactant used to stabilize these latexes remains in the film, and its location can have a drastic effect on the application properties. Among the processing parameters, the alkyd hydrophobicity can strongly influence this loca...

  3. Interaction of biocompatible natural rosin-based surfactants with human serum albumin: A biophysical study

    International Nuclear Information System (INIS)

    Ishtikhar, Mohd; Ali, Mohd Sajid; Atta, Ayman M.; Al-Lohedan, H.A.; Nigam, Lokesh; Subbarao, Naidu; Hasan Khan, Rizwan

    2015-01-01

    Biophysical insight into interaction of biocompatible rosin-based surfactants with human serum albumin (HSA) was studied at physiological conditions using various spectroscopic, calorimetric and molecular docking approaches. The binding constant (K b ), enthalpy (ΔH 0 ), entropy (ΔS 0 ) and Gibbs free energy change (ΔG 0 ) were calculated by spectroscopic and calorimetric method. We have also calculated the probability of energy transfer by FRET analysis. The circular dichroism study showed that the cationic surfactant QRMAE significantly altered the secondary structure of HSA as compared to the nonionic rosin surfactants. The thermodynamic study was performed by ITC to determine binding constant as well as change in enthalpy of HSA in presence of rosin surfactants. It clearly showed that hydrogen binding and hydrophobic interaction play an important role in the binding of HSA to rosin surfactants. We have also performed molecular docking studies to locate the binding site on HSA and to visualize the mode of interaction. The present study provides a significant insight into HSA–rosin surfactants interaction, which also improves our understanding of the possible effect of rosin surfactants on human health. - Highlights: • RMPEG 750 has the highest Kb, Kq and Ksv value as compared to other rosin surfactants. • The probability of energy transfer from HSA to rosin surfactants was maximum in the case of RMPEG 750. • Cationic surfactant QRMAE significantly altered the secondary structure of the HSA as compared to other rosin surfactants. • Molecular docking and ITC experiment studies, to locate the binding site on HSA and to investigate the mode of interaction

  4. Interaction of biocompatible natural rosin-based surfactants with human serum albumin: A biophysical study

    Energy Technology Data Exchange (ETDEWEB)

    Ishtikhar, Mohd [Protein Biophysics Laboratory, Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002 (India); Ali, Mohd Sajid [Surfactant Research Chair, Department of Chemistry, King Saud University, P.O. Box-2455, Riyadh 11451 (Saudi Arabia); Atta, Ayman M. [Surfactant Research Chair, Department of Chemistry, King Saud University, P.O. Box-2455, Riyadh 11451 (Saudi Arabia); Petroleum Application department, Egyptian Petroleum Research Institute, Ahmad Elzomor St., Nasr city, Cairo-11727 (Egypt); Al-Lohedan, H.A. [Surfactant Research Chair, Department of Chemistry, King Saud University, P.O. Box-2455, Riyadh 11451 (Saudi Arabia); Nigam, Lokesh; Subbarao, Naidu [Centre for Computational Biology and Bioinformatics, School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi 110067 (India); Hasan Khan, Rizwan, E-mail: rizwanhkhan@hotmail.com [Protein Biophysics Laboratory, Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002 (India)

    2015-11-15

    Biophysical insight into interaction of biocompatible rosin-based surfactants with human serum albumin (HSA) was studied at physiological conditions using various spectroscopic, calorimetric and molecular docking approaches. The binding constant (K{sub b}), enthalpy (ΔH{sup 0}), entropy (ΔS{sup 0}) and Gibbs free energy change (ΔG{sup 0}) were calculated by spectroscopic and calorimetric method. We have also calculated the probability of energy transfer by FRET analysis. The circular dichroism study showed that the cationic surfactant QRMAE significantly altered the secondary structure of HSA as compared to the nonionic rosin surfactants. The thermodynamic study was performed by ITC to determine binding constant as well as change in enthalpy of HSA in presence of rosin surfactants. It clearly showed that hydrogen binding and hydrophobic interaction play an important role in the binding of HSA to rosin surfactants. We have also performed molecular docking studies to locate the binding site on HSA and to visualize the mode of interaction. The present study provides a significant insight into HSA–rosin surfactants interaction, which also improves our understanding of the possible effect of rosin surfactants on human health. - Highlights: • RMPEG 750 has the highest Kb, Kq and Ksv value as compared to other rosin surfactants. • The probability of energy transfer from HSA to rosin surfactants was maximum in the case of RMPEG 750. • Cationic surfactant QRMAE significantly altered the secondary structure of the HSA as compared to other rosin surfactants. • Molecular docking and ITC experiment studies, to locate the binding site on HSA and to investigate the mode of interaction.

  5. Expression, stabilization and purification of membrane proteins via diverse protein synthesis systems and detergents involving cell-free associated with self-assembly peptide surfactants.

    Science.gov (United States)

    Zheng, Xuan; Dong, Shuangshuang; Zheng, Jie; Li, Duanhua; Li, Feng; Luo, Zhongli

    2014-01-01

    G-protein coupled receptors (GPCRs) are involved in regulating most of physiological actions and metabolism in the bodies, which have become most frequently addressed therapeutic targets for various disorders and diseases. Purified GPCR-based drug discoveries have become routine that approaches to structural study, novel biophysical and biochemical function analyses. However, several bottlenecks that GPCR-directed drugs need to conquer the problems including overexpression, solubilization, and purification as well as stabilization. The breakthroughs are to obtain efficient protein yield and stabilize their functional conformation which are both urgently requiring of effective protein synthesis system methods and optimal surfactants. Cell-free protein synthesis system is superior to the high yields and post-translation modifications, and early signs of self-assembly peptide detergents also emerged to superiority in purification of membrane proteins. We herein focus several predominant protein synthesis systems and surfactants involving the novel peptide detergents, and uncover the advantages of cell-free protein synthesis system with self-assembling peptide detergents in purification of functional GPCRs. This review is useful to further study in membrane proteins as well as the new drug exploration. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Protolytic properties and complexation of DL-alpha-alanine and DL-alpha-valine and their dipeptides in aqueous and micellar solutions of surfactants

    NARCIS (Netherlands)

    Chernyshova, O. S.; Boychenko, Oleksandr; Abdulrahman, H.; Loginova, L. P.

    In this work we investigated the effect of the micellar media of anionic (sodium dodecylsulfate, SDS), cationic (cetylpiridinium chloride, CPC) and non-ionic (Brij-35) surfactants on the protolytic properties of amino acids DL-alpha-alanine, DL-alpha-valine and dipeptides

  7. Optimization of surfactant-aided remediation of industrially contaminated soils

    International Nuclear Information System (INIS)

    Joshi, M.M.; Lee, S.

    1996-01-01

    Soil matrices contaminated with polycyclic aromatic hydrocarbons (PAHs) abound at the sites of coke-oven gas plants, refineries, and many other major chemical industries. The removal of PAHs from soil using pure water, via soil washing (ex situ) or soil flushing (in situ), is quite ineffective due to their low solubility and hydrophobicity. However, addition of suitable surfactant(s) has been shown to increase the removal efficiency several fold. For the present work, the removal of PAHs occurring in industrially contaminated soil was studied. The objective was to use a nonionic surfactant solution for in situ soil flushing and to evaluate the optimal range of process parameters that can significantly increase the removal efficiency. The process parameters chosen were surfactant concentration, ratio of washing solution volume to soil weight, and temperature of washing solution. These parameters were found to have a significant effect on PAH removal from the contaminated soil and an optimal range was determined for each parameter under given washing conditions

  8. A PIV Study of Drop-interface Coalescence with Surfactants

    Science.gov (United States)

    Weheliye, Weheliye Hashi; Dong, Teng; Angeli, Panagiota

    2017-11-01

    In this work, the coalescence of a drop with an aqueous-organic interface was studied by Particle Image Velocimetry (PIV). The effect of surfactants on the drop surface evolution, the vorticity field and the kinetic energy distribution in the drop during coalescence were investigated. The coalescence took place in an acrylic rectangular box with 79% glycerol solution at the bottom and Exxsol D80 oil above. The glycerol solution drop was generated through a nozzle fixed at 2cm above the aqueous/oil interface and was seeded with Rhodamine particles. The whole process was captured by a high-speed camera. Different mass ratios of non-ionic surfactant Span80 to oil were studied. The increase of surfactant concentration promoted deformation of the interface before the rupture of the trapped oil film. At the early stages after film rupture, two counter-rotating vortices appeared at the bottom of the drop which then travelled to the upper part. The propagation rates, as well as the intensities of the vortices decreased at high surfactant concentrations. At early stages, the kinetic energy was mainly distributed near the bottom part of the droplet, while at later stages it was distributed near the upper part of the droplet. Programme Grant MEMPHIS, Chinese Scholarship Council (CSC).

  9. Lactose oleate as new biocompatible surfactant for pharmaceutical applications.

    Science.gov (United States)

    Perinelli, D R; Lucarini, S; Fagioli, L; Campana, R; Vllasaliu, D; Duranti, A; Casettari, L

    2018-03-01

    Sugar fatty acid esters are an interesting class of non-ionic, biocompatible and biodegradable sugar-based surfactants, recently emerged as a valid alternative to the traditional commonly employed (e.g. polysorbates and polyethylene glycol derivatives). By varying the polar head (carbohydrate moiety) and the hydrophobic tail (fatty acid), surfactants with different physico-chemical characteristics can be easily prepared. While many research papers have focused on sucrose derivatives, relatively few studies have been carried out on lactose-based surfactants. In this work, we present the synthesis and the physico-chemical characterization of lactose oleate. The new derivative was obtained by enzymatic mono-esterification of lactose with oleic acid. Thermal, surface, and aggregation properties of the surfactant were studied in detail and the cytotoxicity profile was investigated by MTS and LDH assays on intestinal Caco-2 monolayers. Transepithelial electrical resistance (TEER) measurements on Caco-2 cells showed a transient and reversible effect on the tight junctions opening, which correlates with the increased permeability of 4 kDa fluorescein-labelled dextran (as model for macromolecular drugs) in a concentration dependent manner. Moreover, lactose oleate displayed a satisfactory antimicrobial activity over a range of Gram-positive and Gram-negative bacteria. Overall, the obtained results are promising for a further development of lactose oleate as an intestinal absorption enhancer and/or an alternative biodegradable preservative for pharmaceutical and food applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Differences in phytotoxicity and dissipation between ionized and nonionized oil sands naphthenic acids in wetland plants.

    Science.gov (United States)

    Armstrong, Sarah A; Headley, John V; Peru, Kerry M; Germida, James J

    2009-10-01

    Naphthenic acids (NAs) are composed of alkyl-substituted acyclic and cycloaliphatic carboxylic acids and, because they are acutely toxic to fish, are of toxicological concern. During the caustic hot-water extraction of oil from the bitumen in oil sands deposits, NAs become concentrated in the resulting tailings pond water. The present study investigated if dissipation of NAs occurs in the presence of hydroponically grown emergent macrophytes (Typha latifolia, Phragmites australis, and Scirpus acutus) to determine the potential for phytoremediation of these compounds. Plants were grown with oil sands NAs (pKa approximately 5-6) in medium at pH 7.8 (predominantly ionized NAs) and pH 5.0 (predominantly nonionized NAs) to determine if, by altering their chemical form, NAs may be more accessible to plants and, thus, undergo increased dissipation. Whereas the oil sands NA mixture in its nonionized form was more toxic to wetland plants than its ionized form, neither form appeared to be sequestered by wetland plants. The present study demonstrated that plants may selectively enhance the dissipation of individual nonionized NA compounds, which contributes to toxicity reduction but does not translate into detectable total NA dissipation within experimental error and natural variation. Plants were able to reduce the toxicity of a NA system over 30 d, increasing the median lethal concentration (LC50; % of hydroponic solution) of the medium for Daphnia magna by 23.3% +/- 8.1% (mean +/- standard error; nonionized NAs) and 37.0% +/- 2.7% (ionized NAs) as determined by acute toxicity bioassays. This reduction in toxicity was 7.3% +/- 2.6% (nonionized NAs) and 45.0% +/- 6.8% (ionized NAs) greater than that in unplanted systems.

  11. Pulmonary surfactant and lung transplantation

    NARCIS (Netherlands)

    Erasmus, Michiel Elardus

    1997-01-01

    Pulmonary surfactant lowers the surface tension at the air-water interface inside the alveolus. This is achieved by adsorption of surfactant phospholipids at the air-water interface, a process controlled by surfactant-associated proteins, such as SP-A. In this way, surfactant prevents collapse of

  12. Effect of presence of benzene ring in surfactant hydrophobic chain on the transformation towards one dimensional aggregate

    Directory of Open Access Journals (Sweden)

    Rabah A. Khalil

    2015-07-01

    Full Text Available The formation of wormlike micelle and the following significant changes in rheological properties suffer misunderstanding from both theoretical and fundamental aspects. Recently, we have introduced a theory for interpreting such important phenomenon which is referred to as critical intermolecular forces (CIF. The theory has stated that the hydrophobic effect is the main factor for the formation of worm-like aggregates. Therefore, it seems interesting to check out the validity of this new physical insight through investigating the presence of benzene ring as less hydrophobic group in contrast to that of alkyl in surfactant tail. The mixture of anionic sodium dodecylbenzenesulphonate (SDBS and cationic cetyltrimethylammonium bromide (CTAB shows a high dynamic viscosity peak at the ratio of 80/20 of 3 wt.% CTAB/SDBS indicating the formation of wormlike micelles. The thermodynamic properties have been evaluated for this mixture exhibiting good agreement with the rheological changes. Interestingly, the results show the presence of benzene ring (in SDBS causing a negative effect towards the formation of one dimensional aggregate in contrast to previous results which support the proposed CIF theory. The presence of nonionic surfactant TritonX-100 in binary and ternary systems of SDBS and CTAB prohibits the formation of wormlike micelles.

  13. α-TCP cements prepared by syringe-foaming: Influence of Na2HPO4 and surfactant concentration.

    Science.gov (United States)

    Vásquez, A F; Domínguez, S; Loureiro Dos Santos, L A

    2017-12-01

    The lack of intrinsic open porosity in calcium phosphate cements slows down the resorption rate and bone ingrowth when implanted In Vivo. In this study, macroporous structures were obtained by mixing α-TCP cement with a foamed liquid phase containing different concentrations of sodium hydrogen phosphate and a nonionic surfactant. The cement paste was prepared by hand mixing in a novel system of two syringes connected by a tube. Two different liquid to powder (L/P) ratios were used to prepare the cement paste. The cement samples showed open macropores with diameters>100μm. The specimens prepared with lower L/P ratio showed smaller porosity, macroporosity and pore size distribution. The cohesion of the cement paste in liquid solutions was assessed by adding 2wt% sodium alginate to the liquid phase. This study suggests that the final macrostructure of the foamed cements can be controlled by varying the phosphate and surfactant concentrations in the liquid phase and the L/P ratio. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Ecological effects assessment of anionic surfactant on aquatic ecosystem using microcosm system; Microcosm wo mochiita in ion kaimen kasseizai no suiken seitaikei ni oyobosu eikyo hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Takamatsu, Y. [University of Tsukuba, Tsukuba (Japan); Inamori, Y. [National Institute for Environmental Studies, Tsukuba (Japan); Sudo, R. [Tohoku University, Sendai (Japan). Faculty of Engineering; Kurihara, Y. [Ou Univ., Fukushima (Japan). Faculty of Engineering; Matsumura, M. [University of Tsukuba, Tsukuba (Japan). Institute of Applied Biochemical

    1997-11-10

    Microcosm system was applied to assess effect of anionic surfactant (LAS) on aquatic ecosystem. Anionic surfactant such as LAS was added to an flask microcosm consisting of four species of bacteria as decomposer, one species of ciliate protozoa (Cyclidium glaucoma), two rotifers (Philodina sp. and Lepadella sp.) and one aquatic oligochaete (Aeolosoma hemprichi) as predator, and a green alga (Chlorella sp.) and a filamentous blue-green alga (Tolypothrix sp.) as producer, comparing with that of an natural lake model ecosystem derived from natural lake water. In the flask microcosm system and the natural lake model ecosystem, biodegradation rates of LAS were almost same and NOECs (no observed effect concentration) of LAS were also below 1.5 mg{center_dot} l{sup -1}. It was found that flask microcosm test could provide precise ecological effect assessment of LAS on number of microorganisms because the system showed higher reproducibility and stability than natural take model ecosystem. It was suggested that flask microcosm test was useful ecological effect assessment method which can reflect natural aquatic ecosystem. 10 refs., 4 figs., 2 tabs.

