WorldWideScience

Sample records for surfactant hydrocarbon chain

  1. 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.

  2. 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)

  3. Recovering hydrocarbons with surfactants from lignin

    Energy Technology Data Exchange (ETDEWEB)

    Naae, D.G.; Whittington, L.E.; Ledoux, W.A.; Debons, F.E.

    1988-11-29

    This patent describes a method of recovering hydrocarbons from an underground hydrocarbon formation penetrated by at least one injection well and at least one production well, which comprises: injecting into the formation through an injection well a surfactant slug comprising about 0.1% to about 10% by weight of surfactants produced from lignin, the surfactants produced by placing lignin in contact with water, converting the lignin into low molecular weight lignin phenols by reducing the lignin in the presence of a reducing agent of carbon monoxide or hydrogen creating a reduction reaction mixture comprising oil soluble lignin phenols, the reduction occurring at a temperature greater than about 200/sup 0/C and a pressure greater than about 100 psi, recovering the oil soluble lignin phenols from the reduction mixture, and converting the lignin phenols into lignin surfactants by a reaction selected from the group consisting of alkoxylation, sulfonation, sulfation, aklylation, sulfomethylation, and alkoxysulfation; injecting into the formation through the injection well a drive fluid to push the surfactant slug towards a production well; and recovering hydrocarbons at the production well.

  4. Hydrocarbon-degrading bacteria isolation and surfactant influence ...

    African Journals Online (AJOL)

    Hydrocarbons are substantially insoluble in water, often remaining partitioned in the non-aqueous phase liquid (NAPL). However, there had been little or no attempts to advance the bioavailability of hydrocarbons through the use of surfactants. This study was conducted based on the need to isolate hydrocarbon degrading ...

  5. HYDROCARBON-DEGRADING BACTERIA AND SURFACTANT ACTIVITY

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, R; Topher Berry, T; Grazyna A. Plaza, G; jacek Wypych, j

    2006-08-15

    Fate of benzene ethylbenzene toluene xylenes (BTEX) compounds through biodegradation was investigated using two different bacteria, Ralstonia picketti (BP-20) and Alcaligenes piechaudii (CZOR L-1B). These bacteria were isolated from extremely polluted petroleum hydrocarbon contaminated soils. PCR and Fatty Acid Methyl Ester (FAME) were used to identify the isolates. Biodegradation was measured using each organism individually and in combination. Both bacteria were shown to degrade each of the BTEX compounds. Alcaligenes piechaudii biodegraded BTEXs more efficiently while mixed with BP-20 and individually. Biosurfactant production was observed by culture techniques. In addition 3-hydroxy fatty acids, important in biosurfactant production, was observed by FAME analysis. In the all experiments toluene and m+p- xylenes were better growth substrates for both bacteria than the other BTEX compounds. In addition, the test results indicate that the bacteria could contribute to bioremediation of aromatic hydrocarbons (BTEX) pollution increase biodegradation through the action by biosurfactants.

  6. 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

  7. Biodegradation of an oil-hydrocarbon contaminated soil, enhanced by surfactants: Effect of the type and dose of surfactant

    International Nuclear Information System (INIS)

    Torres, L. G.; Galindo, C.; Rojas, N.; Iturbe, R.

    2009-01-01

    The aim of this work was to study the effect of different parameters, such as surfactant type an dose, soil initial hydrocarbons concentration, and soil granulometry, over the total petroleum hydrocarbons TPH degradation, as well as over the microbial count (as colony formation units CFU/g soil) along the process. (Author)

  8. Surfactant-enhanced recovery of dissolved hydrocarbons at petroleum production facilities

    International Nuclear Information System (INIS)

    Freeman, J.T.; Mayes, M.; Wassmuth, F.; Taylor, K.; Rae, W.; Kuipers, F.

    1997-01-01

    The feasibility and cost effectiveness of surfactant-enhanced pumping to reduce source concentrations of petroleum hydrocarbons from contaminated soils was discussed. Light non-aqueous phase liquids (LNAPL) hydrocarbons are present beneath many petroleum production processing facilities in western Canada. Complete removal of LNAPLs from geologic materials is difficult and expensive. Treatment technologies include costly ex-situ methods such as excavation and in-situ methods such as physical extraction by soil venting and pumping, bioremediation, and combination methods such as bioventing, bioslurping or air sparging. Surfactant-aided pumping can reduce source hydrocarbon concentrations when used in conjunction with traditional pump and treat, or deep well injection. This study involved the selection of an appropriate surfactant from a wide variety of commercially available products. A site contaminated by hydrocarbons in Turner Valley, Alberta, was used for field scale testing. One of the major problems was quantifying the increase in the dissolved hydrocarbon concentrations in the recovered water once a surfactant was added. From the 30 surfactants screened in a series of washing and oil solubilization tests, two surfactants, Brij 97 and Tween 80, were selected for further evaluation. Increased hydrocarbon recovery was observed within 10 days of the introduction of the first surfactant. 2 refs., 7 figs

  9. 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.

  10. 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.

  11. 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.

  12. 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.)

  13. Phase behavior, rheological property, and transmutation of vesicles in fluorocarbon and hydrocarbon surfactant mixtures.

    Science.gov (United States)

    Yuan, Zaiwu; Qin, Menghua; Chen, Xiushan; Liu, Changcheng; Li, Hongguang; Hao, Jingcheng

    2012-06-26

    We present a detailed study of a salt-free cationic/anionic (catanionic) surfactant system where a strongly alkaline cationic surfactant (tetradecyltrimethylammonium hydroxide, TTAOH) was mixed with a single-chain fluorocarbon acid (nonadecafluorodecanoic acid, NFDA) and a hyperbranched hydrocarbon acid [di-(2-ethylhexyl)phosphoric acid, DEHPA] in water. Typically the concentration of TTAOH is fixed while the total concentration and mixing molar ratio of NFDA and DEHPA is varied. In the absence of DEHPA and at a TTAOH concentration of 80 mmol·L(-1), an isotropic L(1) phase, an L(1)/L(α) two-phase region, and a single L(α) phase were observed successively with increasing mixing molar ratio of NFDA to TTAOH (n(NFDA)/n(TTAOH)). In the NFDA-rich region (n(NFDA)/n(TTAOH) > 1), a small amount of excess NFDA can be solubilized into the L(α) phase while a large excess of NFDA eventually leads to phase separation. When NFDA is replaced gradually by DEHPA, the mixed system of TTAOH/NFDA/DEHPA/H(2)O follows the same phase sequence as that of the TTAOH/NFDA/H(2)O system and the phase boundaries remain almost unchanged. However, the viscoelasticity of the samples in the single L(α) phase region becomes higher at the same total surfactant concentration as characterized by rheological measurements. Cryo-transmission electron microscopic (cryo-TEM) observations revealed a microstructural evolution from unilamellar vesicles to multilamellar ones and finally to gaint onions. The size of the vesicle and number of lamella can be controlled by adjusting the molar ratio of NFDA to DEHPA. The dynamic properties of the vesicular solutions have also been investigated. It is found that the yield stress and the storage modulus are time-dependent after a static mixing process between the two different types of vesicle solutions, indicating the occurrence of a dynamic fusion between the two types of vesicles. The microenvironmental changes induced by aggregate transitions were probed by

  14. Micellization Behavior of Long-Chain Substituted Alkylguanidinium Surfactants

    Directory of Open Access Journals (Sweden)

    Roza Bouchal

    2016-02-01

    Full Text Available Surface activity and micelle formation of alkylguanidinium chlorides containing 10, 12, 14 and 16 carbon atoms in the hydrophobic tail were studied by combining conductivity and surface tension measurements with isothermal titration calorimetry. The purity of the resulting surfactants, their temperatures of Cr→LC and LC→I transitions, as well as their propensity of forming birefringent phases, were assessed based on the results of 1H and 13C NMR, differential scanning calorimetry (DSC, and polarizing microscopy studies. Whenever possible, the resulting values of Krafft temperature (TK, critical micelle concentration (CMC, minimum surface tension above the CMC, chloride counter-ion binding to the micelle, and the standard enthalpy of micelle formation per mole of surfactant (ΔmicH° were compared to those characterizing alkyltrimethylammonium chlorides or bromides with the same tail lengths. The value of TK ranged between 292 and 314 K and increased strongly with the increase in the chain length of the hydrophobic tail. Micellization was described as both entropy and enthalpy-driven. Based on the direct calorimetry measurements, the general trends in the CMC with the temperature, hydrophobic tail length, and NaCl addition were found to be similar to those of other types of cationic surfactants. The particularly exothermic character of micellization was ascribed to the hydrogen-binding capacity of the guanidinium head-group.

  15. Screening and Optimization of Bio surfactant Production by the Hydrocarbon-Degrading Bacteria

    International Nuclear Information System (INIS)

    Ainon Hamzah; Noramiza Sabturani; Shahidan Radiman

    2013-01-01

    Bio surfactants are amphiphilic compounds produced by microorganisms as secondary metabolite. The unique properties of bio surfactants make them possible to replace or to be added to synthetic surfactants which are mainly used in food, cosmetics and pharmaceutical industries and in environmental applications. In this study twenty hydrocarbon-degrading bacteria were screened for bio surfactant production. All of the bacterial isolates were grown in mineral salt medium (MSM) with addition of 1 % (v/v) Tapis crude oil as carbon source. The presence of bio surfactant was determined by the drop-collapse test, microplate analysis, oil spreading technique, emulsification index (%EI24) and surface tension measurement. Only one isolate, Pseudomonas aeruginosa UKMP14T, was found to be positive for all the qualitative tests and reducing the surface tension of the medium to 49.5 dynes/ with emulsification index of 25.29 %. This isolate produced bio surfactant optimally at pH 9.0 and incubation temperature of 37 degree Celsius. Furthermore, P. aeruginosa UKMP14T when grown in MSM with addition of 1 % (v/v) glycerol and 1.3 g/ L ammonium sulphate with C/N ratio 14:1 produced bio surfactant with percentage of surface tension reduction at 55 % or 30.6 dynes/ cm with %EI24 of 43 %. This percentage of surface tension reduction represents an increasing reduction in surface tension of medium by 39 % over the value before optimization. This study showed that P. aeruginosa UKMP14T has the ability to biodegrade hydrocarbon and concurrently produce bio surfactant. (author)

  16. Surfactant-enhanced electrokinetic remediation of soil contaminated with hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J.W.; Park, J.Y.; Lee, H.H.; Cho, H.J. [Dept. of Chemical Engineering, Korea Advanced Inst. of Science and Technology, Taejon (Korea)

    2001-07-01

    Removal of hydrophobic organic contaminants (HOCs) using electrokinetic method was studied in a model system. Kaolinite and phenanthrene were selected as the model clay soil and representative HOC. Three different types of surfactants, APG (alkyl polyglucoside), Brij30 (polyoxyethylene 4 lauryl ether), and SDS (sodium dodecyl sulfate), were used to enhance the solubility of HOCs. Electrokinetic (EK) column experiments were performed using water, surfactant solution, and acetate buffer solution under a constant current condition. Voltage and flow through the soil system were interpreted with time. Electrolyte pH at the anode and cathode compartments was observed for operation time. Removal efficiency of phenanthrene was examined after the end of EK operation during 2, 4, and 6 weeks. (orig.)

  17. 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...

  18. Superhydrophilic surfaces from short and medium chain solvo-surfactants

    Directory of Open Access Journals (Sweden)

    Valentin Romain

    2013-01-01

    Full Text Available Pure monoglycerides (GM-Cs and glycerol carbonate esters (GCE-Cs are two families of oleochemical molecules composed of a polar part, glycerol for GM-Cs, glycerol carbonate for GCE-Cs, and a fatty acid lipophilic part. From a chemical point of view, GM-Cs include two free oxygen atoms in the hydroxyl functions and one ester function between the fatty acid and the glycerol parts. GCE-Cs contain two blocked oxygen atoms in the cyclic carbonate backbone and three esters functions: two endocyclic in the five-membered cyclic carbonate function, one exocyclic between the fatty acid and glycerol carbonate parts. At the physico-chemical level, GMCs and GCE-Cs are multifunctional molecules with amphiphilic structures: a common hydrophobic chain to the both families and a polar head, glycerol for GMs and glycerol carbonate for GCE-Cs. Physicochemical properties depend on chain lengths, odd or even carbon numbers on the chain, and glyceryl or cyclocarbonic polar heads. The solvo-surfactant character of GM-Cs and overall GCE-Cs were discussed through the measurements of critical micellar concentration (CMC or critical aggregation concentration (CAC. These surface active glycerol esters/glycerol carbonate esters were classified following their hydrophilic/hydrophobic character correlated to their chain length (LogPoctanol/water = f(atom carbon number. Differential scanning calorimetry and optical polarized light microscopy allow us to highlight the selfassembling properties of the glycerol carbonate esters alone and in presence of water. We studied by thermal analysis the polymorphic behaviour of GCE-Cs, and the correlation between their melting points versus the chain lengths. Coupling the self-aggregation and crystallization properties, superhydrophilic surfaces were obtained by formulating GM-Cs and GCE-Cs. An efficient durable water-repellent coating of various metallic and polymeric surfaces was allowed. Such surfaces coated by self-assembled fatty acid

  19. Uptake of Hydrocarbon by Pseudomonas fluorescens (P1) and Pseudomonas putida (K1) Strains in the Presence of Surfactants: A Cell Surface Modification

    OpenAIRE

    Kaczorek, Ewa; Olszanowski, Andrzej

    2010-01-01

    The objective of this research was the evaluation of the effects of exogenous added surfactants on hydrocarbon biodegradation and on cell surface properties. Crude oil hydrocarbons are often difficult to remove from the environment because of their insolubility in water. The addition of surfactants enhances the removal of hydrocarbons by raising the solubility of these compounds. These surfactants cause them to become more vulnerable to degradation, thereby facilitating transportation across ...

  20. Decontamination of solid substrates using supercritical carbon dioxide - Application with trade hydro-carbonated surfactants

    International Nuclear Information System (INIS)

    Galy, J.; Fournel, B.; Sawada, K.; Lacroix-Desmazes, P.; Lagerge, S.; Persin, M.

    2007-01-01

    The phase behavior of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) tri-block copolymers (PEO-PPO-PEO Pluronics) in liquid and supercritical carbon dioxide has been studied by cloud point measurements. It shows that such trade hydro-carbonated surfactants are fairly soluble (0.1 wt.%) in carbon dioxide in relatively mild conditions of temperature and pressure (T ≤ 65 degrees C, P ≤ 30 MPa). An empirical model based on the molecular weight of the copolymer has been proposed to predict the pressure-temperature phase diagram for a series of Pluronics (10 wt.% of ethylene oxide). Furthermore, the water/CO 2 interfacial tension has been measured to investigate the interactions between water and the polar moieties of the surfactants (PEO blocks and hydroxyl end-groups) as well as the interactions between CO 2 and the 'CO 2 -philic' moiety of the surfactants (PPO block). An interfacial saturation concentration was evidenced and it was shown to depend on the temperature at a given pressure. The cloud point curves and interfacial tension data are fully consistent with a change in the affinity of the surfactant for CO 2 versus pressure and temperature. A correlation between CO 2 -philic characteristics and surface active properties of the copolymers is given. (authors)

  1. Interactions of short chain phenylalkanoic acids within ionic surfactant micelles in aqueous media

    Directory of Open Access Journals (Sweden)

    Naeem Kashif

    2012-01-01

    Full Text Available % SDS KR nema Solubilization and interactions of phenylalkanoic acids induced by cationic surfactant, cetyltrimethylammonium bromide (CTAB and an anionic surfactant, sodium dodecyl sulfate (SDS was investigated spectrophotometrically at 25.0°C. The UV spectra of the additives (acids were measured with and without surfactant above and below critical micelle concentration (cmc of the surfactant. The presence of alkyl chain in phenylalkanoic acids is responsible for hydrophobic interaction resulting in shift of the spectra towards longer wavelength (red shift. The value of partition coefficient (Kx between the bulk water and surfactant micelles and in turn standard free energy change of solubilization (ΔGpº were also estimated by measuring the differential absorbance (ΔA of the additives in micellar solutions.

  2. Alteration in cell surface properties of Burkholderia spp. during surfactant-aided biodegradation of petroleum hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, Sagarika; Mukherji, Suparna [Indian Institute of Technology Bombay, Mumbai (India). Centre for Environmental Science and Engineering (CESE)

    2012-04-15

    Chemical surfactants may impact microbial cell surface properties, i.e., cell surface hydrophobicity (CSH) and cell surface charge, and may thus affect the uptake of components from non-aqueous phase liquids (NAPLs). This work explored the impact of Triton X-100, Igepal CA 630, and Tween 80 (at twice the critical micelle concentration, CMC) on the cell surface characteristics of Burkholderia cultures, Burkholderia cepacia (ES1, aliphatic degrader) and Burkholderia multivorans (NG1, aromatic degrader), when grown on a six-component model NAPL. In the presence of Triton X-100, NAPL biodegradation was enhanced from 21% to 60% in B. cepacia and from 18% to 53% in B. multivorans. CSH based on water contact angle (50-52 ) was in the same range for both strains while zeta potential at neutral pH was -38 and -31 mV for B. cepacia and B. multivorans, respectively. In the presence of Triton X-100, their CSH increased to greater than 75 and the zeta potential decreased. This induced a change in the mode of uptake and initiated aliphatic hydrocarbon degradation by B. multivorans and increased the rate of aliphatic hydrocarbon degradation in B. cepacia. Igepal CA 630 and Tween 80 also altered the cell surface properties. For B. cepacia grown in the presence of Triton X-100 at two and five times its CMC, CSH increased significantly in the log growth phase. Growth in the presence of the chemical surfactants also affected the abundance of chemical functional groups on the cell surface. Cell surface changes had maximum impact on NAPL degradation in the presence of emulsifying surfactants, Triton X-100 and Igepal CA630.

  3. Evaporation and Hydrocarbon Chain Conformation of Surface Lipid Films

    Science.gov (United States)

    Sledge, Samiyyah M.; Khimji, Hussain; Borchman, Douglas; Oliver, Alexandria; Michael, Heidi; Dennis, Emily K.; Gerlach, Dylan; Bhola, Rahul; Stephen, Elsa

    2016-01-01

    Purpose The inhibition of the rate of evaporation (Revap) by surface lipids is relevant to reservoirs and dry eye. Our aim was to test the idea that lipid surface films inhibit Revap. Methods Revap were determined gravimetrically. Hydrocarbon chain conformation and structure were measured using a Raman microscope. Six 1-hydroxyl hydrocarbons (11–24 carbons in length) and human meibum were studied. Reflex tears were obtained from a 62-year-old male. Results The Raman scattering intensity of the lipid film deviated by about 7 % for hydroxyl lipids and varied by 21 % for meibum films across the entire film at a resolution of 5 µm2. All of the surface lipids were ordered. Revap of the shorter chain hydroxyl lipids were slightly (7%) but significantly lower compared with the longer chain hydroxyl lipids. Revap of both groups was essentially similar to that of buffer. A hydroxyl lipid film did not influence Revap over an estimated average thickness range of 0.69 to >6.9 µm. Revap of human tears and buffer with and without human meibum (34.4 µm thick) was not significantly different. Revap of human tears was not significantly different from buffer. Conclusions Human meibum and hydroxyl lipids, regardless of their fluidity, chain length, or thickness did not inhibit Revap of buffer or tears even though they completely covered the surface. It is unlikely that hydroxyl lipids can be used to inhibit Revap of reservoirs. Our data do not support the widely accepted (yet unconfirmed) idea that the tear film lipid layer inhibits Revap of tears. PMID:27395776

  4. Novel Pyridinium Surfactants with Unsaturated Alkyl Chains : Aggregation Behavior and Interactions with Methyl Orange in Aqueous Solution

    NARCIS (Netherlands)

    Kuiper, Johanna M.; Buwalda, Rixt T.; Hulst, Ron; Engberts, Jan B.F.N.

    2001-01-01

    This paper presents the synthesis and a study of the aggregation behavior of 4-undecyl-1-methyl- and 4-undecenyl-1-methylpyridinium iodide surfactants. The effect of the position of the double bond in the alkyl chain of the surfactant on the critical micelle concentration (cmc), degree of counterion

  5. Theoretical model to investigate the alkyl chain and anion dependent interactions of gemini surfactant with bovine serum albumin.

    Science.gov (United States)

    Vishvakarma, Vijay K; Kumari, Kamlesh; Patel, Rajan; Dixit, V S; Singh, Prashant; Mehrotra, Gopal K; Chandra, Ramesh; Chakrawarty, Anand Kumar

    2015-05-15

    Surfactants are used to prevent the irreversible aggregation of partially refolded proteins and they also assist in protein refolding. We have reported the design and screening of gemini surfactant to stabilize bovine serum albumin (BSA) with the help of computational tool (iGEMDOCK). A series of gemini surfactant has been designed based on bis-N-alkyl nicotinate dianion via varying the alkyl group and anion. On changing the alkyl group and anion of the surfactant, the value of Log P changes means polarity of surfactant can be tuned. Further, the virtual screening of the gemini surfactant has been carried out based on generic evolutionary method. Herein, thermodynamic data was studied to determine the potential of gemini surfactant as BSA stabilizer. Computational tools help to find out the efficient gemini surfactant to stabilize the BSA rather than to use the surfactant randomly and directionless for the stabilization. It can be confirmed through the experimental techniques. Previously, researcher synthesized one of the designed and used gemini surfactant to stabilize the BSA and their interactions were confirmed through various techniques and computational docking. But herein, the authors find the most competent gemini surfactant to stabilize BSA using computational tools on the basis of energy score. Different from the single chain surfactant, the gemini surfactants exhibit much stronger electrostatic and hydrophobic interactions with the protein and are thus effective at much lower concentrations. Based on the present study, it is expected that gemini surfactants may prove useful in the protein stabilization operations and may thus be effectively employed to circumvent the problem of misfolding and aggregation. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Gamma-radiation induced polymerization of methyl methacrylate in aliphatic hydrocarbons: kinetics and evidence for incorporation of hydrocarbon in the polymer chain

    International Nuclear Information System (INIS)

    Mohan, H.; Iyer, R.M.

    1989-01-01

    On γ-radiolysis, the rate of polymerization of methyl methacrylate in hydrocarbon solvents is observed to decrease. It is explained by hydrocarbon entry into the polymer chains. The hydrocarbon entry into the polymer chains is observed to take place at later stages of polymerization and increases with hydrocarbon chain length. The extent of hydrocarbon entry into the polymer chains is estimated by NMR and GLC analysis. It is observed to be equal to ∼ 12% corresponding to ∼ 97 hexadecane molecules in each polymer chain. The IR, DSC, MW determination and radiation effects on the polymer showed evidences for hydrocarbon entry into the polymer. It is explained by chain transfer from the growing polymer radical to the hydrocarbon molecules. The chain transfer constant is determined to be equal to 1 x 10 -2 . (author)

  7. Comparative study of the physicochemical properties of aqueous solutions of the hydrocarbon and fluorocarbon surfactants and their ternary mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Szymczyk, Katarzyna, E-mail: katarzyna.szymczyk@poczta.umcs.lublin.pl

    2014-03-03

    Highlights: • Acoustic properties of hydrocarbon and fluorocarbon surfactants were studied. • Auerbach’s relation is not proper for mixtures with fluorocarbon surfactants. • Values of the hydration number decreases at concentrations higher than CMC. • FSO100 and its mixtures are the strongest chaotropes. - Abstract: Speed of sound and density of aqueous solutions of hydrocarbon p-(1,1,3,3-tetramethylbutyl) phenoxypoly(ethyleneglycols) (Triton X-100 (TX100), Triton X-165 (TX165)) and fluorocarbon (Zonyl FSN-100 (FSN100), Zonyl FSO-100 (FSO100)) surfactants as well as their ternary mixtures were measured at 293 K. Taking into account these values and the literature data of the surface tension and viscosity of the studied systems, the values of the isentropic compressibility, apparent specific adiabatic compressibility, hydration number, apparent specific volume and Jones Dole’s A and B-coefficients were determined. For the systems containing FSO100 also the values of dB/dT were determined on the basis of the values of viscosity measured at different temperatures. Next, the calculated thermodynamic properties have been discussed in the term of intermolecular interactions between the components of the mixtures.

  8. Shifts in microbial community structure during in situ surfactant-enhanced bioremediation of polycyclic aromatic hydrocarbon-contaminated soil.

    Science.gov (United States)

    Wang, Lingwen; Li, Feng; Zhan, Yu; Zhu, Lizhong

    2016-07-01

    This study aims to reveal the microbial mechanism of in situ surfactant-enhanced bioremediation (SEBR). Various concentrations of rhamnolipids, Tween 80, and sodium dodecyl benzenesulfonate (SDBS) were separately sprayed onto soils contaminated with polycyclic aromatic hydrocarbons (PAHs) for years. Within 90 days, the highest level of degradation (95 %) was observed in the soil treated with rhamnolipids (10 mg/kg), followed by 92 % degradation with Tween 80 (50 mg/kg) and 90 % degradation with SDBS (50 mg/kg). The results of the microbial phospholipid fatty acids (PLFAs) suggest that bacteria dominated the enhanced PAH biodegradation (94 % of the maximum contribution). The shift of bacterial community structure during the surfactant treatment was analyzed by using the 16S rRNA gene high-throughput sequencing. In the presence of surfactants, the number of the operational taxonomic units (OTUs) associated with Bacillus, Pseudomonas, and Sphingomonas increased from 2-3 to 15-30 % at the end of the experiment (two to three times of control). Gene prediction with phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) shows that the PAH-degrading genes, such as 1-hydroxy-2-naphthoate dioxygenase and PAH dioxygenase large subunit, significantly increased after the surfactant applications (p bioremediation.

  9. 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.

  10. 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

  11. Combination of surfactant enhanced soil washing and electro-Fenton process for the treatment of soils contaminated by petroleum hydrocarbons.

    Science.gov (United States)

    Huguenot, David; Mousset, Emmanuel; van Hullebusch, Eric D; Oturan, Mehmet A

    2015-04-15

    In order to improve the efficiency of soil washing treatment of hydrocarbon contaminated soils, an innovative combination of this soil treatment technique with an electrochemical advanced oxidation process (i.e. electro-Fenton (EF)) has been proposed. An ex situ soil column washing experiment was performed on a genuinely diesel-contaminated soil. The washing solution was enriched with surfactant Tween 80 at different concentrations, higher than the critical micellar concentration (CMC). The impact of soil washing was evaluated on the hydrocarbons concentration in the leachates collected at the bottom of the soil columns. These eluates were then studied for their degradation potential by EF treatment. Results showed that a concentration of 5% of Tween 80 was required to enhance hydrocarbons extraction from the soil. Even with this Tween 80 concentration, the efficiency of the treatment remained very low (only 1% after 24 h of washing). Electrochemical treatments performed thereafter with EF on the collected eluates revealed that the quasi-complete mineralization (>99.5%) of the hydrocarbons was achieved within 32 h according to a linear kinetic trend. Toxicity was higher than in the initial solution and reached 95% of inhibition of Vibrio fischeri bacteria measured by Microtox method, demonstrating the presence of remaining toxic compounds even after the complete degradation. Finally, the biodegradability (BOD₅/COD ratio) reached a maximum of 20% after 20 h of EF treatment, which is not enough to implement a combined treatment with a biological treatment process. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Integration of chemical scrubber with sodium hypochlorite and surfactant for removal of hydrocarbons in cooking oil fume

    International Nuclear Information System (INIS)

    Cheng, Hsin-Han; Hsieh, Chu-Chin

    2010-01-01

    There are many types of technologies to control cooking oil fumes (COFs), but current typical technologies, such as electrostatic precipitator, conventional scrubber, catalyst, or condenser, are unable to efficiently remove the odorous materials present in COFs which are the primary cause of odor-complaint cases. There is also a lack of information about using sodium hypochlorite (NaOCl) and surfactants to remove contaminants in COFs, and previous studies lack on-site investigations in restaurants. This study presents a chemical scrubber integrated with an automatic control system (ACS) to treat hydrocarbons (HCs) in COFs, and to monitor non-methane HCs (NMHC) and odor as indicators for its efficiency evaluation. The chemical scrubber effectively treats hydrophobic substances in COFs by combining surfactant and NaOCl under optimal operational conditions with NHMC removal efficiency as high as 85%. The mass transfer coefficient (K L a) of NMHC was enhanced by 50% under the NaOCl and surfactant conditions, as compared to typical wet scrubber. Further, this study establishes the fuzzy equations of the ACS, including the relationship between the removal efficiency and K L a, liquid/gas ratio, pH and C NaOCl .

  13. Integration of chemical scrubber with sodium hypochlorite and surfactant for removal of hydrocarbons in cooking oil fume

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Hsin-Han [Graduate School of Engineering Science and Technology, National Yunlin University of Science and Technology, Touliu, Yunlin, Taiwan (China); Hsieh, Chu-Chin, E-mail: hsiehcc@yuntech.edu.tw [Department of Environmental and Safety Engineering, National Yunlin University of Science and Technology, Touliu, Yunlin, Taiwan (China)

    2010-10-15

    There are many types of technologies to control cooking oil fumes (COFs), but current typical technologies, such as electrostatic precipitator, conventional scrubber, catalyst, or condenser, are unable to efficiently remove the odorous materials present in COFs which are the primary cause of odor-complaint cases. There is also a lack of information about using sodium hypochlorite (NaOCl) and surfactants to remove contaminants in COFs, and previous studies lack on-site investigations in restaurants. This study presents a chemical scrubber integrated with an automatic control system (ACS) to treat hydrocarbons (HCs) in COFs, and to monitor non-methane HCs (NMHC) and odor as indicators for its efficiency evaluation. The chemical scrubber effectively treats hydrophobic substances in COFs by combining surfactant and NaOCl under optimal operational conditions with NHMC removal efficiency as high as 85%. The mass transfer coefficient (K{sub L}a) of NMHC was enhanced by 50% under the NaOCl and surfactant conditions, as compared to typical wet scrubber. Further, this study establishes the fuzzy equations of the ACS, including the relationship between the removal efficiency and K{sub L}a, liquid/gas ratio, pH and C{sub NaOCl}.

  14. Effect of surfactant chain length on drug release kinetics from microemulsion-laden contact lenses.

    Science.gov (United States)

    Maulvi, Furqan A; Desai, Ankita R; Choksi, Harsh H; Patil, Rahul J; Ranch, Ketan M; Vyas, Bhavin A; Shah, Dinesh O

    2017-05-30

    The effect of surfactant chain lengths [sodium caprylate (C 8 ), Tween 20 (C 12 ), Tween 80 (C 18 )] and the molecular weight of block copolymers [Pluronic F68 and Pluronic F 127] were studied to determine the stability of the microemulsion and its effect on release kinetics from cyclosporine-loaded microemulsion-laden hydrogel contact lenses in this work. Globule size and dilution tests (transmittance) suggested that the stability of the microemulsion increases with increase in the carbon chain lengths of surfactants and the molecular weight of pluronics. The optical transmittance of direct drug-laden contact lenses [DL-100] was low due to the precipitation of hydrophobic drugs in the lenses, while in microemulsion-laden lenses, the transmittance was improved when stability of the microemulsion was achieved. The results of in vitro release kinetics revealed that drug release was sustained to a greater extent as the stability of microemulsion was improved as well. This was evident in batch PF127-T80, which showed sustained release for 15days in comparison to batch DL-100, which showed release up to 7days. An in vivo drug release study in rabbit tear fluid showed significant increase in mean residence time (MRT) and area under curve (AUC) with PF-127-T80 lenses (stable microemulsion) in comparison to PF-68-SC lenses (unstable microemulsion) and DL-100 lenses. This study revealed the correlation between the stability of microemulsion and the release kinetics of drugs from contact lenses. Thus, it was inferred that the stable microemulsion batches sustained the release of hydrophobic drugs, such as cyclosporine from contact lenses for an extended period of time without altering critical lens properties. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Distinct changes in pulmonary surfactant homeostasis in common beta-chain-and GM-CSF-deficient mice

    NARCIS (Netherlands)

    Reed, JA; Ikegami, M; Robb, L; Begley, CG; Ross, G; Whitsett, JA

    Pulmonary alveolar proteinosis (PAP) is caused by inactivation of either granulocyte-macrophage colony-stimulating factor (GMCSF) or GM receptor common beta-chain (beta(c)) genes in mice [GM(-/-), beta(c)(-/-)], demonstrating a critical role of GM-CSF signaling in surfactant homeostasis. To

  16. Drivers and applications of integrated clean-up technologies for surfactant-enhanced remediation of environments contaminated with polycyclic aromatic hydrocarbons (PAHs).

    Science.gov (United States)

    Liang, Xujun; Guo, Chuling; Liao, Changjun; Liu, Shasha; Wick, Lukas Y; Peng, Dan; Yi, Xiaoyun; Lu, Guining; Yin, Hua; Lin, Zhang; Dang, Zhi

    2017-06-01

    Surfactant-enhanced remediation (SER) is considered as a promising and efficient remediation approach. This review summarizes and discusses main drivers on the application of SER in removing polycyclic aromatic hydrocarbons (PAHs) from contaminated soil and water. The effect of PAH-PAH interactions on SER efficiency is, for the first time, illustrated in an SER review. Interactions between mixed PAHs could enhance, decrease, or have no impact on surfactants' solubilization power towards PAHs, thus affecting the optimal usage of surfactants for SER. Although SER can transfer PAHs from soil/non-aqueous phase liquids to the aqueous phase, the harmful impact of PAHs still exists. To decrease the level of PAHs in SER solutions, a series of SER-based integrated cleanup technologies have been developed including surfactant-enhanced bioremediation (SEBR), surfactant-enhanced phytoremediation (SEPR) and SER-advanced oxidation processes (SER-AOPs). In this review, the general considerations and corresponding applications of the integrated cleanup technologies are summarized and discussed. Compared with SER-AOPs, SEBR and SEPR need less operation cost, yet require more treatment time. To successfully achieve the field application of surfactant-based technologies, massive production of the cost-effective green surfactants (i.e. biosurfactants) and comprehensive evaluation of the drivers and the global cost of SER-based cleanup technologies need to be performed in the future. Copyright © 2017. Published by Elsevier Ltd.

  17. Influence of the chain length of surfactant in the modification of zeolites and clays. Removal of atrazine from water solutions.

    Science.gov (United States)

    Toledo-Jaldin, Helen Paola; Blanco-Flores, Alien; Sánchez-Mendieta, Víctor; Martín-Hernández, Osnieski

    2017-08-30

    Removal potentials of a surfactant modified zeolite (SMZ) and clay (SMC) for atrazine adsorption were evaluated. Materials were modified with hexadecyl trimethyl ammonium bromide (HDTMA-Br) and benzyl octadecyl dimethyl ammonium (BODA) chloride considering the critical micellar concentration (CMC) of each one (0.94 and 0.041 meq/L, respectively). The influence of the surfactant was analyzed in detail, particularly the formation of surfactant layers (complete or partial) connected with the length of the surfactant tail (16 and 18 methyl groups or number of carbons in the chain). Raw materials were characterized by XRD and Fourier transform infrared spectroscopy (FTIR), SMZ and SMC were analyzed by FTIR. Results obtained from kinetic adsorption experiments shown that equilibrium time is less for materials modified with HDTMA (8 h) than materials with BODA (10 and 12 h). Materials modified with the largest chain surfactant (BODA) showed more resistance to atrazine masse transference. The chemisorption was presented in the adsorption mechanisms of atrazine and adsorbent materials. Based on the results of adsorption isotherms Langmuir isotherms showed the better correlation coefficients value. The q max is greater for materials modified with BODA (0.9232 and 4.2448 mg/g) than for materials modified with HDTMA (0.6731 and 3.9121 mg/g). Therefore, SMZ and SMC modified with the largest chain surfactant has more affinity for the pesticide. The removal process at high concentration of atrazine depends of the partition process but at lower concentration, it occurs not only by this process but also by absorption process.

  18. Superlattice configurations in linear chain hydrocarbon binary mixtures

    Indian Academy of Sciences (India)

    monoclinic, monoclinic-monoclinic) are realizable, because of discrete orientational changes in the alignment of molecules of -C28H58 hydrocarbon, through an angle , where = 1, 2, 3 … and angle has an average value of 3.3°.

  19. Effect of hydrocarbon chain length of aliphatic diluents on hydrodynamic properties of irradiated solutions of extractant

    International Nuclear Information System (INIS)

    Gumenyuk, V.E.; Pribush, A.G.; Egorov, G.F.

    1990-01-01

    To optimize the composition of n-paraffin mixtures with different molecular weight, used as a diluent (D) of extractant during extraction reprocessing of spent fuel, interrelation between D hydrocarbon chain length and change in hydrodynamic properties of extraction mixture on D basis depending on the dose has been considered. It is shown that the value of threshold dose loading (D crit ), at which a sharp change in hydrodynamic properties of tri-n-butyl phosphate solutions in D is observed, decreases with hydrocarbon chain length growth. Empiric ratio relating D crit value and the number of carbon atoms of D is obtained

  20. 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.

  1. Superlattice configurations in linear chain hydrocarbon binary mixtures

    Indian Academy of Sciences (India)

    Unknown

    Long-chain alkanes; binary mixtures; superlattices; discrete orientational changes. 1. Introduction ... tem and a model of superlattice configuration was proposed4, in terms of .... C18 system,4 the angle with value = 3⋅3° was seen to play an ...

  2. Effect of Difference in Fatty Acid Chain Lengths of Medium- Chain Lipids on Lipid/Surfactant/Water Phase Diagrams and Drug Solubility

    Directory of Open Access Journals (Sweden)

    Hetal N. Prajapati

    2011-09-01

    Full Text Available Lipids consisting of medium chain fatty acids are commonly used in the development of lipid-based selfemulsifying and self-microemulsifying drug delivery systems. However, no systematic approach to selecting one lipid over another has been reported in the literature. In this study, propylene glycol (PG monoester (PG monocaprylate, Capmul PG-8® and PG diester (PG dicaprylocaprate, Captex 200P® of C8-fatty acids were compared with PG monoester (PG monolaurate, Capmul PG-12® and PG diester (PG dilaurate, Capmul PG-2L® of C12-fatty acids with respect to their phase diagrams, and especially for their ability to form microemulsions in the presence of a common surfactant, Cremophor EL®, and water. The solubility of two model drugs, danazol and probucol, in the lipids and lipid/surfactant mixtures were also compared. The effect of the chain length of medium-chain fatty acids (C8 versus C12 on the phase diagrams of the lipids was minimal. Both shorter and longer chain lipids formed essentially similar microemulsion and emulsion regions in the presence of Cremophor EL® and water, although the C12-fatty acid esters formed larger gel regions in the phase diagrams than the C8-fatty acid esters. When monoesters were mixed with their respective diesters at 1:1 ratios, larger microemulsion regions with lower lipid particle sizes were observed compared to those obtained with individual lipids alone. While the solubility of both danazol and probucol increased greatly in all lipids studied, compared to their aqueous solubility, the solubility in C12-fatty acid esters was found to be lower than in C8-fatty acid esters when the lipids were used alone. This difference in solubility due to the difference in fatty acid chain length, practically disappeared when the lipids were combined with the surfactant.

  3. Adsorption of polynuclear aromatic hydrocarbons from aqueous solution: Agrowaste-modified kaolinite vs surfactant modified bentonite

    Directory of Open Access Journals (Sweden)

    E. I. Unuabonah

    2017-01-01

    Full Text Available The adsorption efficiency of a new hybrid clay adsorbent for polynuclear aromatic hydrocarbons (PAHs is compared with known modified clay adsorbents. The new hybrid clay adsorbent (HYCA showed far higher adsorption capacities for the adsorption of various PAH molecules compared with sodium dodecyl sulfate modified and humic acid modified Bentonite clay adsorbents. With the new hybrid clay adsorbent (HYCA, the adsorption of some of the larger PAH molecules was complete in the first 1 h as compared with ≈ 62% and ≈ 76% observed for both humic acid modified and sodium dodecyl sulfate modified Bentonite clay adsorbents respectively. In 24 h adsorption of the PAHs was complete for all adsorbents with HYCA adsorbent showing better efficiency in the removal of the PAH molecules from aqueous solutions. No significant change was observed with increase in time up to 48 h. The adsorption was observed to be more spontaneous with HYCA adsorbent than with either modified Bentonite adsorbents. The enthalpy of adsorption did not follow any specific order and were not consistent for all PAH molecules considered.

  4. Process for the selective cracking of straight-chained and slightly branched hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Gorring, R L; Shipman, G F

    1975-01-23

    The invention describes a method for the selective (hydro) cracking of petroleum materials, containing normal straight-chained and/or slightly branched-chained hydrocarbons. The mixture is brought into contact with a selective, crystalline alumino silicate zeolite cracking catalyst housing a silicon oxide/aluminum oxide ratio of at least about 12 and a constraint index of about 1 to 12 under cracking conditions. A zeolite catalyst with a crystal size of up to 0.05 ..mu.. is used. Solidification point and viscosity in particular of oils are to be lowered through the catalytic dewaxing.

  5. Effect of surfactant alkyl chain length on the dispersion, and thermal and dynamic mechanical properties of LDPE/organo-LDH composites

    Directory of Open Access Journals (Sweden)

    2011-05-01

    Full Text Available Low density polyethylene/layered double hydroxide (LDH composites were prepared via melt compounding using different kinds of organo-LDHs and polyethylene-grafted maleic anhydride as the compatibilizer. The organo-LDHs were successfully prepared by converting a commercial MgAl-carbonate LDH into a MgAl-nitrate LDH, which was later modified by anion exchange with linear and branched sodium alkyl sulfates having different alkyl chain lengths (nc = 6, 12 and 20. It was observed that, depending on the size of the surfactant alkyl chain, different degrees of polymer chain intercalation were achieved, which is a function of the interlayer distance of the organo-LDHs, of the packing level of the alkyl chains, and of the different interaction levels between the surfactant and the polymer chains. In particular, when the number of carbon atoms of the surfactant alkyl chain is larger than 12, the intercalation of polymer chains in the interlayer space and depression of the formation of large aggregates of organo-LDH platelets are favored. A remarkable improvement of the thermal-oxidative degradation was evidenced for all of the composites; whereas only a slight increase of the crystallization temperature and no significant changes of both melting temperature and degree of crystallinity were achieved. By thermodynamic mechanical analysis, it was evidenced that a softening of the matrix is may be due to the plasticizing effect of the surfactant.

  6. Phase transitions in surfactant monolayers

    International Nuclear Information System (INIS)

    Casson, B.D.

    1998-01-01

    Two-dimensional phase transitions have been studied in surfactant monolayers at the air/water interface by sum-frequency spectroscopy and ellipsometry. In equilibrium monolayers of medium-chain alcohols C n H 2n+1 OH (n = 9-14) a transition from a two-dimensional crystalline phase to a liquid was observed at temperatures above the bulk melting point. The small population of gauche defects in the solid phase increased only slightly at the phase transition. A model of the hydrocarbon chains as freely rotating rigid rods allowed the area per molecule and chain tilt in the liquid phase to be determined. The area per molecule, chain tilt and density of the liquid phase all increased with increasing chain length, but for each chain length the density was higher than in a bulk liquid hydrocarbon. In a monolayer of decanol adsorbed at the air/water interface a transition from a two-dimensional liquid to a gas was observed. A clear discontinuity in the coefficient of ellipticity as a function of temperature showed that the transition is first-order. This result suggests that liquid-gas phase transitions in surfactant monolayers may be more widespread than once thought. A solid-liquid phase transition has also been studied in mixed monolayers of dodecanol with an anionic surfactant (sodium dodecyl sulphate) and with a homologous series of cationic surfactants (alkyltrimethylammonium bromides: C n TABs, n = 12, 14, 16). The composition and structure of the mixed monolayers was studied above and below the phase transition. At low temperatures the mixed monolayers were as densely packed as a monolayer of pure dodecanol in its solid phase. At a fixed temperature the monolayers under-went a first-order phase transition to form a phase that was less dense and more conformationally disordered. The proportion of ionic surfactant in the mixed monolayer was greatest in the high temperature phase. As the chain length of the C n TAB increased the number of conformational defects

  7. Programmable Self-assembly of Hydrocarbon-capped Nanoparticles: Role of Chain Conformations

    Science.gov (United States)

    Waltmann, Curt; Horst, Nathan; Travesset, Alex

    Nanoparticle superlattices (NPS), i.e. crystalline arrangements of nanoparticles, are materials with fascinating structures, which in many cases are not possible to attain from simple atoms or molecules. They also span a wide range of possible applications such as metamaterials, new energy sources, catalysis, and many others. In this talk, we present a theoretical and computational description of the self-assembly of nanoparticles with hydrocarbons as capping ligands. Usually, these systems have been described with hard sphere packing models. In this talk, we show that the conformations of the hydrocarbon chains play a fundamental role in determining the equilibrium phases, including and especially in binary systems. The work of CW was supported by a DOE-SULI internship from May-December 2016, and by NSF, DMR-CMMT 1606336 CDS&E: Design Principles for Ordering Nanoparticles into Super-crystals after January 1st.

  8. Aggregation behavior and intermicellar interactions of cationic Gemini surfactants: Effects of alkyl chain, spacer lengths and temperature

    International Nuclear Information System (INIS)

    Hajy Alimohammadi, Marjan; Javadian, Soheila; Gharibi, Hussein; Tehrani-Bagha, Ali reza; Alavijeh, Mohammad Rashidi; Kakaei, Karim

    2012-01-01

    Graphical abstract: Highlights: → Enthalpy-entropy compensation relation was found between and for gemini surfactants. → The intermicellar interaction parameters are influenced with increasing the lengths of the tail and the spacer of gemini surfactants. → Increasing temperature decreases the intermicellar interaction parameters. → The changes in micellar surface charge density, and phase transition between spherical and rod geometries explain the data. - Abstract: The aggregation behavior of the cationic Gemini surfactants C m H 2m+1 N(CH 3 ) 2 (CH 2 ) S (CH 3 ) 2 N C m H 2m+1 ,2Br - with m = 12, 14 and s = 2, 4 were studied by performing surface tension, electrical conductivity, pulsed field gradient nuclear magnetic resonance (PFG-NMR), and cyclic voltammetry (CV) measurements over the temperature range 298 K to 323 K. The critical micelle concentration (CMC), surface excess (Γ max ), mean molecular surface area (A min ), degree of counter ion dissociation (α), and the thermodynamic parameters of micellization were determined from the surface tension and conductance data. An enthalpy-entropy compensation effect was observed and all the plots of enthalpy-entropy compensation exhibit excellent linearity. The micellar self-diffusion coefficients (D m ) and intermicellar interaction parameters (k d ) were obtained from the PFG-NMR and CV measurements. These results are discussed in terms of the intermicellar interactions, the effects of the chain and spacer lengths on the micellar surface charge density, and the phase transition between spherical and rod geometries. The intermicellar interaction parameters were found to decrease slightly with increasing temperature for 14-4-14, which suggests that the micellar surface charge density decreases with increasing temperature. The mean values of the hydrodynamic radius, R h , and the aggregation number, N agg , of the Gemini surfactants'm-4-m micelles were calculated from the micellar self-diffusion coefficient

  9. Volatile Short-chain Chlorinated Hydrocarbons in the Groundwater of the City of Zagreb

    OpenAIRE

    Marijanović-Rajčić, M.; Senta, A.

    2008-01-01

    The aim of the study was to assess the quality of the groundwater sampled from private wells and the public water-supply system in terms of estimating the contamination caused by short-chain chlorinated hydrocarbons, as well as to estimate the exposure of the citizens dwelling in different suburbs to these pollutants of their drinking water (Fig. 1). The aim of the study was also to determine which suburb is supplied through the public water-supply system with water originating from the Sašna...

  10. Influence of dispersants on trophic transfer of petroleum hydrocarbons in a marine food chain

    International Nuclear Information System (INIS)

    Wolfe, M. F.; Schwartz, G. J. B.; Singaram, S.; Tjeerdema, R. S.

    1997-01-01

    Experiments were conducted to determine the impact of dispersing agents on petroleum hydrocarbons (PH) bioavailability and trophic transfer in primary levels of a marine food chain. Uptake, bioaccumulation and metabolic transformation of a model PH, ( 1 4C)naphthalene, were measured and compared with Prudhoe Bay Crude Oil (PBCO) dispersed with Corexit 9527, and undispersed preparations of PBCO. The model food chain consisted of a primary algae producer and a primary rotifer consumer. Results showed that uptake of naphthalene increased significantly in the presence of a dispersant in algae. A significant increase in uptake was also recorded in rotifers via trophic transfer. Trophic transfer played a significant, sometimes even dominant, role in uptake and bioaccumulation. 27 refs., 6 figs

  11. Nighttime oxidation of surfactants at the air-water interface: effects of chain length, head group and saturation

    Science.gov (United States)

    Sebastiani, Federica; Campbell, Richard A.; Rastogi, Kunal; Pfrang, Christian

    2018-03-01

    Reactions of the key atmospheric nighttime oxidant NO3 with organic monolayers at the air-water interface are used as proxies for the ageing of organic-coated aqueous aerosols. The surfactant molecules chosen for this study are oleic acid (OA), palmitoleic acid (POA), methyl oleate (MO) and stearic acid (SA) to investigate the effects of chain length, head group and degree of unsaturation on the reaction kinetics and products formed. Fully and partially deuterated surfactants were studied using neutron reflectometry (NR) to determine the reaction kinetics of organic monolayers with NO3 at the air-water interface for the first time. Kinetic modelling allowed us to determine the rate coefficients for the oxidation of OA, POA and MO monolayers to be (2.8±0.7) × 10-8, (2.4±0.5) × 10-8and (3.3±0.6) × 10-8 cm2 molecule-1 s-1 for fitted initial desorption lifetimes of NO3 at the closely packed organic monolayers, τd, NO3, 1, of 8.1±4.0, 16±4.0 and 8.1±3.0 ns, respectively. The approximately doubled desorption lifetime found in the best fit for POA compared to OA and MO is consistent with a more accessible double bond associated with the shorter alkyl chain of POA facilitating initial NO3 attack at the double bond in a closely packed monolayer. The corresponding uptake coefficients for OA, POA and MO were found to be (2.1±0.5) × 10-3, (1.7±0.3) × 10-3 and (2.1±0.4) × 10-3, respectively. For the much slower NO3-initiated oxidation of the saturated surfactant SA we estimated a loss rate of approximately (5±1) × 10-12 cm2 molecule-1 s-1, which we consider to be an upper limit for the reactive loss, and estimated an uptake coefficient of ca. (5±1) × 10-7. Our investigations demonstrate that NO3 will contribute substantially to the processing of unsaturated surfactants at the air-water interface during nighttime given its reactivity is ca. 2 orders of magnitude higher than that of O3. Furthermore, the relative contributions of NO3 and O3 to the oxidative

  12. Nighttime oxidation of surfactants at the air–water interface: effects of chain length, head group and saturation

    Directory of Open Access Journals (Sweden)

    F. Sebastiani

    2018-03-01

    Full Text Available Reactions of the key atmospheric nighttime oxidant NO3 with organic monolayers at the air–water interface are used as proxies for the ageing of organic-coated aqueous aerosols. The surfactant molecules chosen for this study are oleic acid (OA, palmitoleic acid (POA, methyl oleate (MO and stearic acid (SA to investigate the effects of chain length, head group and degree of unsaturation on the reaction kinetics and products formed. Fully and partially deuterated surfactants were studied using neutron reflectometry (NR to determine the reaction kinetics of organic monolayers with NO3 at the air–water interface for the first time. Kinetic modelling allowed us to determine the rate coefficients for the oxidation of OA, POA and MO monolayers to be (2.8±0.7 × 10−8, (2.4±0.5 × 10−8and (3.3±0.6 × 10−8 cm2 molecule−1 s−1 for fitted initial desorption lifetimes of NO3 at the closely packed organic monolayers, τd, NO3, 1, of 8.1±4.0, 16±4.0 and 8.1±3.0 ns, respectively. The approximately doubled desorption lifetime found in the best fit for POA compared to OA and MO is consistent with a more accessible double bond associated with the shorter alkyl chain of POA facilitating initial NO3 attack at the double bond in a closely packed monolayer. The corresponding uptake coefficients for OA, POA and MO were found to be (2.1±0.5 × 10−3, (1.7±0.3 × 10−3 and (2.1±0.4 × 10−3, respectively. For the much slower NO3-initiated oxidation of the saturated surfactant SA we estimated a loss rate of approximately (5±1 × 10−12 cm2 molecule−1 s−1, which we consider to be an upper limit for the reactive loss, and estimated an uptake coefficient of ca. (5±1 × 10−7. Our investigations demonstrate that NO3 will contribute substantially to the processing of unsaturated surfactants at the air–water interface during nighttime given its reactivity is ca. 2 orders of magnitude higher

  13. Influence of dispersants on trophic transfer of petroleum hydrocarbons in a marine food chain

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, M.; Tjeerdema, R. [Univ. of California, Santa Cruz, CA (United States). Dept. of Chemistry and Biochemistry; Sowby, M. [California Dept. of Fish and Game, Sacramento, CA (United States)

    1995-12-31

    When crude oil is accidentally released into the ocean, it threatens many levels of marine life. Intervention, in the form of chemical dispersing agents, alters the normal behavior of petroleum hydrocarbons (PH) by increasing their functional water solubility and the extent of their exposure to sub-surface organisms. Dispersing agents may modify bioavailability as a result of altered interactions between dispersed PH droplets and organismal cell membranes.The objective of this research was to determine the impact of dispersing agents on PH bioavailability and trophic transfer in primary levels of a marine food chain. Uptake, bioaccumulation, depuration, and metabolic transformation of a model PH, {sup 14}C-naphthalene, were measured and compared for Prudhoe Bay Crude Oil (PBCO) dispersed with Corexit 9527 and undispersed preparations of the water-accommodated fractions (WAF) of PBCO at two salinities and temperatures. The model food chain consisted of Isochrysis galbana and Brachionus plicatilis. Direct aqueous exposure was compared with combined aqueous and dietary exposure. Fractionation and identification of metabolites was done by HPLC co-chromatography with analytical standards, and quantitation was done by liquid scintillation counting. GC-FID characterization of WAF and dispersed oil (DO) preparations shows higher concentrations of petroleum hydrocarbons and a greater number of individual constituents in the dispersed oil preparations.

  14. Influence of dispersants on trophic transfer of petroleum hydrocarbons in a marine food chain

    International Nuclear Information System (INIS)

    Wolfe, M.; Tjeerdema, R.

    1995-01-01

    When crude oil is accidentally released into the ocean, it threatens many levels of marine life. Intervention, in the form of chemical dispersing agents, alters the normal behavior of petroleum hydrocarbons (PH) by increasing their functional water solubility and the extent of their exposure to sub-surface organisms. Dispersing agents may modify bioavailability as a result of altered interactions between dispersed PH droplets and organismal cell membranes.The objective of this research was to determine the impact of dispersing agents on PH bioavailability and trophic transfer in primary levels of a marine food chain. Uptake, bioaccumulation, depuration, and metabolic transformation of a model PH, 14 C-naphthalene, were measured and compared for Prudhoe Bay Crude Oil (PBCO) dispersed with Corexit 9527 and undispersed preparations of the water-accommodated fractions (WAF) of PBCO at two salinities and temperatures. The model food chain consisted of Isochrysis galbana and Brachionus plicatilis. Direct aqueous exposure was compared with combined aqueous and dietary exposure. Fractionation and identification of metabolites was done by HPLC co-chromatography with analytical standards, and quantitation was done by liquid scintillation counting. GC-FID characterization of WAF and dispersed oil (DO) preparations shows higher concentrations of petroleum hydrocarbons and a greater number of individual constituents in the dispersed oil preparations

  15. Raman spectra of long chain hydrocarbons: anharmonic calculations, experiment and implications for imaging of biomembranes.

    Science.gov (United States)

    Šebek, Jiří; Pele, Liat; Potma, Eric O; Gerber, R Benny

    2011-07-28

    First-principles anharmonic vibrational calculations are carried out for the Raman spectrum of the C-H stretching bands in dodecane, and for the C-D bands in the deuterated molecule. The calculations use the Vibrational Self-Consistent Field (VSCF) algorithm. The results are compared with liquid-state experiments, after smoothing the isolated-molecule sharp-line computed spectra. Very good agreement between the computed and experimental results is found for the two systems. The combined theoretical and experimental results provide insights into the spectrum, elucidating the roles of symmetric and asymmetric CH(3) and CH(2) hydrogenic stretches. This is expected to be very useful for the interpretation of spectra of long-chain hydrocarbons. The results show that anharmonic effects on the spectrum are large. On the other hand, vibrational degeneracy effects seem to be rather modest at the resolution of the experiments. The degeneracy effects may have more pronounced manifestations in higher-resolution experiments. The results show that first-principles anharmonic vibrational calculations for hydrocarbons are feasible, in good agreement with experiment, opening the way for applications to many similar systems. The results may be useful for the analysis of CARS imaging of lipids, for which dodecane is a representative molecule. It is suggested that first-principles vibrational calculations may be useful also for CARS imaging of other systems. This journal is © the Owner Societies 2011

  16. Hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    1927-02-22

    Coal tar, mineral oils, bitumens, coal extraction products, hydrogenation products of coal, oil schists can be atomized and heated with steam to decompose pyrogenetically and form gases rich in olefins which may be heated with or without pressure and with or without catalysts to produce liquid hydrocarbons of low boiling point, some of which may be aromatic. The apparatus should be lined with copper, silica, or ferrosilicon to prevent contact of the bases with iron which causes deposition of soot. Catalysts used may be metal oxides, silica, graphite, active charcoal, mica, pumice, porcelain, barium carbonate, copper, silver, gold, chromium, boron, or their compounds. At temperatures from 300 to 400/sup 0/C, olefins are produced. At higher temperatures, naphthenes and benzene hydrocarbons are produced.