  15. BINDING OF IONIC SURFACTANTS ON OPPOSITELY CHARGED POLYELECTROLYTES OBSERVED BY FLUORESCENCE METHODS

    Institute of Scientific and Technical Information of China (English)

    Zhen Tong; Chao-yang Wang; Bi-ye Ren; Xin-xing Liu; Fang Zeng

    2003-01-01

    Our recent studies concerning the binding of ionic surfactants on oppositely charged polyelectrolytes observed with fluorescence techniques are reviewed. The cationic surfactants cetyltrimethylammonium bromide (CTAB),dodecyltrimethylammonium chloride (DTAC), and nonionic surfactant octaethylene glycol monododecyl ether (C12E8) were allowed to bind on anionic poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) and its pyrene and/or naphthalene labeled copolymers. The relative excimer emission intensity IE/IM of a cationic probe 1-pyrenemethylamine hydrochloride were chosen to monitor the binding process and the conformation change of surfactant-bound polyelectrolytes. The 1:1aggregation of polyelectrolyte-CTAB with respect to the charge was found as long as the CTAB concentration was slightly higher than its critical aggregation concentration (CAC). The intermolecular NRET indicated that the CTAB-bound polyelectrolytes aggregated together through the hydrophobic interaction between the CTAB tails. However, neither 1:1polyelectrolyte-DTAC aggregation nor intermolecular aggregation of DTAC-bound polyelectrolyte was observed owing to its weaker hydrophobicity of 12 carbon atoms in the tail, which is shorter than that of CTAB. As known from the fluorescence results, nonionic surfactant C12E8 did not bind on the anionic polyelectrolytes, but the presence of PAMPS promoted the micelle formation for C12E8 at the CAC slightly below its critical micelle concentration (CMC). The solid complex of dansyl labeled AMPS copolymer-surfactant exhibited a decrease in local polarity with increasing charge density of the polyelectrolyte or with alkane tail length of the surfactant. SAXS suggested a lamella structure for the AMPS copolymersurfactant solid complexes with a long period of 3.87 nm for CTAB and 3.04 nm for DTAC, respectively.

  16. [Biological effects of non-ionizing electromagnetic radiation].

    Science.gov (United States)

    Fedorowski, A; Steciwko, A

    1998-01-01

    Since the mid 1970's, when Adey discovered that extremely-low-frequency electromagnetic field (ELF EMF) may affect the calcium ions efflux from various cells, bioeffects of non-ionizing radiation (NIR) have become the subject of growing interest and numerous research projects. At present, the fact that NIR exerts both stimulatory and inhibitory effects on different physiological cellular parameters is rather unquestionable. At the same time, some epidemiological studies suggest that exposure to EMF is potentially harmful even if its intensity is very low. It has been proved that thermal factors are not responsible for these effects, therefore nowadays, they are called 'non-thermal effects'. Our paper deals with three different aspects of biological effects of non-ionizing radiation, bioelectromagnetism, electromagnetobiology and electromagnetic bioinformation. Firstly, we describe how EMF and photons can be produced within a living cell, how biological cycles are controlled, and what are the features of endogenous electromagnetic radiation. Secondly, we discuss various facets of external EMF interactions with living matter, focusing on extremely-low-frequencies, radio- and microwaves. Possible mechanisms of these interactions are also mentioned. Finally, we present a short overview of current theories which explain how electromagnetic couplings may control an open and dissipative structure, namely the living organism. The theory of electromagnetic bioinformation seems to explain how different physiological processes are triggered and controlled, as well as how long-range interactions may possibly occur within the complex biological system. The review points out that the presented research data must be assessed very carefully since its evaluation is crucial to set the proper limits of EMF exposure, both occupational and environmental. The study of biological effects of non-ioinizing radiation may also contribute to the development of new diagnostic and therapeutic

  17. Non-Ionizing Radiation - sources, exposure and health effects

    International Nuclear Information System (INIS)

    Hietanen, M.

    2003-01-01

    Non-ionizing radiation contains the electromagnetic wavelengths from ultraviolet (UV) radiation to static electric and magnetic fields. Optical radiation consists of UV, visible and infrared (IR) radiation while EM fields include static, extremely low (ELF), low frequency (LF) and radiofrequency (RF) fields. The principal scientific organization on non-ionizing radiation is the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The main activity of ICNIRP is to provide guidance on safe exposure and protection of workers and members of the public by issuing statements and recommendations. (orig.)

  18. Boundary layers of aqueous surfactant and block copolymer solutions against hydrophobic and hydrophilic solid surfaces

    International Nuclear Information System (INIS)

    Steitz, Roland; Schemmel, Sebastian; Shi Hongwei; Findenegg, Gerhard H

    2005-01-01

    The boundary layer of aqueous surfactants and amphiphilic triblock copolymers against flat solid surfaces of different degrees of hydrophobicity was investigated by neutron reflectometry (NR), grazing incidence small angle neutron scattering (GISANS) and atomic force microscopy (AFM). Solid substrates of different hydrophobicities were prepared by appropriate surface treatment or by coating silicon wafers with polymer films of different chemical natures. For substrates coated with thin films (20-30 nm) of deuterated poly(styrene) (water contact angle θ w ∼ 90), neutron reflectivity measurements on the polymer/water interface revealed a water depleted liquid boundary layer of 2-3 nm thickness and a density about 90% of the bulk water density. No pronounced depletion layer was found at the interface of water against a less hydrophobic polyelectrolyte coating (θ w ∼ 63). It is believed that the observed depletion layer at the hydrophobic polymer/water interface is a precursor of the nanobubbles which have been observed by AFM at this interface. Decoration of the polymer coatings by adsorbed layers of nonionic C m E n surfactants improves their wettability by the aqueous phase at surfactant concentrations well below the critical micellar concentration (CMC) of the surfactant. Here, GISANS experiments conducted on the system SiO 2 /C 8 E 4 /D 2 O reveal that there is no preferred lateral organization of the C 8 E 4 adsorption layers. For amphiphilic triblock copolymers (PEO-PPO-PEO) it is found that under equilibrium conditions they form solvent-swollen brushes both at the air/water and the solid/water interface. In the latter case, the brushes transform to uniform, dense layers after extensive rinsing with water and subsequent solvent evaporation. The primary adsorption layers maintain properties of the precursor brushes. In particular, their thickness scales with the number of ethylene oxide units (EO) of the block copolymer. In the case of dip-coating without

  19. Tools to discover anionic and nonionic polyfluorinated alkyl surfactants by liquid chromatography electrospray ionisation mass spectrometry

    DEFF Research Database (Denmark)

    Trier, Xenia; Granby, Kit; Christensen, Jan H.

    2011-01-01

    peaks, belonging to homologues series with m/z of n×50Da (CF2) or n×100Da (CF2CF2). The elemental composition of the precursor ions were deducted from the accurate m/z values of the deprotonated molecules [M−H]−. In case of in-source fragmentation, the presence of dimers, e.g. [M2−H]− and adduct ions...

  20. Synthesis of nonionic surfactants with azole ring bearing N-glycosides and their antibacterial activity

    Directory of Open Access Journals (Sweden)

    Fawzia Taieb Brahimi

    2017-05-01

    Full Text Available Six azoles with n-pentyl side chain 6–9, 11 and 12 were synthesized from n-hexanoic acid. Three N-glycosides namely: 5-pentyl-2-(d-amino arabinoside-1,3,4-oxadiazole (13, 5-pentyl-2-(d-aminoglycoside-1,3,4-thiadiazole (14, and 3-pentyl-4-(d-amino xyloside-4H-1,2,4-triazole-5-thiol (15 were prepared from already synthesized n-pentyl azoles 6, 7 and 11, respectively. Surface activity properties of water soluble synthesized compounds 6, 7, and 11–15 were studied in terms of surface tension, cloud point and critical micelle concentration. The antibacterial activities were assessed using the paper disk diffusion and broth dilution methods against gram-positive and gram-negative bacteria. Some of the synthetic compounds showed promising activity against microorganisms under test in comparison to commercially available antibiotics polymixine and oxytetracycline.

  1. Competitive adsorption of monoclonal antibodies and nonionic surfactants at solid hydrophobic surfaces

    DEFF Research Database (Denmark)

    Kapp, Sebastian J; Larsson, Iben; van de Weert, Marco

    2015-01-01

    Two monoclonal antibodies from the IgG subclasses one and two were compared in their adsorption behavior with hydrophobic surfaces upon dilution to 10 mg/mL with 0.9% NaCl. These conditions simulate handling of the compounds at hospital pharmacies and surfaces encountered after preparation, such ....... and the American Pharmacists Association J Pharm Sci....

  2. Effects of non-ionic surfactants on the interactions between cellulases and tannic acid

    DEFF Research Database (Denmark)

    Olsen, Søren Nymand; Bohlin, Christina Helena; Murphy, Leigh

    2011-01-01

    of cellulases to lignin. In the current work we address this hypothesis using tannic acid (TAN) as a general poly-phenolic model compound (for lignin and soluble phenolics) and measure the mutual interactions of cellulases (CBHI, CBHII, EGI, EGII and BG), TAN and NIS (Triton X-100) using isothermal titration...

  3. In vitro surfactant structure-toxicity relationships: implications for surfactant use in sexually transmitted infection prophylaxis and contraception.

    Directory of Open Access Journals (Sweden)

    Ângela S Inácio

    Full Text Available BACKGROUND: The need for woman-controlled, cheap, safe, effective, easy-to-use and easy-to-store topical applications for prophylaxis against sexually transmitted infections (STIs makes surfactant-containing formulations an interesting option that requires a more fundamental knowledge concerning surfactant toxicology and structure-activity relationships. METHODOLOGY/PRINCIPAL FINDINGS: We report in vitro effects of surfactant concentration, exposure time and structure on the viability of mammalian cell types typically encountered in the vagina, namely, fully polarized and confluent epithelial cells, confluent but non-polarized epithelial-like cells, dendritic cells, and human sperm. Representatives of the different families of commercially available surfactants--nonionic (Triton X-100 and monolaurin, zwitterionic (DDPS, anionic (SDS, and cationic (C(nTAB (n = 10 to 16, C(12PB, and C(12BZK--were examined. Triton X-100, monolaurin, DDPS and SDS were toxic to all cell types at concentrations around their critical micelle concentration (CMC suggesting a non-selective mode of action involving cell membrane destabilization and/or destruction. All cationic surfactants were toxic at concentrations far below their CMC and showed significant differences in their toxicity toward polarized as compared with non-polarized cells. Their toxicity was also dependent on the chemical nature of the polar head group. Our results suggest an intracellular locus of action for cationic surfactants and show that their structure-activity relationships could be profitably exploited for STI prophylaxis in vaginal gel formulations. The therapeutic indices comparing polarized epithelial cell toxicity to sperm toxicity for all surfactants examined, except C(12PB and C(12BZK, does not justify their use as contraceptive agents. C(12PB and C(12BZK are shown to have a narrow therapeutic index recommending caution in their use in contraceptive formulations. CONCLUSIONS

  4. Effects of silica-based nanostructures with raspberry-like morphology and surfactant on the interfacial behavior of light, medium, and heavy crude oils at oil-aqueous interfaces

    Science.gov (United States)

    Bai, Lingyun; Li, Chunyan; Korte, Caroline; Huibers, Britta M. J.; Pales, Ashley R.; Liang, Wei-zhen; Ladner, David; Daigle, Hugh; Darnault, Christophe J. G.

    2017-11-01

    Any efficient exploitation of new petroleum reservoirs necessitates developing methods to mobilize the crude oils from such reservoirs. Here silicon dioxide nanoparticles (SiO2 NPs) were used to improve the efficiency of the chemical-enhanced oil recovery process that uses surfactant flooding. Specifically, SiO2 NPs (i.e., 0, 0.001, 0.005, 0.01, 0.05, and 0.1 wt%) and Tween®20, a nonionic surfactant, at 0, 0.5, and 2 critical micelle concentration (CMC) were varied to determine their effect on the stability of nanofluids and the interfacial tension (IFT) at the oil-aqueous interface for 5 wt% brine-surfactant-SiO2 nanofluid-oil systems for West Texas Intermediate light crude oil, Prudhoe Bay medium crude oil, and Lloydminster heavy crude oil. Our study demonstrates that SiO2 NPs may either decrease, increase the IFT of the brine-surfactant-oil systems, or exhibit no effects at all. For the brine-surfactant-oil systems, the constituents of the oil and aqueous substances affected the IFT behavior, with the nanoparticles causing a contrast in IFT trends according to the type of crude oil. For the light oil system (0.5 and 2 CMC Tween®20), the IFT increased as a function of SiO2 NP concentration, while a threshold concentration of SiO2 NPs was observed for the medium (0.5 and 2 CMC Tween®20) and heavy (2 CMC Tween®20) oil systems in terms of IFT trends. Concentrations below the SiO2 NP threshold concentration resulted in a decrease in IFT, and concentrations above this threshold resulted in an increase in IFT. The IFT decreased until the NP concentration reached a threshold concentration where synergetic effects between nonionic surfactants and SiO2 NPs are the opposite and result in antagonistic effects. Adsorption of both SiO2 NPs and surfactants at an interface caused a synergistic effect and an increased reduction in IFT. The effectiveness of the brine-surfactant-SiO2 nanofluids in decreasing the IFT between the oil-aqueous phase for the three tested crude oils

  5. Health Effects of Non-Ionizing Radiation on Human

    International Nuclear Information System (INIS)

    Zubaidah-Alatas; Yanti Lusiyanti

    2001-01-01

    Increases of development and use of equipment that procedures non-ionizing radiant energy such as laser, radar, microwave ovens, power lines and hand phones, bring about public concern about the possible health effects owing to the non-ionizing radiation exposure. Non ionizing electromagnetic radiation compared to ionizing radiation, has longer wavelength, lower frequency, and lower photon energy in its interaction with body tissues. The term on non-ionizing radiation refers to the groups of electromagnetic radiations with energies less than about 10 eV corresponding to wavelengths in the ultraviolet, visible, infra red microwave and radiofrequency spectral regions. This paper describes the current state of knowledge about types of non-ionizing radiation and the health effects at molecular and cellular levels as well as its effects on human health. (author)

  6. Enhanced Oil Recovery with Surfactant Flooding

    DEFF Research Database (Denmark)

    Sandersen, Sara Bülow

    , thus reducing the interfacial tension (IFT) to ultra low (0.001 mN/m), which consequently will mobilize the residual oil and result in improved oil recovery. This EOR technology is, however, made challenging by a number of factors, such as the adsorption of surfactant and co-surfactant to the rock...... be resistant to and remain active at reservoir conditions such as high temperatures, pressures and salinities. Understanding the underlying mechanisms of systems that exhibit liquid-liquid equilibrium (e.g. oil-brine systems) at reservoir conditions is an area of increasing interest within EOR. This is true...... studied. The effect of increased pressure became more significant when combined with increasing temperature. The experiments performed on the oil/ seawater systems were similar to the high pressure experiments for the surfactant system discussed above. Oil was contacted with different brine solutions...

  7. Predicting for thermodynamic instabilities in water/oil/surfactant microemulsions: A mesoscopic modelling approach

    Energy Technology Data Exchange (ETDEWEB)

    Duvail, Magali, E-mail: magali.duvail@icsm.fr; Zemb, Thomas; Dufrêche, Jean-François [Institut de Chimie Séparative de Marcoule (ICSM), UMR 5257, CEA-CNRS-Université Montpellier 2-ENSCM, Site de Marcoule, Bâtiment 426, BP 17171, F-30207 Bagnols-sur-Cèze Cedex (France); Arleth, Lise [Niels Bohr Institute, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C (Denmark)

    2014-04-28

    The thermodynamics and structural properties of flexible and rigid nonionic water/oil/surfactant microemulsions have been investigated using a two level-cut Gaussian random field method based on the Helfrich formalism. Ternary stability diagrams and scattering spectra have been calculated for different surfactant rigidities and spontaneous curvatures. A more important contribution of the Gaussian elastic constants compared to the bending one is observed on the ternary stability diagrams. Furthermore, influence of the spontaneous curvature of the surfactant points out a displacement of the instability domains which corresponds to the difference between the spontaneous and effective curvatures. We enlighten that a continuous transition from a connected water in oil droplets to a frustrated locally lamellar (oil in water in oil droplets) microstructure is found to occur when increasing the temperature for an oil-rich microemulsion. This continuous transition translated in a shift in the scattering functions, points out that the phase inversion phenomenon occurs by a coalescence of the water droplets.

  8. Acid-base, optical and extraction properties of Rose Bengal in the presence of surfactants

    International Nuclear Information System (INIS)

    Lengyel, J.; Krtil, J.; Kuban, V.

    1989-01-01

    Changes in the optical and acid-base characteristics of Rose Bengal in the presence of cationic (Septones - SPX, hexadecyltrimethylammonium bromide - CTMAB and hexadecylpyridinium bromide - CPB), anionic (sodium dodecylsuulfate - SDS) and nonionic (Triton X-100) surfactants in submicellar and micellar concentrations were studied spectrophotometrically. The conditional dissociation constants of Rose Bengal pK ai * depend on the kind and concentration of cationic surfactant. Changes in pK ai * values are described in terms of formation of ion associates of the dye with the surfactant of the composition QHB and Q 2 B. The extraction constants of the ion associates in chloroform were determined radiometrically with the aid of Rose Bengal labelled with 131 I. (author). 4 figs., 3 tabs., 22 refs

  9. Optimization of Water/Oil/Surfactant System for Preparation of Medium-Chain-Length Poly-3-Hydroxyalkanoates (mcl-PHA)-Incorporated Nanoparticles via Nanoemulsion Templating Technique.

    Science.gov (United States)

    Ishak, K A; Annuar, M Suffian M; Ahmad, N

    2017-12-01

    Polymeric nanoparticles gain a widespread interest in food and pharmaceutical industries as delivery systems that encapsulate, protect, and release lipophilic compounds such as omega-3 fatty acids, fat-soluble vitamins, carotenoids, carvedilol, cyclosporine, and ketoprofen. In this study, medium-chain-length poly-3-hydroxyalkanoate (mcl-PHA)-incorporated nanoparticle was developed via facile organic solvent-free nanoemulsion templating technique. The water content (W/surfactant-to-oil (S/O)), S/O, and Cremophor EL-to-Span 80 (Cremo/Sp80) ratios were first optimized using response surface methodology (RSM) to obtain nanoemulsion template prior to incorporation of mcl-PHA. Their effects on nanoemulsion formation were investigated. The mcl-PHA-incorporated nanoparticle system showed a good preservation capability of β-carotene and extended storage stability.