  17. Volatile Short-chain Chlorinated Hydrocarbons in the Groundwater of the City of Zagreb

    Directory of Open Access Journals (Sweden)

    Marijanović-Rajčić, M.

    2008-01-01

    Full Text Available The aim of the study was to assess the quality of the groundwater sampled from private wells and the public water-supply system in terms of estimating the contamination caused by short-chain chlorinated hydrocarbons, as well as to estimate the exposure of the citizens dwelling in different suburbs to these pollutants of their drinking water (Fig. 1. The aim of the study was also to determine which suburb is supplied through the public water-supply system with water originating from the Sašnak spring that is contaminated with volatile chlorinated short-chain hydrocarbons.Drinking water samples were taken from 3 private wells and 1 public water-supply system situated in 3 Zagreb suburbs - Pešćenica, Trnje, and Trešnjevka. The sampling was carried out during 2003 and was undertaken on a seasonal basis. Short-chain chlorinated hydrocarbons - 1,1,1-trichloroethane, carbon tetrachloride, 1,1,2-trichloroethene and 1,1,2,2-tetrachloroethene - were determined by gas chromatography, following "liquid-liquid extraction" in pentane. For that purpose, we applied the gas chromatograph equipped with an electron-capture detector, thermo-programmable operations, and a suitable capillary column. The technique applied was that of split-injection.The groundwater of the City of Zagreb was found to be contaminated with volatile chlorinated hydrocarbons. The concentration level of 1,1,1-trichloroethane, determined in most of the samples, was found to be low (Fig. 2. On the other hand, 1,1,2-trichloroethene was present in all samples in concentrations of about 1 µg l-1- (Fig. 3. Only the drinking water samples taken from private wells in the suburb of Trnje contained somewhat higher mass concentrations of 1,1,1-trichloroethane, with the peak value of 19.03 µg l-1, measured in the winter season. In the samples taken from private wells in Trnje, the mass concentrations of 1,1,2,2-tetrachloroethene rangedfrom 15.30 µg l-1 to 18.65 µg l-1, as measured in autumn

  18. Photophysical properties of a surfactive long-chain styryl merocyanine dye as fluorescent probe

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, L.F.M., E-mail: Lailafmi@yahoo.com [Al-Azhar University, Faculty of Science, Chemistry Department, Nasr City, 12 Ibrahim El-Nagar, El-Hegaz Sq. Heliopolis, Cairo 11315 (Egypt)

    2012-09-15

    This work deals with detailed investigations of the photophysical properties of a styryl merocyanine dye, namely 1-cetyl-4-[4 Prime -(methoxy) styryl]-pyridinium bromide (CMSPB) of molecular rotor type. The solvatochromic analyses of the data in different solvents using the Kamlet-Taft parameters ({alpha}, {beta}, {pi}{sup Low-Asterisk }) were discussed. Optical excitation of the studied merocyanine dye populates a CT S{sub 1} state with about 22.64 folds higher dipole moment value relative to that in the S{sub 0} state. Moreover, the effect of solvent viscosity (glycerol at various temperatures (299.0-351.0 K)) on CMSPB fluorescent properties is analyzed to understand the molecular mechanisms of the characteristic increase in CMSPB fluorescence intensity. The results indicate that CMSPB exhibits fluorescent properties typical for molecular rotors. The results show that torsional relaxation dynamics of molecular rotors in high-viscosity solvents cannot be described by the simple stick boundary hydrodynamics defined by the Debye-Stokes-Einstein (DSE) equation. The fluorescence depolarization behavior in glycerol at various temperatures (299.0-351.0 K) shows that the molecular rotational diffusion is controlled by the free volume of the medium. Furthermore, excited state studies in ethanol/chloroform mixture revealed the formation of weak complex with chloroform of stoichiometry 1:1 with formation constant of 0.004l mol{sup -1}. Moreover, the increase of the quantum yield values in micellar solutions of CTAB and SDS relative to that of water indicates that the guest dye molecules are microencapsulated into the hydrophobic interior of host micelle. The obtained non-zero values of fluorescence polarization in micellar solution imply reduced rotational depolarization of dye molecules via association with the surfactant. Upon comparing the spectral data in micelles with those in homogeneous solvent systems, more can be learned of the structural details of the micellar

  19. Nonionic diethanolamide amphiphiles with isoprenoid-type hydrocarbon chains: thermotropic and lyotropic liquid crystalline phase behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Sagnella, Sharon M.; Conn, Charlotte E.; Krodkiewska, Irena; Drummond, Calum J. (CSIRO/MSE)

    2014-09-24

    The thermotropic and lyotropic liquid crystalline phase behaviour of a series of diethanolamide amphiphiles with isoprenoid-type hydrocarbon chains (geranoyl, H-farnesoyl, and phytanoyl) has been investigated. When neat, both H-farnesoyl and phytanoyl diethanolamide form a smectic liquid crystalline structure at sub-zero temperatures. In addition, all three diethanolamides exhibit a glass transition temperature at around -73 C. Geranoyl diethanolamide forms a lamellar crystalline phase with a lattice parameter of 17.4 {angstrom} following long term storage accompanied by the loss of the glass transition. In the presence of water, H-farnesoyl and phytanoyl diethanolamide form lyotropic liquid crystalline phases, whilst geranoyl diethanolamide forms an L{sub 2} phase. H-farnesoyl diethanolamide forms a fluid lamellar phase (L{sub {alpha}}) at room temperature and up to {approx} 40 C. Phytanoyl diethanolamide displays a rich mesomorphism forming the inverse diamond (Q{sub II}{sup D}) and gyroid (Q{sub II}{sup G}) bicontinuous cubic phases in addition to an L{sub {alpha}} phase.

  20. Synthetic high-charge organomica: effect of the layer charge and alkyl chain length on the structure of the adsorbed surfactants.

    Science.gov (United States)

    Pazos, M Carolina; Castro, Miguel A; Orta, M Mar; Pavón, Esperanza; Valencia Rios, Jesús S; Alba, María D

    2012-05-15

    A family of organomicas was synthesized using synthetic swelling micas with high layer charge (Na(n)Si(8-n)Al(n)Mg(6)F(4)O(20)·XH(2)O, where n = 2, 3, and 4) exchanged with dodecylammonium and octadecylammonium cations. The molecular arrangement of the surfactant was elucidated on the basis on XRD patterns and DTA. The ordering conformation of the surfactant molecules into the interlayer space of micas was investigated by (13)C, (27)Al, and (29)Si MAS NMR. The arrangement of alkylammonium ions in these high-charge synthetic micas depends on the combined effects of the layer charge of the mica and the chain length of the cation. In the organomicas with dodecylammonium, a transition from a parallel layer to a bilayer-paraffin arrangement is observed when the layer charge of the mica increases. However, when octadecylammonium is the interlayer cation, the molecular arrangement of the surfactant was found to follow the bilayer-paraffin model for all values of layer charge. The amount of ordered conformation all-trans is directly proportional of layer charge.

  1. A novel high-performance thin layer chromatography method for quantification of long chain aliphatic hydrocarbons from Cissus quadrangularis

    Directory of Open Access Journals (Sweden)

    Vandana Jain

    2016-08-01

    Full Text Available Context: A high-performance thin layer chromatography (HPTLC is an analytical technique, which can be used for the determination of constituents or marker components in various parts of the plants. Earlier studies have estimated phytoconstituents from the stem and other aerial plant parts of Cissus quadrangularis Linn. Estimation of hydrocarbons can also be successfully done using HPTLC technique using suitable derivatization. Aims: To develop and validate a simple and rapid method for the estimation of long chain aliphatic hydrocarbons from the leaves of C. quadrangularis using HPTLC technique. Methods: Precoated silica gel 60 F254 plates were used as stationary phase. The mobile phase used was hexane (100 %. The detection of spots was carried out using berberine sulphate as detecting reagent. Results: The method was validated in terms of linearity, sensitivity, accuracy, and precision. Linearity range was found to be 2-10 µg/mL, limit of detection 0.127 µg/mL, and limit of quantification 0.384 µg/mL. Conclusions: A novel, simple, accurate, precise and sensitive HPTLC method has been developed and validated for the estimation of long chain aliphatic hydrocarbons obtained from the leaves of C. quadrangularis Linn.

  2. Polarization-dependent NEXAFS study of adsorption of long-chain surfactants on mechanically milled iron powder

    Energy Technology Data Exchange (ETDEWEB)

    Syugaev, A.V., E-mail: syual@mail.ru; Maratkanova, A.N.

    2014-08-15

    Highlights: • Plate-like particles modified with surfactant molecules were obtained under high-energy ball milling. • Adsorption layers were studied with polarization-dependent NEXAFS spectroscopy. • For the first time, arrangement of surfactants molecules on the powdered metal surface has been determined. • Tails of surfactant molecules (C-F/C-H) are shown to be oriented perpendicular to the particle surface. • Arrangement of carboxylate groups on the particle surfaces is discussed. - Abstract: In this work we have demonstrated the possibility of using the polarization-dependent NEXAFS spectra to study the structure of organic layers at the surface of powdered materials with plate-like shaped particles. The polarization dependence of the NEXAFS spectra may be easily obtained by just changing the angle between the X-ray beam direction and the substrate onto which the powder particles are set. For the first time, we have carried out a detailed study of the surfactant layers (n-perfluorononanoic and stearic acid), which are formed at the surface of iron plate-like particles under mechanical milling of iron powder with an addition of corresponding surfactants. The surfactant molecules are predominantly oriented perpendicular to the surface of the mechanically milled particles. Such orientation is similar to the arrangement of the molecules in the layers formed under equilibrium conditions, e.g. deposition from solutions. The changes in the chemical environment occurring in the molecule tails (defluorination or dehydrogenation) under mechanochemical treatment, do not result in a significant change in the molecular orientation and disordering of the adsorbed layer.

  3. 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 ...

  4. 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.

  5. Use of nuclear magnetic resonance of hydrogen in the characterization of saturated hydrocarbonic chains

    International Nuclear Information System (INIS)

    Costa Neto, A.; Soares, V.L.P.; Costa Neto, C.

    1979-01-01

    Alkanes and cycloalkanes are characterized by a methyl-methylene-methine groups proportion, the percentual absorption in prefixed regions and the pattern of the spectrum of nuclear magnetic resonance of hydrogen. The GPI is calculated from the contribution of the areas corresponding to prefixed regions of the hydrogen magnetic resonance spectra (60 Mc). These regions are (for the saturated hydrocarbons): 0,5-1,05ppm (X), 1,05ppm (Y) and 1,50-2,00ppm (Z). The validity of the index was verified for the homologous series of linear hydrocarbons and methyl-, dimethyl-, ethyl-, cyclopentyl- and cyclohexyl-branched hydrocarbons. Its application to shale oil chemistry (xistoquimica) is discussed. (author) [pt

  6. Thermodynamic stability and retinol binding property of {beta}-lactoglobulin in the presence of cationic surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Sahihi, M. [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Bordbar, A.K., E-mail: bordbar@chem.ui.ac.ir [Department of Chemistry, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Ghayeb, Y. [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2011-08-15

    Highlights: > The stability parameters of {beta}-lactoglobulin, BLG, in the presence of C{sub n}TAB have been evaluated. > Rising in hydrocarbon chain length increases the denaturating power of surfactants. > C{sub n}TAB enhances the retinol binding affinity of BLG in all of its concentration range. - Abstract: In this work the stability parameters of bovine {beta}-lactoglobulin, variant A (BLG-A), with regard to their transition curves induced by dodecyltrimethylammonium bromide (C{sub 12}TAB), tetradecyltrimethylammonium bromide (C{sub 14}TAB) and hexadecyltrimethylammonium bromide (C{sub 16}TAB) as cationic surfactants, were determined at 298 K. For each transition curve, the conventional method of analysis which assumes a linear concentration dependence of the pre- and post-transition base lines, gave the most realistic values for {Delta}G{sub D}(H{sub 2}O). The results represent the increase in the denaturating power of surfactants with an increase in hydrocarbon chain length. The value of about 22.27 kJ . mol{sup -1} was obtained for {Delta}G{sub D}(H{sub 2}O) from transition curves. Subsequently, the retinol binding property of BLG as its functional indicator was investigated in the presence of these surfactants using the spectrofluorimeter titration method. The results represent the substantial enhancement of retinol binding affinity of BLG in the presence of these surfactants.

  7. 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.

  8. Long-chain alkylimidazolium ionic liquids, a new class of cationic surfactants coated on ODS columns for anion-exchange chromatography.

    Science.gov (United States)

    Qiu, Hongdeng; Zhang, Qinghua; Chen, Limei; Liu, Xia; Jiang, Shengxiang

    2008-08-01

    Separations of common inorganic anions were carried out on ODS columns coated with two long-chain alkylimidazolium ionic liquids ([C(12)MIm]Br and [C(14)MIm]Br) as new cationic surfactants for ion chromatography. With phthalate buffer solution as the mobile phases and non-suppressed conductivity detection, high column efficiencies and excellent selectivity were obtained in the separation of inorganic anions. Chromatographic parameters are calculated and the results show that the coated column possesses significant potential for the analysis of some inorganic anions such as CH(3)COO(-), IO(3)(-), Cl(-), BrO(3)(-), NO(2)(-), Br(-), NO(3)(-), SO(4)(2-), I(-), BF(4)(-), and SCN(-). The effect of eluent pH values on the separation of anions has been studied on the column coated with [C(12)MIm]Br. The stability of the coated columns was also examined.

  9. 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.)

  10. 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.

  11. Surface properties and aggregate morphology of partially fluorinated carboxylate-type anionic gemini surfactants.

    Science.gov (United States)

    Yoshimura, Tomokazu; Bong, Miri; Matsuoka, Keisuke; Honda, Chikako; Endo, Kazutoyo

    2009-11-01

    Three anionic homologues of a novel partially fluorinated carboxylate-type anionic gemini surfactant, N,N'-di(3-perfluoroalkyl-2-hydroxypropyl)-N,N'-diacetic acid ethylenediamine (2C(n)(F) edda, where n represents the number of carbon atoms in the fluorocarbon chain (4, 6, and 8)) were synthesized. In these present gemini surfactants, the relatively small carboxylic acid moieties form hydrophilic head groups. The surface properties or structures of the aggregates of these surfactants are strongly influenced by the nonflexible fluorocarbons and small head groups; this is because these surfactants have a closely packed molecular structure. The equilibrium surface tension properties of these surfactants were measured at 298.2K for various fluorocarbon chain lengths. The plot of the logarithm of the critical micelle concentration (cmc) against the fluorocarbon chain lengths for 2C(n)(F) edda (n=4, 6, and 8) showed a minimum for n=6. Furthermore, the lowest surface tension of 2C(6)(F) edda at the cmc was 16.4mNm(-1). Such unique behavior has not been observed even in the other fluorinated surfactants. Changes in the shapes and sizes of these surfactant aggregate with concentration were investigated by dynamic light scattering and transmission electron microscopy (TEM). The TEM micrographs showed that in an aqueous alkali solution, 2C(n)(F) edda mainly formed aggregates with stringlike (n=4), cagelike (n=6), and distorted bilayer structures (n=8). The morphological changes in the aggregates were affected by the molecular structure composed of nonflexible fluorocarbon chains and flexible hydrocarbon chains.

  12. 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.

  13. Reactivity of polyester aliphatic amine surfactants as corrosion inhibitors for carbon steel in formation water (deep well water)

    International Nuclear Information System (INIS)

    Alsabagh, A.M.; Migahed, M.A.; Awad, Hayam S.

    2006-01-01

    Effect of different concentrations, 40-200 ppm, of various polyester aliphatic amine surfactants on inhibition of the corrosion of carbon steel in the formation water (deep well water) was investigated. These surfactants exhibit different levels of inhibition particularly at high concentration (200 ppm). Inhibition efficiencies in the range 86-96% were determined by weight loss method. Comparable results were obtained from electrochemical measurements using Tafel extrapolation and polarisation resistance methods. It was shown that all the investigated surfactants act primarily as anodic inhibitors; however, they also affect the rate and mechanism of the cathodic reaction. These compounds function via adsorption on reactive sites on the corroding surface reducing the corrosion rate of the metal. It was revealed that the adsorption of these surfactants obey Langmuir adsorption isotherm. The inhibition effectiveness increases with the length of the aliphatic hydrocarbon chain, being a maximum in the presence of surfactant IV (∼96% efficiency). The corrosion inhibition feature of this compound is attributed to the presence of a long hydrocarbon chain that ensures large surface coverage as well as the presence of multiple active centers for adsorption. Scanning electron microscopy, SEM, has been applied to identify the surface morphology of carbon steel alloy in the absence and presence of the inhibitor molecules

  14. Reactivity of polyester aliphatic amine surfactants as corrosion inhibitors for carbon steel in formation water (deep well water)

    Energy Technology Data Exchange (ETDEWEB)

    Alsabagh, A.M. [Department of Petroleum Applications, Egyptian Petroleum Research Institute (EPRI), Ahmed El-Zomor Street 1, Nasr City, Cairo 11727 (Egypt); Migahed, M.A. [Department of Petroleum Applications, Egyptian Petroleum Research Institute (EPRI), Ahmed El-Zomor Street 1, Nasr City, Cairo 11727 (Egypt)]. E-mail: mohamedatiyya707@hotmail.com; Awad, Hayam S. [Chemistry Department, Faculty of Girls for Science, Art and Education, Ain Shams University, Asmaa Fahmi Street, Helliopolis, Cairo (Egypt)

    2006-04-15

    Effect of different concentrations, 40-200 ppm, of various polyester aliphatic amine surfactants on inhibition of the corrosion of carbon steel in the formation water (deep well water) was investigated. These surfactants exhibit different levels of inhibition particularly at high concentration (200 ppm). Inhibition efficiencies in the range 86-96% were determined by weight loss method. Comparable results were obtained from electrochemical measurements using Tafel extrapolation and polarisation resistance methods. It was shown that all the investigated surfactants act primarily as anodic inhibitors; however, they also affect the rate and mechanism of the cathodic reaction. These compounds function via adsorption on reactive sites on the corroding surface reducing the corrosion rate of the metal. It was revealed that the adsorption of these surfactants obey Langmuir adsorption isotherm. The inhibition effectiveness increases with the length of the aliphatic hydrocarbon chain, being a maximum in the presence of surfactant IV ({approx}96% efficiency). The corrosion inhibition feature of this compound is attributed to the presence of a long hydrocarbon chain that ensures large surface coverage as well as the presence of multiple active centers for adsorption. Scanning electron microscopy, SEM, has been applied to identify the surface morphology of carbon steel alloy in the absence and presence of the inhibitor molecules.

  15. Study of the Radical Chain Mechanism of Hydrocarbon Oxidation for In Situ Combustion Process

    Directory of Open Access Journals (Sweden)

    Alexandra Ushakova

    2017-01-01

    Full Text Available Despite the abundance of in situ combustion models of oil oxidation, many of the effects are still beyond consideration. For example, until now, initial stages of oxidation were not considered from a position of radical chain process. This is a serious difficulty for the simulation of oil recovery process that involves air injection. To investigate the initial stages of oxidation, the paper considers the sequence of chemical reactions, including intermediate short-living compounds and radicals. We have attempted to correlate the main stages of the reaction with areas of heat release observed in the experiments. The system of differential equations based on the equations of oxidation reactions was solved. Time dependence of peroxides formation and start of heat release is analytically derived for the initial stages. We have considered the inhibition of initial oxidation stages by aromatic oil compounds and have studied the induction time in dependence on temperature. Chain ignition criteria for paraffins and crude oil in presence of core samples were obtained. The calculation results are compared with the stages of oxidation that arise by high-pressure differential scanning calorimetry. According to experimental observations we have determined which reactions are important for the process and which can be omitted or combined into one as insignificant.

  16. 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.

  17. On optimal length of hydrocarbon chain of fatty-acid collectors of rare earth ions

    International Nuclear Information System (INIS)

    Skrylev, L.D.; Sazonova, V.F.; Markina, Eh.L.

    1978-01-01

    The mechanism of the effect of the length of alkyl chain in fatty-acid collectors on the efficiency of flotation separation of the ions of rare earth elements (REE) collected by them has been investigated. REE flotation separation was studied on gadolinium chloride. Aqueous solutions of potassium caprinata, indecanate, laurate, tridecanate, myristate, pentadecanate and palmitate were used as collectors of Gd ions. The interaction of Gd ions with these compounds proceeds rapidly and is accompanied by stable colloidal solutions of Gd soaps being formed. Infrared spectra and radiograms of the sublates have been studied. It has been found that, with the number of carbon atoms in the collector molecule increasing from 10 to 16, the rate of flotation separation of Gd ions from solutions with pH 6 and 8 at first practically does not change (for potassium caprinate, undecanate and laurate), then drops sharply (potassium tridecanate and myristate), after which is again increases sharply (potassium pentadecanata and palmitate). The separation rate of Gd ions does not rise in solutions with pH 10. The nature of the sublate is shown to be determined by the solubility of the corresponing fatty acids and gadolinium soaps

  18. A metabolomics strategy to assess the combined toxicity of polycyclic aromatic hydrocarbons (PAHs) and short-chain chlorinated paraffins (SCCPs).

    Science.gov (United States)

    Wang, Feidi; Zhang, Haijun; Geng, Ningbo; Ren, Xiaoqian; Zhang, Baoqin; Gong, Yufeng; Chen, Jiping

    2018-03-01

    The combined toxicity of mixed chemicals is usually evaluated according to several specific endpoints, and other potentially toxic effects are disregarded. In this study, we provided a metabolomics strategy to achieve a comprehensive understanding of toxicological interactions between mixed chemicals on metabolism. The metabolic changes were quantified by a pseudotargeted analysis, and the types of combined effects were quantitatively discriminated according to the calculation of metabolic effect level index (MELI). The metabolomics strategy was used to assess the combined effects of polycyclic aromatic hydrocarbons (PAHs) and short-chain chlorinated paraffins (SCCPs) on the metabolism of human hepatoma HepG2 cells. Our data suggested that exposure to a combination of PAHs and SCCPs at human internal exposure levels could result in an additive effect on the overall metabolism, whereas diverse joint effects were observed on various metabolic pathways. The combined exposure could induce a synergistic up-regulation of phospholipid metabolism, an additive up-regulation of fatty acid metabolism, an additive down-regulation of tricarboxylic acid cycle and glycolysis, and an antagonistic effect on purine metabolism. SCCPs in the mixture acted as the primary driver for the acceleration of phospholipid and fatty acid metabolism. Lipid metabolism disorder caused by exposure to a combination of PAHs and SCCPs should be an important concern for human health. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. One-step production of long-chain hydrocarbons from waste-biomass-derived chemicals using bi-functional heterogeneous catalysts.

    Science.gov (United States)

    Wen, Cun; Barrow, Elizabeth; Hattrick-Simpers, Jason; Lauterbach, Jochen

    2014-02-21

    In this study, we demonstrate the production of long-chain hydrocarbons (C8+) from 2-methylfuran (2MF) and butanal in a single step reactive process by utilizing a bi-functional catalyst with both acid and metallic sites. Our approach utilizes a solid acid for the hydroalkylation function and as a support as well as a transition metal as hydrodeoxygenation catalyst. A series of solid acids was screened, among which MCM-41 demonstrated the best combination of activity and stability. Platinum nanoparticles were then incorporated into the MCM-41. The Pt/MCM-41 catalyst showed 96% yield for C8+ hydrocarbons and the catalytic performance was stable over four reaction cycles of 20 hour each. The reaction pathways for the production of long-chain hydrocarbons is probed with a combination of infrared spectroscopy and steady-state reaction experiments. It is proposed that 2MF and butanal go through hydroalkylation first on the acid site followed by hydrodeoxygenation to produce the hydrocarbon fuels.

  20. Synthesis of single- and double-chain fluorocarbon and hydrocarbon galactosyl amphiphiles and their anti-HIV-1 activity.

    Science.gov (United States)

    Faroux-Corlay, B; Clary, L; Gadras, C; Hammache, D; Greiner, J; Santaella, C; Aubertin, A M; Vierling, P; Fantini, J

    2000-07-24

    Galactosylceramide (GalCer) is an alternative receptor allowing HIV-1 entry into CD4(-)/GalCer(+) cells. This glycosphingolipid recognizes the V3 loop of HIV gp120, which plays a key role in the fusion of the HIV envelope and cellular membrane. To inhibit HIV uptake and infection, we designed and synthesized analogs of GalCer. These amphiphiles and bolaamphiphiles consist of single and double hydrocarbon and/or fluorocarbon chain beta-linked to galactose and galactosamine. They derive from serine (GalSer), cysteine (GalCys), and ethanolamine (GalAE). The anti-HIV activity and cytotoxicity of these galactolipids were evaluated in vitro on CEM-SS (a CD4(+) cell line), HT-29, a CD4(-) cell line expressing high levels of GalCer receptor, and/or HT29 genetically modified to express CD4. GalSer and GalAE derivatives, tested in aqueous medium or as part of liposome preparation, showed moderate anti-HIV-1 activities (IC50 in the 20-220 microM range), whereas none of the GalCys derivatives was found to be active. Moreover, only some of these anti-HIV active analogs inhibited the binding of [3H]suramin (a polysulfonyl compound which displays a high affinity for the V3 loop) to SPC3, a synthetic peptide which contains the conserved GPGRAF region of the V3 loop. Our results most likely indicate that the neutralization of the virion through masking of this conserved V3 loop region is not the only mechanism involved in the HIV-1 antiviral activity of our GalCer analogs.

  1. Methanol to olefin Conversion on HSAPO-34 zeolite from periodic density functional theory calculations: a complete cycle of side chain hydrocarbon pool mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C.M.; Wang, Y.D.; Xie, Z.K.; Liu, Z.P. [SINOPEC, Shanghai (China)

    2009-03-15

    For its unique position in the coal chemical industry, the methanol to olefin (MTO) reaction has been a hot topic in zeolite catalysis. Due to the complexities of catalyst structure and reaction networks, many questions such as how the olefin chain is built from methanol remain elusive. On the basis of periodic density functional theory calculations, this work establishes the first complete catalytic cycle for MTO reaction via hexamethylbenzene (HMB) trapped in HSAPO-34 zeolite based on the so-called side chain hydrocarbon pool mechanism. The cycle starts from the methylation of HMB that leads to heptamethylbenzenium ion (heptaMB{sup +}) intermediate. This is then followed by the growth of side chain via repeated deprotonation of benzenium ions and methylation of the exocyclic double bond. Ethene and propene can finally be released from the side ethyl and isopropyl groups of benzenium ions by deprotonation and subsequent protonation steps. We demonstrate that (i) HMB/HSAPO-34 only yields propene as the primary product based on the side chain hydrocarbon pool mechanism and (ii) an indirect proton-shift step mediated by water that is always available in the system is energetically more favorable than the traditionally regarded internal hydrogen-shift step. Finally, the implications of our results toward understanding the effect of acidity of zeolite on MTO activity are also discussed.

  2. 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.

  3. The structure of normal ionic micelles by interpretation of small-angle neutron scattering data from selectively labeled (2H, 19F) surfactant solutions

    International Nuclear Information System (INIS)

    Berr, S.S.

    1986-12-01

    We have determined the structure of micelles formed in water by several classes of ionic surfactants under a variety of experimental conditions using small-angle neutron scattering (SANS) techniques. Contrast between the micelles and the solvent was achieved through either selective deuteration or fluorination of the surfactant, or through the use of D 2 O. Interpretation of SANS data was facilitated by the use of Hayter, Penfold, and Hansen's rescaled Mean Spherical Approximation theory to calculate the scattering due to interparticle interactions. We have devised a number of micelle models, both spherical and ellipsoidal, to account for the scattering due to single micelles. It was found that changing the solvent from H 2 O to D 2 O results in the formation of larger micelles due to changes in the solvent-surfactant hydrocarbon interactions. This solvent isotope effect increased as the length of the alkyl chain increased. The fractional micellar charge did not change with respect to isotopic composition of solvent. We found that alkyltrimethylammonium bromide surfactants form drier micelles than do the sodium alkyl sulfate surfactants of equal chain length. Also, all micelles studied were found to be dry near the critical micelle concentration (cmc) and to become increasingly wetter as the concentration increased. The increase in aggregation number with respect to the square root of surfactant concentration was found to be linear for all systems studied. 80 figs

  4. 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.

  5. Synthesis of All-carbon Chains and Nanoparticles by Chemical Transformation of Halogenated Hydrocarbons at Low Temperatures

    Czech Academy of Sciences Publication Activity Database

    Kavan, Ladislav

    č. 196 (2001), s. 22-38 ISSN 0371-5345 R&D Projects: GA ČR GA203/98/1168; GA ČR GA203/99/1015; GA ČR GA203/00/0634 Institutional research plan: CEZ:AV0Z4040901 Keywords : halogenated hydrocarbon * electrochemical carbon * fullerenes Subject RIV: CG - Electrochemistry

  6. 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.

  7. 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.

  8. Biodegradation of Medium Chain Hydrocarbons by Acinetobacter venetianus 2AW Immobilized to Hair-Based Adsorbent Mats (Postprint)

    Science.gov (United States)

    2010-09-01

    open- water oil spills or treatment of large contaminated volumes such as ballast water or holding ponds. The practi- cal application of the mat is...SS, Al-Hasan RH, Salamah S, Al-Dabbous A. Biore- mediation of oily sea water by bacteria immobilized in biofilms coating macroalgae . Int Biodeter...adsorbent, for in situ degradation of hydrocarbons, has practical application in the bioremediation of oil in water emulsions. acinetobacter

  9. Phase behavior of fluorocarbon and hydrocarbon double-chain hydroxylated and galactosylated amphiphiles and bolaamphiphiles. Long-term shelf-stability of their liposomes.

    Science.gov (United States)

    Clary, L; Gadras, C; Greiner, J; Rolland, J P; Santaella, C; Vierling, P; Gulik, A

    1999-06-01

    This paper describes the morphological characterization, by freeze-fracture electron microscopy, and the thermotropic phase behavior, by differential scanning calorimetry and/or X-ray scattering, of aqueous dispersions of various hydroxylated and galactosylated double-chain amphiphiles and bolaamphiphiles, several of them containing one or two hydrophobic fluorocarbon chains. Colloidal systems are observed in water with the hydroxylated hydrocarbon or fluorocarbon bolaamphiphiles only when they are dispersed with a co-amphiphile such as rac-1,2-dimyristoylphosphatidylcholine (DMPC) or rac-1,2-distearoylphosphatidylcholine (DSPC). Liposomes are formed providing the relative content of bolaamphiphiles does not exceed 20% mol. Most of these liposomes can be thermally sterilized and stored at room temperature for several months without any significant modification of their size and size distribution. The hydrocarbon galactosylated bolaamphiphile HO[C24][C12]Gal forms in water a lamellar phase (the gel to liquid-crystal phase transition is complete at 45 degrees C) and a Im3m cubic phase above 47 degrees C. The fluorocarbon HO[C24][F6C5]Gal analog displays a more complex and metastable phase behavior. The fluorinated non-bolaform galactosylated [F8C7][C16]AEGal and SerGal amphiphiles form lamellar phases in water. Low amounts (10% molar ratio) of the HO[C24][F6C5]Gal or HO[C24][C12]Gal bolaamphiphiles or of the single-headed [F8C7][C16]AEGal improve substantially the shelf-stability of reference phospholipon/cholesterol 2/1 liposomes. These liposomes when co-formulated with a single-headed amphiphile from the SerGal series are by far less stable.

  10. Biomimicry of surfactant protein C.

    Science.gov (United States)

    Brown, Nathan J; Johansson, Jan; Barron, Annelise E

    2008-10-01

    considerations but makes use of a non-natural, poly-N-substituted glycine or "peptoid" scaffold to circumvent the difficulties associated with SP-C. By incorporating unique biomimetic side chains in a non-natural backbone, the peptoid mimic captures both SP-C's hydrophobic patterning and its helical secondary structure. Despite the differences in structure, both SP-C33 and the SP-C peptoid mimic capture many requisite features of SP-C. In a surfactant environment, these analogues also replicate many of the key surface activities necessary for a functional biomimetic surfactant therapy while overcoming the difficulties associated with the natural protein. With improved stability, greater production potential, and elimination of possible pathogenic contamination, these biomimetic surfactant formulations offer not only the potential to improve the treatment of respiratory distress syndrome but also the opportunity to treat other respiratory-related disorders.

  11. Production of a biological surfactant

    Directory of Open Access Journals (Sweden)

    N. Gladys Rosero

    2002-01-01

    Full Text Available This paper summarizes the scale up work performed at the Colombian Petroleum Institute on a process to produce at pilot plant level a biosurfactant of the rhamnolipid type. By examination of both the activation conditions of the microorganism and design aspects of the broth, a stable condition was achieved which consistently triggers the production mechanisms and thus it was obtained a significant increment in biosurfactant productivity. The biological surfactant exhibited high efficiency in applications such as hydrocarbon biodegradation in saline environments, corrosion inhibition, and crude oil recovery from storage tank bottom sludges.

  12. 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.

  13. 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.

  14. Synthesis of butyl acrylate-styrene block copolymers in emulsion by reversible addition-fragmentation chain transfer : effect of surfactant migration upon film formation

    NARCIS (Netherlands)

    Monteiro, M.J.; Sjöberg, M.; Göttgens, C.M.; Vlist, van der J.

    2000-01-01

    The synthesis of block copolymers in an environmentally friendly medium was carried out in emulsion polymerizations through the reversible addition-fragmentation chain transfer process, using a transfer active xanthate (MADIX) agent, under batch and starved-feed conditions. First, ab initio

  15. Single well surfactant test to evaluate surfactant floods using multi tracer method

    Science.gov (United States)

    Sheely, Clyde Q.

    1979-01-01

    Data useful for evaluating the effectiveness of or designing an enhanced recovery process said process involving mobilizing and moving hydrocarbons through a hydrocarbon bearing subterranean formation from an injection well to a production well by injecting a mobilizing fluid into the injection well, comprising (a) determining hydrocarbon saturation in a volume in the formation near a well bore penetrating formation, (b) injecting sufficient mobilizing fluid to mobilize and move hydrocarbons from a volume in the formation near the well bore, and (c) determining the hydrocarbon saturation in a volume including at least a part of the volume of (b) by an improved single well surfactant method comprising injecting 2 or more slugs of water containing the primary tracer separated by water slugs containing no primary tracer. Alternatively, the plurality of ester tracers can be injected in a single slug said tracers penetrating varying distances into the formation wherein the esters have different partition coefficients and essentially equal reaction times. The single well tracer method employed is disclosed in U.S. Pat. No. 3,623,842. This method designated the single well surfactant test (SWST) is useful for evaluating the effect of surfactant floods, polymer floods, carbon dioxide floods, micellar floods, caustic floods and the like in subterranean formations in much less time and at much reduced cost compared to conventional multiwell pilot tests.

  16. The Effect Of Organic Surfactants On The Properties Of Common Hygroscopic Particles: Effective Densities, Reactivity And Water Evaporation Of Surfactant Coated Particles

    Science.gov (United States)

    Cuadrarodriguez, L.; Zelenyuk, A.; Imre, D.; Ellison, B.

    2006-12-01

    Measurements of atmospheric aerosol compositions routinely show that organic compounds account for a very large fraction of the particle mass. The organic compounds that make up this aerosol mass represent a wide range of molecules with a variety of properties. Many of the particles are composed of hygroscopic salts like sulfates, nitrates and sea-salt internally mixed with organics. While the properties of the hygroscopic salts are known, the effect of the organic compounds on the microphysical and chemical properties which include CCN activity is not clear. .One particularly interesting class of internally mixed particles is composed of aqueous salts solutions that are coated with organic surfactants which are molecules with long aliphatic chain and a water soluble end. Because these molecules tend to coat the particles' surfaces, a monolayer might be sufficient to drastically alter their hygroscopic properties, their CCN activity, and reactivity. The aliphatic chains, being exposed to the oxidizing atmosphere are expected to be transformed through heterogeneous chemistry, yielding complex products with mixed properties. We will report the results from a series of observations on ammonium sulfate, sodium chloride and sea salt particles coated with three types of surfactant molecules: sodium lauryl sulfate, sodium oleate and laurtrimonium chloride. We have been able to measure the effective densities of internally mixed particles with a range of surfactant concentration that start below a monolayer and extend all the way to particles composed of pure surfactant. For many of the measurements the data reveal a rather complex picture that cannot be simply interpreted in terms of the known pure-compound densities. For unsaturated hydrocarbons we observed and quantified the effect of oxidation by ozone on particle size, effective density and individual particle mass spectral signatures. One of the more important properties of these surfactants is that they can form a

  17. Cu sbnd Al sbnd Fe layered double hydroxides with CO32- and anionic surfactants with different alkyl chains in the interlayer

    Science.gov (United States)

    Trujillano, Raquel; Holgado, María Jesús; González, José Luis; Rives, Vicente

    2005-08-01

    Layered double hydroxides (LDHs), with the hydrotalcite-like structure containing Cu(II), Al(III) and Fe(III) in the layers, and different alkyl sulfonates in the interlayer, have been prepared and characterized by powder X-ray diffraction, FT-IR spectroscopy, differential thermal analysis and thermogravimetric analysis. Pure crystalline phases have been obtained in all cases. Upon heating, combustion of the organic chain takes place at lower temperature than the corresponding sodium salts.

  18. 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.

  19. Preparation, physicochemical characterisation and magnetic properties of Cu-Al layered double hydroxides with CO 32- and anionic surfactants with different alkyl chains in the interlayer

    Science.gov (United States)

    Trujillano, Raquel; Holgado, María Jesús; Pigazo, Fernando; Rives, Vicente

    2006-03-01

    Layered double hydroxides with the hydrotalcite-like structure, containing Cu(II) and Al(III) in the layers, and different alkyl sulphonates in the interlayer, have been prepared and characterised by powder X-ray diffraction, FT-IR spectroscopy, differential thermal analysis and thermogravimetric analysis. Their magnetic properties have been also studied. Except for the sample containing octadecanesulphonate in the interlayer, for which an excess of sulphonate exists, pure crystalline phases have been obtained in the other cases. Upon heating, combustion of the organic chain takes place at lower temperature than for the corresponding sodium salts. A two-dimensional antiferromagnetic behaviour is observed at 200 K in all samples containing intercalated sulphonate. The χT value is lower for the samples containing interlayer sulphonates (with layer-layer distances in the 21-31 Å range), than for a carbonate-containing analogue (basal spacing 7.51 Å).

  20. 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

  1. Effect of Gemini-type surfactant on methane hydrate formation

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, K.E.; Park, J.M.; Kim, C.U.; Chae, H.J.; Jeong, S.Y. [Korea Research Inst. of Chemical Technology, Jang-Dong, Yuseong-Gu, Daejeon (Korea, Republic of)

    2008-07-01

    Natural gas hydrates are formed from water and natural gas molecules at particular temperatures and pressures that become ice-like inclusion compounds. Gas hydrates offer several benefits such as energy resource potential and high storage capacity of natural gas in the form of hydrates. However, the application of natural gas hydrates has been deterred by its low formation rate and low conversion ratio of water into hydrate resulting in low actual storage capacity. This paper presented an experimental study to determine the effect of adding a novel Gemini-type surfactant on methane hydrate formation. The experimental study was described with reference to the properties of prepared diols and properties of prepared disulfonates. Gemini surfactant is the family of surfactant molecules possessing more than one hydrophobic tail and hydrophilic head group. They generally have better surface-active properties than conventional surfactants of equal chain length. The paper presented the results of the study in terms of the reactions of diols with propane sultone; storage capacity of hydrate formed with and without surfactant; and methane hydrate formation with and without disulfonate. It was concluded that the methane hydrate formation was accelerated by the addition of novel anionic Gemini-type surfactants and that hydrate formation was influenced by the surfactant concentration and alkyl chain length. For a given concentration, the surfactant with the highest chain length demonstrated the highest formation rate and storage capacity. 5 refs., 3 tabs., 4 figs.

  2. Practical Considerations and Challenges Involved in Surfactant Enhanced Bioremediation of Oil

    Directory of Open Access Journals (Sweden)

    Sagarika Mohanty

    2013-01-01

    Full Text Available Surfactant enhanced bioremediation (SEB of oil is an approach adopted to overcome the bioavailability constraints encountered in biotransformation of nonaqueous phase liquid (NAPL pollutants. Fuel oils contain n-alkanes and other aliphatic hydrocarbons, monoaromatics, and polynuclear aromatic hydrocarbons (PAHs. Although hydrocarbon degrading cultures are abundant in nature, complete biodegradation of oil is rarely achieved even under favorable environmental conditions due to the structural complexity of oil and culture specificities. Moreover, the interaction among cultures in a consortium, substrate interaction effects during the degradation and ability of specific cultures to alter the bioavailability of oil invariably affect the process. Although SEB has the potential to increase the degradation rate of oil and its constituents, there are numerous challenges in the successful application of this technology. Success is dependent on the choice of appropriate surfactant type and dose since the surfactant-hydrocarbon-microorganism interaction may be unique to each scenario. Surfactants not only enhance the uptake of constituents through micellar solubilization and emulsification but can also alter microbial cell surface characteristics. Moreover, hydrocarbons partitioned in micelles may not be readily bioavailable depending on the microorganism-surfactant interactions. Surfactant toxicity and inherent biodegradability of surfactants may pose additional challenges as discussed in this review.

  3. Practical Considerations and Challenges Involved in Surfactant Enhanced Bioremediation of Oil

    Science.gov (United States)

    Mohanty, Sagarika; Jasmine, Jublee

    2013-01-01

    Surfactant enhanced bioremediation (SEB) of oil is an approach adopted to overcome the bioavailability constraints encountered in biotransformation of nonaqueous phase liquid (NAPL) pollutants. Fuel oils contain n-alkanes and other aliphatic hydrocarbons, monoaromatics, and polynuclear aromatic hydrocarbons (PAHs). Although hydrocarbon degrading cultures are abundant in nature, complete biodegradation of oil is rarely achieved even under favorable environmental conditions due to the structural complexity of oil and culture specificities. Moreover, the interaction among cultures in a consortium, substrate interaction effects during the degradation and ability of specific cultures to alter the bioavailability of oil invariably affect the process. Although SEB has the potential to increase the degradation rate of oil and its constituents, there are numerous challenges in the successful application of this technology. Success is dependent on the choice of appropriate surfactant type and dose since the surfactant-hydrocarbon-microorganism interaction may be unique to each scenario. Surfactants not only enhance the uptake of constituents through micellar solubilization and emulsification but can also alter microbial cell surface characteristics. Moreover, hydrocarbons partitioned in micelles may not be readily bioavailable depending on the microorganism-surfactant interactions. Surfactant toxicity and inherent biodegradability of surfactants may pose additional challenges as discussed in this review. PMID:24350261

  4. 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.

  5. Aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Roder, M.

    1985-01-01

    Papers dealing with radiolysis of aromatic hydrocarbons of different composition (from benzene to terphenyls and hydrocarbons with condensed rings) as well as their mixtures (with alkanes, alkenes, other aromatic hydrocarbons) are reviewed. High radiation stability of aromatic hydrocarbons in condensed phases associated with peculiarities of molecular structure of compounds is underlined. Mechanisms of radiolytic processes, vaues of product yields are considered

  6. Effect of alkyl length of cationic surfactants on desorption of Cs from contaminated clay

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bo Hyun; Park, Chan Woo; Yang, Hee Man; Seo, Bum Kyoung; Lee, Kune Woo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, So Jin [Chungnam National University, Daejeon (Korea, Republic of)

    2017-03-15

    In this study, desorption characteristics of Cs from clay according to the hydrophobic alkyl chain length of the cationic surfactant were investigated. Alkyltrimethylammonium bromide was used as a cationic surfactant, and the length of the hydrophobic alkyl chain of the cationic surfactant was varied from –octyl to –cetyl. The adsorbed amount of the cationic surfactant on montmorillonite increased with the length of the hydrophobic alkyl chain, and intercalation of the cationic surfactant into the clay interlayer increased the interlayer distances. The Cs removal efficiency was also enhanced with increasing alkyl chain length, and the cationic surfactant with the cetyl group showed a maximum Cs removal efficiency of 99±2.9%.

  7. 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

  8. 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.

  9. MICROORGANISMS’ SURFACE ACTIVE SUBSTANCES ROLE IN HYDROCARBONS BIODEGRADATION

    Directory of Open Access Journals (Sweden)

    Оlga Vasylchenko

    2012-09-01

    Full Text Available  Existing data and publications regarding oil, hydrocarbon biodegradation, metabolism, and bioremediation were analyzed. Search of hydrocarbon degrading bacteria which are producers of biosurfactants was provided, types of microbial surfactants and their physiological role were analyzed and ordered. The study of factors affecting the surface active properties of producers’ cultures was done.

  10. Effect of surfactant types and their concentration on the structural characteristics of nanoclay

    Science.gov (United States)

    Zawrah, M. F.; Khattab, R. M.; Saad, E. M.; Gado, R. A.

    2014-03-01

    A series of organo-modified nanoclays was synthesized using three different surfactants having different alkyl chain lengths and concentrations [0.5-5.0 cation exchange capacity (CEC)]. These surfactants were Ethanolamine (EA), Cetyltrimethylammoniumbromide (CTAB) and Tetraoctadecylammoniumbromide (TO). The obtained modified nanoclays were characterized by X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM) and compared with unmodified nanoclay. The results of XRD analysis indicated that the basal d-spacing has increased with increasing alkyl chain length and surfactant concentration. From the obtained microstructures of these organo-modified nanoclays, the mechanism of surfactant adsorption was proposed. At relatively low loading of surfactant, most of surfactant entered the spacing by an ion-exchange mechanism and is adsorbed onto the interlayer cation sites. When the concentration of the surfactant exceeds the CEC of clay, the surfactant molecules then adhere to the surface adsorbed surfactant. Some surfactants entered the interlayers, whereas the others were attached to the clay surface. When the concentration of surfactant increased further beyond 2.0 CEC, the surfactants might occupy the inter-particle space within the house-of-cards aggregate structure.

  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 a Long Chain Carboxylate Acid on Sodium Dodecyl Sulfate Micelle Structure: A Small-angle Neutron Scattering Study

    International Nuclear Information System (INIS)

    Arum Patriati; Edy Giri Rachman Putra

    2009-01-01

    The effect of different hydrocarbon chain length of carboxylate acid, i.e. dodecanoic acid, CH 3 (CH 2 ) 10 COOH and hexadecanoic acid, CH 3 (CH 2 ) 14 COOH as a co-surfactant in the 0.3M SDS micellar solution has been studied using small angle neutron scattering (SANS). Here, the present of dodecanoic acid has induced the SDS structural micelles. The ellipsoid micelles structures changed significantly in length (major axis) from 21.7 Armstrong to 35.5 Armstrong at a fixed minor axis of 16.7 Armstrong in the present of 0.005M to 0.1M dodecanoic acid. Nevertheless, this effect was not shown in the present of hexadecanoic acid with the same concentration range. The present of hexadecanoic acid molecules gave a small effect on growth of SDS micelles where the major axis of the micelle was simply elongated from 21.5 Armstrong to 23.5 Armstrong. It showed that the appropriate hydrocarbon chain length between surfactant and co-surfactant molecules is one of the determining factors in forming a mixed micelles structure. (author)

  13. The interactions between ionic surfactants and phosphatidylcholine vesicles: Conductometry

    Science.gov (United States)

    Tsao, Heng-Kwong; Tseng, Wen Liang

    2001-11-01

    The interaction between ionic surfactants and phosphatidylcholine vesicles, which are prepared without addition of buffer and salt, is investigated by conductivity measurements. On the basis of the vesicle acting as a trap of charge carriers, the bilayer/aqueous phase partition coefficient K and the surfactant/lipid molar ratio Re of nine surfactants are determined. The thermodynamic consistency is satisfied by the measured parameters. The effects of the alkyl chain length (C10-C16) and ionic head group are then studied. The inverse partition coefficient K-1 is linearly related to the critical micelle concentration. The solubilizing ability Reb is a consequence of the competition between the surfactant incorporation into the bilayer and the formation of micelles. Consequently, the K parameter rises whereas the Reb parameter declines as the chain length is increased. The influence due to addition of salt is also discussed.

  14. 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

  15. 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.

  16. Petroleum hydrocarbons

    International Nuclear Information System (INIS)

    Farrington, J.W.; Teal, J.M.; Parker, P.L.

    1976-01-01

    Methods for analysis of petroleum hydrocarbons in marine samples are presented. Types of hydrocarbons present and their origins are discussed. Principles and methods of analysis are outlined. Infrared spectrometry, uv spectrometry, gas chromatography, mass spectroscopy, and carbon 14 measurements are described

  17. Petroleum Contaminated Soil Treatment Using Surfactant and Hydrogen Peroxide

    Directory of Open Access Journals (Sweden)

    Ilza Lobo

    2010-12-01

    Full Text Available The process of washing soil with surfactants, sodium lauryl ether sulphate (LESS and sodium lauryl sulphate (SDS was combined with chemical oxidation using hydrogen peroxide, with a view to in situ remediation of clay soil contaminated with hydrocarbons oil. The evaluation of the efficiency of the procedure was the removal of polyaromatic hydrocarbons and the comparison of physical and chemical characteristics of contaminated soil and uncontaminated from the same region. The combination of these two techniques, soil washing and application of an oxidizing agent, presented as a process of effective remediation for soils contaminated with petroleum products in subtropical regions.

  18. 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.

  19. 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.

  20. 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.

  1. Production of bio surfactants (Rhamnolipids) by pseudomonas aeruginosa isolated from colombian sludges

    International Nuclear Information System (INIS)

    Pimienta, A.L; Diaz M, M. P; Carvajal S, F.G; Grosso V, J.L.

    1997-01-01

    The bio surfactant production by strains of Pseudomonas aeruginosa isolated from Colombian hydrocarbon contaminated sludge has been determined. The methodology included the isolation of microorganisms, standardization of batch culture conditions for good surfactant production and characterization of the produced rhamnolipid. Several carbon sources were evaluated with regard to the growth and production curves. The stability of the rhamnolipid was also determined under variable conditions of pH, temperature and salt concentration. The strain Pseudomonas aeruginosa BS 3 showed bio surfactant production capabilities of rhamnolipid resulting in concentrations up to 2 g-dm with surface tensions of 30 - 32 mN-m in batch cultures with commercial nutrients

  2. Effect of double-tailed surfactant architecture on the conformation, self-assembly, and processing in polypeptide-surfactant complexes.

    Science.gov (United States)

    Junnila, Susanna; Hanski, Sirkku; Oakley, Richard J; Nummelin, Sami; Ruokolainen, Janne; Faul, Charl F J; Ikkala, Olli

    2009-10-12

    This work describes the solid-state conformational and structural properties of self-assembled polypeptide-surfactant complexes with double-tailed surfactants. Poly(L-lysine) was complexed with three dialkyl esters of phosphoric acid (i.e., phosphodiester surfactants), where the surfactant tail branching and length was varied to tune the supramolecular architecture in a facile way. After complexation with the branched surfactant bis(2-ethylhexyl) phosphate in an aqueous solution, the polypeptide chains adopted an alpha-helical conformation. These rod-like helices self-assembled into cylindrical phases with the amorphous alkyl tails pointing outward. In complexes with dioctyl phosphate and didodecyl phosphate, which have two linear n-octyl or n-dodecyl tails, respectively, the polypeptide formed antiparallel beta-sheets separated by alkyl layers, resulting in well-ordered lamellar self-assemblies. By heating, it was possible to trigger a partial opening of the beta-sheets and disruption of the lamellar phase. After repeated heating/cooling, all of these complexes also showed a glass transition between 37 and 50 degrees C. Organic solvent treatment and plasticization by overstoichiometric amount of surfactant led to structure modification in poly(L-lysine)-dioctyl phosphate complexes, PLL(diC8)(x) (x = 1.0-3.0). Here, the alpha-helical PLL is surrounded by the surfactants and these bottle-brush-like chains self-assemble in a hexagonal cylindrical morphology. As x is increased, the materials are clearly plasticized and the degree of ordering is improved: The stiff alpha-helical backbones in a softened surfactant matrix give rise to thermotropic liquid-crystalline phases. The complexes were examined by Fourier transform infrared spectroscopy, small- and wide-angle X-ray scattering, transmission electron microscopy, differential scanning calorimetry, polarized optical microscopy, and circular dichroism.

  3. Effect of surfactants on the fluorescence spectra of water-soluble ...

    Indian Academy of Sciences (India)

    TECS

    Effect of surfactants on the fluorescence spectra of water-soluble. MEHPPV ... polyacrylic acid (PAA) chains grafted onto their backbone were found to be water soluble, and they exhi- ..... in other words the variation of emission intensity.

  4. Rationalization and Prediction of the Equivalent Alkane Carbon Number (EACN) of Polar Hydrocarbon Oils with COSMO-RS σ-Moments.

    Science.gov (United States)

    Lukowicz, Thomas; Benazzouz, Adrien; Nardello-Rataj, Véronique; Aubry, Jean-Marie

    2015-10-20

    The equivalent alkane carbon numbers (EACNs) of 20 polar hydrocarbon oils are determined by the fishtail method. These values supplemented by 43 already reported EACNs of other hydrocarbons are rationalized by using the COSMO-RS σ-moments as descriptors for a QSPR analysis. A reliable model, with only two meaningful physicochemical parameters, namely the surface area (M0(X)) and the overall polarity (M2(X)) of the oil X, is able to predict the EACN values of a large variety of oils including (cyclo)alkanes, (cyclo)alkenes, terpenes, aromatics, alkynes, and chloroalkanes and to rationalize structural effects on EACNs. Furthermore, the dependence of the EACN of homologous oils on the chain length provides some molecular insight into how the different oils penetrate into the interfacial film of surfactants.

  5. 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.

  6. Microbial production of surfactants and their commercial potential.

    OpenAIRE

    Desai, J D; Banat, I M

    1997-01-01

    Many microorganisms, especially bacteria, produce biosurfactants when grown on water-immiscible substrates. Biosurfactants are more effective, selective, environmentally friendly, and stable than many synthetic surfactants. Most common biosurfactants are glycolipids in which carbohydrates are attached to a long-chain aliphatic acid, while others, like lipopeptides, lipoproteins, and heteropolysaccharides, are more complex. Rapid and reliable methods for screening and selection of biosurfactan...

  7. Preparation of Ultra Low-κ Porous SiOCH Films from Ring-Type Siloxane with Unsaturated Hydrocarbon Side Chains by Spin-On Deposition

    International Nuclear Information System (INIS)

    Chun-Xiao, Yang; Chi, Zhang; Qing-Qing, Sun; Sai-Sheng, Xu; Li-Feng, Zhang; Yu, Shi; Shi-Jin, Ding; Wei, Zhang

    2010-01-01

    An ultra-low-dielectric-constant (ultra low-k, or ULK) porous SiOCH film is prepared using a single ring-type siloxane precursor of the 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane by means of spin-on deposition, followed by crosslinking reactions between the precursor monomers under UV irradiation. The as-prepared film has an ultra low k of 2.41 at 1 MHz due to incorporation of pores and hydrocarbon crosslinkages, a leakage current density of 9.86 × 10 −7 A/cm 2 at 1 MV/cm, as well as a breakdown field strength of ∼1.5 MV/cm. Further, annealing at 300°C results in lower k (i.e., 1.94 at 1 MHz), smaller leakage current density (2.96 × 10 −7 A/cm 2 at 1 MV/cm) and higher breakdown field strength (about 3.5 MV/cm), which are likely caused by the short-ranged structural rearrangement and reduction of defects in the film. Finally, the mechanical properties and surface morphology of films are also evaluated after different temperature annealing. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  8. Photoactivation and perturbation of photoluminescent properties of aqueous ZnS nanoparticles: Probing the surfactant-semiconductor interfaces

    International Nuclear Information System (INIS)

    Mehta, S.K.; Kumar, Sanjay

    2011-01-01

    Graphical abstract: The variation in PL emission intensity of growing ZnS NPs during first hour of their growth depends upon the nature of surfactants used for their stabilization. Highlights: ► Photoluminescence (PL) intensity of growing ZnS NPs increases linearly with time. ► Significant PL enhancement in anionic surfactant stabilized ZnS NPs on irradiation. ► PL decay with delay time after removing from UV-irradiation in all the surfactants. ► Better PL stability of ZnS NPs stabilized in anionic surfactants than cationic ones. - Abstract: The in situ photochemistry of aqueous colloidal ZnS has been studied in relation to variety of the surfactants as surface passivating agents. The photoluminescence (PL) intensity of ZnS nanoparticles (NPs) has been drastically enhanced as compared to their bare counterparts due to surface passivation by surfactants depending upon their molecular structure. Cationic surfactants of alkyltrimethylammonium bromide series with different chain lengths (C 16 , C 14 and C 12 ) have been tested. The PL emission of ZnS NPs decreases with decrease in chain length because of ineffective stabilization and passivation of surface because the larger sized NPs were produced in the surfactant with smaller chain length. On the other hand, three anionic surfactants with C 12 chain length with different head groups have been capable of comparatively effective passivation to produce stable NPs with better luminescence. The changing nature of surface states during growth and long time ripening of ZnS NPs has also been monitored by comparing time evolution PL emission in different surfactants. The influence of UV-light irradiation in enhancing the PL emission has been found to be surfactant structure dependent with maximum enhancement observed with the surfactants having π-electrons in their head group functionalities. The anionic surfactants also display better tendency to retain the enhanced PL of ZnS NPs for longer time durations.