  10. Physico-chemical study of new functionalized surfactants having thermo sensitive de-mixing behaviour: use in extraction of uranyl nitrate

    International Nuclear Information System (INIS)

    Prevost, S.

    2006-04-01

    New thermo-sensitive functionalized surfactants with metal-chelating properties have been developed and their physical-chemistry studied. They associate a polyethoxylated nonionic surfactant (CiEj) block and a amino-acid residue as a chelating group. Functionalization preserves both properties of the thermo-sensitive surfactant moiety and the chelating group, a diamide closed to uranyl ionophore.The complexing group participates to the polar head group of the surfactant, increasing the area per molecule. As a result, functionalized surfactants form spherical micelles when diluted in water, and the concentrated part of their phase diagrams exhibits structures having higher curvatures than the nonionic precursor CiEj. The structure of the uranyl - diamide complex has been elucidated by NMR and ESI-MS and is of the type UO 2 (NO 3 ) 2 .L; the associated complexation constant, which is very low, has been evaluated by 1 H NMR.A nitrate salt, LiNO 3 , is added at high concentration to improve complexation. The effect of this salt has been analyzed, and was found to be rather similar to the effect on classical CiEj. When uranyl nitrate complexation occurs, the cloud point decreases dramatically, together with the reduction of the area per head group at micelle/solution interface. This effect can be minimized by using a nonionic precursor having a larger polar head group. The functionalized surfactants have been tested in the cloud point extraction of uranyl nitrate, and have proved their efficiency. Those results demonstrate the viability of the functionalized surfactants design, with a covalent link between a thermo-sensitive surfactant block and a chelating group. (author)

  11. Non-ionizing radiation: an occupational apathy

    International Nuclear Information System (INIS)

    Mohd Yusof Mohd Ali

    2000-01-01

    Non-ionizing radiation, NIR, is widely used in various modern applications to the extent that its presence is common in some work places. However, due to inability of human beings to detect its presence make the radiation 'invisible' to the workers most of the time. Of late it is known that the radiation can be hazardous to human health if the exposure received is excessively high. Such proven health effects has led international organizations, such as, IRPA establishing standard guidelines and maximum permissible limits to control its exposure. Recent studies reveal that some work places do indicate the presence of the radiation at levels far exceeding the IRPA recommended limits. It is, therefore, the objective of this paper to highlight such hazardous situations, magnitude of the hazards involved and ways and means how to overcome the hazard so that workers can take necessary precaution and action to minimize the health risk associated with the hazard. However, due to time and space constraint, only five types of the NIR are elaborated in this paper, namely ELF, RF and microwave, UV, IR and laser

  12. Non-Ionizing Radiation: Nature and Protection

    International Nuclear Information System (INIS)

    Abukasem, E.; Abdemalek, H.; Mosbah, D. S.

    2011-01-01

    Last century, the humanity witnessed a vast development, after the industrial revolution, in many aspects of life. There was a real revolution in world of communications, the electromagnetic waves were produced and used in many applications like wireless communications, radio and television transmissions, information transfer, medical diagnosis and many other useful applications. Non-ionizing radiation, the radiation which has no enough energy to remove an electron from an atom, becomes indispensable life necessity and currently it is a subject of public debate about its effects and hazards on human life and environments. The Arab Atomic Energy Agency recognized this fact and tried to raise the public awareness towards by organizing seminars, workshops and expert meetings in the Arab region in order to study the theoretical and applies aspects of this type of radiation as well as to shed the light on its possible hazards and effects on human life. This booklet came as a result of many expert meetings to be an Arabic simple and comprehensive guide line about the nature of and the different methods of protection from its possible effects and hazards.(author)

  13. Micro-scale displacement of NAPL by surfactant and microemulsion in heterogeneous porous media

    Science.gov (United States)

    Javanbakht, Gina; Arshadi, Maziar; Qin, Tianzhu; Goual, Lamia

    2017-07-01

    Industrial processes such as remediation of oil-contaminated aquifers and enhanced oil recovery (EOR) often utilize chemical additives to increase the removal of non-aqueous phase liquids (NAPLs) from subsurface formations. Although the majority of crude oils are classified as LNAPLs, they often contain heavy molecules (DNAPLs) such as asphaltenes that tend to adsorb on minerals and alter their wettability. Effective additives are therefore those that can reduce the threshold capillary pressure, thus mobilizing LNAPL inside pore spaces and solubilizing DNAPL from rock surfaces. Nonionic surfactants in brine have often been injected to oil or contaminated aquifer formations in order to enhance NAPL displacement through IFT reduction. Recent studies revealed that surfactant-based microemulsions have a higher tendency to alter the wettability of surfaces, compared to surfactants alone, leading to more effective NAPL removal. However, the impact of these additives on pore-scale displacement mechanisms and multi-phase fluid occupancy in porous media is, to date, still unclear. In this study, x-ray microtomography experiments were performed to investigate the impact of surfactants and microemulsions on the mobilization and solubilization of NAPL in heterogeneous rocks. Saturation profiles indicated that an incremental NAPL removal was attained by addition of microemulsion to brine, compared with surfactant. Residual cluster size distributions revealed that microemulsions could break up large clusters into smaller disconnected ones, improving their mobilization in the rock. In-situ contact angle measurements showed that microemulsions could reverse the wettability of rough contaminated surfaces to a higher extent than surfactants. Unlike surfactant alone, the surfactant-solvent blend in the carrier fluid of microemulsions was able to penetrate rough grain surfaces, particularly those of dolomite cement, and desorb asphaltenes in the form of small-emulsified NAPL droplets

  14. Surfactant adsorption study in sandstone for enhanced oil recovery; Estudo da adsorcao de tensoativos em arenitos para recuperacao avancada de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Curbelo, Fabiola D.S.; Santanna, Vanessa C.; Barros Neto, Eduardo L. de; Dutra Junior, Tarcilio V.; Dantas Neto, Afonso A. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Engenharia Quimica; Garnica, Alfredo I.C. [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Dept. de Tecnologia Quimica e de Alimentos; Lucena Neto, Marciano [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Dantas, Tereza N.C. [Faculdade Natalense para o Desenvolvimento do RN (FARN), Natal, RN (Brazil)

    2004-07-01

    Adsorption of surfactants from aqueous solutions in porous media is very important in Enhanced Oil Recovery (EOR) of oil reservoirs because surfactant loss due to adsorption on the reservoir rocks weakens the effectiveness of the injected chemical slug in reducing oil-water tension (IFT) and makes the process uneconomical. In this paper, two nonionic surfactants, such as alkyl phenol polyoxyethylene, with different ethoxylation degrees were studied, ENP95 and ENP150. The results of flow experiments of surfactant solutions in porous media showed that adsorption was higher for ENP95 because it has smaller ethoxylation degree than ENP150. This occurs what with increasing length of the head group, the molecules become more hydrophilic and, in associated structures, the steric hindrance between the head groups increases. Generally speaking, adsorption appears to be a cooperative process involving lateral interaction between surfactant and weak interaction with the solid surface. (author)

  15. Surfactant-induced mobilisation of trace metals from estuarine sediment: Implications for contaminant bioaccessibility and remediation

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Anu [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Turner, Andrew [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)], E-mail: aturner@plymouth.ac.uk

    2009-02-15

    The mobilisation of metals (Al, Fe, Cd, Cu, Mn, Ni, Pb, Sn, Zn) from contaminated estuarine sediment has been examined using commercially available surfactants. Metal release by the anionic surfactant, sodium dodecyl sulphate (SDS), increased with increasing amphiphile concentration up to and above its critical micelle concentration (CMC). Metal mobilisation by the bile acid salt, sodium taurocholate, and the nonionic surfactant, Triton X-100, however, did not vary with amphiphile concentration. SDS was the most efficient surfactant in mobilising metals from the sample, and Cd, Cu and Ni were released to the greatest extents (12-18% of total metal at [SDS] > CMC). Metal mobilisation appeared to proceed via complexation with anionic amphiphiles and denudation of hydrophobic host phases. Surfactants may play an important role in the solubilisation of metals in the digestive environment of deposit-feeding animals and, potentially, in the remediation of metal-contaminated soil and sediment. - Significant quantities of metals are mobilised from estuarine sediment by commercially available surfactants.

  16. Myelography in the dog with non-ionic contrast media at different iodine concentrations

    International Nuclear Information System (INIS)

    Fatone, G.; Lamagna, F.; Pasolini, M.P.; Potena, A.; Brunetti, A.

    1997-01-01

    Image quality and side effects were evaluated retrospectively in a series of 183 myelographic studies performed with two non-ionic contrast media (iohexol and iopamidol) at different concentrations. Side effects during and following the procedure were recorded. Image quality was assessed using an arbitrary scoring system and statistical analysis was performed with the cross-tabulation test (4 times 2 table) by comparing two groups receiving contrast medium at higher and lower concentrations. No significant differences in side effects were observed between the two groups but the ratings for image quality were significantly higher in the group receiving contrast medium at the higher concentration than in the group receiving the lower concentration. The results suggest that a high concentration of non-ionic contrast media can safely be used in dogs and may improve image quality

  17. In vitro assessment of skin irritation potential of surfactant-based formulations by using a 3-D skin reconstructed tissue model and cytokine response.

    Science.gov (United States)

    Walters, Russel M; Gandolfi, Lisa; Mack, M Catherine; Fevola, Michael; Martin, Katharine; Hamilton, Mathew T; Hilberer, Allison; Barnes, Nicole; Wilt, Nathan; Nash, Jennifer R; Raabe, Hans A; Costin, Gertrude-Emilia

    2016-12-01

    The personal care industry is focused on developing safe, more efficacious, and increasingly milder products, that are routinely undergoing preclinical and clinical testing before becoming available for consumer use on skin. In vitro systems based on skin reconstructed equivalents are now established for the preclinical assessment of product irritation potential and as alternative testing methods to the classic Draize rabbit skin irritation test. We have used the 3-D EpiDerm™ model system to evaluate tissue viability and primary cytokine interleukin-1α release as a way to evaluate the potential dermal irritation of 224 non-ionic, amphoteric and/or anionic surfactant-containing formulations, or individual raw materials. As part of our testing programme, two representative benchmark materials with known clinical skin irritation potential were qualified through repeated testing, for use as references for the skin irritation evaluation of formulations containing new surfactant ingredients. We have established a correlation between the in vitro screening approach and clinical testing, and are continually expanding our database to enhance this correlation. This testing programme integrates the efforts of global manufacturers of personal care products that focus on the development of increasingly milder formulations to be applied to the skin, without the use of animal testing. 2016 FRAME.

  18. Surface rheology of surfactant solutions close to equilibrium

    NARCIS (Netherlands)

    Baets, P.J.M.; Stein, H.N.

    1994-01-01

    In this paper the authors present surface rheol. measurements of various surfactant solns. close to equil. in a Langmuir trough. The authors find that the storage modulus is, in the systems investigated, higher than the loss modulus. The rheol. behavior depends strongly on the surfactant concn.,

  19. Effect of synthetic surfactants, salinity and alkalinity on the properties of asphalt emulsions

    Directory of Open Access Journals (Sweden)

    Prat, F.

    2009-07-01

    Full Text Available This paper studies the effect of salinity, alkalinity and amount of ionic and non-ionic synthetic surfactants in the aqueous emulsifier used to prepare oil-in-water or asphaltic emulsions on the performance of such substances as waterproofing on buildings. The emulsion systems studied here were prepared with Venezuelan extra heavy oil. The findings showed that the four variables modified viscosity, surface tension and mean particle size, physical properties that are instrumental to asphalt emulsion stability.Este trabajo estudia la influencia de las variables salinidad, alcalinidad y cantidad de surfactantes sintéticos, tanto iónicos como no iónicos, existentes en el emulsivo acuoso empleado para formular emulsiones asfálticas, con vistas a la aplicación de las mismas como recubrimientos impermeabilizantes en edificaciones. Para la preparación de los sistemas emulsionados objeto de estudio, se utilizó como producto bituminoso un crudo extrapesado procedente de Venezuela. En tal sentido, los resultados obtenidos muestran cómo las cuatro variables de formulación anteriormente mencionadas modifican una serie de propiedades físicas (viscosidad, tensión superficial y diámetro promedio de partícula muy determinantes para la estabilidad de las referidas emulsiones asfálticas.

  20. The Performance of Surfactant-Polymer Flooding in Horizontal Wells Consisting of Multilayers in a Reservoir System

    Directory of Open Access Journals (Sweden)

    Si Le Van

    2016-03-01

    Full Text Available Surfactant-polymer (SP flooding has been demonstrated to be an effective method to recover oil in the enhanced oil recovery (EOR stage when water flooding is no longer relevant. Theoretically, adding surfactant causes the reduction of the interfacial tension between oil and water in pores, therefore reducing the residual oil saturation, whereas the sweep efficiency will be significantly improved by the polymer injection as a result of proper mobility control. With regard to the well patterns, water flooding has demonstrated a high productivity in horizontal wells. Recently, other EOR processes have been increasingly applied to the horizontal wells in various well patterns. In this study, the efficiency of SP flooding applied to horizontal wells in various well configurations is investigated in order to select the best EOR performance in terms of either a technical or economical point of view. Furthermore, the reservoir is assumed to be anisotropic with four different layers that have same porosity but different permeability between each layer. The study figures out that, the utilization of a horizontal injector and producer always gives a higher oil production in comparison with the reference case of a conventional vertical injector and producer; however, the best EOR performances that demonstrate the higher oil recovery and lower fluid injected volume than those of the reference case are achieved when the production well is located in bottom layers and parallel with the injection well at a distance. While the location of producer decides oil productivity, the location of injector yet affects the uniformity of fluids propagation in the reservoir. A predefined feasibility factor is also taken into consideration in order to reject the infeasible cases that might give a high oil production but require a higher injected volume than the reference case. This factor is used as an economic parameter to evaluate the success of the EOR performance. The

  1. Gemini (dimeric) Surfactants

    Indian Academy of Sciences (India)

    is in turn bonded to an identical hydrocarbon tail; alternatively,. ~. Tail spacer ... formed is dependent on surfactant structure, temperature, ionic strength and pH. The models of GS are .... micelle to the air/water interface. Moreover, GS can be ...

  2. PEO-related block copolymer surfactants

    DEFF Research Database (Denmark)

    Mortensen, K.

    2001-01-01

    Non-ionic block copolymer systems based on hydrophilic poly(ethylene oxide) and more hydrophobic co-polymer blocks are used intensively in a variety of industrial and personal applications. A brief description on the applications is presented. The physical properties of more simple model systems...... of such PEG-based block copolymers in aqueous suspensions are reviewed. Based on scattering experiments using either X-ray or neutrons, the phase behavior is characterized, showing that the thermo-reversible gelation is a result of micellar ordering into mesoscopic crystalline phases of cubic, hexagonal...

  3. Influence of chemical surfactants on the biodegradation of crude oil by a mixed bacterial culture

    International Nuclear Information System (INIS)

    Van Hamme, J.D.; Ward, O.P.

    1999-01-01

    A study was conducted in which the effects of surfactant physicochemical properties on crude oil biodegradation by a mixed-bacterial culture were examined. The effects of hydrophile-lipophile balance (HLB) and molecular structure on the biodegradation of Bow River crude oil were determined. It was shown that chemical surfactants have the potential to improve crude oil biodegradation in complex microbial systems. Surfactant selection should consider factors such as molecular structure, HLB and surfactant concentration. 26 refs., 4 tabs., 3 figs

  4. Contrast media inhibit exogenous surfactant therapy in rats with acute respiratory distress syndrome

    NARCIS (Netherlands)

    Kesecioglu, Jozef; Haitsma, Jack J.; Schultz, Marcus J.; den Heeten, Gerard J.; Lachmann, Burkhard

    2006-01-01

    AIM: To test the effects of various contrast media on the pulmonary surfactant system. MATERIAL AND METHODS: In a rat model of acute respiratory distress syndrome (ARDS) induced by lung lavage, the effects of surfactant suspended in saline were compared with surfactant suspended in the contrast

  5. Better and safer diagnostic possibilities with non-ionic contrast media

    International Nuclear Information System (INIS)

    Dalmstrom, K.; Svinn, K.

    1991-01-01

    The synthesis of contrast media for medical radiography is followed out since their introduction in late 50's. A discussion is presented on the genesis of undesirable side effects of ionic contrast media due to the sodium and meglumine cations, the hypertonicity of the media and the iodinated molecule itself. The advantages of the new non-ionic non-dissociating low osmolar contrast media is stressed and its low chemotoxicity is explained in the light of their chemical structure. The qualities of the specific representatives of new three generations of non-ionic contrast media are analysed and compared: 1) metrizamide (Amipaque, Nycomed) - a soluble monomer; 2) iopamidol (Iopamiro, Bracco), iohexol (Omnipaque, Nycomed), iopromid (Ultravist, Schering), iopentol (Imagopaque, Nycomed), ioversol (Optiray Mallincrodt) - monomers, more tolerable and with lower toxicity; 3) ioxaglat, iotrolan and iodixanol -monoacidic dimers with lower osmolarity. Results from clinical trial and monitoring programs in large patients' groups are presented. The severity and incidence of the observed side effects in different organs and systems including the risk's groups are given. Compared to the conventional ionic media, the occurence of undesired effects has been reduced to about 1/6 with the use of the new products. The review unabiguously show the advantages of the non-ionic contrast media. 6 tabs., 2 figs., 26 refs

  6. Experimental Studies for the Evaluation of Non-Ionizing Radiation Levels

    International Nuclear Information System (INIS)

    Nasr, A.; Ashour, M.