  9. 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

  10. Purifying hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Demoulins, H D; Garner, F H

    1923-02-07

    Hydrocarbon distillates, including natural gases and vapors produced by cracking hydrocarbon oils, are desulfurized etc. by treating the vapor with an aqueous alkaline solution of an oxidizing agent. The hydrocarbons may be previously purified by sulfuric acid. In examples aqueous solutions of sodium or calcium hydrochlorite containing 1.5 to 5.0 grams per liter of available chlorine and sufficient alkali to give an excess of 0.1 percent in the spent reagent are preheated to the temperature of the vapor, and either sprayed or atomized into the vapors near the outlet of the dephlegmator or fractionating tower, or passed in countercurrent to the vapors through one or a series of scrubbers.

  11. 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.

  12. 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.

  13. Enhanced solubilization of curcumin in mixed surfactant vesicles.

    Science.gov (United States)

    Kumar, Arun; Kaur, Gurpreet; Kansal, S K; Chaudhary, Ganga Ram; Mehta, S K

    2016-05-15

    Self-assemblies of equimolar double and single chain mixed ionic surfactants, with increasing numbers of carbon atoms of double chain surfactant, were analyzed on the basis of fluorescence and conductivity results. Attempts were also made to enhance the solubilization of curcumin in aqueous equimolar mixed surfactant systems. Mixed surfactant assembly was successful in retarding the degradation of curcumin in alkaline media (only 25-28 40% degraded in 10h at pH 13). Fluorescence spectroscopy and fluorescence quenching methods were employed to predict the binding position and mechanism of curcumin with self-assemblies. Results indicate that the interactions take place according to both dynamic and static quenching mechanisms and curcumin was distributed in a palisade layer of mixed aggregates. Antioxidant activity (using DPPH radical) and biocompatibility (using calf-thymus DNA) of curcumin-loaded mixed surfactant formulations were also evaluated. The prepared systems improved the stability, solubility and antioxidant activity of curcumin and additionally are biocompatible. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Porcine lung surfactant protein B gene (SFTPB)

    DEFF Research Database (Denmark)

    Cirera Salicio, Susanna; Fredholm, Merete

    2008-01-01

    The porcine surfactant protein B (SFTPB) is a single copy gene on chromosome 3. Three different cDNAs for the SFTPB have been isolated and sequenced. Nucleotide sequence comparison revealed six nonsynonymous single nucleotide polymorphisms (SNPs), four synonymous SNPs and an in-frame deletion of 69...... bp in the region coding for the active protein. Northern analysis showed lung-specific expression of three different isoforms of the SFTPB transcript. The expression level for the SFTPB gene is low in 50 days-old fetus and it increases during lung development. Quantitative real-time polymerase chain...

  15. Cooperative Effects of Zwitterionic-Ionic Surfactant Mixtures on the Interfacial Water Structure Revealed by Sum Frequency Generation Vibrational Spectroscopy.

    Science.gov (United States)

    Pan, Xuecong; Yang, Fangyuan; Chen, Shunli; Zhu, Xuefeng; Wang, Chuanyi

    2018-05-08

    Cooperative effects of a series of equimolar binary zwitterionic-ionic surfactant mixtures on the interfacial water structure at the air-water interfaces have been studied by sum frequency generation vibrational spectroscopy (SFG-VS). For zwitterionic surfactant palmityl sulfobetaine (SNC 16 ), anionic surfactant sodium hexadecyl sulfate (SHS), and cationic surfactant cetyltrimethylammonium bromide (CTAB) with the same length of alkyl chain, significantly enhanced ordering of interfacial water molecules was observed for the zwitterionic-anionic surfactant mixtures SNC 16 -SHS, indicating that SNC 16 interacts more strongly with SHS than with CTAB because of the strong headgroup-headgroup electrostatic attraction for SNC 16 -SHS. Meanwhile, the SFG amplitude ratio of methyl and methylene symmetric stretching modes was used to verify the stronger interaction between SNC 16 and SHS. The conformational order indicator increased from 0.64 for SNC 16 to 7.17 for SNC 16 -SHS but only 0.94 for SNC 16 -CTAB. In addition, another anionic surfactant sodium dodecyl sulfate (SDS) was introduced to study the influence of chain-chain interaction. Decreased SFG amplitude of interfacial water molecules for SNC 16 -SDS was observed. Therefore, both the headgroup-headgroup electrostatic interaction and chain-chain van der Waals attractive interaction of the surfactants play an important role in enhancing the ordering of interfacial water molecules. The results provided experimental and theoretical bases for practical applications of the surfactants.

  16. 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

  17. Purifying hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Dunstan, A E

    1918-06-03

    Ligroin, kerosene, and other distillates from petroleum and shale oil, are purified by treatment with a solution of a hypochlorite containing an excess of alkali. The hydrocarbon may be poured into brine, the mixture stirred, and an electric current passed through. Heat may be applied.

  18. 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

  19. The impact of alkyl sulfate surfactant geometry and electrolyte on the co-adsorption of anionic surfactants with model perfumes at the air-solution interface.

    Science.gov (United States)

    Bradbury, Robert; Penfold, Jeffrey; Thomas, Robert K; Tucker, Ian M; Petkov, Jordan T; Jones, Craig

    2013-08-01

    The impact of surfactant geometry and electrolyte on the co-adsorption of anionic surfactants and model perfumes at the air-solution interface has been studied by neutron reflectivity. The more hydrophobic perfume linalool, competes more favourably for the surface with sodium dodecylsulfate than was previously reported for the anionic surfactant, sodium dodecyl 6-benzenesulfonate. Due to an increase in surface activity of the sodium dodecylsulfate, the addition of electrolyte results in a reduction in the linalool adsorption. Changing the alkyl chain length affects the relative adsorption of linalool and surfactant at the interface. Similar measurements for the different alkyl sulfates and with electrolyte with the more hydrophilic perfume phenyl ethanol, reveal broadly similar trends. Although the relative adsorption of phenyl ethanol with sodium dodecylsulfate is substantially enhanced compared to sodium dodecyl-6-benzenesulfonate the effects are not as significant as was observed with linalool. The variations with alkyl chain geometry show the importance of the hydrophobic interaction between the perfume and surfactant and changes in the packing constraints on the relative adsorption. The results highlight the importance of the specific interaction between the surfactant and perfume, and the surfactant and perfume geometries on the relative adsorption at the interface. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Polyelectrolyte surfactant aggregates and their deposition on macroscopic surfaces

    International Nuclear Information System (INIS)

    Voisin, David

    2002-01-01

    Oppositely charged surfactant and polyelectrolyte are present in hair shampoos and conditioners, together with particles (e.g. anti-dandruff agents for scalp) and droplets (e.g. silicone oil for the hair). These are normally formulated at high surfactant concentrations, beyond the flocculation region for the polyelectrolyte concentration used. However, on dilution with water, during application, flocs are formed which carry the particles and droplets to the scalp and hair. The addition of an anionic surfactant to an aqueous solution of cationic polyelectrolyte, at a given concentration, can lead to the formation of polyelectrolyte-surfactant 'particles', in which the surfactant 'binds' to the polyelectrolyte. This occurs from the critical association concentration (CAC), up to the surfactant concentration corresponding to maximum binding. Within this range of surfactant concentrations, the surfactant bound to the polyelectrolyte is thought to associate to form what might be termed 'internal micelles'. Each polyelectrolyte-surfactant particle in the region of the CAC, and just beyond, contains many polyelectrolyte chains, held together essentially by micelle bridges. These particles, however, remain net positively charged, and therefore stable. At the other end of the binding range of the surfactant, so many internal micelles are present that the polymer-surfactant particles are now net negatively charged. Indeed binding stops since no further micelles can be accommodated. Again, the particles are stable. However, there exists a range of surfactant concentrations, lying within the range referred to above, where the net charge is reduced sufficiently that the polymer-surfactant particles will flocculate to form much larger structures. The onset of this second range might be termed the 'critical flocculation concentration' (CFC), and the end, the 'critical stabilisation concentration' (CSC). In this work, the CFC and the CSC have been determined for mixtures of

  1. Polyelectrolyte surfactant aggregates and their deposition on macroscopic surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Voisin, David

    2002-07-01

    Oppositely charged surfactant and polyelectrolyte are present in hair shampoos and conditioners, together with particles (e.g. anti-dandruff agents for scalp) and droplets (e.g. silicone oil for the hair). These are normally formulated at high surfactant concentrations, beyond the flocculation region for the polyelectrolyte concentration used. However, on dilution with water, during application, flocs are formed which carry the particles and droplets to the scalp and hair. The addition of an anionic surfactant to an aqueous solution of cationic polyelectrolyte, at a given concentration, can lead to the formation of polyelectrolyte-surfactant 'particles', in which the surfactant 'binds' to the polyelectrolyte. This occurs from the critical association concentration (CAC), up to the surfactant concentration corresponding to maximum binding. Within this range of surfactant concentrations, the surfactant bound to the polyelectrolyte is thought to associate to form what might be termed 'internal micelles'. Each polyelectrolyte-surfactant particle in the region of the CAC, and just beyond, contains many polyelectrolyte chains, held together essentially by micelle bridges. These particles, however, remain net positively charged, and therefore stable. At the other end of the binding range of the surfactant, so many internal micelles are present that the polymer-surfactant particles are now net negatively charged. Indeed binding stops since no further micelles can be accommodated. Again, the particles are stable. However, there exists a range of surfactant concentrations, lying within the range referred to above, where the net charge is reduced sufficiently that the polymer-surfactant particles will flocculate to form much larger structures. The onset of this second range might be termed the 'critical flocculation concentration' (CFC), and the end, the 'critical stabilisation concentration' (CSC). In this work, the CFC and

  2. 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.

  3. 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...

  4. Poloxamer-Decorated Polymer Nanoparticles for Lung Surfactant Compatibility

    DEFF Research Database (Denmark)

    Beck-Broichsitter, Moritz; Bohr, Adam; Ruge, Christian A

    2017-01-01

    Lung-delivered polymer nanoparticles provoked dysfunction of the essential lung surfactant system. A steric shielding of the nanoparticle surface with poloxamers could minimize the unwanted interference of polymer nanoparticles with the biophysical function of lung surfactant. The extent of poly......(styrene) and poly(lactide) nanoparticle-induced lung surfactant inhibition could be related to the type and content of the applied poloxamer. Escalations of the adsorbed coating layer thickness (>3 nm) as well as concentration (brush- rather than mushroom-like conformation of poly(ethylene glycol), chain......-associated proteins. Poloxamer-modified polymer nanoparticles represent a promising nanomedicine platform intended for respiratory delivery revealing negligible effects on the biophysical functionality of the lining layer present in the deep lungs....

  5. 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

  6. Biogeochemistry of Halogenated Hydrocarbons

    Science.gov (United States)

    Adriaens, P.; Gruden, C.; McCormick, M. L.

    2003-12-01

    Halogenated hydrocarbons originate from both natural and industrial sources. Whereas direct anthropogenic emissions to the atmosphere and biosphere are often easy to assess, particularly when they are tied to major industrial activities, the attribution of emissions to other human activities (e.g., biomass burning), diffuse sources (e.g., atmospheric discharge, run off), and natural production (e.g., soils, fungi, algae, microorganisms) are difficult to quantify. The widespread occurrence of both alkyl and aryl halides in groundwater, surface water, soils, and various trophic food chains, even those not affected by known point sources, suggests a substantial biogeochemical cycling of these compounds (Wania and Mackay, 1996; Adriaens et al., 1999; Gruden et al., 2003). The transport and reactive fate mechanisms controlling their reactivity are compounded by the differences in sources of alkyl-, aryl-, and complex organic halides, and the largely unknown impact of biogenic processes, such as enzymatically mediated halogenation of organic matter, fungal production of halogenated hydrocarbons, and microbial or abiotic transformation reactions (e.g., Asplund and Grimvall, 1991; Gribble, 1996; Watling and Harper, 1998; Oberg, 2002). The largest source may be the natural halogenation processes in the terrestrial environment, as the quantities detected often exceed the amount that can be explained by human activities in the surrounding areas ( Oberg, 1998). Since biogeochemical processes result in the distribution of a wide range of halogenated hydrocarbon profiles, altered chemical structures, and isomer distributions in natural systems, source apportionment (or environmental forensics) can often only be resolved using multivariate statistical methods (e.g., Goovaerts, 1998; Barabas et al., 2003; Murphy and Morrison, 2002).This chapter will describe the widespread occurrence of halogenated hydrocarbons, interpret their distribution and biogeochemical cycling in light of

  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. (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.

  9. Nonlinear vibrational spectroscopy of surfactants at liquid interfaces

    Science.gov (United States)

    Miranda, Paulo Barbeitas

    solid/liquid interface. It is shown that the conformation of a monolayer adsorbed onto a solid substrate and immersed in a liquid is highly dependent on the monolayer surface density and on the nature of intermolecular interactions in the liquid. Fully packed monolayers are well ordered in any environment due to strong surfactant-surfactant interactions and limited liquid penetration into the monolayer. In contrast, loosely packed monolayers are very sensitive to the liquid environment. Non-polar liquids cause a mild increase in the surfactant conformational disorder. Polar liquids induce more disorder and hydrogen-bonding liquids produce highly disordered conformations due to the hydrophobic effect. When immersed in alkanes, under certain conditions the surfactant chains may become highly ordered due to their interaction with the liquid molecules (chain-chain interaction). In the case of long-chain alcohols, competition between the hydrophobic effect and chain-chain interaction is observed.

  10. Aerobic biodegradation of amphoteric amine-oxide-based surfactants: Effect of molecular structure, initial surfactant concentration and pH.

    Science.gov (United States)

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

    2017-03-01

    The present study was designed to provide information regarding the effect of the molecular structure of amphoteric amine-oxide-based surfactants and the initial surfactant concentration on their ultimate biodegradation. Moreover, given this parameter's pH-dependence, the effect of pH was also investigated. Three amine-oxide-based surfactants with structural differences in their hydrophobic alkyl chain were tested: Lauramine oxide (AO-R 12 ), Myristamine oxide (AO-R 14 ) and Cocamidopropylamine oxide (AO-Cocoamido). We studied the ultimate biodegradation using the Modified OECD Screening Test at initial surfactant concentrations ranged from 5 to 75 mg L -1 and at pH levels from 5 to 7.4. The results demonstrate that at pH 7.4, amine-oxide-based surfactants are readily biodegradable. In this study, we concluded that ω-oxidation can be assumed to be the main biodegradation pathway of amine-oxides and that differences in the biodegradability between them can be explained by the presence of an amide group in the alkyl chain of AO-Cocoamido; the CN fission of the amide group slows down their mineralization process. In addition, the increase in the concentration of the surfactant from 5 to 75 mg L -1 resulted in an increase in the final biodegradation of AO-R 12 and AO-R 14 . However, in the case of AO-Cocoamido, a clear relationship between the concentration and biodegradation cannot be stated. Conversely, the biodegradability of AO-R 12 and AO-R 14 was considerably lower in an acid condition than at a pH of 7.4, whereas AO-Cocoamido reached similar percentages in acid conditions and at a neutral pH. However, microorganisms required more time to acclimate. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Preparation of a Fluorocarbon Polymerizable Surfactant and Its Application in Emulsion Polymerization of Fluorine-Containing Acrylate

    Directory of Open Access Journals (Sweden)

    Meng Zhao

    2017-11-01

    Full Text Available A novel polymerizable fluorocarbon surfactant, perfluoro (4–methyl–3, 6–dioxaoct–7–ene sodium sulfonate (PSVNa, was synthesized and characterized. The fluorocarbon surfactant PSVNa and its mixture PSVNa/SDS were used as emulsifiers during the emulsion polymerization of DFHMA/MMA. The investigation of polymerization kinetics, particle size, and stability of the emulsions revealed that PSVNa has excellent emulsifying properties. The NMR spectrum of the copolymer and the detection of residual PSVNa show that more than 95% of the fluorocarbon surfactants have been linked to the polymer chains by radical polymerization, which will greatly reduce the environmental pollution caused by fluorinated surfactants.

  12. Adsorption of sugar surfactants at the air/water interface.

    Science.gov (United States)

    Varga, Imre; Mészáros, Róbert; Stubenrauch, Cosima; Gilányi, Tibor

    2012-08-01

    The adsorption isotherms of n-decyl-β-D-glucoside (β-C(10)G(1)) as well as various n-alkyl-β-D-maltosides (β-C(n)G(2)) with n=8, 10, 12 and 14 were determined from surface tension measurements. Based on the analysis of the adsorption isotherms, the total free energy change of adsorption was determined and a novel method was proposed to determine the maximum adsorbed amount of surfactant. It can be concluded that the driving force for adsorption first increases with increasing adsorbed amount of the sugar surfactants and then levels off in a plateau. This peculiar behaviour is interpreted as formation of a thin liquid-like alkane film of overlapping alkyl chains at the air/water interface once a certain adsorbed amount is exceeded. The driving force of adsorption depends on the alkyl chain length only and is not affected by the type of the head group. The hydrophobic contribution to the standard free energy change of adsorption was compared with the values of sodium alkylsulfate and alkyltrimethylammonium bromide surfactants. This comparison reveals that the hydrophobic driving force of adsorption is the largest for the sodium alkylsulfates, whereas it is the same for the sugar surfactants and the alkyltrimethylammonium bromides. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Cracking hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Forwood, G F; Lane, M; Taplay, J G

    1921-10-07

    In cracking and hydrogenating hydrocarbon oils by passing their vapors together with steam over heated carbon derived from shale, wood, peat or other vegetable or animal matter, the gases from the condenser are freed from sulfuretted hydrogen, and preferably also from carbon dioxide, and passed together with oil vapors and steam through the retort. Carbon dioxide may be removed by passage through slaked lime, and sulfuretted hydrogen by means of hydrated oxide of iron. Vapors from high-boiling oils and those from low-boiling oils are passed alternately through the retort, so that carbon deposited from the high-boiling oils is used up during treatment of low-boiling oils.

  14. Distilling hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Bataafsche, N V; de Brey, J H.C.

    1918-10-30

    Hydrocarbons containing a very volatile constituent and less volatile constituents, such as casing-head gases, still gases from the distillation of crude petroleum and bituminous shale are separated into their constituents by rectification under pressure; a pressure of 20 atmospheres and limiting temperatures of 150/sup 0/C and 40/sup 0/C are mentioned as suitable. The mixture may be subjected to a preliminary treatment consisting in heating to a temperature below the maximum rectification temperature at a pressure greater than that proposed to be used in the rectification.

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

    Science.gov (United States)

    Mendenhall, Jonathan D.

    's and other micellization properties for a variety of linear and branched surfactant chemical architectures which are commonly encountered in practice. Single-component surfactant solutions are investigated, in order to clarify the specific contributions of the surfactant head and tail to the free energy of micellization, a quantity which determines the cmc and all other aspects of micellization. First, a molecular-thermodynamic (MT) theory is presented which makes use of bulk-phase thermodynamics and a phenomenological thought process to describe the energetics related to the formation of a micelle from its constituent surfactant monomers. Second, a combined computer-simulation/molecular-thermodynamic (CSMT) framework is discussed which provides a more detailed quantification of the hydrophobic effect using molecular dynamics simulations. A novel computational strategy to identify surfactant head and tail using an iterative dividing surface approach, along with simulated micelle results, is proposed. Force-field development for novel surfactant structures is also discussed. Third, a statistical-thermodynamic, single-chain, mean-field theory for linear and branched tail packing is formulated, which enables quantification of the specific energetic penalties related to confinement and constraint of surfactant tails within micelles. Finally, these theoretical and simulations-based strategies are used to predict the micellization behavior of 55 linear surfactants and 28 branched surfactants. Critical micelle concentration and optimal micelle properties are reported and compared with experiment, demonstrating good agreement across a range of surfactant head and tail types. In particular, the CSMT framework is found to provide improved agreement with experimental cmc's for the branched surfactants considered. (Copies available exclusively from MIT Libraries, libraries.mit.edu/docs - docs mit.edu)

  16. Molecular self assembly of mixed comb-like dextran surfactant polymers for SPR virus detection.

    Science.gov (United States)

    Mai-Ngam, Katanchalee; Kiatpathomchai, Wansika; Arunrut, Narong; Sansatsadeekul, Jitlada

    2014-11-04

    The synthesis of two comb-like dextran surfactant polymers, that are different in their dextran molecular weight (MW) distribution and the presence of carboxylic groups, and their characterization are reported. A bimodal carboxylic dextran surfactant polymer consists of poly(vinyl amine) (PVAm) backbone with carboxyl higher MW dextran, non-functionalized lower MW dextran and hydrophobic hexyl branches; while a monomodal dextran surfactant polymer is PVAm grafted with non-functionalized lower MW dextran and hexyl branches. Layer formation of non-covalently attached dextran chains with bimodal MW distributions on a surface plasmon resonance (SPR) chip was investigated from the perspective of mixed physisorption of the bimodal and monomodal surfactant polymers. Separation distances between the carboxylic longer dextran side chains within the bimodal surfactant polymer and between the whole bimodal surfactant molecules on the chip surface could be well-controlled. SPR analysis of shrimp yellow head virus using our mixed surfactant chips showed dependence on synergetic adjustment of these separation distances. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Thermodynamic Insights into the Binding of Mono- and Dicationic Imidazolium Surfactant Ionic Liquids with Methylcellulose in the Diluted Regime.

    Science.gov (United States)

    Ziembowicz, Francieli Isa; Bender, Caroline Raquel; Frizzo, Clarissa Piccinin; Martins, Marcos Antonio Pinto; de Souza, Thiane Deprá; Kloster, Carmen Luisa; Santos Garcia, Irene Teresinha; Villetti, Marcos Antonio

    2017-09-07

    Alkylimidazolium salts are an important class of ionic liquids (ILs) due to their self-assembly capacity when in solution and due to their potential applications in chemistry and materials science. Therefore, detailed knowledge of the physicochemical properties of this class of ILs and their mixtures with natural polymers is highly desired. This work describes the interactions between a homologous series of mono- (C n MIMBr) and dicationic imidazolium (C n (MIM) 2 Br 2 ) ILs with cellulose ethers in aqueous medium. The effects of the alkyl chain length (n = 10, 12, 14, and 16), type, and concentration range of ILs (below and above their cmc) on the binding to methylcellulose (MC) were evaluated. The thermodynamic parameters showed that the interactions are favored by the increase of the IL hydrocarbon chain length, and that the binding of monocationic ILs to MC is driven by entropy. The monocationic ILs bind more effectively on the methoxyl group of MC when compared to dicationic ILs, and this outcome may be rationalized by considering the structural difference between the conventional (C n MIMBr) and the bolaform (C n (MIM) 2 Br 2 ) surfactant ILs. The C 16 MIMBr interacts more strongly with hydroxypropylcellulose when compared to methylcellulose, indicating that the strength of the interaction also depends on the hydrophobicity of the cellulose ethers. Our findings highlight that several parameters should be taken into account when designing new complex formulations.

  18. Studying the silver nanoparticles influence on thermodynamic behavior and antimicrobial activities of novel amide Gemini cationic surfactants.

    Science.gov (United States)

    Shaban, Samy M; Abd-Elaal, Ali A

    2017-07-01

    Three novels amide Gemini cationic surfactants with various alkyl chains and their silver nanohybrid with silver nanoparticles were synthesized and a confirmation study for surfactant and their nanoparticles formation has been established using IR, 1 HNMR, TEM and UV-Vis spectroscopy. The surface-active properties of these surfactants and their nanoform were investigated through surface tension and electrical conductivity measurements and a comparative study has been established. The thermodynamic parameters of micellization and adsorption were assessed at temperatures range from 25 to 65°C. The effect of silver particles on the surface behavior of the synthesized surfactant has been discussed. The aggregation behavior of silver nanoparticles with these synthesized Gemini surfactants in water were investigated using dynamic light scattering and transmission electron microscopy. Furthermore, the antimicrobial activities of these synthesized amide Gemini surfactants and their nanostructure with silver against both Gram positive and Gram negative bacteria were also investigated. Copyright © 2017 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. Utilization of Triton X-100 and polyethylene glycols during surfactant-mediated biodegradation of diesel fuel

    International Nuclear Information System (INIS)

    Wyrwas, Bogdan; Chrzanowski, Łukasz; Ławniczak, Łukasz; Szulc, Alicja; Cyplik, Paweł; Białas, Wojciech; Szymański, Andrzej; Hołderna-Odachowska, Aleksandra

    2011-01-01

    Highlights: ► Efficient degradation of Triton X-100 under both aerobic and aerobic conditions. ► Triton X-100 was most likely degraded via the ‘central fission’ mechanism. ► Preferential degradation of Triton X-100 over diesel oil. ► The presence of surfactants decreased diesel oil biodegradation efficiency. - Abstract: The hypothesis regarding preferential biodegradation of surfactants applied for enhancement of microbial hydrocarbons degradation was studied. At first the microbial degradation of sole Triton X-100 by soil isolated hydrocarbon degrading bacterial consortium was confirmed under both full and limited aeration with nitrate as an electron acceptor. Triton X-100 (600 mg/l) was utilized twice as fast for aerobic conditions (t 1/2 = 10.3 h), compared to anaerobic conditions (t 1/2 = 21.8 h). HPLC/ESI-MS analysis revealed the preferential biodegradation trends in both components classes of commercial Triton X-100 (alkylphenol ethoxylates) as well as polyethylene glycols. The obtained results suggest that the observed changes in the degree of ethoxylation for polyethylene glycol homologues occurred as a consequence of the ‘central fission’ mechanism during Triton X-100 biodegradation. Subsequent experiments with Triton X-100 at approx. CMC concentration (150 mg/l) and diesel oil supported our initial hypothesis that the surfactant would become the preferred carbon source even for hydrocarbon degrading bacteria. Regardless of aeration regimes Triton X-100 was utilized within 48–72 h. Efficiency of diesel oil degradation was decreased in the presence of surfactant for aerobic conditions by approx. 25% reaching 60 instead of 80% noted for experiments without surfactant. No surfactant influence was observed for anaerobic conditions.

  2. Waste Plastic Converting into Hydrocarbon Fuel Materials

    Energy Technology Data Exchange (ETDEWEB)

    Sarker, Moinuddin; Mamunor Rashid, Mohammad; Molla, Mohammad

    2010-09-15

    The increased demand and high prices for energy sources are driving efforts to convert organic compounds into useful hydrocarbon fuels. Although much of this work has focused on biomass, there are strong benefits to deriving fuels from waste plastic material. Natural State Research Inc. (NSR) has invented a simple and economically viable process to decompose the hydrocarbon polymers of waste plastic into the shorter chain hydrocarbon of liquid fuel (patent pending). The method and principle of the production / process will be discussed. Initial tests with several widely used polymers indicate a high potential for commercialization.

  3. 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

  4. Hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    Foorwood, G F; Taplay, J G

    1916-12-12

    Hydrocarbon oils are hydrogenated, cracked, or treated for the removal of sulfur by bringing their vapors mixed with steam at temperatures between 450 and 600/sup 0/C into contact with a form of carbon that is capable of decomposing steam with the production of nascent hydrogen at those temperatures. The forms of carbon used include lamp-black, soot, charcoals derived from wood, cellulose, and lignite, and carbons obtained by carbonizing oil residues and other organic bodies at temperatures below 600/sup 0/C. The process is applied to the treatment of coal oil, shale oil, petroleum, and lignite oil. In examples, kerosene is cracked at 570/sup 0/C, cracked spirit is hydrogenated at 500/sup 0/C, and shale spirit is desulfurized at 530/sup 0/C. The products are led to a condenser and thence to a scrubber, where they are washed with creosote oil. After desulfurization, the products are washed with dilute caustic soda to remove sulfurretted hydrogen.