    2008-01-01

    This article concerns the characteristic studies of non-ionizing; microwave, radiations. The power density levels, frequency ranges, modulation types, and the Fast Fourier Transform (FFT) are discussed. The experimental data are collected from the Egyptian Atomic Energy Authority (EAEA) locations in Nasr city and Anshas. This study has been carried out by Spectrum analyzer (SA) system, which implied radio frequency coaxial cable and horn antenna with height holders. The horn antenna was adjusted to scan all directions for investigating the signal strength. From this study, we obtain two main non-ionizing signals at center frequencies 900, and 1800 MHz, which are exploited by mobile communications networks. During the silence state, the measured maximum power densities levels for both frequencies are 0.553 μ W/cm 2 and 0.0191μW/cm 2 , respectively. While the measured maximum power densities, during alarm (ringing) state, are 98.67μ W/cm 2 and 2.961μ W/cm 2 for considered two frequencies, correspondingly. One can notice that the power densities are multiplied 178 times and 155 times for the same mentioned frequencies in that order. Moreover, these non-ionizing signals are analyzed theoretically and experimentally by utilizing FFT functions to clarify the Amplitude Modulations (AM) ratios and voltage strengths of these signals. Furthermore, the Occupied Band Width (OBW) ratio, and the division from the center frequency of the channel, (δFc) are clarified

  7. Comet assay as a procedure for detecting possible genotoxicity induced by non-ionizing radiation

    Directory of Open Access Journals (Sweden)

    Zsuzsanna Nemeth

    2015-05-01

    In our laboratory we use comet assay for testing genotoxicity of non-ionizing radiation for more than ten years. In the experiments we use whole blood samples (human or dog, cell lines (e.g. H295R cell line or 3 dimensional in vitro skin tissue (epidermis models. In our protocol a slightly modified alkaline Comet assay method of Singh et al. (1988 is used. On our poster there will be presented a brief summary of our experiments with exposure to different types of radiation (ELF, RF, and intermediate frequency. In our protocols the non-ionizing radiation was often combined with ionizing radiation to see whether the non-ionizing radiation can influence the repair of the DNA damage induced by ionizing radiation. For the evaluation of the slides mainly Komet 4.0 image analysis system software (Kinetic Imaging, Liverpool, UK was used, but as we got familiarized with other methods for slide evaluation like grading the comets by visual scoring into 5 categories or the CaspLab software, the comparison of these three methods will be also presented.

  8. Surfactant mediated liquid phase exfoliation of graphene

    Science.gov (United States)

    Narayan, Rekha; Kim, Sang Ouk

    2015-10-01

    Commercialization of graphene based applications inevitably requires cost effective mass production. From the early days of research on graphene, direct liquid phase exfoliation (LPE) of graphite has been considered as the most promising strategy to produce high-quality mono or few-layer graphene sheets in solvent dispersion forms. Substantial success has been achieved thus far in the LPE of graphene employing numerous solvent systems and suitable surfactants. This invited review article principally showcase the recent research progress as well as shortcomings of surfactant assisted LPE of graphene. In particular, a comprehensive assessment of the quality and yield of the graphene sheets produced by different categories of the surfactants are summarized. Future direction of LPE methods is also proposed for the eventual success of commercial applications.

  9. Changes in hydration of the stratum corneum are the most suitable indicator to evaluate the irritation of surfactants on the skin.

    Science.gov (United States)

    Fujimura, T; Shimotoyodome, Y; Nishijima, T; Sugata, K; Taguchi, H; Moriwaki, S

    2017-02-01

    Irritancy levels of surfactants on human skin have not been clarified completely. The relationships between skin damage and changes of skin properties caused by various surfactants were investigated using non-invasive measurements. Aqueous solutions of seven kinds of anionic, non-ionic, and amphoteric surfactants were exposed to the inside of forearm skin of 20 human subjects in two separate studies using the cup method. Hydration of the stratum corneum (SC), transepidermal water loss (TEWL), pH, skin surface roughness, and contents of the SC were measured before and after one exposure and after five and nine consecutive exposures to various surfactants. The discontinuation ratio of subjects for testing in each surfactant was determined by skin irritation symptoms and was defined as the degree of skin damage. Significant changes were observed only in hydration, TEWL, and natural moisturizing factors (NMF) content in the SC following surfactant exposure. A significant correlation was observed between the discontinuation ratio of each surfactant and the changes of hydration, TEWL, and NMF. Especially, the change of SC hydration showed an excellent correlation with the discontinuation ratio both for single (r = 0.942, P hydration of the SC is equivalent to the skin damage caused by surfactants, and therefore is the most suitable indicator to evaluate the irritation of surfactants on the skin. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Adsorption at the biocompatible α-pinene-water interface and emulsifying properties of two eco-friendly surfactants.

    Science.gov (United States)

    Trujillo-Cayado, Luis Alfonso; Ramírez, Pablo; Alfaro, María Carmen; Ruíz, Manuela; Muñoz, José

    2014-10-01

    In this contribution, we provide an accurate characterization at the α-pinene/water interface of two commercial polyoxytheylene glycerol ester surfactants which differ in the number of ethylene oxide (EO) groups, comprising a systematic analysis of interfacial pressure isotherms, dynamic curves, interfacial rheology and emulsifying properties. Polyoxyethylene glycerol esters derived from cocoa oil are non-ionic surfactants obtained from a renewable source which fulfill the environmental and toxicological requirements to be used as eco-friendly emulsifying agents. α-Pinene is a renewable biosolvent completely insoluble in water, which could find numerous applications. Interfacial rheology and equilibrium interfacial pressure data fitted a rigorous reorientation model that assumes that the surfactant molecules, when adsorbed at the interface, can acquire two orientations. The surfactant with the highest number of EO groups (Levenol C201) turned out to be more surface active at the α-pinene/water interface. In addition, the surfactant with the lowest number of EO groups (Levenol H&B) is solubilized into the adjacent oil phase. Slightly concentrated α-pinene emulsions were obtained using both surfactants. Nevertheless, more stable α-pinene emulsions with smaller droplet sizes and lower polidispersity were obtained when Levenol C201 was used as emulsifier instead of Levenol H&B. The systematic characterization presented in this work provides important new findings on the interfacial and emulsifying properties of polyoxytheylene glycerol ester surfactants, which can be applied in the rational development of new biocompatible products. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Destabilization Mechanism of Ionic Surfactant on Curcumin Nanocrystal against Electrolytes

    Directory of Open Access Journals (Sweden)

    Heni Rachmawati

    2016-10-01

    Full Text Available We have successfully developed curcumin nanosuspension intended for oral delivery. The main purpose is to improve bioavailability through enhancing its solubility. The nanoparticles were stabilized using various stabilizers, including polyvinyl pyrrolidone (PVP, polyvinyl alcohol (PVA, sodium carboxymethylcellulose (Na-CMC, d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS, and sodium dodecyl sulfate (SDS. The average diameter of particles, microscopic appearance, and sedimentation of each preparation was observed and compared. Each stabilizer demonstrated a different degree of inhibition of particle aggregation under electrolyte-containing simulated gastrointestinal (GIT fluid. Non-ionic stabilizers (PVA, PVP, and TPGS were shown to preserve the nanosuspension stability against electrolytes. In contrast, strong ionic surfactants such as SDS were found to be very sensitive to electrolytes. The results can provide useful information for the formulators to choose the most suitable stabilizers by considering the nature of stabilizers and physiological characteristics of the target site of the drug.

  12. Effect of protein-surfactant interactions on aggregation of β-lactoglobulin.

    Science.gov (United States)

    Hansted, Jon G; Wejse, Peter L; Bertelsen, Hans; Otzen, Daniel E

    2011-05-01

    The milk protein β-lactoglobulin (βLG) dominates the properties of whey aggregates in food products. Here we use spectroscopic and calorimetric techniques to elucidate how anionic, cationic and non-ionic surfactants interact with bovine βLG and modulate its heat-induced aggregation. Alkyl trimethyl ammonium chlorides (xTAC) strongly promote aggregation, while sodium alkyl sulfates (SxS) and alkyl maltopyranosides (xM) reduce aggregation. Sodium dodecyl sulfate (SDS) binds to non-aggregated βLG in several steps, but reduction of aggregation was associated with the first binding step, which occurs far below the critical micelle concentration. In contrast, micellar concentrations of xMs are required to reduce aggregation. The ranking order for reduction of aggregation (normalized to their tendency to self-associate) was C10-C12>C8>C14 for SxS and C8>C10>C12>C14>C16 for xM. xTAC promote aggregation in the same ranking order as xM reduce it. We conclude that SxS reduce aggregation by stabilizing the protein's ligand-bound state (the melting temperature t(m) increases by up to 10°C) and altering its charge potential. xM monomers also stabilize the protein's ligand-bound state (increasing t(m) up to 6°C) but in the absence of charged head groups this is not sufficient by itself to prevent aggregation. Although micelles of both anionic and non-ionic surfactants destabilize βLG, they also solubilize unfolded protein monomers, leaving them unavailable for protein-protein association and thus inhibiting aggregation. Cationic surfactants promote aggregation by a combination of destabilization and charge neutralization. The food compatible surfactant sodium dodecanoate also inhibited aggregation well below the cmc, suggesting that surfactants may be a practical way to modulate whey protein properties. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Performance improvement of ionic surfactant flooding in carbonate rock samples by use of nanoparticles

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Ahmadi

    2016-07-01

    Full Text Available Abstract Various surfactants have been used in upstream petroleum processes like chemical flooding. Ultimately, the performance of these surfactants depends on their ability to reduce the interfacial tension between oil and water. The surfactant concentration in the aqueous solution decreases owing to the loss of the surfactant on the rock surface in the injection process. The main objective of this paper is to inhibit the surfactant loss by means of adding nanoparticles. Sodium dodecyl sulfate and silica nanoparticles were used as ionic surfactant and nanoparticles in our experiments, respectively. AEROSIL® 816 and AEROSIL® 200 are hydrophobic and hydrophilic nanoparticles. To determine the adsorption loss of the surfactant onto rock samples, a conductivity approach was used. Real carbonate rock samples were used as the solid phase in adsorption experiments. It should be noted that the rock samples were water wet. This paper describes how equilibrium adsorption was investigated by examining adsorption behavior in a system of carbonate sample (solid phase and surfactant solution (aqueous phase. The initial surfactant and nanoparticle concentrations were 500–5000 and 500–2000 ppm, respectively. The rate of surfactant losses was extremely dependent on the concentration of the surfactant in the system, and the adsorption of the surfactant decreased with an increase in the nanoparticle concentration. Also, the hydrophilic nanoparticles are more effective than the hydrophobic nanoparticles.

  14. Topological transformation of a surfactant bilayer

    DEFF Research Database (Denmark)

    Le, T.D.; Olsson, U.; Mortensen, K.

    2000-01-01

    Surfactant lamellar phases are often complicated by the formation of multilamellar (onions) under shear, which can originate simply by shaking the sample. A systematic study has been performed on the C10E3-D2O system in which different bilayer structures under a steady shear flow were investigated...

  15. Technical sheets of ionizing radiations. 2. Non-ionizing radiations

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    The biological effects of different non-ionizing radiations are studied: ultra-violet radiation, visible radiation, infrared radiation, micrometric waves, ultrasonics. In spite of their apparent diversity these radiations are similar in their physico-chemical effects, but in view of their widely varying production methods and types of application each type is considered separately. It is pointed out that no organization resembling the CIPR exists in the field of non-ionizing radiations, the result being a great disparity amongst the different legislations in force [fr

  16. Protection criteria from the non-ionizing radiations

    International Nuclear Information System (INIS)

    Touzet, Rodolfo E.

    2004-01-01

    The first objective of the protection philosophy is to determinate the relation reason-effect in order to establish the exposition thresholds to acceptable values. To establish the radioprotection criteria is important to considerate the following: a-) The damage and effects of the non-ionizing radiation; b-) The physical aspects of the fields exposition; and c-) The dosimetry of the involucrate tissues. The non-ionizing radiation includes the optics radiations (ultraviolet, visible, infrared and laser), and the electromagnetic radiations (microwave, radars, magnetic and electrostatics fields)

  17. Dust as a surfactant

    International Nuclear Information System (INIS)

    Ignatov, A M; Schram, P P J M; Trigger, S A

    2003-01-01

    We argue that dust immersed in a plasma sheath acts as a surfactant. By considering the momentum balance in a plasma sheath, we evaluate the dependence of the plasma surface pressure on the dust density. It is shown that the dust may reduce the surface pressure, giving rise to a sufficiently strong tangential force. The latter is capable of confining the dust layer inside the sheath in the direction perpendicular to the ion flow

  18. MICROBIAL SURFACTANTS. I. GLYCOLIPIDS

    Directory of Open Access Journals (Sweden)

    Pirog T. Р.

    2014-02-01

    Full Text Available The review is devoted to surface-active glycolipids. The general characteristics, the physiological role of the rhamnolipids, trehalose lipids, sophorolipids, mannosylerythritol lipids and their traditional producers — the representatives of the genera Pseudozyma, Pseudomonas, Rhodococcus and Candida are given. The detailed analysis of the chemical structure, the stages of the biosynthesis and the regulation of some low molecular glycolipids are done. The own experimental data concerning the synthesis intensification, the physiological role and the practical use of Rhodococcus erythropolis IMV Ac-5017, Acinetobacter calcoaceticus IMV B-7241 and Nocardia vaccinii IMV B-7405 surfactants, which are a complex of the glyco-, phospho-, amino- and neutral lipids (glycolipids of all strains are presented by trehalose mycolates are summarized. It was found that R. erythropolis IMV Ac-5017, A. calcoaceticus IMV B-7241 and N. vaccinii IMV B-7405 surfactants have protective, antimicrobial and antiadhesive properties. It was shown that R. erythropolis IMV Ac-5017, A. calcoaceticus IMV B-7241 and N. vaccinii IMV B-7405 surfactants preparation of cultural liquid intensified the degradation of oil in water due to the activation of the natural petroleum-oxidizing microflora.

  19. Biodegradability of bacterial surfactants.

    Science.gov (United States)

    Lima, Tânia M S; Procópio, Lorena C; Brandão, Felipe D; Carvalho, André M X; Tótola, Marcos R; Borges, Arnaldo C

    2011-06-01

    This work aimed at evaluating the biodegradability of different bacterial surfactants in liquid medium and in soil microcosms. The biodegradability of biosurfactants by pure and mixed bacterial cultures was evaluated through CO(2) evolution. Three bacterial strains, Acinetobacter baumanni LBBMA ES11, Acinetobacter haemolyticus LBBMA 53 and Pseudomonas sp. LBBMA 101B, used the biosurfactants produced by Bacillus sp. LBBMA 111A (mixed lipopeptide), Bacillus subtilis LBBMA 155 (lipopeptide), Flavobacterium sp. LBBMA 168 (mixture of flavolipids), Dietzia Maris LBBMA 191(glycolipid) and Arthrobacter oxydans LBBMA 201(lipopeptide) as carbon sources in minimal medium. The synthetic surfactant sodium dodecyl sulfate (SDS) was also mineralized by these microorganisms, but at a lower rate. CO(2) emitted by a mixed bacterial culture in soil microcosms with biosurfactants was higher than in the microcosm containing SDS. Biosurfactant mineralization in soil was confirmed by the increase in surface tension of the soil aqueous extracts after incubation with the mixed bacterial culture. It can be concluded that, in terms of biodegradability and environmental security, these compounds are more suitable for applications in remediation technologies in comparison to synthetic surfactants. However, more information is needed on structure of biosurfactants, their interaction with soil and contaminants and scale up and cost for biosurfactant production.

  20. Effect of surfactants and temperature on germination and vegetative growth of Beauveria bassiana

    Directory of Open Access Journals (Sweden)

    Lizzy A. Mwamburi

    2015-03-01

    Full Text Available Three non-ionic surfactants: Tween20, Tween80 and Breakthru® were screened for their effects on spore germination and mycelial growth rates and for their influence on three isolates of Beauveria bassianaspore germination at various temperatures. Tween20 and Tween80 were compatible with all the B. bassiana isolates in the germination studies, but inhibited germination at higher surfactant concentrations, irrespective of the conidial concentrations. Breakthru® had an inhibitory effect on germination even at the lowest concentration of 0.1% on all the B. bassiana isolates. The effects of the surfactants on spore germination did not correspond with their effects on colony growth. Conidial viability within the same formulation declined significantly with increases in temperature, irrespective of the surfactant. The optimal temperature for conidial germination of B. bassiana isolates was approximately 25 °C with an upper limit at 30 °C. Isolate 7320 was identified as the least affected by the different surfactants. This isolate was able to germinate rapidly in a broad temperature range of 25–30 °C after 24 h, this characteristic being an essential factor in controlling house fly populations in poultry houses.