  5. Hydrocarbon exploration

    Energy Technology Data Exchange (ETDEWEB)

    Lerche, I. (South Carolina Univ., Columbia, SC (United States). Dept. of Geological Sciences)

    1993-01-01

    This special issue of the journal examines various aspects of the on-going search for hydrocarbons, ranging from frontier basins where little data are available, to more mature areas where considerable data are available. The incentives underlying the search for oil are roughly: the social, economic and industrial needs of a nation; the incentive of a corporation to be profitable; and the personal incentives of individuals in the oil industry and governments, which range from financial wealth to power and which are as diverse as the individuals who are involved. From a geopolitical perspective, the needs, requirements, goals, strategies, and philosophies of nations, and groups of nations, also impact on the oil exploration game. Strategies that have been employed have ranged from boycott to austerity and rationing, to physical intervention, to global ''flooding'' with oil by over-production. (author)

  6. Bioremediation of petroleum hydrocarbons in soil environments

    International Nuclear Information System (INIS)

    Rowell, M.J.; Ashworth, J.; Qureshi, A.A.

    1992-12-01

    The bioremediation of petroleum hydrocarbons in soil environments was reviewed via a literature survey and discussions with workers in relevant disciplines. The impacts of hydrocarbons on soil are discussed along with a range of methods available to assist in their decomposition by soil microorganisms. The range of petroleum-based materials considered includes conventional and synthetic crude oils, refined oils, sludges, asphalts and bitumens, drilling mud residues, creosote tars, and some pesticides. The degradability of hydrocarbons largely depends upon their aqueous solubility and their adsorption on soil surfaces and, therefore, is related to their molecular structures. The ease of decomposition decreases with increasing complexity of structure, in the order aliphatics > aromatics > heterocyclics and asphaltenes (most recalcitrant). Most soils contain an adequate population of microorganisms and hence bioaugmentation may only be needed in special circumstances. Decomposition is fastest in soils where the hydrocarbon loading rate, aeration, nutrition, moisture, and pH are all optimized. At spill sites there is little control over the application rate, although containment measures can assist in either limiting contamination or distributing it more evenly. The enhancement of bioremediation is discussed in light of all these factors. Other techniques such as enhanced aeration, hydrocarbon decomposition by anaerobic processes, surfactants, and burning are also discussed. 211 refs., 11 figs., 10 tabs

  7. Bioremediation of petroleum hydrocarbons in soil environments

    Energy Technology Data Exchange (ETDEWEB)

    Rowell, M J; Ashworth, J; Qureshi, A A

    1992-12-01

    The bioremediation of petroleum hydrocarbons in soil environments was reviewed via a literature survey and discussions with workers in relevant disciplines. The impacts of hydrocarbons on soil are discussed along with a range of methods available to assist in their decomposition by soil microorganisms. The range of petroleum-based materials considered includes conventional and synthetic crude oils, refined oils, sludges, asphalts and bitumens, drilling mud residues, creosote tars, and some pesticides. The degradability of hydrocarbons largely depends upon their aqueous solubility and their adsorption on soil surfaces and, therefore, is related to their molecular structures. The ease of decomposition decreases with increasing complexity of structure, in the order aliphatics > aromatics > heterocyclics and asphaltenes (most recalcitrant). Most soils contain an adequate population of microorganisms and hence bioaugmentation may only be needed in special circumstances. Decomposition is fastest in soils where the hydrocarbon loading rate, aeration, nutrition, moisture, and pH are all optimized. At spill sites there is little control over the application rate, although containment measures can assist in either limiting contamination or distributing it more evenly. The enhancement of bioremediation is discussed in light of all these factors. Other techniques such as enhanced aeration, hydrocarbon decomposition by anaerobic processes, surfactants, and burning are also discussed. 211 refs., 11 figs., 10 tabs.

  8. Optimized CO{sub 2} miscible hydrocarbon fracturing fluids

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, R.S.; Funkhouser, G.P.; Fyten, G.; Attaway, D.; Watkins, H. [Halliburton Energy Services, Calgary, AB (Canada); Lestz, R.S. [Chevron Canada Resources, Calgary, AB (Canada); Loree, D. [FracEx Inc. (Canada)

    2006-07-01

    Carbon dioxide (CO{sub 2}) miscible hydrocarbon fracturing fluids address issues of fluid retention in low-permeability gas reservoirs, including undersaturated and underpressured reservoirs. An optimized surfactant gel technology using carbon dioxide (CO{sub 2}) hydrocarbon fracturing fluids applicable to all gas-well stimulation applications was discussed in this paper. The crosslinked surfactant gel technology improved proppant transport, leakoff control, and generation of effective fracture half-length. Tests indicated that application of the surfactant cooled the fracture face, which had the effect of extending break times and increasing viscosity during pumping periods. Rapid recovery of the fracturing fluid eliminated the need for swabbing in some cases, and the fluid system was not adversely affected by shear. However, rheological test equipment capable of mixing liquid CO{sub 2} and viscosified hydrocarbons at downhole temperatures is required to determine rheology and required chemical concentrations. It was recommended that to achieve an effective methane-drive cleanup mechanism, treatments should be designed so that the gellant system can be effective with up to 50 per cent CO{sub 2} dissolved in oil. It was concluded that it should be possible to apply the technology to low permeability gas reservoirs. Viscosity curves and friction data were presented. Issues concerning the selection of tubulars and flowback procedures were also discussed. It was suggested that the cost of the hydrocarbon fracturing fluid can be recovered by the sale of recovered load fluid. 6 refs., 4 figs.

  9. Versatility of hydrocarbon production in cyanobacteria.

    Science.gov (United States)

    Xie, Min; Wang, Weihua; Zhang, Weiwen; Chen, Lei; Lu, Xuefeng

    2017-02-01

    Cyanobacteria are photosynthetic microorganisms using solar energy, H 2 O, and CO 2 as the primary inputs. Compared to plants and eukaryotic microalgae, cyanobacteria are easier to be genetically engineered and possess higher growth rate. Extensive genomic information and well-established genetic platform make cyanobacteria good candidates to build efficient biosynthetic pathways for biofuels and chemicals by genetic engineering. Hydrocarbons are a family of compounds consisting entirely of hydrogen and carbon. Structural diversity of the hydrocarbon family is enabled by variation in chain length, degree of saturation, and rearrangements of the carbon skeleton. The diversified hydrocarbons can be used as valuable chemicals in the field of food, fuels, pharmaceuticals, nutrition, and cosmetics. Hydrocarbon biosynthesis is ubiquitous in bacteria, yeasts, fungi, plants, and insects. A wide variety of pathways for the hydrocarbon biosynthesis have been identified in recent years. Cyanobacteria may be superior chassis for hydrocabon production in a photosynthetic manner. A diversity of hydrocarbons including ethylene, alkanes, alkenes, and terpenes can be produced by cyanobacteria. Metabolic engineering and synthetic biology strategies can be employed to improve hydrocarbon production in cyanobacteria. This review mainly summarizes versatility and perspectives of hydrocarbon production in cyanobacteria.

  10. 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

  11. Functional and molecular characterization of a lipopeptide surfactant from the marine sponge-associated eubacteria Bacillus licheniformis NIOT-AMKV06 of Andaman and Nicobar Islands, India.

    Science.gov (United States)

    Lawrance, Anburajan; Balakrishnan, Meena; Joseph, Toms Cheriath; Sukumaran, Dheenan Palaiya; Valsalan, Vinithkumar Nambali; Gopal, Dharani; Ramalingam, Kirubagaran

    2014-05-15

    The production of a lipopeptide surfactant from the sponge-associated eubacteria Bacillus licheniformis NIOT-AMKV06 from the Andaman and Nicobar Islands was investigated. The highest production was attained with glucose and yeast extracts as the carbon and nitrogen sources (1.789 mg mL(-1)), respectively. The surfactant was highly stable over a pH range of 5.0-10 and a temperature range of 20-70°C with high NaCl concentrations. Excellent emulsification activity was exhibited by the purified surfactant with crude oil, kerosene, and diesel. A two-fold increase in surfactant production (3.0 mg mL(-1)) was observed using the newly formulated medium in this study. The surfactant biosynthesis gene cluster (sfp, sfpO, and srfA) from B. licheniformis NIOT-AMKV06 was heterologously expressed in Escherichia coli, and the production was increased three-fold (11.78 g L(-1)) over the original strain. The results confirm the potential of the surfactant for use in bioremediation of hydrocarbons in a marine environment and for enhanced oil recovery. To our knowledge, this is the first report on the ability of a hydrocarbon degrading B. licheniformis from marine sponges for the biosynthesis of a potent lipopeptide surfactant possessing characteristics of maximum stability, outstanding surfactant activity, and exceptional emulsifying capability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Microbial surfactant activities from a petrochemical landfarm in a humid tropical region of Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Maciel, B.M.; Dias, J.C.T.; Santos, A.C.F.; Argolo-Filho, R.C.; Fontana, R.; Loguercio, L.L.; Rezende, R.P. [Univ. Estadual de Santa Cruz, Santa Cruz (Brazil). Dept. de Ciencias Biologicas

    2007-08-15

    Studies have suggested that biosurfactants can enhance the biodegradation of almost insoluble organics by increasing cell uptake availability. In this study, micro-organisms were isolated from a soil sample from a Brazilian petrochemical waste landfarm and grown in petroleum as a carbon source in order to assess their surfactant potential. Isolated colonies were inoculated into tubes, and a drop-collapse method was used to select micro-organisms with surfactant activity. Surfactant activity of the isolates was assessed when the activity was detected for the first time in each culture. The supernatant of each micro-organism was then diluted. The surfactant activity of each dilution was then observed via micelles formation. DNA was then extracted from the samples. A total of 60 microbial strains were selected. Results showed that a variety of petroleum-grown micro-organisms obtained from the landfarm soil showed surfactant activity. Results showed that the micro-organisms were able to use petroleum as a sole carbon source. The production of surfactant compounds occurred during the declining stages of microbial culture curves, which suggested that the nutritional stress achieved on the fourth day of the culture induced the synthesis and secretion of biosurfactants by the isolates. It was concluded that micro-organisms derived from soils polluted with hydrocarbons can be used in bioremediation processes. 21 refs., 1 tab., 3 figs.

  13. Effect of surfactants on the properties of hydrotalcites prepared by the reverse micelle method

    Energy Technology Data Exchange (ETDEWEB)

    Holgado, Patricia H., E-mail: h.holgado@usal.es; Holgado, María J., E-mail: holgado@usal.es; San Román, María S., E-mail: sanroman@usal.es; Rives, Vicente, E-mail: vrives@usal.es

    2015-02-01

    Layered double hydroxides with the hydrotalcite-type structure have been prepared by the reverse micelles method. The layer cations were Ni{sup 2+} and Fe{sup 3+} in all cases and the interlayer anion was carbonate. We have studied the effect of the surfactant used (with linear chains of different lengths, or cyclic) and the effect of the pH on the properties of the solids formed. These have been characterized by element chemical analysis, powder X-ray diffraction, thermogravimetric analysis, temperature-programmed reduction, FT-IR and Vis–UV spectroscopies and scanning electron microscopy. It has been found that the samples prepared at pH 9 are more crystalline than those prepared at pH 11 and their crystallite sizes are always larger than for samples prepared by the conventional precipitation method. Surfactants with cyclic organic chains lead to a larger crystallite size, probably because the water pool vesicle where the crystallite grows is larger due to sterical hindrance of the organic chains. - Graphical abstract: Layered double hydroxides with the hydrotalcite-type structure with Ni{sup 2+} and Fe{sup 3+} cations in the layers have been prepared by the reverse micelles method. Different surfactants were used at different pH synthesis. Samples prepared at pH 9 are higher crystalline than those prepared at pH 11. Surfactants with cyclic organic chains lead to a larger crystallite size. - Highlights: • Hydrotalcites were prepared by the micelles reverse method. • Straight alkyl or cyclic chain surfactants were used. • All hydrotalcites are well crystallized at pH = 9 and 11. • The crystallite size depends on the linear/cyclic nature of the surfactant chain.

  14. Effect of surfactants on the properties of hydrotalcites prepared by the reverse micelle method

    International Nuclear Information System (INIS)

    Holgado, Patricia H.; Holgado, María J.; San Román, María S.; Rives, Vicente

    2015-01-01

    Layered double hydroxides with the hydrotalcite-type structure have been prepared by the reverse micelles method. The layer cations were Ni 2+ and Fe 3+ in all cases and the interlayer anion was carbonate. We have studied the effect of the surfactant used (with linear chains of different lengths, or cyclic) and the effect of the pH on the properties of the solids formed. These have been characterized by element chemical analysis, powder X-ray diffraction, thermogravimetric analysis, temperature-programmed reduction, FT-IR and Vis–UV spectroscopies and scanning electron microscopy. It has been found that the samples prepared at pH 9 are more crystalline than those prepared at pH 11 and their crystallite sizes are always larger than for samples prepared by the conventional precipitation method. Surfactants with cyclic organic chains lead to a larger crystallite size, probably because the water pool vesicle where the crystallite grows is larger due to sterical hindrance of the organic chains. - Graphical abstract: Layered double hydroxides with the hydrotalcite-type structure with Ni 2+ and Fe 3+ cations in the layers have been prepared by the reverse micelles method. Different surfactants were used at different pH synthesis. Samples prepared at pH 9 are higher crystalline than those prepared at pH 11. Surfactants with cyclic organic chains lead to a larger crystallite size. - Highlights: • Hydrotalcites were prepared by the micelles reverse method. • Straight alkyl or cyclic chain surfactants were used. • All hydrotalcites are well crystallized at pH = 9 and 11. • The crystallite size depends on the linear/cyclic nature of the surfactant chain

  15. Chain chemical reactions during matrix devitrification

    International Nuclear Information System (INIS)

    Barkalov, I.M.

    1980-01-01

    Investigation results of chain reaction mechanisms, proceeding at devitrification of glass-like matrices under the effect of γ-irradiation are summarized. Peculiarities of kinetics and mechanism of chain reactions proceeding at devitrification are considered: hydrocarbon chlorination, polymerization of vinyl monomers, copolymerization and graft polymerization. Possible application aspects of the chain reaction conducting during matrix devitrification are also considered

  16. Comparison between different bio-treatments of a hydrocarbon ...

    African Journals Online (AJOL)

    Ramya

    2011-10-31

    Oct 31, 2011 ... We investigated the bio-remediation of a hydrocarbon contaminated soil pile that was slated for landfill ... soils, plants and in the food chain (Kipopoulou et al., ...... Scientific and Social Research, Putra Palace, Perlis, Malaysia.

  17. Synthesis of carbohydrate-based surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Pemberton, Jeanne E.; Polt, Robin L.; Maier, Raina M.

    2016-11-22

    The present invention provides carbohydrate-based surfactants and methods for producing the same. Methods for producing carbohydrate-based surfactants include using a glycosylation promoter to link a carbohydrate or its derivative to a hydrophobic compound.

  18. Effect of Dialkyl Ammonium Cationic Surfactants on the Microfluidity of Membranes Containing Raft Domains.

    Science.gov (United States)

    Uyama, Makoto; Inoue, Kaori; Kinoshita, Koichi; Miyahara, Reiji; Yokoyama, Hirokazu; Nakano, Minoru

    2018-01-01

    It has been reported that a lot of receptors localize in lipid raft domains and that the microfluidity of these domains regulates the activation of these receptors. In this study, we focused on the lipid raft and in order to evaluate the physicochemical effects of surfactants on microfluidity of lipid membranes, we used liposomes comprising of egg-yolk L-α-phosphatidylcholine, egg-yolk sphingomyelin, and cholesterol as a model of cell membranes containing raft domains. The microfluidity of the domains was characterized by fluorescence spectrometry using 1,6-diphenyl-1,3,5-hexatriene and 2-dimethylamino-6-lauroylnaphthalene. Among several surfactants, dialkylammonium-type cationic surfactants most efficiently increased the microfluidity. It is therefore concluded that (1) the electrostatic interaction between the cationic surfactant and eggPC/eggSM/cholesterol liposome could be important, (2) surfactants with alkyl chains more effectively inserted into membranes than those with acyl chains, and (3) cationic surfactants with lower T m values have a greater ability to increase the fluidity.

  19. Adsorption of dissymmetric cationic gemini surfactants at silica/water interface

    Science.gov (United States)

    Sun, Yuhai; Feng, Yujun; Dong, Hongwei; Chen, Zhi

    2007-05-01

    Adsorption of a series of cationic gemini surfactants 12-2- m ( m = 8, 12, 16) on the surface of silica was investigated. The critical micelle concentrations, cmcs, of cationic gemini surfactants in the initial solutions and in the supernatants were measured by conductometry and tensiometer. The changes in cmc values indicate that the ion exchanges take place between polar groups of gemini surfactants adsorbed and ions bound on the surface of silica. The adsorption isotherms of cationic gemini surfactants were obtained by a solution depletion method. Based on the driving force, the adsorption includes two steps, one of which is ion exchange, and the other is hydrophobic interaction. In each step, the tendency of surfactant molecules in the solution to form aggregates or to be adsorbed on the silica varies with their structures. The maximum adsorption amount of gemini surfactants on the silica, τmax, decreases as increasing in the length of one alkyl chain, m, from 8, 12 to 16. So the results show that the adsorption behaviors of gemini surfactants are closely related to the dissymmetry of gemini molecules.

  20. 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)

  1. Impact of cationic surfactant on the self-assembly of sodium caseinate.

    Science.gov (United States)

    Vinceković, Marko; Curlin, Marija; Jurašin, Darija

    2014-08-27

    The impact of a cationic surfactant, dodecylammonium chloride (DDACl), on the self-assembly of sodium caseinate (SC) has been investigated by light scattering, zeta potential, and rheological measurements as well as by microscopy (transmission electron and confocal laser scanning microscopy). In SC dilute solutions concentration-dependent self-assembly proceeds through the formation of spherical associates and their aggregation into elongated structures composed of connected spheres. DDACl interacts with SC via its hydrophilic and hydrophobic groups, inducing changes in SC self-assembled structures. These changes strongly depend on the surfactant aggregation states (monomeric or micellar) as well as concentration ratio of both components, leading to the formation of soluble and insoluble complexes of nano- to microdimensions. DDACl monomers interact with SC self-assembled entities in a different way compared to their micelles. Surfactant monomers form soluble complexes (similar to surfactant mixed micelles) at lower SC concentration but insoluble gelatinous complexes at higher SC concentration. At surfactant micellar concentration soluble complexes with casein chains wrapped around surfactant micelles are formed. This study suggests that the use of proper cationic surfactant concentration will allow modification and control of structural changes of SC self-assembled entities.

  2. Interactions of a zwitterionic thiophene-based conjugated polymer with surfactants

    DEFF Research Database (Denmark)

    Costa, Telma; De Azevedo, Diego; Stewart, Beverly

    2015-01-01

    In this paper we investigate the optical and structural properties of a zwitterionic poly[3-(N-(4-sulfonato-1-butyl)-N,N-diethylammonium)hexyl-2,5-thiophene] (P3SBDEAHT) conjugated polyelectrolyte (CPE) and its interaction in water with surfactants, using absorption, photoluminescence (PL......), electrical conductivity, molecular dynamics simulations (MDS) and small-angle X-ray scattering (SAXS). Different surfactants were studied to evaluate the effect of the head group and chain length on the self-assembly. PL data emphasize the importance of polymer-surfactant electrostatic interactions...... in the formation of complexes. Nevertheless, conductivity and MDS data have shown that nonspecific interactions also play an important role. These seem to be responsible for the spatial position of the surfactant tail in the complex and, eventually, for breaking-up P3SBDEAHT aggregates. SAXS measurements on P3...

  3. Binding of cationic surfactants to humic substances

    NARCIS (Netherlands)

    Ishiguro, M.; Tan, W.; Koopal, L.K.

    2007-01-01

    Commercial surfactants are introduced into the environment either through waste products or site-specific contamination. The amphiphilic nature of both surfactants and humic substances (HS) leads to their mutual attraction especially when surfactant and HS are oppositely charged. Binding of the

  4. Photoluminescence and self-assembly of cesium lead halide perovskite nanocrystals: Effects of chain length of organic amines and reaction temperature

    International Nuclear Information System (INIS)

    Yuan, Yi; Liu, Zheming; Liu, Zhenyang; Peng, Lan; Li, Yongjie; Tang, Aiwei

    2017-01-01

    oleylamine (OLAm), but only flat nanoplates are observed in the products in the presence of OTAm at 120 °C. The results indicate that the lower reaction temperature and hydrocarbon chain length of the organic ligands play a significant role in the self-assembly of CsPbBr_3 NCs. This work opens up an alternative approach to controllable-synthesis of perovskite NCs through varying the carbon chain length of organic surfactants, and enlightens the fabrication of different nanostructures via self-assembly methods for further optoelectronic applications.

  5. Photoluminescence and self-assembly of cesium lead halide perovskite nanocrystals: Effects of chain length of organic amines and reaction temperature

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Yi; Liu, Zheming; Liu, Zhenyang; Peng, Lan; Li, Yongjie; Tang, Aiwei, E-mail: awtang@bjtu.edu.cn

    2017-05-31

    product synthesized in the presence of oleylamine (OLAm), but only flat nanoplates are observed in the products in the presence of OTAm at 120 °C. The results indicate that the lower reaction temperature and hydrocarbon chain length of the organic ligands play a significant role in the self-assembly of CsPbBr{sub 3} NCs. This work opens up an alternative approach to controllable-synthesis of perovskite NCs through varying the carbon chain length of organic surfactants, and enlightens the fabrication of different nanostructures via self-assembly methods for further optoelectronic applications.

  6. Partition thermodynamics of ionic surfactants between phosphatidylcholine vesicle and water phases

    Science.gov (United States)

    Chu, Shin-Chi; Hung, Chia-Hui; Wang, Shun-Cheng; Tsao, Heng-Kwong

    2003-08-01

    The partition of ionic surfactants (sodium alkyl sulfate and alkyl trimethyl ammonium bromide) between phosphatidylcholine vesicles and aqueous phase is investigated by simple conductometry under different temperatures. The experimental results can be well represented by the proposed regular solution theory and the thermodynamic parameters satisfy the thermodynamic consistency. The deviation from ideal partition is manifested through the effective interaction energy between lipid and surfactant wb, which is O(kT) large. It is found that wb rises as the alkyl chain is decreased for a specified head group. This is attributed to significant mismatch of chain lengths between surfactant and lipid molecules. The partition coefficient K declines with increasing temperature. The energy barrier from bilayer to aqueous phase, Δμ/kT∝ln K, is in the range of 16-26 kJ/mol. As the alkyl chain length is decreased for a given head group, Δμ is lowered by 1.3-1.5 kJ/mol per methylene group. Two independent analyses are employed to confirm this result. Using the thermodynamic parameters determined from experiments, the internal energy, entropy, and free energy of the partition process can be derived. Partition is essentially driven by the internal energy gain. The solubilizing ability, which is represented by the maximum surfactant-lipid ratio in the bilayer, Reb also decreases in accord with the K parameter. It is because the change in temperature influences the surfactant incorporation into the bilayer more than the formation of micelles.

  7. Persurf, a new method to improve surfactant delivery: a study in surfactant depleted rats.

    Directory of Open Access Journals (Sweden)

    Wolfram Burkhardt

    Full Text Available PURPOSE: Exogenous surfactant is not very effective in adults with ARDS, since surfactant does not reach atelectatic alveoli. Perfluorocarbons (PFC can recruit atelectatic areas but do not replace impaired endogenous surfactant. A surfactant-PFC-mixture could combine benefits of both therapies. The aim of the proof-of-principal-study was to produce a PFC-in-surfactant emulsion (Persurf and to test in surfactant depleted Wistar rats whether Persurf achieves I. a more homogenous pulmonary distribution and II. a more homogenous recruitment of alveoli when compared with surfactant or PFC alone. METHODS: Three different PFC were mixed with surfactant and phospholipid concentration in the emulsion was measured. After surfactant depletion, animals either received 30 ml/kg of PF5080, 100 mg/kg of stained (green dye Curosurf™ or 30 ml/kg of Persurf. Lungs were fixated after 1 hour of ventilation and alveolar aeration and surfactant distribution was estimated by a stereological approach. RESULTS: Persurf contained 3 mg/ml phospholipids and was stable for more than 48 hours. Persurf-administration improved oxygenation. Histological evaluation revealed a more homogenous surfactant distribution and alveolar inflation when compared with surfactant treated animals. CONCLUSIONS: In surfactant depleted rats administration of PFC-in-surfactant emulsion leads to a more homogenous distribution and aeration of the lung than surfactant alone.

  8. Reactive surfactants in heterophase polymerization

    NARCIS (Netherlands)

    Guyot, A.; Tauer, K.; Asua, J.M.; Es, van J.J.G.S.; Gauthier, C.; Hellgren, A.C.; Sherrington, D.C.; Montoya-Goni, A.; Sjöberg, M.; Sindt, O.; Vidal, F.F.M.; Unzue, M.; Schoonbrood, H.A.S.; Schipper, E.T.W.M.; Lacroix-Desmazes, P.

    1999-01-01

    This paper summarizes the work carried out during 3 years in a Network of the program "Human Capital and Mobility" of the European Union CHRX 93-0159 entitled "Reactive surfactants in heterophase polymerization for high performance polymers". A series of about 25 original papers will be published in

  9. Novel star-like surfactant as dispersant for multi-walled carbon nanotubes in aqueous suspensions at high concentration

    Science.gov (United States)

    Qiao, Min; Ran, Qianping; Wu, Shishan

    2018-03-01

    A kind of novel surfactant with star-like molecular structure and terminated sulfonate was synthesized, and it was used as the dispersant for multi-walled carbon nanotubes (CNTs) in aqueous suspensions compared with a traditional single-chained surfactant. The star-like surfactant showed good dispersing ability for multi-walled CNTs in aqueous suspensions. Surface tension analysis, total organic carbon analysis, X-ray photoelectron spectroscopy, zeta potential, dynamic light scattering and transmission electron microscopy were performed to research the effect of star-like surfactant on the dispersion of multi-walled CNTs in aqueous suspensions. With the assistance of star-like surfactant, the CNTs could disperse well in aqueous suspension at high concentration of 50 g/L for more than 30 days, while the CNTs precipitated completely in aqueous suspension after 1 day without any dispersant or after 10 days with sodium 4-dodecylbenzenesulfonic acid as dispersant.

  10. Structure of DNA-Cationic Surfactant Complexes at Hydrophobically Modified and Hydrophilic Silica Surfaces as Revealed by Neutron Reflectometry

    DEFF Research Database (Denmark)

    Cardenas Gomez, Marite; Wacklin, Hanna; Campbell, Richard A.

    2011-01-01

    with dodecyltrimethylammonium bromide (DTAB) and hexadecyltrimethylammonium bromide (CTAB) on hydrophobic surfaces, where we show that DNA molecules are located on top of a self-assembled surfactant monolayer, with the thickness of the DNA layer and the surfactant DNA ratio determined by the surface coverage of the underlying...... interfacial structures, a higher concentration in relation to its cmc is required for the more soluble DTAB surfactant with a shorter alkyl chain than for CTAB. Our results suggest that the DNA Molecules Will spontaneously form a relatively dense, thin layer on top of a surfactant monolayer (hydrophobic...... surface) or a layer of admicelles (hydrophilic surface) as long as the surface concentration of surfactant is great enough to ensure a high interfacial-charge density. These findings have implications for bioanalytical and nanotechnology applications, which require the deposition of DNA layers with well...

  11. Surfactant screening of diesel-contaminated soil

    International Nuclear Information System (INIS)

    Peters, R.W.; Montemagno, C.D.; Shem, L.; Lewis, B.-A.

    1992-01-01

    At one installation in California, approximately 60,000 gal of No. 2 diesel fuel leaked into the subsurface environment, resulting in contamination at depths from 6 to 34 m below the surface. Argonne National Laboratory was contracted to perform treatability studies for site remediation. This paper summarizes a surfactant screening/surfactant flooding research program in which 22 surfactants were screened for their effectiveness in mobilizing the organics from the contaminated soil prior to bioremediation. Anionic surfactants resulted in the greatest degree of diesel mobilization. The most promising surfactants will be employed on contaminated soil samples obtained from the site

  12. Surfactant gene polymorphisms and interstitial lung diseases

    Directory of Open Access Journals (Sweden)

    Pantelidis Panagiotis

    2001-11-01

    Full Text Available Abstract Pulmonary surfactant is a complex mixture of phospholipids and proteins, which is present in the alveolar lining fluid and is essential for normal lung function. Alterations in surfactant composition have been reported in several interstitial lung diseases (ILDs. Furthermore, a mutation in the surfactant protein C gene that results in complete absence of the protein has been shown to be associated with familial ILD. The role of surfactant in lung disease is therefore drawing increasing attention following the elucidation of the genetic basis underlying its surface expression and the proof of surfactant abnormalities in ILD.