  1. Effect of surfactants and temperature on germination and vegetative growth of Beauveria bassiana.

    Science.gov (United States)

    Mwamburi, Lizzy A; Laing, Mark D; Miller, Ray M

    2015-03-01

    Three non-ionic surfactants: Tween20, Tween80 and Breakthru (®) were screened for their effects on spore germination and mycelial growth rates and for their influence on three isolates of Beauveria bassiana spore germination at various temperatures. Tween20 and Tween80 were compatible with all the B. bassiana isolates in the germination studies, but inhibited germination at higher surfactant concentrations, irrespective of the conidial concentrations . Breakthru (®) had an inhibitory effect on germination even at the lowest concentration of 0.1% on all the B. bassiana isolates. The effects of the surfactants on spore germination did not correspond with their effects on colony growth. Conidial viability within the same formulation declined significantly with increases in temperature, irrespective of the surfactant. The optimal temperature for conidial germination of B. bassiana isolates was approximately 25 °C with an upper limit at 30 °C. Isolate 7320 was identified as the least affected by the different surfactants. This isolate was able to germinate rapidly in a broad temperature range of 25-30 °C after 24 h, this characteristic being an essential factor in controlling house fly populations in poultry houses.

  2. Characterization of surfactant/hydrotalcite-like clay/glassy carbon modified electrodes: Oxidation of phenol

    International Nuclear Information System (INIS)

    Hernandez, Maria; Fernandez, Lenys; Borras, Carlos; Mostany, Jorge; Carrero, Hermes

    2007-01-01

    The characteristics of hydrotalcite (HT)-like clay films containing ionic and nonionic surfactants and their ability to oxidize phenol have been examined. The HT clay (Co/Al-NO 3 ) was synthesized by coprecipitation techniques and then modified with surfactants such as sodium dodecylbenzenesulfonate (SDBS), octylphenoxypolyethoxyethanol (TX100) or cetylpyridinium bromide (CPB). X-ray diffraction analysis revealed that the interlayer basal spacing varied depending on the type of surfactant retained by the HT. The presence of SDBS and CPB expanded the HT interlayer, which in the presence of TX100 did not show an appreciable change. Phenol oxidation is favored at surfactant-HT-GC modified electrodes, after a preconcentration time, compared to phenol oxidation at HT-GC or GC electrodes. Surfactant-HT-GC modified electrodes display good stability in continuous electrochemical phenol oxidation. At pH values between 6 and 10.8, both SDBS-HT-GC and TX100-HT-GC modified electrodes seem to be promising electrodes for the detection of phenol in water; while the CPB-HT-GC modified electrode should be affected by the inorganic anions

  3. Evaluation of the mechanism of skin enhancing surfactants on the biomembrane of shed snake skin.

    Science.gov (United States)

    Wonglertnirant, Nanthida; Ngawhirunpat, Tanasait; Kumpugdee-Vollrath, Mont

    2012-01-01

    The aim of the present work was to investigate the effects of different surfactants at various concentrations as a skin penetration enhancer through the biomembrane of the shed skin of Naja kaouthia. Additionally, the enhancer mechanism(s) of each class of surfactants were evaluated using physical characterization techniques, such as scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, and small and wide angle X-ray scattering (SWAXS). Our results showed that skin permeability increased with increasing concentrations of surfactants and the degree of increase was higher for the model hydrophilic permeant, deuterium dioxide (D(2)O), than the lipophilic permeant, ketoprofen (KP). Ionic surfactants, sodium lauryl sulfate (SLS) and cetyl trimethyl ammonium bromide (CTAB), demonstrated higher enhancement ability than the polyoxyethylene (20) sorbitan mono-oleate (Tween 80) non-ionic surfactant, which was consistent with the results from physical characterization studies. Increasing amounts of permeated drug resulted in an increase in membrane interactions. From our observations, it can be assumed that SLS and CTAB can be localized inside the biomembrane and thereby enhance drug permeation mainly through interactions with intercellular lipids in the stratum corneum (SC) and the creation of a perturbed microenvironment among lipid alkyl chains and polar head groups.

  4. Effect of surfactant for magnetic properties of iron oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Haracz, S. [Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89B, 61-614 Poznań (Poland); Hilgendorff, M. [Freie Universität Berlin, Fachbereich Physik, Arnimalle 14, 14195 Berlin (Germany); Rybka, J.D. [Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89B, 61-614 Poznań (Poland); Giersig, M. [Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89B, 61-614 Poznań (Poland); Freie Universität Berlin, Fachbereich Physik, Arnimalle 14, 14195 Berlin (Germany)

    2015-12-01

    Highlights: • Dynamic behavior of magnetic nanoparticles. • Synthesis of iron oxide nanoparticles. • Effect of surfactant for magnetic properties. - Abstract: For different medical applications nanoparticles (NPs) with well-defined magnetic properties have to be used. Coating ligand can change the magnetic moment on the surface of nanostructures and therefore the magnetic behavior of the system. Here we investigated magnetic NPs in a size of 13 nm conjugated with four different kinds of surfactants. The surface anisotropy and the magnetic moment of the system were changed due to the presence of the surfactant on the surface of iron oxide NPs.

  5. Long Term Field Development of a Surfactant Modified Zeolite/Vapor Phase Bioreactor System for Treatment of Produced Waters for Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Lynn Katz; Kerry Kinney; Robert Bowman; Enid Sullivan; Soondong Kwon; Elaine Darby; Li-Jung Chen; Craig Altare

    2007-12-31

    The main goal of this research was to investigate the feasibility of using a combined physicochemical/biological treatment system to remove the organic constituents present in saline produced water. In order to meet this objective, a physical/chemical adsorption process was developed and two separate biological treatment techniques were investigated. Two previous research projects focused on the development of the surfactant modified zeolite adsorption process (DE-AC26-99BC15221) and development of a vapor phase biofilter (VPB) to treat the regeneration off-gas from the surfactant modified zeolite (SMZ) adsorption system (DE-FC26-02NT15461). In this research, the SMZ/VPB was modified to more effectively attenuate peak loads and to maintain stable biodegradation of the BTEX constituents from the produced water. Specifically, a load equalization system was incorporated into the regeneration flow stream. In addition, a membrane bioreactor (MBR) system was tested for its ability to simultaneously remove the aromatic hydrocarbon and carboxylate components from produced water. The specific objectives related to these efforts included the following: (1) Optimize the performance VPBs treating the transient loading expected during SMZ regeneration: (a) Evaluate the impact of biofilter operating parameters on process performance under stable operating conditions. (b) Investigate how transient loads affect biofilter performance, and identify an appropriate technology to improve biological treatment performance during the transient regeneration period of an SMZ adsorption system. (c) Examine the merits of a load equalization technology to attenuate peak VOC loads prior to a VPB system. (d) Evaluate the capability of an SMZ/VPB to remove BTEX from produced water in a field trial. (2) Investigate the feasibility of MBR treatment of produced water: (a) Evaluate the biodegradation of carboxylates and BTEX constituents from synthetic produced water in a laboratory-scale MBR. (b

  6. Surfactant-Mediated Growth Revisited

    International Nuclear Information System (INIS)

    Meyerheim, H. L.; Sander, D.; Popescu, R.; Pan, W.; Kirschner, J.; Popa, I.

    2007-01-01

    The x-ray structure analysis of the oxygen-surfactant-mediated growth of Ni on Cu(001) identifies up to 0.15 monolayers of oxygen in subsurface octahedral sites. This questions the validity of the general view that surfactant oxygen floats on top of the growing Ni film. Rather, the surfactant action is ascribed to an oxygen-enriched zone extending over the two topmost layers. Surface stress measurements support this finding. Our results have important implications for the microscopic understanding of surfactant-mediated growth and the change of the magnetic anisotropy of the Ni films

  7. Study of interactions between hyaluronan and cationic surfactants by means of calorimetry, turbidimetry, potentiometry and conductometry.

    Science.gov (United States)

    Krouská, J; Pekař, M; Klučáková, M; Šarac, B; Bešter-Rogač, M

    2017-02-10

    The thermodynamics of the micelle formation of the cationic surfactants tetradecyltrimethylammonium bromide (TTAB) and cetyltrimethylammonium bromide (CTAB) with and without the addition of hyaluronan of two molecular weights was studied in aqueous solution by titration calorimetry. Macroscopic phase separation, which was detected by calorimetry and also by conductometry, occurs when charges on the surfactant and hyaluronan are balanced. In contrast, turbidimetry and potentiometry showed hyaluronan-surfactant interactions at very low surfactant concentrations. The observed differences between systems prepared with CTAB and TTAB indicate that besides the electrostatic interactions, which probably predominate, hydrophobic effects also play a significant role in hyaluronan interactions with cationic surfactants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Nonthermal effects in thermal treatment applications of nonionizing irradiation

    Science.gov (United States)

    Thomsen, Sharon

    2005-04-01

    Several non-thermal factors influence the primary and secondary effects of interstitial thermal treatments using various types of non-ionizing irradiation. Recognition and understanding of the influences of these various factors are important in choice of energy source, the configuration of the application instrument and the design of treatments.

  9. Adsorption of ionic surfactants at microscopic air-water interfaces using the micropipette interfacial area-expansion method

    DEFF Research Database (Denmark)

    Kinoshita, Koji; Parra, Elisa; Needham, David

    2017-01-01

    The dynamic adsorption of ionic surfactants at air-water interfaces have been less-well studied than that of the simpler non-ionics since experimental limitations on dynamic surface tension (DST) measurements create inconsistencies in their kinetic analysis. Using our newly designed "Micropipette...... interfacial area-expansion method", we have measured and evaluated both equilibrium and dynamic adsorption of a well-known anionic surfactant, sodium dodecyl sulphate (SDS), in the absence or presence of 100mM NaCl. Our focus was to determine if and to what extent the inclusion of a new correction parameter...... for the "ideal ionic activity", A±i, can renormalize both equilibrium and dynamic surface tension measurements and provide better estimates of the diffusion coefficient of ionic surfactants in aqueous media obtained from electroneutral models, namely extended Frumkin isotherm and Ward-Tordai adsorption models...

  10. Micellization of a Cationic Surfactant in Mixed Aqueous and Non ...

    African Journals Online (AJOL)

    Reception

    Department of Chemistry, Rivers State University of Science and Technology, Port ... surfactants in water-organic mixed-solvent systems is ... MATERIALS AND METHODS .... Journal of Applied ... Journal of Chemical and Engineering Data, 54,.

  11. A Simple Two-Step Cloud Point Extraction Process for Removing Fluorescent Whitening Agents VBL in Industrial Wastewater and Recycling of Surfactant.

    Science.gov (United States)

    Han, Juan; Tang, Xu; Wang, Yun; Li, Jing; Ni, Liang; Wang, Lei

    2017-03-01

      With the enhancement of people's environmental consciousness, the treatment of wastewater was studied as the focus of this paper. Here we present a simple two-step extraction to realize efficient separation of fluorescent whitening agents VBL and cyclic utilization of surfactant to reduce the cost of wastewater treatment and environmental pollution. Firstly, the removal of VBL has been achieved by CPE using TX-114 as nonionic surfactant. The results showed that complete extraction was possible using 1% (w/w) TX-114 for VBL concentration not exceeding 17.5 mg/L, otherwise using a higher concentration of 1.5% (w/w) TX-114. Then the surfactant from the coacervate phase was recycled by changing the potential difference between phases. The morphology of micelles and solubilization mechanism of VBL were demonstrated through the observation of a fluorescent microscope. This method was successfully used to remove the VBL from wastewater sample and the surfactant could be reused several times.

  12. Surfactant phosphatidylcholine metabolism and surfactant function in preterm, ventilated lambs

    International Nuclear Information System (INIS)

    Jobe, A.H.; Ikegami, M.; Seidner, S.R.; Pettenazzo, A.; Ruffini, L.

    1989-01-01

    Preterm lambs were delivered at 138 days gestational age and ventilated for periods up to 24 h in order to study surfactant metabolism and surfactant function. The surfactant-saturated phosphatidylcholine pool in the alveolar wash was 13 +/- 4 mumol/kg and did not change from 10 min to 24 h after birth. Trace amounts of labeled natural sheep surfactant were mixed with fetal lung fluid at birth. By 24 h, 80% of the label had become lung-tissue-associated, yet there was no loss of label from phosphatidylcholine in the lungs when calculated as the sum of the lung tissue plus alveolar wash. De novo synthesized phosphatidylcholine was labeled with choline given by intravascular injection at 1 h of age. Labeled phosphatidylcholine accumulated in the lung tissue linearly to 24 h, and the labeled phosphatidylcholine moved through lamellar body to alveolar pools. The turnover time for alveolar phosphatidylcholine was estimated to be about 13 h, indicating an active metabolic pool. A less surface-active surfactant fraction recovered as a supernatant after centrifugation of the alveolar washes at 40,000 x g increased from birth to 10 min of ventilation, but no subsequent changes in the distribution of surfactant phosphatidylcholine in surfactant fractions occurred. The results were consistent with recycling pathway(s) that maintained surface-active surfactant pools in preterm ventilated lambs

  13. Adsorption behavior of hydrophobin and hydrophobin/surfactant mixtures at the air-water interface.

    Science.gov (United States)

    Zhang, Xiaoli L; Penfold, Jeffrey; Thomas, Robert K; Tucker, Ian M; Petkov, Jordan T; Bent, Julian; Cox, Andrew; Campbell, Richard A

    2011-09-20

    The adsorption of the surface-active protein hydrophobin, HFBII, and the competitive adsorption of HFBII with the cationic, anionic, and nonionic surfactants hexadecyltrimethylammonium bromide, CTAB, sodium dodecyl sulfate, SDS, and hexaethylene monododecyl ether, C(12)E(6), has been studied using neutron reflectivity, NR. HFBII adsorbs strongly at the air-water interface to form a dense monolayer ∼30 Å thick, with a mean area per molecule of ∼400 Å(2) and a volume fraction of ∼0.7, for concentrations greater than 0.01 g/L, and the adsorption is independent of the solution pH. In competition with the conventional surfactants CTAB, SDS, and C(12)E(6) at pH 7, the HFBII adsorption totally dominates the surface for surfactant concentrations less than the critical micellar concentration, cmc. Above the cmc of the conventional surfactants, HFBII is displaced by the surfactant (CTAB, SDS, or C(12)E(6)). For C(12)E(6) this displacement is only partial, and some HFBII remains at the surface for concentrations greater than the C(12)E(6) cmc. At low pH (pH 3) the patterns of adsorption for HFBII/SDS and HFBII/C(12)E(6) are different. At concentrations just below the surfactant cmc there is now mixed HFBII/surfactant adsorption for both SDS and C(12)E(6). For the HFBII/SDS mixture the structure of the adsorbed layer is more complex in the region immediately below the SDS cmc, resulting from the HFBII/SDS complex formation at the interface. © 2011 American Chemical Society

  14. Synthesis and Biochemical effects of magnetite nanoparticle by surfactant-free electrochemical method in an aqueous system:the current density effect

    Directory of Open Access Journals (Sweden)

    Mousa Aliahmad

    2016-07-01

    Full Text Available Obejective(s: In this research, magnetite nanoparticles with an average size of 23-36 nm were successfully synthesized via surfactant-free electrochemical method using iron as the anode and water as the electrolyte in a closed aqueous system in the presence of NaOH at room temperature. Methods: The effect of the current density on product formation and particle size was investigated. Particle size was controlled by adjusting the current density. It was found that particle size decreases by decreasing the current density. In addition, the effect of current density  on the structural and optical properties of nanostructures were studied by X-ray diffraction, Field emission scanning electron microscopy, Fourier transformed infrared, and vibrating sample magnetometer techniques.  Results: The results obtained from the magnetization property study of samples at room temperature showed coactivity and saturation manetization of 0-100 Oe and 27.2- 40.5 emu. g-1, respectively. Finally, the results of biological activity study of nanoparticles on liver and kidney function in male wistar rats demonstrated that oral administration of NPs caused significant alterations to the levels of aspartate transaminase, alanine transaminase, and alkaline phosphatase in serum. Conclusions: No significant changes were detected in the groups treated with 10 and 100 ppm/ day nanostructure (P>0.05. There was a significant increase in the serum level of creatinine and blood urea nitrogen level (p

  15. Comparison Between Ionizing and Non-Ionizing Radiation Technologies for Wastewater Remediation

    International Nuclear Information System (INIS)

    Capobianco, Massimo L.; Esposito, Biagio; Navacchia, Maria Luisa; Pretali, Luca; Saracino, Michela; Zanelli, Alberto; Emmi, Salvatore S.

    2012-01-01

    A study on the decomposition of a surfactant (SDBS) and of four emerging pollutants (ofloxacin, carbamazepine, benzophenone-3, benzophenenone-4) in a multicomponent system is presented. These pollutants are decomposed in water by a few types of Advanced Oxidation Processes. The remediation methods included UV and γ-rays, all running in atmospheric conditions. It is shown that UV degradation methods can be improved by adding a photocatalyst (TiO 2 ), or a radical mediator (H 2 O 2 ). The processes were monitored step by step, by determining the concentration of pollutants by UV, HPLC and a specific surfactant selective kit, and measuring the total organic carbon content. (author)

  16. Health and biological effects of non-ionizing radiations

    International Nuclear Information System (INIS)

    De Seze, R.; Souques, M.; Aurengo, A.; Bach, V.; Burais, N.; Cesarini, J.P.; Cherin, A.; Decobert, V.; Dubois, G.; Hours, M.; Lagroye, I.; Leveque, Ph.; Libert, J.P.; Lombard, J.; Loos, N.; Mir, L.; Perrin, A.; Poulletier De Gannes, F.; Thuroczy, G.; Wiart, J.; Lehericy, St.; Pelletier, A.; Marc-Vergnes, J.P.; Douki, Th.; Guibal, F.; Tordjman, I.; Gaillot de Saintignon, J.; Collard, J.F.; Scoretti, R.; Magne, I.; Veyret, B.; Katrib, J.