  13. Degradation of surfactant-modified montmorillonites in HCl

    International Nuclear Information System (INIS)

    Madejová, Jana; Pálková, Helena; Jankovič, Ľuboš

    2012-01-01

    The effect of surfactant size on the extent of montmorillonites decomposition in HCl was investigated. Na-SAz montmorillonite and tetraalkylammonium salts of alkyl-chains length increasing from methyl- Me 4 N to pentyl- Pe 4 N were used for organo-montmorillonites preparation. Decreasing intensity of d 001 diffraction proved destruction of montmorillonite structure connected with gradual surfactant release. A shift of the SiO stretching band to 1097 cm −1 confirmed formation of amorphous silica phase. A new band near 7315 cm −1 corresponding to SiOH overtone revealed creation of protonated silica. This band was observed in the spectra of all acid-treated samples, also in those with minor decomposition of the structure. The size of the cations significantly affected decomposition of montmorillonites in HCl. The less stable were Na-SAz and Me 4 N-SAz in which the content of octahedral atoms dropped to ∼5% of their original values upon 8 h treatments. Et 4 N-SAz and Pr 4 N-SAz were slightly more resistant mainly at short times. Bu 4 N-SAz and Pe 4 N-SAz showed the least structural modifications, only 50% and 35% of octahedral atoms, respectively, were released into solution within 8 h treatments. This observation proves that bulky alkylammonium cations covering the inner and outer surfaces of montmorillonite prevent effectively the access of protons to the layers protecting the mineral from degradation in the acid. - Highlights: ► Hybrid materials were prepared from montmorillonite and alkylammonium cations with short alkyl chains. ► The effect of surfactant on organo-montmorillonites dissolution in HCl was studied. ► With increasing size of cation the extent of montmorillonite decomposition decreased. ► Bulky surfactants prevent the access of protons to the layers and thus protect montmorillonite from degradation.

  14. Biomimetic oligosaccharide and peptide surfactant polymers designed for cardiovascular biomaterials

    Science.gov (United States)

    Ruegsegger, Mark Andrew

    A common problem associated with cardiovascular devices is surface induced thrombosis initiated by the rapid, non-specific adsorption of plasma proteins onto the biomaterial surface. Control of the initial protein adsorption is crucial to achieve the desired longevity of the implanted biomaterial. The cell membrane glycocalyx acts as a non-thrombogenic interface through passive (dense oligosaccharide structures) and active (ligand/receptor interactions) mechanisms. This thesis is designed to investigate biomimicry of the cell glycocalyx to minimize non-specific protein adsorption and promote specific ligand/receptor interactions. Biomimetic macromolecules were designed through the molecular-scale engineering of polymer surfactants, utilizing a poly(vinyl amine) (PVAm) backbone to which hydrophilic (dextran, maltose, peptide) and hydrophobic alkyl (hexanoyl or hexanal) chains are simultaneously attached. The structure was controlled through the molar feed ratio of hydrophobic-to-hydrophilic groups, which also provided control of the solution and surface-active properties. To mimic passive properties, a series of oligomaltose surfactants were synthesized with increasing saccharide length (n = 2, 7, 15 where n is number of glucose units) to investigate the effect of coating height on protein adsorption. The surfactants were characterized by infra red (IR) and nuclear magnetic resonance (NMR) spectroscopies for structural properties and atomic force microscopy (AFM) and contact angle goniometry for surface activity. Protein adsorption under dynamic flow (5 dyn/cm2) was reduced by 85%--95% over the bare hydrophobic substrate; platelet adhesion dropped by ˜80% compared to glass. Peptide ligands were incorporated into the oligosaccharide surfactant to promote functional activity of the passive coating. The surfactants were synthesized to contain 0%, 25%, 50%, 75%, and 100% peptide ligand density and were stable on hydrophobic surfaces. The peptide surface density was

  15. 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.

  16. Converting high boiling hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Terrisse, H; DuFour, L

    1929-02-12

    A process is given for converting high boiling hydrocarbons into low boiling hydrocarbons, characterized in that the high boiling hydrocarbons are heated to 200 to 500/sup 0/C in the presence of ferrous chloride and of such gases as hydrogen, water gas, and the like gases under a pressure of from 5 to 40 kilograms per square centimeter. The desulfurization of the hydrocarbons occurs simultaneously.

  17. Bioavailability of hydrocarbons to bacterial consortia during Triton X-100 mediated biodegradation in aqueous media.

    Science.gov (United States)

    Pęziak, Daria; Piotrowska, Aleksandra; Marecik, Roman; Lisiecki, Piotr; Woźniak, Marta; Szulc, Alicja; Ławniczak, Łukasz; Chrzanowski, Łukasz

    2013-01-01

    The aim of our study was to investigate the effect of Triton X-100 on the biodegradation efficiency of hexadecane and phenanthrene carried out by two bacterial consortia. It was established that the tested consortia were not able to directly uptake compounds closed in micelles. It was observed that in micellar systems the nonionic synthetic surfactant was preferentially degraded (the degradation efficiency of Triton X-100 after 21 days was 70% of the initial concentration - 500 mg/l), followed by a lesser decomposition of hydrocarbon released from the micelles (30% for hexadecane and 20% for phenanthrene). However, when hydrocarbons were used as the sole carbon source, 70% of hexadecane and 30% of phenanthrene were degraded. The degradation of the surfactant did not contribute to notable shifts in bacterial community dynamics, as determined by Real-Time PCR. The obtained results suggest that if surfactant-supplementation is to be used as an integral part of a bioremediation process, then possible bioavailability decrease due to entrapment of the contaminant into surfactant micelles should also be taken into consideration, as this phenomenon may have a negative impact on the biodegradation efficiency. Surfactant-induced mobilization of otherwise recalcitrant hydrocarbons may contribute to the spreading of contaminants in the environment and prevent their biodegradation.

  18. Systems and processes for conversion of ethylene feedstocks to hydrocarbon fuels

    Science.gov (United States)

    Lilga, Michael A.; Hallen, Richard T.; Albrecht, Karl O.; Cooper, Alan R.; Frye, John G.; Ramasamy, Karthikeyan Kallupalayam

    2018-04-03

    Systems, processes, and catalysts are disclosed for obtaining fuel and fuel blends containing selected ratios of open-chain and closed-chain fuel-range hydrocarbons suitable for production of alternate fuels including gasolines, jet fuels, and diesel fuels. Fuel-range hydrocarbons may be derived from ethylene-containing feedstocks and ethanol-containing feedstocks.

  19. Systems and processes for conversion of ethylene feedstocks to hydrocarbon fuels

    Science.gov (United States)

    Lilga, Michael A.; Hallen, Richard T.; Albrecht, Karl O.; Cooper, Alan R.; Frye, John G.; Ramasamy, Karthikeyan Kallupalayam

    2017-09-26

    Systems, processes, and catalysts are disclosed for obtaining fuels and fuel blends containing selected ratios of open-chain and closed-chain fuel-range hydrocarbons suitable for production of alternate fuels including gasolines, jet fuels, and diesel fuels. Fuel-range hydrocarbons may be derived from ethylene-containing feedstocks and ethanol-containing feedstocks.

  20. Thermodynamics on the micellization of various pure and mixed surfactants: Effects of head- and tail-groups

    International Nuclear Information System (INIS)

    Lee, Nam-Min; Lee, Byung-Hwan

    2016-01-01

    Highlights: • The values of critical micelle concentration of various pure and mixed surfactants are measured. • Thermodynamic parameters’ values are calculated to analyze the effects of head- and tail-groups on the micellization. • All the thermodynamic parameters’ values are decreasing with the increase of temperature. • The thermodynamic parameters’ values are depending severely on the chain length of alkyl group. - Abstract: The values of critical micelle concentration (CMC) for the micellization of various pure and mixed surfactants are determined by the UV–Vis spectrophotometric method. And the effects of temperature on the CMC values have been measured and thermodynamic parameters’ values are calculated to analyse the effects of head- and tail-groups on the micellization of surfactant molecules. The results show that the values of ΔG"o are negative and those of ΔS"o are positive for the micellization of all the surfactants within the measured temperature range. But the values of ΔH"o are positive or negative, depending on the kinds of surfactants. All these thermodynamic parameters’ values are decreasing together with the increase of temperature for all the surfactants. And these thermodynamic parameters’ values are depending severely on the chain length of alkyl group also as much as on the head-groups of surfactant molecules.

  1. Comblike poly(ethylene oxide)/hydrophobic C6 branched chitosan surfactant polymers as anti-infection surface modifying agents.

    Science.gov (United States)

    Mai-ngam, Katanchalee

    2006-05-01

    A series of structurally well-defined poly(ethylene oxide)/hydrophobic C6 branched chitosan surfactant polymers that undergo surface induced self assembly on hydrophobic biomaterial surfaces were synthesized and characterized. The surfactant polymers consist of low molecular weight (Mw) chitosan backbone with hydrophilic poly(ethylene oxide) (PEO) and hydrophobic hexyl pendant groups. Chitosan was depolymerized by nitrous acid deaminative cleavage. Hexanal and aldehyde-terminated PEO chains were simultaneously attached to low Mw chitosan hydrochloride via reductive amination. The surfactant polymers were prepared with various ratios of the two side chains. The molecular composition of the surfactant polymers was determined by FT-IR and 1H NMR. Surface active properties at the air-water interface were determined by Langmuir film balance measurements. The surfactant polymers with PEO/hexyl ratios of 1:3.0 and 1:14.4 were used as surface modifying agents to investigate their anti-infection properties. E. coli adhesion on Silastic surface was decreased significantly by the surfactant polymer with PEO/hexyl 1:3.0. Surface growth of adherent E. coli was effectively suppressed by both tested surfactant polymers.

  2. Enhanced diffusion of polycyclic aromatic hydrocarbons in artificial and natural aqueous solutions

    DEFF Research Database (Denmark)

    Mayer, Philipp; Fernqvist, M.M.; Christensen, P.S.

    2007-01-01

    Uptake of hydrophobic organic compounds into organisms is often limited by the diffusive transport through a thin boundary layer. Therefore, a microscale diffusion technique was applied to determine the diffusive mass transfer of 12 polycyclic aromatic hydrocarbons through water, air, surfactant...

  3. Thermal stability and hot-stage Raman spectroscopic study of Ca-montmorillonite modified with different surfactants: A comparative study

    International Nuclear Information System (INIS)

    Sun, Zhiming; Park, Yuri; Zheng, Shuilin; Ayoko, Godwin A.; Frost, Ray L.

    2013-01-01

    Highlights: • A typical Ca-montmorillonite was modified with three surfactants through ion exchange. • The organoclays were characterized by XRD, TG and hot stage Raman. • The structural geometry and thermal properties of organoclays were analyzed. • The prepared organoclays show potential prospects in the environmental remediation. - Abstract: Three long chain cationic surfactants were intercalated into Ca-montmorillonite through ion exchange and the obtained organoclays were characterized by X-ray diffraction (XRD), high resolution thermogravimetric analysis (TG) and Raman spectroscopy. The intercalation of surfactants not only changes the surface properties of clay from hydrophilic to hydrophobic but also greatly increases the basal spacing of the interlayers based on XRD analysis. The thermal stability of organoclays intercalated with three surfactants (TTAB, DTAB and CTAB) and the different arrangements of the surfactant molecules intercalated into Ca-montmorillonite were determined by TG-DTG analysis. A Raman spectroscopic study on the Ca-montmorillonite modified by three surfactants prepared at different concentrations provided the detailed conformational ordering of different intercalated long-chain surfactants under different conditions. The wavenumber of the antisymmetric stretching mode is more sensitive than that of the symmetric stretching mode to the mobility of the tail of the amine chain. At room temperature, the conformational ordering is more easily affected by the packing density in the lateral model. With the increase of the temperature, the positions of both the antisymmetric and symmetric stretching bands shift to higher wavenumbers, which indicates a decrease of conformational ordering. This study offers new insights into the structure and properties of Ca-montmorillonite modified with different long chain surfactants. Moreover, the experimental results confirm the potential applications of organic Ca-montmorillonites for the removal

  4. Gemini Surfactants Based on Bis-Imidazolium Alkoxy Derivatives as Effective Agents for Delivery of Nucleic Acids: A Structural and Spectroscopic Study.

    Directory of Open Access Journals (Sweden)

    Zuzanna Pietralik

    Full Text Available The success rate of gene therapy depends on the efficient transfection of genetic material into cells. The golden mean between harmlessness and high effectiveness can be provided by synthetic lipid-like molecules that are similar to the components of biological membranes. Cationic gemini surfactants are one such moiety and because of their favourable physicochemical properties (double positive electric charge, reduced toxicity, low values of critical micelle concentration, they show great potential as delivery system components for genetic material in gene therapy. The aim of this study was to investigate the process of the complexation of cationic gemini surfactants with nucleic acids: double-stranded DNA of different sizes (21 bp, ~185 bp, ~20 kbp and siRNA (21 bp. The tested series of dicationic surfactants consists of bis-imidazolium quaternary salts with varying lengths of hydrophobic side chains (m = 5, 6, 7, 8, 9, 11, 12, 14, 16. On the basis of the data obtained by circular dichroism spectroscopy and electrophoresis, we concluded that the studied gemini surfactants with long side chains effectively bind nucleic acids at low concentrations, which leads to the formation of stable lipoplexes. Images obtained by atomic force microscopy also confirmed the formation of vesicular structures, i.e., complexes between DNA and surfactants. The cytotoxicity of selected surfactants was also tested on HeLa cells. The surfactant toxicity significantly depends on surfactant geometry (the length of hydrophobic chain.

  5. Kinetic particularities of strained alicyclic compounds formation in catalytic methanol to hydrocarbon transformation process

    OpenAIRE

    Doluda V.; Brovko R.; Giniatullina N.; Sulman M.

    2017-01-01

    The catalytic transformation of methanol into hydrocarbons is a complex chemical process, accompanied by chain parallel chemical transformation reactions. The most valuable products of the methanol to hydrocarbons catalytic transformation reaction are the strained hydrocarbons — cyclopropane derivatives. These compounds can be used as a high-energy fuel, and also as a valuable chemical raw material. However, the yield of strained compounds in methanol to hydrocarbons catalytic transformation ...

  6. Synthesis, surface properties and oil solubilisation capacity of cationic gemini surfactants

    NARCIS (Netherlands)

    Dam, Th.; Engberts, J.B.F.N.; Karthäuser, J.; Karaborni, S.; Os, N.M. van

    1996-01-01

    The critical micelle concentration (CMC) and the surface tension at the CMC have been determined for the gemini surfactants alkanediyl-u,w-bis(dimethyla1kylammoniubmr omide) by means of dynamic surface tension measurements. For the same number of carbon atoms in the hydrophobic chain per hydrophilic

  7. Modulation of the wettability of excipients by surfactant and its impacts on the disintegration and release of tablets.

    Science.gov (United States)

    Yang, Baixue; Xu, Lu; Wang, Qiuxiao; Li, Sanming

    2016-12-01

    To investigate the modulation of the wettability of excipients by different types of surfactants and its impacts on the disintegration of tablets and drug release. The critical micelle concentration (CMC) of surfactants, including sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS), dodecyl trimethyl ammonium bromide (DTAB), cetyltrimethyl ammonium bromide (CTAB) and polysorbate (Tween-20 and Tween-80), was obtained using the platinum ring method. Contact angles of surfactant solutions on the excipient compacts and double-distilled water on the mixture of surfactant and the other excipient (magnesium stearate (MgSt) or sodium alginate (SA)) were measured by the sessile drop technique. Besides, surface free energy of excipients was calculated by the Owens method. Finally, the disintegration of tablets and in vitro dissolution testing were performed according to the method described in USP. The wettability of excipients could be enhanced to different extent with low concentration of surfactant solutions and maintained stable basically after CMC. For MgSt (hydrophobic excipient), the shorter the hydrophobic chain (C 12 , including SDS and DTAB), the better the wettability with the addition of surfactant in the formulation, leading to the shorter disintegration time of tablets and higher drug release rate. In contrast, the wettability of SA (hydrophilic excipient) was reduced by adding surfactant, resulting in the longer disintegration time of tablets and lower release rate. The modulation of the wetting of pharmaceutical excipients by surfactant had changed the disintegration time of tablets and drug release rate to a greater extent.

  8. Strong cooperative effect of oppositely charged surfactant mixtures on their adsorption and packing at the air-water interface and interfacial water structure.

    Science.gov (United States)

    Nguyen, Khoi T; Nguyen, Tuan D; Nguyen, Anh V

    2014-06-24

    Remarkable adsorption enhancement and packing of dilute mixtures of water-soluble oppositely-charged surfactants, sodium dodecyl sulfate (SDS) and dodecyl amine hydrochloride (DAH), at the air-water interface were observed by using sum frequency generation spectroscopy and tensiometry. The interfacial water structure was also observed to be significantly influenced by the SDS-DAH mixtures, differently from the synergy of the single surfactants. Most strikingly, the obtained spectroscopic evidence suggests that the interfacial hydrophobic alkyl chains of the binary mixtures assemble differently from those of single surfactants. This study highlights the significance of the cooperative interaction between the headgroups of oppositely charged binary surfactant systems and subsequently provides some insightful observations about the molecular structure of the air-aqueous interfacial water molecules and, more importantly, about the packing nature of the surfactant hydrophobic chains of dilute SDS-DAH mixtures of concentration below 1% of the CMC.

  9. Catalytic pyrolysis of hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Vail' eva, N A; Buyanov, R A

    1979-01-01

    Catalytic pyrolysis of petroleum fractions (undecane) was performed with the object of clarifying such questions as the mechanism of action of the catalyst, the concepts of activity and selectivity of the catalyst, the role of transport processes, the temperature ranges and limitations of the catalytic process, the effect of the catalyst on secondary processes, and others. Catalysts such as quartz, MgO, Al/sub 2/O/sub 3/, were used. Analysis of the experimental findings and the fact that the distribution of products is independent of the nature of the surface, demonstrate that the pyrolysis of hydrocarbons in the presence of catalysts is based on the heterogeneous-homogeneous radical-chain mechanism of action, and that the role of the catalysts reduces to increasing the concentration of free radicals. The concept of selectivity cannot be applied to catalysts here, since they do not affect the mechanism of the unfolding of the process of pyrolysis and their role consists solely in initiating the process. In catalytic pyrolysis the concepts of kinetic and diffusive domains of unfolding of the catalytic reaction do not apply, and only the outer surface of the catalyst is engaged, whereas the inner surface merely promotes deletorious secondary processes reducing the selectivity of the process and the activity of the catalyst. 6 references, 2 figures.

  10. On the mesoscopic origins of high viscosities in some polyelectrolyte-surfactant mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Ingo, E-mail: ingo.hoffmann@tu-berlin.de [Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 124, Sekr. TC 7, D-10623 Berlin (Germany); Institut Max von Laue-Paul Langevin (ILL), F-38042 Grenoble Cedex 9 (France); Farago, Bela; Schweins, Ralf; Falus, Peter; Sharp, Melissa [Institut Max von Laue-Paul Langevin (ILL), F-38042 Grenoble Cedex 9 (France); Prévost, Sylvain [Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 124, Sekr. TC 7, D-10623 Berlin (Germany); Helmholtz-Zentrum Berlin, D-14109 Berlin (Germany); Gradzielski, Michael, E-mail: michael.gradzielski@tu-berlin.de [Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 124, Sekr. TC 7, D-10623 Berlin (Germany)

    2015-08-21

    Oppositely charged polyelectrolyte (PE) surfactant mixtures allow the control of rheological parameters of a solution even at fairly low concentrations. For example, addition of 0.3 wt. % of anionic surfactant to a 1 wt. % solution of the polycation JR 400 increases the viscosity by 4 orders of magnitude. Recently, we could show that this increase is related to the formation of mixed, rod-like PE/surfactant aggregates which interconnect several polyelectrolyte chains [Hoffmann et al., Europhys. Lett. 104, 28001 (2013)]. In this paper, we refine our structural model of the aggregates to obtain a more consistent picture of their internal structure for different anionic surfactants. Combining small angle neutron scattering (SANS) and neutron spin-echo (NSE) allows us to determine the size of the aggregates. By comparing different contrasts, the internal structure of the aggregates can be elucidated and it is seen that the PE in the aggregates retains a relatively high freedom of movement. We proceeded to investigate the influence of the surfactant concentration and the surfactant type on structure and dynamics of the mixed aggregates. It is seen that the structural parameters of the aggregates depend very little on the surfactant concentration and headgroup. However, it is crucial to incorporate a sufficient amount of PE in the aggregates to increase the viscosity of the aggregates. By comparing viscous samples at 1 wt. % PE concentration with samples at a PE concentration of 0.3 wt. %, where no significant increase in viscosity is observed, we find that similar aggregates are formed already at this lower PE concentrations. However, the amount of PE incorporated in them is insufficient to interconnect several PE chains and therefore, they do not increase viscosity. So, our detailed investigation combining contrast variation SANS and NSE does not only allow to explain the viscosity behavior but also to deduced detailed information regarding the structures and

  11. Characterization of hydrocarbon utilizing fungi from hydrocarbon ...

    African Journals Online (AJOL)

    Prof. Ogunji

    isolated fungi could be useful in the bioremediation of hydrocarbon polluted sites. Keywords: ... Technologies such as mechanical force, burying, evaporation, dispersant application, and ..... The effects of drilling fluids on marine bacteria from a.

  12. Effects of a homologous series of linear alcohol ethoxylate surfactants on fathead minnow early life stages.

    Science.gov (United States)

    Lizotte, R E; Wong, D C; Dorn, P B; Rodgers, J H

    1999-11-01

    Effects of a homologous series of three primarily linear alcohol ethoxylate surfactants were studied in laboratory flow-through 28-day early-life-stage tests with fathead minnow (Pimephales promelas Rafinesque). Surfactants were a C(9-11), C(12-13), and C(14-15) with an average of 6, 6.5, and 7 ethylene oxide units per mole of alcohol, respectively. Average measured surfactant recoveries were 103%, 81%, and 79% of nominal concentrations for the C(9-11) EO 6, C(12-13) EO 6.5, and C(14-15) EO 7 studies, respectively. Embryo survival at 48 h was not adversely affected at any of the concentrations tested. Impaired hatching and deformed fry were observed only in the C(12-13) EO 6.5 study. The 28-day LC50 values were 4.87, 2.39, and 1.02 mg/L for the C(9-11) EO 6, C(12-13) EO 6.5, and C(14-15) EO 7 surfactants, respectively. The corresponding NOECs for survival were 1.01, 1.76, and 0.74 mg/L. Posthatch fry growth was more sensitive than survival for the C(12-13) EO 6.5 and C(14-15) EO 7 surfactants. Survival of posthatch fry decreased with increasing surfactant alkyl chain length. Twenty-eight-day laboratory data were compared to 96-h laboratory, 10-day laboratory and 30-day stream mesocosm data for fathead minnow previously determined for these surfactants. Survival endpoints from the different exposures were comparable and only varied within a factor of two. Similarity of results suggests that it is possible to effectively use 96-h, 10-day, or 28-day laboratory data to predict environmental effects concentrations of these surfactants for fish. http://link.springer-ny. com/link/service/journals/00244/bibs/37n4p536.html

  13. 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 ...

  14. The Biophysical Function of Pulmonary Surfactant

    OpenAIRE

    Rugonyi, Sandra; Biswas, Samares C.; Hall, Stephen B.

    2008-01-01

    Pulmonary surfactant lowers surface tension in the lungs. Physiological studies indicate two key aspects of this function: that the surfactant film forms rapidly; and that when compressed by the shrinking alveolar area during exhalation, the film reduces surface tension to very low values. These observations suggest that surfactant vesicles adsorb quickly, and that during compression, the adsorbed film resists the tendency to collapse from the interface to form a three-dimensional bulk phase....

  15. Acute Pathophysiological Effects of Intratracheal Instillation of Budesonide and Exogenous Surfactant in a Neonatal Surfactant-depleted Piglet Model

    Directory of Open Access Journals (Sweden)

    Chia-Feng Yang

    2010-08-01

    Conclusions: Intratracheal instillation of surfactant or surfactant plus budesonide can improve oxygenation and pulmonary histologic outcome in neonatal surfactant-depleted lungs. The additional use of budesonide does not disturb the function of the exogenous surfactant. Intratracheal administration of a corticosteroid combined with surfactant may be an effective method for alleviating local pulmonary inflammation in severe RDS.

  16. Enhancement of metal bioremediation by use of microbial surfactants

    International Nuclear Information System (INIS)

    Singh, Pooja; Cameotra, Swaranjit Singh

    2004-01-01

    Metal pollution all around the globe, especially in the mining and plating areas of the world, has been found to have grave consequences. An excellent option for enhanced metal contaminated site bioremediation is the use of microbial products viz. microbial surfactants and extracellular polymers which would increase the efficiency of metal reducing/sequestering organisms for field bioremediation. Important here is the advantage of such compounds at metal and organic compound co-contaminated site since microorganisms have long been found to produce surface-active compounds when grown on hydrocarbons. Other options capable of proving efficient enhancers include exploiting the chemotactic potential and biofilm forming ability of the relevant microorganisms. Chemotaxis towards environmental pollutants has excellent potential to enhance the biodegradation of many contaminants and biofilm offers them a better survival niche even in the presence of high levels of toxic compounds

  17. Remediation using trace element humate surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Riddle, Catherine Lynn; Taylor, Steven Cheney; Bruhn, Debra Fox

    2016-08-30

    A method of remediation at a remediation site having one or more undesirable conditions in which one or more soil characteristics, preferably soil pH and/or elemental concentrations, are measured at a remediation site. A trace element humate surfactant composition is prepared comprising a humate solution, element solution and at least one surfactant. The prepared trace element humate surfactant composition is then dispensed onto the remediation site whereby the trace element humate surfactant composition will reduce the amount of undesirable compounds by promoting growth of native species activity. By promoting native species activity, remediation occurs quickly and environmental impact is minimal.

  18. Fluorescent visualization of a spreading surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Fallest, David W; Lichtenberger, Adele M; Fox, Christopher J; Daniels, Karen E, E-mail: kdaniel@ncsu.ed [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States)

    2010-07-15

    The spreading of surfactants on thin films is an industrially and medically important phenomenon, but the dynamics are highly nonlinear and visualization of the surfactant dynamics has been a long-standing experimental challenge. We perform the first quantitative, spatiotemporally resolved measurements of the spreading of an insoluble surfactant on a thin fluid layer. During the spreading process, we directly observe both the radial height profile of the spreading droplet and the spatial distribution of the fluorescently tagged surfactant. We find that the leading edge of a spreading circular layer of surfactant forms a Marangoni ridge in the underlying fluid, with a trough trailing the ridge as expected. However, several novel features are observed using the fluorescence technique, including a peak in the surfactant concentration that trails the leading edge, and a flat, monolayer-scale spreading film that differs from concentration profiles predicted by current models. Both the Marangoni ridge and the surfactant leading edge can be described to spread as R{approx}t{sup {delta}}. We find spreading exponents {delta}{sub H}{approx}0.30 and {delta}{sub {Gamma}}{approx}0.22 for the ridge peak and surfactant leading edge, respectively, which are in good agreement with theoretical predictions of {delta}=1/4. In addition, we observe that the surfactant leading edge initially leads the peak of the Marangoni ridge, with the peak later catching up to the leading edge.

  19. Surfactant nebulisation : lung function, surfactant distribution and pulmonary blood flow distribution in lung lavaged rabbits

    NARCIS (Netherlands)

    Dijk, Peter H.; Heikamp, A; Bambang Oetomo, Sidarto

    1997-01-01

    Objective: Surfactant nebulisation is a promising alternative to surfactant instillation in newborns with the respiratory distress syndrome. Although less surfactant is deposited in the lung, it improves gas exchange, probably due to a superior distribution. We hypothesize that a more uniform

  20. 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.

  1. Photochemical key steps in the synthesis of surfactants from furfural-derived intermediates.

    Science.gov (United States)

    Gassama, Abdoulaye; Ernenwein, Cédric; Hoffmann, Norbert

    2009-01-01

    Furfural is oxidized to 2[5H]-furanone by using hydrogen peroxide or to 5-hydroxy-2[5H]-furanone by using photo-oxygenation. An amine function is introduced by photochemically induced radical addition of tertiairy amines, some of which carry an n-alkyl side chain as hydrophobic moiety. These amines are produced from fatty aldehydes and cyclic secondary amines. The resulting adducts are transformed into amphoteric surfactants possessing an ammonium and a carboxylate function. Amphoteric (pK(N) and isoelectric point) and surfactant properties such as the critical micelle concentration and the adsorption efficiency are determined.