    2011-01-01

    This document gathers the slides of the available presentations given during this conference day on the biological and health effects of non-ionizing radiations. Sixteen presentations out of 17 are assembled in the document and deal with: 1 - NMR: biological effects and implications of Directive 2004/40 on electromagnetic fields (S. Lehericy); 2 - impact of RF frequencies from mobile telephone antennas on body homeostasis (A. Pelletier); 3 - expression of stress markers in the brain and blood of rats exposed in-utero to a Wi-Fi signal (I. Lagroye); 4 - people exposure to electromagnetic waves: the challenge of variability and the contribution of statistics to dosimetry (J. Wiart); 5 - status of knowledge about electromagnetic fields hyper-sensitivity (J.P. Marc-Vergnes; 6 - geno-toxicity of UV radiation: respective impact of UVB and UVA (T. Douki); 7 - National day of prevention and screening for skin cancers (F. Guibal); 8 - UV tan devices: status of knowledge about cancer risks (I. Tordjman, and J. Gaillot de Saintignon); 9 - modulation of brain activity during a tapping task after exposure to a 3000 μT magnetic field at 60 Hz (M. Souques and A. Legros); 10 - calculation of ELF electromagnetic fields in the human body by the finite elements method (R. Scoretti); 11 - French population exposure to the 50 Hz magnetic field (I. Magne); 12 - LF and static fields, new ICNIRP recommendations: what has changed, what remains (B. Veyret); 13 - risk assessment of low energy lighting systems - DELs and CFLs (J.P. Cesarini); 14 - biological effects to the rat of a chronic exposure to high power microwaves (R. De Seze); 15 - theoretical and experimental electromagnetic compatibility approaches of active medical implants in the 10-50 Hz frequency range: the case of implantable cardiac defibrillators (J. Katrib); French physicians and electromagnetic fields (M. Souques). (J.S.)

  17. Non-ionizing electromagnetic fields on offshore installations

    International Nuclear Information System (INIS)

    Stark, G.M.; Heaton, B.

    1996-01-01

    The concern over the effects of occupational exposure to non-ionizing electromagnetic fields (EMF) has greatly increased in recent years. A great deal of knowledge is known about the thermal effects of radiofrequency EMF's and at the moment, many epidemiological and laboratory studies are being performed on extremely low frequency (ELF) and very low frequency (VLF) EMF's. Some studies have reported an increased risk of leukaemia and other cancers in children living close to overhead power cables and power industry electrical workers. Wertheimer and Leeper reported cancer links in children residing near overhead power cables as early as 1979 and many subsequent studies have continued to make similar associations. These studies suggest that prolonged exposure to higher than normal magnetic fields increases the occurrence of certain cancers in both children and adults. The most common associations are between EMF's and leukaemia, other haematopoetic cancers, brain cancers, central nervous system cancers or melanomas. Studies of adults living near overhead lines by Youngson et al. and working in the electricity industry by Armstrong et al. and Savitz and Loomis have also shown associations with certain cancers. The epidemiological studies are incomplete in several areas and many have been openly criticized. As yet, there is no conclusive laboratory evidence but studies are ongoing. The Hendee and Boteler study suggested that 'EMF's might be cancer promoters but are unlikely to be cancer initiators'. In addition to ELF studies, there have been many reports investigating exposure to EMF's from visual display units with equivocal results. Laboratory studies have reported conflicting results and as yet the hazard, if any, is still uncertain. Reports have also recorded exposure levels of operators in broadcast radio stations showing a variety of levels dependent on the occupation. In December 1992, the Commission of the European Communities proposed a council Directive on

  18. Evaluation of some vanillin-modified polyoxyethylene surfactants as additives for water based mud

    Directory of Open Access Journals (Sweden)

    M.M.A. El-Sukkary

    2014-03-01

    Full Text Available Water-based drilling fluids are increasingly being used for oil and gas exploration and are generally considered to be more environmentally acceptable than oil-based or synthetic-based fluids. In this study, new types of vanillin-modified polyoxyethylene surfactants were evaluated as additives in water-based mud. Their rheological properties in water-based mud were investigated which included the apparent viscosity, the plastic viscosity, the yield point, the gel strength, the thixotropy as well as the filtration properties. Also, the effect of high temperature on the rheology of the formulated water based mud was studied. The tested ethoxylated non-ionic surfactants showed good results when utilized in the formulation of water-based mud.

  19. Polyoxyethylene alkyl ether carboxylic acids: An overview of a neglected class of surfactants with multiresponsive properties.

    Science.gov (United States)

    Chiappisi, Leonardo

    2017-12-01

    In this work, an overview on aqueous solutions of polyoxyethylene alkyl ether carboxylic acids is given. Unique properties arise from the combination of the nonionic, temperature-responsive polyoxyethylene block with the weakly ionic, pH-responsive carboxylic acid termination in a single surfactant headgroup. Accordingly, this class of surfactant finds broad application across very different sectors. Despite their large use on an industrial and a technical scale, the literature lacks a systematic and detailed characterization of their physico-chemical properties which is provided herein. In addition, a comprehensive overview is given of their self-assembly and interfacial behavior, of their use as colloidal building blocks and for large-scale applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. ADSORPTION OF SURFACTANT ON CLAYS

    Science.gov (United States)

    Surfactants used to enhance remediation of soils by soil washing are often lost in the process. Neither the amount nor the cause of this loss is known. It is assumed that clays present in the soil are responsible for the loss of the surfactant. In this papere, adsorption prope...

  1. Comparison between radiological protection against ionizing radiation and non-ionizing radiation

    International Nuclear Information System (INIS)

    Jammet, H.P.

    1988-01-01

    The comparison of doctrines concerning protection against ionizing and non-ionizing radiation is a difficult task, because of the many areas in which it is applied. Radiological pollution has grown during the century, but its evolution has not been concomitant. This has resulted in a distortion that can be identified in the successive steps of the evaluation and protection against such radiation. For a better understanding, this discussion deals with the differences in interaction with matter and the induction of the related risks, on the varieties of protection systems and monitoring procedures

  2. Adsorption of surfactants and polymers at interfaces

    Science.gov (United States)

    Rojas, Orlando Jose

    Surface tension and high-resolution laser light scattering experiments were used to investigate the adsorption of isomeric sugar-based surfactants at the air/liquid interface in terms of surfactant surface packing and rheology. Soluble monolayers of submicellar surfactant solutions exhibited a relatively viscous behavior. It was also proved that light scattering of high-frequency thermally-induced capillary waves can be utilized to study surfactant exchange between the surface and the bulk solution. Such analysis revealed the existence of a diffusional relaxation mechanism. A procedure based on XPS was developed for quantification, on an absolute basis, of polymer adsorption on mica and Langmuir-Blodgett cellulose films. The adsorption of cationic polyelectrolytes on negatively-charged solid surfaces was highly dependent on the polymer ionicity. It was found that the adsorption process is driven by electrostatic mechanisms. Charge overcompensation (or charge reversal) of mica occurred after adsorption of polyelectrolytes of ca. 50% charge density, or higher. It was demonstrated that low-charge-density polyelectrolytes adsorb on solid surfaces with an extended configuration dominated by loops and tails. In this case the extent of adsorption is limited by steric constraints. The conformation of the polyelectrolyte in the adsorbed layer is dramatically affected by the presence of salts or surfactants in aqueous solution. The phenomena which occur upon increasing the ionic strength are consistent with the screening of the electrostatic attraction between polyelectrolyte segments and solid surface. This situation leads to polyelectrolyte desorption accompanied by both an increase in the layer thickness and the range of the steric force. Adsorbed polyelectrolytes and oppositely charged surfactants readily associate at the solid/liquid interface. Such association induces polyelectrolyte desorption at a surfactant concentration which depends on the polyelectrolyte charge

  3. Increased drop formation frequency via reduction of surfactant interactions in flow-focusing microfluidic devices.

    Science.gov (United States)

    Josephides, Dimitris N; Sajjadi, Shahriar

    2015-01-27

    Glass capillary based microfluidic devices are able to create extremely uniform droplets, when formed under the dripping regime, at low setup costs due to their ease of manufacture. However, as they are rarely parallelized, simple methods to increase droplet production from a single device are sought. Surfactants used to stabilize drops in such systems often limit the maximum flow rate that highly uniform drops can be produced due to the lowering interfacial tension causing jetting. In this paper we show that by simple design changes we can limit the interactions of surfactants and maximize uniform droplet production. Three flow-focused configurations are explored: a standard glass capillary device (consisting of a single round capillary inserted into a square capillary), a nozzle fed device, and a surfactant shielding device (both consisting of two round capillaries inserted into either end of a square capillary). In principle, the maximum productivity of uniform droplets is achieved if surfactants are not present. It was found that surfactants in the standard device greatly inhibit droplet production by means of interfacial tension lowering and tip-streaming phenomena. In the nozzle fed configuration, surfactant interactions were greatly limited, yielding flow rates comparable to, but lower than, a surfactant-free system. In the surfactant shielding configuration, flow rates were equal to that of a surfactant-free system and could make uniform droplets at rates an order of magnitude above the standard surfactant system.

  4. Nonlinear vibrational spectroscopy of surfactants at liquid interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Paulo B. [Univ. of California, Berkeley, CA (United States)

    1998-12-14

    Surfactants are widely used to modify physical and chemical properties of interfaces. They play an important role in many technological problems. Surfactant monolayer are also of great scientific interest because they are two-dimensional systems that may exhibit a very rich phase transition behavior and can also be considered as a model system for biological interfaces. In this Thesis, we use a second-order nonlinear optical technique (Sum-Frequency Generation - SFG) to obtain vibrational spectra of surfactant monolayer at Iiquidhapor and solid/liquid interfaces. The technique has several advantages: it is intrinsically surface-specific, can be applied to buried interfaces, has submonolayer sensitivity and is remarkably sensitive to the confirmational order of surfactant monolayers.

  5. Wetting behavior of mixtures of water and nonionic polyoxyethylene alcohol.

    Science.gov (United States)

    Wu, Chih-Kang; Chen, Li-Jen

    2005-07-19

    Five binary water + C4Ej mixtures, water + n-C4E0, water + 2-C4E0, water + iso-C4E0, water + n-C4E1, and water + iso-C4E1, were chosen to perform the surface/interfacial tension measurements over the experimental temperature range from 10 to 85 degrees C at the normal pressure by using a homemade pendent drop/bubble tensiometer. The symbol CiEj is the abbreviation of a nonionic polyoxyethylene alcohol CiH(2i+1)(OCH2CH2)jOH. The wetting behavior of the CiEj-rich phase at the interface separating gas and the aqueous phase is systematically examined according to the wetting coefficient resulting from the experimental data of surface/interfacial tensions measurements. For those systems with a lower critical solution temperature, for example, water + n-C6E2, water + n-C4E1, and water + iso-C4E1, a wetting transition from partial wetting to nonwetting is always observed when the system is brought to close to its lower critical solution temperature. On the other hand, to start with a partial wetting CiEj-rich phase, a wetting transition from partial wetting to complete wetting is always observed when the system is driven to approach its upper critical solution temperature. The effect of hydrophobicity of CiEj on the wetting behavior of the CiEj-rich phase at the interface separating gas and the aqueous phase was carefully investigated by using five sets of mixtures: (1) water + n-C4E0, water + n-C5E0, and water + n-C6E0; (2) water + 2-C4E0 and water + 2-C5E0; (3) water + 2-C4E0 and water + n-C4E0; (4) water + n-C4E1, water + n-C5E1, and water + n-C6E1; (5) water + n-C4E0 and water + n-C4E1. The CiEj-rich phase would tend to drive away from complete wetting (or nonwetting) to partial wetting with an increase in the hydrophobicity of CiEj in the binary water + CiEj system. All the wetting behavior observed in the water + CiEj mixtures is consistent with the prediction of the critical point wetting theory of Cahn.

  6. [Ionizing and non-ionizing radiation (comparative risk estimations)].

    Science.gov (United States)

    Grigor'ev, Iu G

    2012-01-01

    The population has widely used mobile communication for already more than 15 years. It is important to note that the use of mobile communication has sharply changed the conditions of daily exposure of the population to EME We expose our brain daily for the first time in the entire civilization. The mobile phone is an open and uncontrollable source of electromagnetic radiation. The comparative risk estimation for the population of ionizing and non-ionizing radiation was carried out taking into account the real conditions of influence. Comparison of risks for the population of ionizing and non-ionizing radiation leads us to a conclusion that EMF RF exposure in conditions of wide use of mobile communication is potentially more harmful than ionizing radiation influence.

  7. MICROBIAL SURFACTANTS IN ENVIRONMENTAL TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    T. P. Pirog

    2015-08-01

    Full Text Available It was shown literature and own experimental data concerning the use of microbial surface active glycolipids (rhamno-, sophoro- and trehalose lipids and lipopeptides for water and soil purification from oil and other hydrocarbons, removing toxic heavy metals (Cu2+, Cd2+, Ni2+, Pb2+, degradation of complex pollution (oil and other hydrocarbons with heavy metals, and the role of microbial surfactants in phytoremediation processes. The factors that limit the use of microbial surfactants in environmental technologies are discussed. Thus, at certain concentrations biosurfactant can exhibit antimicrobial properties and inhibit microorganisms destructing xenobiotics. Microbial biodegradability of surfactants may also reduce the effectiveness of bioremediation. Development of effective technologies using microbial surfactants should include the following steps: monitoring of contaminated sites to determine the nature of pollution and analysis of the autochthonous microbiota; determining the mode of surfactant introduction (exogenous addition of stimulation of surfactant synthesis by autochthonous microbiota; establishing an optimal concentration of surfactant to prevent exhibition of antimicrobial properties and rapid biodegradation; research both in laboratory and field conditions.

  8. Methotrexate intercalated layered double hydroxides with the mediation of surfactants: Mechanism exploration and bioassay study

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Chao-Fan; Tian, De-Ying; Li, Shu-Ping, E-mail: lishuping@njnu.edu.cn; Li, Xiao-Dong

    2015-12-01

    Methotrexatum intercalated layered double hydroxides (MTX/LDHs) hybrids were synthesized by the co-precipitation method and three kinds of nonionic surfactants with different hydrocarbon chain lengths were used. The resulting hybrids were then characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM). XRD and FTIR investigations manifest the successful intercalation of MTX anions into the interlayer of LDHs. TEM graphs indicate that the morphology of the hybrids changes with the variation of the chain length of the surfactants, i.e., the particles synthesized using polyethylene glycol (PEG-7) present regular disc morphology with good monodispersity, while samples with the mediation of alkyl polyglycoside (APG-14) are heavily aggregated and samples with the addition of polyvinylpyrrolidone (PVP-10) exhibit irregular branches. Furthermore, the release and bioassay experiments show that monodisperse MTX/LDHs present good controlled-release and are more efficient in the suppression of the tumor cells. - Highlights: • Surfactants could be used to modify the dispersing state of MTX/LDHs hybrids. • Surfactants have great effect on the morphology of MTX/LDHs hybrids. • MTX/LDHs with good monodisperse degree are more efficient in the suppression of the tumor cells.

  9. Synthesis and characterization of emamectin-benzoate slow-release microspheres with different surfactants.

    Science.gov (United States)

    Wang, Yan; Wang, Anqi; Wang, Chunxin; Cui, Bo; Sun, Changjiao; Zhao, Xiang; Zeng, Zhanghua; Shen, Yue; Gao, Fei; Liu, Guoqiang; Cui, Haixin

    2017-10-06

    Pesticide slow-release formulations provide a way to increase the efficiency of active components by reducing the amount of pesticide that needs to be applied. Slow-release formulations also increase the stability and prolong the control effect of photosensitive pesticides. Surfactants are an indispensable part of pesticide formulations, and the choice of surfactant can strongly affect formulation performance. In this study, emamectin-benzoate (EMB) slow-release microspheres were prepared by the microemulsion polymerization method. We explored the effect of different surfactants on the particle size and dispersity of EMB in slow-release microspheres. The results indicated that the samples had uniform spherical shapes with an average diameter of 320.5 ±5.24 nm and good dispersity in the optimal formulation with the polymeric stabilizer polyvinyl alcohol (PVA) and composite non-ionic surfactant polyoxyethylene castor oil (EL-40). The optimal EMB pesticide slow-release microspheres had excellent anti-photolysis performance, stability, controlled release properties, and good leaf distribution. These results demonstrated that EMB slow-release microspheres are an attractive candidate for improving pesticide efficacy and prolonging the control effect of EMB in the environment.

  10. Optimizing the surfactant for the aqueous processing of LiFePO{sub 4} composite electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Porcher, W.; Jouanneau, S. [Commissariat a l' Energie Atomique, 38054 Grenoble Cedex 9 (France); Lestriez, B.; Guyomard, D. [Institut des Materiaux Jean Rouxel (IMN), Universite de Nantes, CNRS, 44322 Nantes Cedex 3 (France)

    2010-05-01

    Aqueous processing would reduce the costs associated with the making of the composite electrode. To achieve the incorporation and the dispersion of the carbon black (CB) conductive agent in aqueous slurries, a surfactant is needed. In this paper, three surfactants are compared, an anionic one, the sodium dodecyle sulphate (SDS), a non-ionic one, the isooctylphenylether of polyoxyethylene called commercially Triton X-100 and a cationic one, the hexadecyltrimethylammonium bromide (CTAB), by using rheology and laser granulometry measurements on electrode slurries on one hand, and SEM observations, porosity and adhesion measurements and electrochemical testing on composite electrodes on the other hand. Ionic surfactants were found to be not suitable because a corrosion of the aluminium current collector occurred. The utilization of Triton X-100 favoured a more homogeneous CB distribution, resulted in a better electronic wiring of the active material particles and higher rate behavior of the electrode. Optimal electrochemical performances are obtained for an optimal surfactant concentration which depends on the BET surface area of the CB powder. (author)

  11. Role of surfactant on thermoelectric behaviors of organic-inorganic composites

    Science.gov (United States)

    Shin, Sunmi; Roh, Jong Wook; Kim, Hyun-Sik; Chen, Renkun

    2018-05-01

    Hybrid organic/inorganic composites have recently attracted intensive interests as a promising candidate for flexible thermoelectric (TE) devices using inherently soft polymers as well as for increasing the degree of freedom to control TE properties. Experimentally, however, enhanced TE performance in hybrid composites has not been commonly observed, primarily due to inhomogeneous mixing between the inorganic and organic components which leads to limited electrical conduction in the less conductive component and consequently a low power factor in the composites compared to their single-component counterparts. In this study, we investigated the effects of different surfactants on the uniformity of mixing and the TE behaviors of the hybrid composites consisting of Bi0.5Sb1.5Te3 (BST) and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). We found that compared to dimethyl sulfoxide, which is the most widely used surfactant, Triton X-100 (TX-100) can lead to homogenous dispersion of BST in PEDOT:PSS. By systematically studying the effects of the surfactant concentration, we can attribute the better mixing capability of TX-100 to its non-ionic property, which results in homogenous mixing with a lower critical micelle concentration. Consequently, we observed simultaneous increase in electrical conductivity and Seebeck coefficient in the BST/PEDOT:PSS composites with the TX-100 surfactant.

  12. Effect of laundry surfactants on surface charge and colloidal stability of silver nanoparticles.

    Science.gov (United States)

    Skoglund, Sara; Lowe, Troy A; Hedberg, Jonas; Blomberg, Eva; Wallinder, Inger Odnevall; Wold, Susanna; Lundin, Maria

    2013-07-16

    The stability of silver nanoparticles (Ag NPs) potentially released from clothing during a laundry cycle and their interactions with laundry-relevant surfactants [anionic (LAS), cationic (DTAC), and nonionic (Berol)] have been investigated. Surface interactions between Ag NPs and surfactants influence their speciation and stability. In the absence of surfactants as well as in the presence of LAS, the negatively charged Ag NPs were stable in solution for more than 1 day. At low DTAC concentrations (≤1 mM), DTAC-Ag NP interactions resulted in charge neutralization and formation of agglomerates. The surface charge of the particles became positive at higher concentrations due to a bilayer type formation of DTAC that prevents from agglomeration due to repulsive electrostatic forces between the positively charged colloids. The adsorption of Berol was enhanced when above its critical micelle concentration (cmc). This resulted in a surface charge close to zero and subsequent agglomeration. Extended DLVO theory calculations were in compliance with observed findings. The stability of the Ag NPs was shown to depend on the charge and concentration of the adsorbed surfactants. Such knowledge is important as it may influence the subsequent transport of Ag NPs through different chemical transients and thus their potential bioavailability and toxicity.

  13. Study of the enhanced oil recovery with surfactant based systems; Estudo de recuperacao avancada de petroleo por sistemas a base de tensoativos

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro Neto, Valdir Cotrim; Paulino, Luisa Cimatti; Acyoly, Alessandra; Santos, Enio Rafael M.; Dantas Neto, Afonso Avelino [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    The recent changes in the world scenario, the large reserves of heavy oils and also the lack of new discoveries of large petroleum fields are indications that, in the near future, the oil recovery by conventional methods will be limited. In order to increase the efficiency of the extraction process, it must be used enhanced recovery methods. One of these technologies is the injection of surfactant solutions, where exists a chemical interaction between the injected fluid and the reservoir's fluid. With this in mind, this work was developed with two main objectives: to study of parameters that influence the surfactant behavior in solution, namely the critical micelle concentration (CMC), the surface and interface tensions between fluids and the evaluation of oil recovery with these solutions. After the Botucatu sandstone (Brazil) porosity study, the plug samples were submitted to assay steps comprising saturation with seawater and petroleum, conventional recovery with seawater and enhanced recovery with surfactant solutions. The solutions were studied in enhanced recovery step, when the plug samples could already be compared to a mature field. The PJN surfactant, at a concentration 1000% above CMC in water, had a higher recovery factor, causing the original oil in place to be recovered by an extra 20.97%, after conventional recovery with seawater. (author)

  14. Dynamics of Surfactant Clustering at Interfaces and Its Influence on the Interfacial Tension: Atomistic Simulation of a Sodium Hexadecane-Benzene Sulfonate-Tetradecane-Water System.

    Science.gov (United States)

    Paredes, Ricardo; Fariñas-Sánchez, Ana Isabel; Medina-Rodrı Guez, Bryan; Samaniego, Samantha; Aray, Yosslen; Álvarez, Luis Javier

    2018-03-06

    The process of equilibration of the tetradecane-water interface in the presence of sodium hexadecane-benzene sulfonate is studied using intensive atomistic molecular dynamics simulations. Starting as an initial point with all of the surfactants at the interface, it is obtained that the equilibration time of the interface (several microseconds) is orders of magnitude higher than previously reported simulated times. There is strong evidence that this slow equilibration process is due to the aggregation of surfactants molecules on the interface. To determine this fact, temporal evolution of interfacial tension and interfacial formation energy are studied and their temporal variations are correlated with cluster formation. To study cluster evolution, the mean cluster size and the probability that a molecule of surfactant chosen at random is free are obtained as a function of time. Cluster size distribution is estimated, and it is observed that some of the molecules remain free, whereas the rest agglomerate. Additionally, the temporal evolution of the interfacial thickness and the structure of the surfactant molecules on the interface are studied. It is observed how this structure depends on whether the molecules agglomerate or not.

  15. Radiation protection problems by nonionizing electromagnetic radiation in Austria

    International Nuclear Information System (INIS)

    Duftschmid, K.E.

    1984-03-01

    Since about one year an interdisciplinary study group has been established to investigate possible radiation protection problems caused by nonionizing electromagnetic radiation in this country. The aim of this project is to identify major fields of concern, to establish appropriate techniques of measurement and control and eventually develop a sound basis for future legislation. The paper gives a summary on the present results of this study. (Author)

  16. Can Serum Surfactant Protein D or CC-Chemokine Ligand 18 Predict Outcome of Interstitial Lung Disease in Patients with Early Systemic Sclerosis?

    Science.gov (United States)

    Elhaj, Mona; Charles, Julio; Pedroza, Claudia; Liu, Xiaochun; Zhou, Xiaodong; Estrada-Y-Martin, Rosa M.; Gonzalez, Emilio B.; Lewis, Dorothy E.; Draeger, Hilda T.; Kim, Sarah; Arnett, Frank C.; Mayes, Maureen D.; Assassi, Shervin

    2013-01-01

    Objective To examine the predictive significance of 2 pneumoproteins, surfactant protein D (SP-D) and CC-chemokine ligand 18 (CCL18), for the course of systemic sclerosis (SSc)-related interstitial lung disease. Methods The pneumoproteins were determined in the baseline plasma samples of 266 patients with early SSc enrolled in the GENISOS observational cohort. They also were measured in 83 followup patient samples. Pulmonary function tests were obtained annually. The primary outcome was decline in forced vital capacity (FVC percentage predicted) over time. The predictive significance for longterm change in FVC was investigated by a joint analysis of longitudinal measurements (sequentially obtained FVC percentage predicted) and survival data. Results SP-D and CCL18 levels were both higher in patients with SSc than in matched controls (p < 0.001 and p = 0.015, respectively). Baseline SP-D levels correlated with lower concomitantly obtained FVC (r = −0.27, p < 0.001), but did not predict the short-term decline in FVC at 1 year followup visit or its longterm decline rate. CCL18 showed a significant correlation with steeper short-term decline in FVC (p = 0.049), but was not a predictor of its longterm decline rate. Similarly, a composite score of SP-D and CCL18 was a significant predictor of short-term decline in FVC but did not predict its longterm decline rate. Further, the longitudinal change in these 2 pneumoproteins did not correlate with the concomitant percentage change in FVC. Conclusion SP-D correlated with concomitantly obtained FVC, while CCL18 was a predictor of short-term decline in FVC. However, neither SP-D nor CCL18 was a longterm predictor of FVC course in patients with early SSc. PMID:23588945

  17. Tuning the probe location on zwitterionic micellar system with variation of pH and addition of surfactants with different alkyl chains: solvent and rotational relaxation studies.

    Science.gov (United States)

    Banerjee, Chiranjib; Mandal, Sarthak; Ghosh, Surajit; Rao, Vishal Govind; Sarkar, Nilmoni

    2012-09-13

    In this manuscript, we have modulated the location of an anionic probe, Coumarin-343 (C-343) in a zwitterionic (N-hexadecyl-N,N-dimethylammonio-1-propanesulfonate (SB-16)) micellar system by three different approaches. The effect of addition of the surfactant sodium dodecyl sulfate (SDS) and the room temperature ionic liquid (RTIL), 1-ethyl-3-methylimidazolium octylsulfate (EmimOs) and N,N-dimethylethanol hexanoate (DAH), to the micellar solution has been studied. The effect of pH variation has been studied as well using solvent and rotational measurements. Migration of the anionic probe, C-343, from the palisade layer of SB-16 micelle to the bulk water has been observed to varying extents with the addition of SDS and EmimOs. The effect is much more pronounced in the presence of SDS and can be ascribed to the presence of the long alkyl (dodecyl) chain on SDS which can easily orient itself and fuse inside the SB-16 micelle and facilitate the observed migration of the probe molecule. This phenomenon is confirmed by faster solvation and rotational relaxation of the investigated probe molecule. The analogous fusion process is difficult in case of EmimOs and DAH because of their comparatively smaller alkyl (octyl and hexanoate) chain. However, the direction of C-343 migration is reversed with the decrease of pH of the SB-16 micellar medium. An increase in the average solvation and rotational relaxation time of the probe in acidic medium has been observed. Since experimental conditions are maintained such that the probe molecules and the zwitterionic SB-16 micelles remain oppositely charged, the observed results can be attributed to the increased electrostatic interaction (attractive) between them. Temperature dependent study also supports this finding.

  18. Interaction between water-soluble rhodium complex RhCl(CO)(TPPTS)₂ and surfactants probed by spectroscopic methods.

    Science.gov (United States)

    Zhou, Li-Mei; Guo, Cai-Hong; Fu, Hai-Yan; Jiang, Xiao-Hui; Chen, Hua; Li, Rui-Xiang; Li, Xian-Jun

    2012-07-01

    The interactions of rhodium complex RhCl(CO)(TPPTS)(2) [TPPTS=P(m-C(6)H(4)SO(3)Na)(3)] with cationic, nonionic, and anionic surfactants have been investigated by UV-vis, fluorescence and (1)H NMR measurements. The presence of four different species of RhCl(CO)(TPPTS)(2) in cationic cetyltrimethylammonium (CTAB) solution has been demonstrated: free rhodium complex, rhodium complex bound to CTAB monomer, rhodium complex bound to CTAB premicelles, rhodium complex bound to CTAB micelles. The spectroscopy data show that RhCl(CO)(TPPTS)(2) can adsorb on the interface of cationic CTAB micelles by strong electrostatic attraction, weakly bind to the nonionic polyoxyethylene (20) sorbitan monolaurate (Tween 20) micelles by hydrophobic interaction, and does not interact with anion sodium dodecyl sulfate (SDS) micelles due to the strong electrostatic repulsion. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Biodegradation of surfactant bearing wastes

    International Nuclear Information System (INIS)

    Chitra, S.; Chandran, S.; Sasidhar, P.; Lal, K.B.; Amalraj, R.V.

    1991-01-01

    In nuclear industry, during decontamination of protective wears and contaminated materials, detergents are employed to bring down the level of radioactive contamination within safe limits. However, the surfactant present in these wastes interferes in the chemical treatment process, reducing the decontamination factor. Biodegradation is an efficient and ecologically safe method for surfactant removal. A surfactant degrading culture was isolated and inoculated separately into simulated effluents containing 1% yeast extract and 5-100 ppm sodium lauryl sulphate (SLS) and 1% yeast extract and 5-100 ppm of commercial detergent respectively. The growth of the bacterial culture and the degradation characteristics of the surfactant in the above effluents were monitored under both dynamic and static conditions. (author). 6 refs., 6 figs., 1 tab

  20. Treatment with exogenous surfactant stimulates endogenous surfactant synthesis in premature infants with respiratory distress syndrome

    NARCIS (Netherlands)

    Bunt, JEH; Carnielli, VP; Janssen, DJ; Wattimena, JLD; Hop, WC; Sauer, PJ; Zimmermann, LJI

    2000-01-01

    Objective: Treatment of preterm infants with respiratory distress syndrome (RDS) with exogenous surfactant has greatly improved clinical outcome. Some infants require multiple doses, and it has not been studied whether these large amounts of exogenous surfactant disturb endogenous surfactant

  1. Molecular dynamics simulations of surfactant and nanoparticle self-assembly at liquid-liquid interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Luo Mingxiang; Dai, Lenore L [Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409 (United States)

    2007-09-19

    We have performed molecular dynamics (MD) simulations to investigate self-assembly at water-trichloroethylene (TCE) interfaces with the emphasis on systems containing modified hydrocarbon nanoparticles (1.2 nm in diameter) and sodium dodecyl sulfate (SDS) surfactants. The nanoparticles and surfactants were first distributed randomly in the water phase. The MD simulations have clearly shown the progress of migration and final equilibrium of the SDS molecules at the water-TCE interfaces with the nanoparticles either at or in the vicinity of the interfaces. One unique feature is the 'attachment' of surfactant molecules to the nanoparticle clusters in the water phase followed by the 'detachment' at the water-TCE interfaces. At low concentrations of surfactants, the surfactants and nanoparticles co-equilibrate at the interfaces. However, the surfactants, at high concentrations, competitively dominate the interfaces and deplete nanoparticles away from the interfaces. The interfacial properties, such as interfacial thickness and interfacial tension, are significantly influenced by the presence of the surfactants, but not the nanoparticles. The order of the surfactants at the interfaces increases with increasing surfactant concentration, but is independent of nanoparticle concentration. Finally, the simulation has shown that surfactants can aggregate along the water-TCE interfaces, with and without the presence of nanoparticles.

  2. Surfactant therapy for maternal blood aspiration: an unusual cause of neonatal respiratory distress syndrome.

    Science.gov (United States)

    Celik, Istemi Han; Demirel, Gamze; Canpolat, Fuat Emre; Erdeve, Omer; Dilmen, Ugur

    2012-10-01

    Surfactant replacement therapy is the main treatment of neonatal respiratory distress syndrome. However, surfactant therapy has been shown to be effective in the treatment of other diseases causing neonatal respiratory diseases such as pulmonary hemorrhage, meconium aspiration syndrome, pneumonia/sepsis, pulmonary edema or acute lung injury resulting a secondary surfactant deficiency (SSD). Rarely, as like as in the present patient, exogenous blood aspiration such as breast milk or formula aspiration may lead to SSD. Blood in alveolus leads to a significant biochemical and functional disturbance of the surfactant system and inhibits surfactant production. Here, the authors report a preterm infant of 33 wk gestational age with secondary surfactant deficiency due to maternal blood aspiration because of abruptio placentae. She was received two courses of beractant, a natural bovine surfactant, therapy in 24 h. She was extubated on second day and did not require oxygen on 4(th) day. To the authors' knowledge, this is the first reported case of SSD due to maternal blood aspiration treated with surfactant. In conditions such as abruptio placentae, infant should be protected from blood aspiration and if respiratory distress occurs, surfactant inhibition and need for surfactant administration should be considered.

  3. Enhanced oil recovery with surfactant flooding

    Energy Technology Data Exchange (ETDEWEB)

    Buelow Sandersen, S.

    2012-05-15

    Understanding the underlying mechanisms of systems that exhibit liquid-liquid equilibrium (e.g. oil-brine systems) at reservoir conditions is an area of increasing interest within EOR. This is true both for complex surfactant systems as well as for oil and brine systems. It is widely accepted that an increase in oil recovery can be obtained through flooding, whether it is simple waterflooding, waterflooding where the salinity has been modified by the addition or removal of specific ions (socalled ''smart'' waterflooding) or surfactant flooding. High pressure experiments have been carried out in this work on a surfactant system (surfactant/ oil/ brine) and on oil/ seawater systems (oil/ brine). The high pressure experiments were carried out on a DBR JEFRI PVT cell, where a glass window allows observation of the phase behavior of the different systems at various temperatures and pressures inside the high pressure cell. Phase volumes can also be measured visually through the glass window using precision equipment. The surfactant system for which an experimental study was carried out consisted of the mixture heptane, sodium dodecyl sulfate (SDS)/ 1-butanol/ NaCl/ water. This system has previously been examined at ambient pressures and temperatures but this has been extended here to pressures up to 400 bar and to slightly higher temperatures (40 deg. C, 45 deg. C and 50 deg. C). Experiments were performed at constant salinity (6.56 %), constant surfactant-alcohol ratio (SAR) but with varying water-oil ratios (WOR). At all temperatures it was very clear that the effect of pressure was significant. The system changed from the two phase region, Winsor II, to the three phase region, Winsor III, as pressure increased. Increasing pressures also caused a shift from the three phase region (Winsor III), to a different two phase region, (Winsor I). These changes in equilibrium phase behavior were also dependent on the composition of the system. A number of

  4. Dispersion of nanoparticulate suspensions using self-assembled surfactant aggregates

    Science.gov (United States)

    Singh, Pankaj Kumar

    The dispersion of particles is critical for several industrial applications such as paints, inks, coatings, and cosmetics. Several emerging applications such as abrasives for precision polishing, and drug delivery systems are increasingly relying on nanoparticulates to achieve the desired performance. In the case of nanoparticles, the dispersion becomes more challenging because of the lack of fundamental understanding of dispersant adsorption and interparticle force prediction. Additionally, many of these processes use severe processing environments such as high normal forces (>100 mN/m), high shear forces (>10,000 s -1), and high ionic strengths (>0.1 M). Under such processing conditions, traditionally used dispersants based on electrostatics, and steric force repulsion mechanism may not be adequate. Hence, the development of optimally performing dispersants requires a fundamental understanding of the dispersion mechanism at the atomic/molecular scale. This study explores the use of self-assembled surfactant aggregates at the solid-liquid interface for dispersing nanoparticles in severe processing environments. Surfactant molecules can provide a feasible alternative to polymeric or inorganic dispersants for stabilizing ultrafine particles. The barrier to aggregation in the presence of surfactant molecules was measured using atomic force microscopy. The barrier heights correlated to suspension stability. To understand the mechanism for nanoparticulate suspension stability in the presence of surfactant films, the interface was characterized using zeta potential, contact angle, adsorption, and FT-IR (adsorbed surfactant film structure measurements). The effect of solution conditions such as pH and ionic strength on the suspension stability, and the self-assembled surfactant films was also investigated. It was determined that a transition from a random to an ordered orientation of the surfactant molecules at the interface was responsible for stability of

  5. Nanoparticle decoration with surfactants: Molecular interactions, assembly, and applications

    Science.gov (United States)

    Heinz, Hendrik; Pramanik, Chandrani; Heinz, Ozge; Ding, Yifu; Mishra, Ratan K.; Marchon, Delphine; Flatt, Robert J.; Estrela-Lopis, Irina; Llop, Jordi; Moya, Sergio; Ziolo, Ronald F.

    2017-02-01

    Nanostructures of diverse chemical nature are used as biomarkers, therapeutics, catalysts, and structural reinforcements. The decoration with surfactants has a long history and is essential to introduce specific functions. The definition of surfactants in this review is very broad, following its lexical meaning ;surface active agents;, and therefore includes traditional alkyl modifiers, biological ligands, polymers, and other surface active molecules. The review systematically covers covalent and non-covalent interactions of such surfactants with various types of nanomaterials, including metals, oxides, layered materials, and polymers as well as their applications. The major themes are (i) molecular recognition and noncovalent assembly mechanisms of surfactants on the nanoparticle and nanocrystal surfaces, (ii) covalent grafting techniques and multi-step surface modification, (iii) dispersion properties and surface reactions, (iv) the use of surfactants to influence crystal growth, as well as (v) the incorporation of biorecognition and other material-targeting functionality. For the diverse materials classes, similarities and differences in surfactant assembly, function, as well as materials performance in specific applications are described in a comparative way. Major factors that lead to differentiation are the surface energy, surface chemistry and pH sensitivity, as well as the degree of surface regularity and defects in the nanoparticle cores and in the surfactant shell. The review covers a broad range of surface modifications and applications in biological recognition and therapeutics, sensors, nanomaterials for catalysis, energy conversion and storage, the dispersion properties of nanoparticles in structural composites and cement, as well as purification systems and classical detergents. Design principles for surfactants to optimize the performance of specific nanostructures are discussed. The review concludes with challenges and opportunities.

  6. Controlling Active Liquid Crystal Droplets with Temperature and Surfactant Concentration

    Science.gov (United States)

    Shechter, Jake; Milas, Peker; Ross, Jennifer

    Active matter is the study of driven many-body systems that span length scales from flocking birds to molecular motors. A previously described self-propelled particle system was made from liquid crystal (LC) droplets in water with high surfactant concentration to move particles via asymmetric surface instabilities. Using a similar system, we investigate the driving activity as a function of SDS surfactant concentration and temperature. We then use an optical tweezer to trap and locally heat the droplets to cause hydrodynamic flow and coupling between multiple droplets. This system will be the basis for a triggerable assembly system to build and couple LC droplets. DOD AROMURI 67455-CH-MUR.

  7. Non-ionic, thermo-responsive DEA/DMA nanogels: synthesis, characterization, and use for DNA separations by microchip electrophoresis.

    Science.gov (United States)

    Lu, Xihua; Sun, Mingyun; Barron, Annelise E

    2011-05-15

    Thermo-responsive polymer "nanogels" (crosslinked hydrogel particles with sub-100 nm diameters) are intriguing for many potential applications in biotechnology and medicine. There have been relatively few reports of electrostatically neutral, thermosensitive nanogels comprising a high fraction of hydrophilic co-monomer. Here we demonstrate the syntheses and characterization of novel, non-ionic nanogels based on random N,N-diethylacrylamide (DEA)/N,N-dimethylacrylamide (DMA) copolymers, made by free-radical, surfactant-free dispersion polymerization. The volume-phase transition temperatures of these DEA/DMA nanogels are strongly affected by co-monomer composition, providing a way to "tune" the phase transition temperature of these non-ionic nanogels. While DEA nanogels (comprising no DMA) can be obtained at 70 °C by standard emulsion precipitation, DEA/DMA random co-polymer nanogels can be obtained only in a particular range of temperatures, above the initial phase transition temperature and below the critical precipitation temperature of the DEA/DMA copolymer, controlled by co-monomer composition. Increasing percentages of DMA in the nanogels raises the phase transition temperature, and attenuates and broadens it as well. We find that concentrated DEA/DMA nanogel dispersions are optically clear at room temperature. This good optical clarity was exploited for their use in a novel DNA sieving matrix for microfluidic chip electrophoresis. An ultrafast, high-efficiency dsDNA separation was achieved in less than 120 s for dsDNA ranging from 75 bp to 15,000 bp. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Respiratory Mechanics and Gas Exchange: The Effect of Surfactants

    Science.gov (United States)

    Jbaily, Abdulrahman; Szeri, Andrew J.

    2017-11-01

    The purpose of the lung is to exchange gases, primarily oxygen and carbon dioxide, between the atmosphere and the circulatory system. To enable this exchange, the airways in the lungs terminate in some 300 million alveoli that provide adequate surface area for transport. During breathing, work must be done to stretch various tissues to accommodate a greater volume of gas. Considerable work must also be done to expand the liquid lining (hypophase) that coats the interior surfaces of the alveoli. This is enabled by a surface active lipo-protein complex, known as pulmonary surfactant, that modifies the surface tension at the hypophase-air interface. Surfactants also serve as physical barriers that modify the rate of gas transfer across interfaces. We develop a mathematical model to study the action of pulmonary surfactant and its determinative contributions to breathing. The model is used to explore the influence of surfactants on alveolar mechanics and on gas exchange: it relates the work of respiration at the level of the alveolus to the gas exchange rate through the changing influence of pulmonary surfactant over the breathing cycle. This work is motivated by a need to develop improved surfactant replacement therapies to treat serious medical conditions.

  9. Splash Dynamics of Falling Surfactant-Laden Droplets

    Science.gov (United States)

    Sulaiman, Nur; Buitrago, Lewis; Pereyra, Eduardo

    2017-11-01

    Splashing dynamics is a common issue in oil and gas separation technology. In this study, droplet impact of various surfactant concentrations onto solid and liquid surfaces is studied experimentally using a high-speed imaging analysis. Although this area has been widely studied in the past, there is still not a good understanding of the role of surfactant over droplet impact and characterization of resulting splash dynamics. The experiments are conducted using tap water laden with anionic surfactant. The effects of system parameters on a single droplet impingement such as surfactant concentration (no surfactant, below, at and above critical micelle concentration), parent drop diameter (2-5mm), impact velocity and type of impact surface (thin and deep pool) are investigated. Image analysis technique is shown to be an effective technique for identification of coalescence to splashing transition. In addition, daughter droplets size distributions are analyzed qualitatively in the events of splashing. As expected, it is observed that the formation of secondary droplets is affected by the surfactant concentration. A summary of findings will be discussed.

  10. Study of surfactant-free microemulsions and microemulsions with fatty acid salts

    OpenAIRE

    Marcus, Julien

    2016-01-01

    This thesis deals with the study of microemulsions and is composed of two main parts. In the first part, surfactant-free microemulsions are studied, whereas in the second part microemulsions with surfactants and cosurfactants are investigated. Over the last few years, surfactant-free microemulsions became a major topic at our institute and were thoroughly studied using the reference system water/ethanol/1-octanol. As explained later in the Fundamentals part (see section 1.2), fluctuating ...

  11. Structure-function relationships in pulmonary surfactant membranes: from biophysics to therapy.

    Science.gov (United States)

    Lopez-Rodriguez, Elena; Pérez-Gil, Jesús

    2014-06-01

    Pulmonary surfactant is an essential lipid-protein complex to maintain an operative respiratory surface at the mammalian lungs. It reduces surface tension at the alveolar air-liquid interface to stabilise the lungs against physical forces operating along the compression-expansion breathing cycles. At the same time, surfactant integrates elements establishing a primary barrier against the entry of pathogens. Lack or deficiencies of the surfactant system are associated with respiratory pathologies, which treatment often includes supplementation with exogenous materials. The present review summarises current models on the molecular mechanisms of surfactant function, with particular emphasis in its biophysical properties to stabilise the lungs and the molecular alterations connecting impaired surfactant with diseased organs. It also provides a perspective on the current surfactant-based strategies to treat respiratory pathologies. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Surfactant flooding of diesel-contaminated soils

    International Nuclear Information System (INIS)

    Peters, R.W.; Montemagno, C.D.; Shem, L.; Lewis, B.A.

    1991-01-01

    At one installation, approximately 60,000 gallons of No. 2 diesel fuel leaked into the subsurface environment, with contamination at depths of 6 to 34 m below the surface. Argonne National Laboratory was contracted to perform treatability studies for site remediation. The treatability studies focused on four separate phases: (1) leachability studies on the various contaminated soil borings, (2) air stripping studies, (3) bioremediation studies, and (4) surfactant screening/surfactant flooding studies. This paper summarizes the fourth phase of this research program after initial surfactant screening of 21 surfactants. Three of the surfactants were used for the surfactant flooding studies; the results from that phase of the research program are described

  13. Determination of the Critical Micelle Concentration of Neutral and Ionic Surfactants with Fluorometry, Conductometry, and Surface Tension-A Method Comparison.

    Science.gov (United States)

    Scholz, Norman; Behnke, Thomas; Resch-Genger, Ute

    2018-01-01

    Micelles are of increasing importance as versatile carriers for hydrophobic substances and nanoprobes for a wide range of pharmaceutical, diagnostic, medical, and therapeutic applications. A key parameter indicating the formation and stability of micelles is the critical micelle concentration (CMC). In this respect, we determined the CMC of common anionic, cationic, and non-ionic surfactants fluorometrically using different fluorescent probes and fluorescence parameters for signal detection and compared the results with conductometric and surface tension measurements. Based upon these results, requirements, advantages, and pitfalls of each method are discussed. Our study underlines the versatility of fluorometric methods that do not impose specific requirements on surfactants and are especially suited for the quantification of very low CMC values. Conductivity and surface tension measurements yield smaller uncertainties particularly for high CMC values, yet are more time- and substance consuming and not suitable for every surfactant.

  14. Application of Surfactant Micellar Solutions as Extractants and Mobile Phases for TLC-Determination of Purine Bases and Doping Agents in Biological Liquids

    Directory of Open Access Journals (Sweden)

    Daria Victorovna Yedamenko

    2015-04-01

    Full Text Available Separation of caffeine and its metabolites (theophylline and theobromine and doping agents (spironolactone, propranolol, and ephedrine and determination of caffeine in serum sample and propranolol and ephedrine in urine were studied on normal-phase thin layers (“Sorbfil-UV-254”. Aqueous organic solvents and aqueous micellar surfactant solutions were compared as the mobile phases for separation. The acceptable separation of purine bases and doping agents was achieved by micellar Thin Layer Chromatography and normal-phase Thin Layer Chromatography. Anionic surfactant solution with added 1-propanol was the best eluent as for caffeine, theophylline, and theobromine separation, as for doping agents. The best characteristics of caffeine extraction from serum, and propranolol and ephedrine from urine were achieved when micellar eluent based on non-ionic Tween-80 surfactant was used. DOI: http://dx.doi.org/10.17807/orbital.v7i1.632

  15. Mutagenicity of diesel exhaust soot dispersed in phospholipid surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, W.; Keane, M.; Xing, S.; Harrison, J.; Gautam, M.; Ong, T.

    1994-06-01

    Organics extractable from respirable diesel exhaust soot particles by organic solvents have been known for some time to be direct acting frameshift mutagens in the Ames Salmonella typhimurium histidine reversion assay. Upon deposition in a pulmonary alveolus or respiratory bronchiole, respirable diesel soot particles will contact first the hypophase which is coated by and laden with surfactants. To model interactions of soot and pulmonary surfactant, the authors dispersed soots in vitro in the primary phospholipid pulmonary surfactant dipalmitoyl glycerophosphorylcholine (lecithin) (DPL) in physiological saline. They have shown that diesel soots dispersed in lecithin surfactant can express mutagenic activity, in the Ames assay system using S. typhimurium TA98, comparable to that expressed by equal amounts of soot extracted by dichloromethane/dimethylsulfoxide (DCM/DMSO). Here the authors report additional data on the same system using additional exhaust soots and also using two other phospholipids, dipalmitoyl glycerophosphoryl ethanolamine (DPPE), and dipalmitoyl phosphatidic acid (DPPA), with different ionic character hydrophilic moieties. A preliminary study of the surfactant dispersed soot in an eucaryotic cell test system also is reported.

  16. Impacts of Natural Surfactant Soybean Phospholipid on Wettability of High-rank Coal Reservoir

    Science.gov (United States)

    Lyu, S.; Xiao, Y.; Yuan, M.; Wang, S.

    2017-12-01

    It is significant to change the surface wettability of coal rock with the surfactant in coal mining and coalbed methane exploitation. Soybean phospholipid (SP) is a kind of natural zwitterionic surfactant which is non-toxic and degradable. In order to study the effects of soybean phospholipid on wettability of high-rank coal in Qinshui Basin, some experiments including surface tension test, contact angle measurement on the coal surface, coal fines imbibition, observation of dispersion effect and gas permeability test were carried out, and water locking mechanism of fracturing fluid in micro fractures of coal reservoir was analyzed. The results show that the surface of high-rank coal was negatively charged in solution and of weak hydrophilicity. The soybean phospholipid with the mass fraction of 0.1% reduced the surface tension of water by 69%, and increased the wettability of coal. Meanwhile, the soybean phospholipid helped coal fines to disperse by observation of the filter cake with the scanning electron microscope. The rising rate of soybean phospholipid solution in the pipe filled with coal fines was lower than that of anionic and cationic surfactant, higher than that of clean water and non-ionic surfactant. Composite surfactant made up of soybean phospholipid and OP-10 at the ratio of 1:3 having a low surface tension and large contact angle, reduced the capillary force effectively, which could be conducive to discharge of fracturing fluid from coal reservoir micro fracture and improve the migration channels of gas. Therefore it has a broad application prospect.

  17. Surfactants enhance recovery of poorly soluble drugs during microdialysis sampling

    DEFF Research Database (Denmark)

    Koplin, Sebastian; Kumpugdee-Vollrath, Mont; Bauer-Brandl, Annette

    2017-01-01

    Aim of this project was to investigate the applicability of a recently developed in vitro microdialysis-sampling approach in connection with a dissolution-/permeation (D/P) system, especially the impact of surfactants within the perfusion fluid. The D/P-system is based on side-by-side chambers...... drug-dissolution (-release) and drug permeation. Furthermore, it should allow quantification of the unbound (free) drug concentration. In the first step, it was assessed, if the addition of the anionic surfactant sodium dodecyl sulphate (SDS) to the perfusate of the microdialysis system affects...... celecoxib, i.e. the fraction of drug, which is not associated with taurocholate surfactant micelles. In buffer, the measured concentrations matched the overall CXB concentrations. By the use of SDS-containing perfusates microdialysis sampling enabled reliable quantification of minute amounts of free CXB...

  18. Acidity Constants Determination of Triazine Dye Derivative in the presence of some Surfactants by Multiwavelength Spectrophotometr