  2. Phase behaviour of an ionic microemulsion system as a function of the cosurfactant chain length

    NARCIS (Netherlands)

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

    1993-01-01

    The phase behaviour of a microemulsion system consisting of equal volumes of brine and oil, sodium dodecyl sulphate (SDS) as surfactant and alcohols of different chain lengths (pentanol, hexanol and heptanol) as cosurfactant was studied. In the case of pentanol, at low surfactant concentrations and

  3. Electrostatic self-assembly in polyelectrolyte-neutral block copolymers and oppositely charged surfactant solutions

    International Nuclear Information System (INIS)

    Berret, J.-F.Jean-Francois; Oberdisse, Julian

    2004-01-01

    We report on small-angle neutron scattering (SANS) of colloidal complexes resulting from the electrostatic self-assembly of polyelectrolyte-neutral copolymers and oppositely charged surfactants. The polymers are double hydrophilic block copolymers of low molecular weight (between 5000 and 50 000 g/mol). One block is a polyelectrolyte chain, which can be either positively or negatively charged, whereas the second block is neutral and in good solvent conditions. In aqueous solutions, surfactants with an opposite charge to that of the polyelectrolyte interact strongly with these copolymers. The two species associate into stable 100 nm-colloidal complexes which exhibit a core-shell microstructure. For different polymer/surfactant couples, we have shown that the core is constituted from densely packed surfactant micelles connected by the polyelectrolyte chains. The outer part of the complex is a corona formed by the neutral soluble chains. Using a model of aggregation based on a Monte-Carlo algorithm, we have simulated the internal structure of the aggregates. The model assumes spherical cages containing one to several hundreds of micelles in a closely packed state. The agreement between the model and the data is remarkable

  4. Hydrocarbons and air pollution

    International Nuclear Information System (INIS)

    Herz, O.

    1992-01-01

    This paper shows the influence of hydrocarbons vapors, emitted by transports or by volatile solvents using, on air pollution. Hydrocarbons are the principal precursors of photochemical pollution. After a brief introduction on atmospheric chemistry and photochemical reactions, the author describes the french prevention program against hydrocarbons emissions. In the last chapter, informations on international or european community programs for photochemical pollution study are given. 5 figs., 10 tabs

  5. Production of hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Day, D T; Day, R E

    1920-04-27

    A process is disclosed of converting hydro-carbon oils having high boiling points to hydro-carbon oils having low boiling points, which process comprises adding the oil to be treated to a mass of hydro-carbon oil bearing shale, passing the shale with the oil through a conveyor retort and subjecting the material while in the retort to a heat treatment involving a temperature of at least 500/sup 0/F.

  6. Solvation thermodynamics of phenylalcohols in lamellar phase surfactant dispersions

    International Nuclear Information System (INIS)

    Martyniak, A.; Scheuermann, R.; Dilger, H.; Tucker, I.M.; Burkert, T.; Hashmi, A.S.K.; Vujosevic', D.; Roduner, E.

    2006-01-01

    The distribution and the stability of five phenylalcohols in a lamellar phase composed of simple bilayers separated by water at 298 and 348K is explored using avoided-level-crossing muon-spin resonance (ALC-μSR). The dependence of the alignment of the bilayer chains on temperature appears to be a crucial factor determining the phenylalcohol partitioning: increasing order of the surfactant tails leads to expulsion of the solute. Moreover, we observed a systematic trend, the longer the chain the deeper the phenyl group dips into the lipid bilayer. Recent studies have shown that the hydrophobic effect is adequate to describe membrane partitioning of small amphiphilic molecules. The solvation thermodynamic properties ΔG sol , ΔH sol , and ΔS sol which determine the solute transfer from the double layer into water prove that the distribution also strongly depends on shape, chemical nature and different structure of phenylalcohols

  7. Solvation thermodynamics of phenylalcohols in lamellar phase surfactant dispersions

    Energy Technology Data Exchange (ETDEWEB)

    Martyniak, A. [Institut fuer Physikalische Chemie, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart (Germany); Scheuermann, R. [Laboratory for muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen (Switzerland); Dilger, H. [Institut fuer Physikalische Chemie, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart (Germany); Tucker, I.M. [Unilever Research and Development, Port Sunlight, Wirral CH63 3JW (United Kingdom); Burkert, T. [Institut fuer Organische Chemie, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart (Germany); Hashmi, A.S.K. [Institut fuer Organische Chemie, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart (Germany); Vujosevic' , D. [Institut fuer Physikalische Chemie, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart (Germany); Roduner, E. [Institut fuer Physikalische Chemie, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart (Germany)]. E-mail: e.roduner@ipc.uni-stuttgart.de

    2006-03-31

    The distribution and the stability of five phenylalcohols in a lamellar phase composed of simple bilayers separated by water at 298 and 348K is explored using avoided-level-crossing muon-spin resonance (ALC-{mu}SR). The dependence of the alignment of the bilayer chains on temperature appears to be a crucial factor determining the phenylalcohol partitioning: increasing order of the surfactant tails leads to expulsion of the solute. Moreover, we observed a systematic trend, the longer the chain the deeper the phenyl group dips into the lipid bilayer. Recent studies have shown that the hydrophobic effect is adequate to describe membrane partitioning of small amphiphilic molecules. The solvation thermodynamic properties {delta}G{sub sol}, {delta}H{sub sol}, and {delta}S{sub sol} which determine the solute transfer from the double layer into water prove that the distribution also strongly depends on shape, chemical nature and different structure of phenylalcohols.

  8. 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...

  9. Cuticle hydrocarbons in saline aquatic beetles

    Directory of Open Access Journals (Sweden)

    María Botella-Cruz

    2017-07-01

    Full Text Available Hydrocarbons are the principal component of insect cuticle and play an important role in maintaining water balance. Cuticular impermeability could be an adaptative response to salinity and desiccation in aquatic insects; however, cuticular hydrocarbons have been poorly explored in this group and there are no previous data on saline species. We characterized cuticular hydrocarbons of adults and larvae of two saline aquatic beetles, namely Nebrioporus baeticus (Dytiscidae and Enochrus jesusarribasi (Hydrophilidae, using a gas chromatograph coupled to a mass spectrometer. The CHC profile of adults of both species, characterized by a high abundance of branched alkanes and low of unsaturated alkenes, seems to be more similar to that of some terrestrial beetles (e.g., desert Tenebrionidae compared with other aquatic Coleoptera (freshwater Dytiscidae. Adults of E. jesusarribasi had longer chain compounds than N. baeticus, in agreement with their higher resistance to salinity and desiccation. The more permeable cuticle of larvae was characterized by a lower diversity in compounds, shorter carbon chain length and a higher proportion of unsaturated hydrocarbons compared with that of the adults. These results suggest that osmotic stress on aquatic insects could exert a selection pressure on CHC profile similar to aridity in terrestrial species.

  10. Plasma devices for hydrocarbon reformation

    KAUST Repository

    Cha, Min

    2017-01-01

    Plasma devices for hydrocarbon reformation are provided. Methods of using the devices for hydrocarbon reformation are also provided. The devices can include a liquid container to receive a hydrocarbon source, and a plasma torch configured

  11. Surfactant screening of diesel-contaminated soil

    International Nuclear Information System (INIS)

    Peters, R.W.; Shem, L.; Montemagno, C.D.; Lewis, B.

    1991-01-01

    At one installation, approximately 60,000 gal 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 the research program in which 21 surfactants were screened for possible use to mobilize the organics from the contaminated soil prior to bioremediation. Anionic surfactants resulted in the greatest degree of diesel mobilization. The most promising surfactants will be employed on actual contaminated soil samples obtained from the site

  12. Microbial Hydrocarbon and ToxicPollutant Degradation Method

    Energy Technology Data Exchange (ETDEWEB)

    Schlueter, Dietrich [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Janabi, Mustafa [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); O' Neil, James [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Budinger, Thomas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2011-08-16

    The goal of this project is to determine optimum conditions for bacterial oxidation of hydrocarbons and long-chain alkanes that are representative of petroleum contamination of the environment. Polycyclic Aromatic Hydrocarbons (PAHs) are of concern because of their toxicity, low volatility, and resistance to microbial degradation, especially under anaerobic conditions. The uniqueness of our approach is to use carbon-11 in lieu of the traditional use of carbon-14.

  13. Bioremediation of diesel fuel contaminated soil: effect of non ionic surfactants and selected bacteria addition.

    Science.gov (United States)

    Collina, Elena; Lasagni, Marina; Pitea, Demetrio; Franzetti, Andrea; Di Gennaro, Patrizia; Bestetti, Giuseppina

    2007-09-01

    Aim of this work was to evaluate influence of two commercial surfactants and inoculum of selected bacteria on biodegradation of diesel fuel in different systems. Among alkyl polyethossilates (Brij family) and sorbitan derivates (Tween family) a first selection of surfactants was performed by estimation of Koc and Dafnia magna EC50 with molecular descriptor and QSAR model. Further experiments were conducted to evaluate soil sorption, biodegradability and toxicity. In the second part of the research, the effect of Brij 56, Tween 80 and selected bacteria addition on biodegradation of diesel fuel was studied in liquid cultures and in slurry and solid phase systems. The latter experiments were performed with diesel contaminated soil in bench scale slurry phase bioreactor and solid phase columns. Tween 80 addition increased the biodegradation rate of hydrocarbons both in liquid and in slurry phase systems. Regarding the effect of inoculum, no enhancement of biodegradation rate was observed neither in surfactant added nor in experiments without addition. On the contrary, in solid phase experiments, inoculum addition resulted in enhanced biodegradation compared to surfactant addition.

  14. Bioremediation of Diesel Fuel Contaminated Soil: Effect of Non Ionic Surfactants and Selected Bacteria Addition

    International Nuclear Information System (INIS)

    Collina, E.; Lasagni, M.; Pitea, D.; Franzetti, A.; Di Gennaro, P.; Bestetti, G.

    2007-01-01

    Aim of this work was to evaluate influence of two commercial surfactants and inoculum of selected bacteria on biodegradation of diesel fuel in different systems. Among alkyl polyethossilates (Brij family) and sorbitan derivates (Tween family) a first selection of surfactants was performed by estimation of Koc and Dafnia magna EC 50 with molecular descriptor and QSAR model. Further experiments were conducted to evaluate soil sorption, biodegradability and toxicity. In the second part of the research, the effect of Brij 56, Tween 80 and selected bacteria addition on biodegradation of diesel fuel was studied in liquid cultures and in slurry and solid phase systems. The latter experiments were performed with diesel contaminated soil in bench scale slurry phase bioreactor and solid phase columns. Tween 80 addition increased the biodegradation rate of hydrocarbons both in liquid and in slurry phase systems. Regarding the effect of inoculum, no enhancement of biodegradation rate was observed neither in surfactant added nor in experiments without addition. On the contrary, in solid phase experiments, inoculum addition resulted in enhanced biodegradation compared to surfactant addition

  15. Plasma devices for hydrocarbon reformation

    KAUST Repository

    Cha, Min Suk

    2017-02-16

    Plasma devices for hydrocarbon reformation are provided. Methods of using the devices for hydrocarbon reformation are also provided. The devices can include a liquid container to receive a hydrocarbon source, and a plasma torch configured to be submerged in the liquid. The plasma plume from the plasma torch can cause reformation of the hydrocarbon. The device can use a variety of plasma torches that can be arranged in a variety of positions in the liquid container. The devices can be used for the reformation of gaseous hydrocarbons and/or liquid hydrocarbons. The reformation can produce methane, lower hydrocarbons, higher hydrocarbons, hydrogen gas, water, carbon dioxide, carbon monoxide, or a combination thereof.

  16. 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)

  17. Biodegradable surfactant stabilized nanoscale zero-valent iron for in situ treatment of vinyl chloride and 1,2-dichloroethane

    International Nuclear Information System (INIS)

    Wei, Yu-Ting; Wu, Shian-chee; Yang, Shi-Wei; Che, Choi-Hong; Lien, Hsing-Lung; Huang, De-Huang

    2012-01-01

    Highlights: ► Biodegradable surfactant stabilized nanoscale zero-valent iron (NZVI) is tested. ► Vinyl chloride and 1,2-dichloroethane are remediated by NZVI in the field. ► Multiple functions of biodegradable surfactants are confirmed. ► Biodegradable surfactants stabilize NZVI and facilitate the bioremediation. ► NZVI creates reducing conditions beneficial to an anaerobic bioremediation. - Abstract: Nanoscale zero-valent iron (NZVI) stabilized with dispersants is a promising technology for the remediation of contaminated groundwater. In this study, we demonstrated the use of biodegradable surfactant stabilized NZVI slurry for successful treatment of vinyl chloride (VC) and 1,2-dichloroethane (1,2-DCA) in a contaminated site in Taiwan. The biodegradable surfactant stabilized NZVI was coated with palladium and synthesized on-site. From monitoring the iron concentration breakthrough and distribution, it was found that the stabilized NZVI is capable of transporting in the aquifer at the test plot (200 m 2 ). VC was effectively degraded by NZVI while the 1,2-DCA degradation was relatively sluggish during the 3-month field test. Nevertheless, as 1,2-DCA is known to resist abiotic reduction by NZVI, the observation of 1,2-DCA degradation and hydrocarbon production suggested a bioremediation took place. ORP and pH results revealed that a reducing condition was achieved at the testing area facilitating the biodegradation of chlorinated organic hydrocarbons. The bioremediation may be attributed to the production of hydrogen gas as electron donor from the corrosion of NZVI in the presence of water or the added biodegradable surfactant serving as the carbon source as well as electron donor to stimulate microbial growth.

  18. Surfactant replacement therapy--economic impact.

    Science.gov (United States)

    Pejaver, R K; al Hifzi, I; Aldussari, S

    2001-06-01

    Surfactant replacement is an effective treatment for neonatal respiratory distress syndrome. (RDS). As widespread use of surfactant is becoming a reality, it is important to assess the economic implications of this new form of therapy. A comparison study was carried out at the Neonatal Intensive Care Unit (NICU) of Northwest Armed Forces Hospital, Saudi Arabia. Among 75 infants who received surfactant for RDS and similar number who were managed during time period just before the surfactant was available, but by set criteria would have made them eligible for surfactant. All other management modalities except surfactant were the same for all these babies. Based on the intensity of monitoring and nursing care required by the baby, the level of care was divided as: Level IIIA, IIIB, Level II, Level I. The cost per day per bed for each level was calculated, taking into account the use of hospital immovable equipment, personal salaries of nursing, medical, ancillary staff, overheads and maintenance, depreciation and replacement costs. Medications used, procedures done, TPN, oxygen, were all added to individual patient's total expenditure. 75 infants in the Surfactant group had 62 survivors. They spent a total of 4300 days in hospital. (av 69.35) Out of which 970 d (av 15.65 per patient) were ventilated days. There were 56 survivors in the non-surfactant group of 75. They had spent a total of 5023 days in the hospital (av 89.69/patient) out of which 1490 were ventilated days (av 26.60 d). Including the cost of surfactant (two doses), cost of hospital stay for each infant taking the average figures of stay would be SR 118, 009.75 per surfactant treated baby and SR 164, 070.70 per non-surfactant treated baby. The difference of 46,061 SR is 39.03% more in non-surfactant group. One Saudi rial = 8 Rs (approx at the time study was carried out.) Medical care cost varies from place to place. However, it is definitely cost-effective where surfactant is concerned. Quality adjusted

  19. Properties of surfactant films in water-in-CO2 microemulsions obtained by small-angle neutron scattering.

    Science.gov (United States)

    Yan, Ci; Sagisaka, Masanobu; James, Craig; Rogers, Sarah; Alexander, Shirin; Eastoe, Julian

    2014-12-01

    The formation, stability and structural properties of normal liquid phase microemulsions, stabilized by hydrocarbon surfactants, comprising water and hydrocarbon oils can be interpreted in terms of the film bending rigidity (energy) model. Here, this model is tested for unusual water-in-CO2 (w/c) microemulsions, formed at high pressure with supercritical CO2 (sc-CO2) as a solvent and fluorinated surfactants as stabilizers. Hence, it is possible to explore the generality of this model for other types of microemulsions. High Pressure Small-Angle Neutron Scattering (HP-SANS) has been used to study w/c microemulsions, using contrast variation to highlight scattering from the stabilizing fluorinated surfactant films: these data show clear evidence for spherical core-shell structures for the microemulsion droplets. The results extend understanding of w/c microemulsions since previous SANS studies are based only on scattering from water core droplets. Here, detailed structural parameters for the surfactant films, such as thickness and film bending energy, have been extracted from the core-shell SANS profiles revealed by controlled contrast variation. Furthermore, at reduced CO2 densities (∼0.7gcm(-3)), elongated cylindrical droplet structures have been observed, which are uncommon for CO2 microemulsions/emulsions. The implications of the presence of cylindrical micelles and droplets for applications of CO2, and viscosity enhancements are discussed. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. 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.

  1. Rhamnolipids--next generation surfactants?

    Science.gov (United States)

    Müller, Markus Michael; Kügler, Johannes H; Henkel, Marius; Gerlitzki, Melanie; Hörmann, Barbara; Pöhnlein, Martin; Syldatk, Christoph; Hausmann, Rudolf

    2012-12-31

    The demand for bio-based processes and materials in the petrochemical industry has significantly increased during the last decade because of the expected running out of petroleum. This trend can be ascribed to three main causes: (1) the increased use of renewable resources for chemical synthesis of already established product classes, (2) the replacement of chemical synthesis of already established product classes by new biotechnological processes based on renewable resources, and (3) the biotechnological production of new molecules with new features or better performances than already established comparable chemically synthesized products. All three approaches are currently being pursued for surfactant production. Biosurfactants are a very promising and interesting substance class because they are based on renewable resources, sustainable, and biologically degradable. Alkyl polyglycosides are chemically synthesized biosurfactants established on the surfactant market. The first microbiological biosurfactants on the market were sophorolipids. Of all currently known biosurfactants, rhamnolipids have the highest potential for becoming the next generation of biosurfactants introduced on the market. Although the metabolic pathways and genetic regulation of biosynthesis are known qualitatively, the quantitative understanding relevant for bioreactor cultivation is still missing. Additionally, high product titers have been exclusively described with vegetable oil as sole carbon source in combination with Pseudomonas aeruginosa strains. Competitive productivity is still out of reach for heterologous hosts or non-pathogenic natural producer strains. Thus, on the one hand there is a need to gain a deeper understanding of the regulation of rhamnolipid production on process and cellular level during bioreactor cultivations. On the other hand, there is a need for metabolizable renewable substrates, which do not compete with food and feed. A sustainable bioeconomy approach should

  2. Surfactants tailored by the class Actinobacteria

    Directory of Open Access Journals (Sweden)

    Johannes H Kügler

    2015-03-01

    Full Text Available Gloablly, the drive towards the establishment of a bio-based economy has resulted in an increased need for bio-based applications. This, in turn, has served as a driving force for the discovery and application of novel biosurfactants. The class Actinobacteria represents a vast group of microorganisms with the ability to produce a diverse range of secondary metabolites, including surfactants. Understanding the extensive nature of the biosurfactants produced by actinobacterial strains can assist in finding novel biosurfactants with new potential applications. This review therefore presents a comprehensive overview of the knowledge available on actinobacterial surfactants, the chemical structures that have been completely or partly elucidated, as well as the identity of the biosurfactant-producing strains. Producer strains of not yet elucidated compounds are discussed, as well as the original habitats of all the producer strains, which seems to indicate that biosurfactant production is environmentally driven. Methodology applied in the isolation, purification and structural elucidation of the different types of surface active compounds, as well as surfactant activity tests, are also discussed. Overall, actinobacterial surfactants can be summarized to include the dominantly occurring trehalose-comprising surfactants, other non-trehalose containing glycolipids, lipopeptides and the more rare actinobacterial surfactants. The lack of structural information on a large proportion of actinobacterial surfactants should be considered as a driving force to further explore the abundance and diversity of these compounds. This would allow for a better understanding of actinobacterial surface active compounds and their potential for biotechnological application.

  3. Surfactants tailored by the class Actinobacteria

    Science.gov (United States)

    Kügler, Johannes H.; Le Roes-Hill, Marilize; Syldatk, Christoph; Hausmann, Rudolf

    2015-01-01

    Globally the change towards the establishment of a bio-based economy has resulted in an increased need for bio-based applications. This, in turn, has served as a driving force for the discovery and application of novel biosurfactants. The class Actinobacteria represents a vast group of microorganisms with the ability to produce a diverse range of secondary metabolites, including surfactants. Understanding the extensive nature of the biosurfactants produced by actinobacterial strains can assist in finding novel biosurfactants with new potential applications. This review therefore presents a comprehensive overview of the knowledge available on actinobacterial surfactants, the chemical structures that have been completely or partly elucidated, as well as the identity of the biosurfactant-producing strains. Producer strains of not yet elucidated compounds are discussed, as well as the original habitats of all the producer strains, which seems to indicate that biosurfactant production is environmentally driven. Methodology applied in the isolation, purification and structural elucidation of the different types of surface active compounds, as well as surfactant activity tests, are also discussed. Overall, actinobacterial surfactants can be summarized to include the dominantly occurring trehalose-comprising surfactants, other non-trehalose containing glycolipids, lipopeptides and the more rare actinobacterial surfactants. The lack of structural information on a large proportion of actinobacterial surfactants should be considered as a driving force to further explore the abundance and diversity of these compounds. This would allow for a better understanding of actinobacterial surface active compounds and their potential for biotechnological application. PMID:25852670

  4. DNA compaction by azobenzene-containing surfactant

    International Nuclear Information System (INIS)

    Zakrevskyy, Yuriy; Kopyshev, Alexey; Lomadze, Nino; Santer, Svetlana; Morozova, Elena; Lysyakova, Ludmila; Kasyanenko, Nina

    2011-01-01

    We report on the interaction of cationic azobenzene-containing surfactant with DNA investigated by absorption and fluorescence spectroscopy, dynamic light scattering, and atomic force microscopy. The properties of the surfactant can be controlled with light by reversible switching of the azobenzene unit, incorporated into the surfactant tail, between a hydrophobic trans (visible irradiation) and a hydrophilic cis (UV irradiation) configuration. The influence of the trans-cis isomerization of the azobenzene on the compaction process of DNA molecules and the role of both isomers in the formation and colloidal stability of DNA-surfactant complexes is discussed. It is shown that the trans isomer plays a major role in the DNA compaction process. The influence of the cis isomer on the DNA coil configuration is rather small. The construction of a phase diagram of the DNA concentration versus surfactant/DNA charge ratio allows distancing between three major phases: colloidally stable and unstable compacted globules, and extended coil conformation. There is a critical concentration of DNA above which the compacted globules can be hindered from aggregation and precipitation by adding an appropriate amount of the surfactant in the trans configuration. This is because of the compensation of hydrophobicity of the globules with an increasing amount of the surfactant. Below the critical DNA concentration, the compacted globules are colloidally stable and can be reversibly transferred with light to an extended coil state.

  5. Bioavailability enhanced rhizosphere remediation of petroleum hydrocarbon contaminated soil

    International Nuclear Information System (INIS)

    Marchenko, A.; Vorobyov, A.; Zharikov, G.; Ermolenko, Z.; Dyadishchev, N.; Borovick, R.; Sokolov, M.; Ortega-Calvo, J.J.

    2005-01-01

    Aliphatic, aromatic and polycyclic aromatic oil hydrocarbons are structurally complicated man-caused pollutants that are constantly brought into biosphere. Oil production in Russia, so as all over the world, is connected with pollution of biotopes, ecosystems and agro-landscapes. Presently large funds are allocated either for oil leak prevention or for discharged oil gathering. At the same time, in spite of large necessity in technologies for efficient reconstruction of soil bio-productivity, reliable regional systems of their remediation in situ have not been developed yet. One such method is rhizosphere remediation, a biotechnology, based on the functioning of plant-microbial complexes. Little is known about bioavailability in phyto-remediation systems. Specific bioavailability-promoting mechanisms, operating in soil with hydrocarbon-degrading populations, may be responsible for increased rates of pollutant transformation (increased bacterial adherence to the pollutants, production of bio-surfactants by bacteria or by plants, possible role of chemotaxis). In the course of work collection of 42 chemo-tactically active bio-surfactant producing strain-degraders of petroleum hydrocarbons including polycyclic aromatic hydrocarbons (PAHs) was created. Two representative strains were selected for detailed chemotaxis studies with PAHs (naphthalene, phenanthrene, anthracene, and pyrene), bacterial lipopolysaccharide and root exudates from seven different plants. These strains are produce the bio-surfactants (rhamno-lipid). The chemotactic response was quantified with a capillary and densitometric chemotaxis assay. Surface tension of cultural liquid was measured after cultivation of strains in the presence of hexadecane or phenanthrene with the use of a ring tensiometer. Before measuring of surface tension microbial cells were collected from liquid culture by centrifugation. Total petroleum Hydrocarbons (TPH) in soil were analyzed by infra-red spectroscopy method. PAHs

  6. Bioavailability enhanced rhizosphere remediation of petroleum hydrocarbon contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Marchenko, A.; Vorobyov, A.; Zharikov, G.; Ermolenko, Z.; Dyadishchev, N.; Borovick, R.; Sokolov, M. [Research Centre for Toxicology and Hygienic Regulation of Biopreparations, Moscow region (Russian Federation); Ortega-Calvo, J.J. [Instituto de Recursos Naturales y Agrobiologia, CSIC, Sevilla (Spain)

    2005-07-01

    Aliphatic, aromatic and polycyclic aromatic oil hydrocarbons are structurally complicated man-caused pollutants that are constantly brought into biosphere. Oil production in Russia, so as all over the world, is connected with pollution of biotopes, ecosystems and agro-landscapes. Presently large funds are allocated either for oil leak prevention or for discharged oil gathering. At the same time, in spite of large necessity in technologies for efficient reconstruction of soil bio-productivity, reliable regional systems of their remediation in situ have not been developed yet. One such method is rhizosphere remediation, a biotechnology, based on the functioning of plant-microbial complexes. Little is known about bioavailability in phyto-remediation systems. Specific bioavailability-promoting mechanisms, operating in soil with hydrocarbon-degrading populations, may be responsible for increased rates of pollutant transformation (increased bacterial adherence to the pollutants, production of bio-surfactants by bacteria or by plants, possible role of chemotaxis). In the course of work collection of 42 chemo-tactically active bio-surfactant producing strain-degraders of petroleum hydrocarbons including polycyclic aromatic hydrocarbons (PAHs) was created. Two representative strains were selected for detailed chemotaxis studies with PAHs (naphthalene, phenanthrene, anthracene, and pyrene), bacterial lipopolysaccharide and root exudates from seven different plants. These strains are produce the bio-surfactants (rhamno-lipid). The chemotactic response was quantified with a capillary and densitometric chemotaxis assay. Surface tension of cultural liquid was measured after cultivation of strains in the presence of hexadecane or phenanthrene with the use of a ring tensiometer. Before measuring of surface tension microbial cells were collected from liquid culture by centrifugation. Total petroleum Hydrocarbons (TPH) in soil were analyzed by infra-red spectroscopy method. PAHs

  7. Effect of Amphiphilic Alkyl Chain Length Upon Purified LATEX Stability

    International Nuclear Information System (INIS)

    Amira Amir Hassan; Amir Hashim Mohd Yatim

    2015-01-01

    Rubber particles in purified latex (PL) are stabilized by a film of protein and fatty acid soap (surfactant). Saturated straight-chain fatty acid soaps can assist an enhancement of latex stability. However, whether the alkyl chain length plays an important role in increasing the stability is still an issue. The aim of this study is to investigate the effect of alkyl chain length of anionic surfactant on the stability of purified latex. The fatty acid soap of decanoate (9), laurate (11), sodium dodecyl sulphate (SDS) (12) and palmitate (15) were used. The numbers in parentheses indicating the number of carbon present in alkyl chain of the soap. The results showed that the impact of alkyl chain length on the stability of latex is in the order of laurate > decanoate > SDS > palmitate > purified latex accordingly. The alkyl chain length does giving a significant effect on latex stability after longer stirring time. The particle size of latex with the presence of surfactant is greater compare to a single particle itself due to extension of particles diameter. Thus suitable interaction of the nonpolar tail of surfactant with the hydrophobic regions of latex surface played a major role in maintaining a stable latex system. (author)

  8. Interactions between ionic liquid surfactant [C12mim]Br and DNA in dilute brine.

    Science.gov (United States)

    He, Yunfei; Shang, Yazhuo; Liu, Zhenhai; Shao, Shuang; Liu, Honglai; Hu, Ying

    2013-01-01

    Interactions between ionic liquid surfactant [C(12)mim]Br and DNA in dilute brine were investigated in terms of various experimental methods and molecular dynamics (MD) simulation. It was shown that the aggregation of [C(12)mim]Br on DNA chains is motivated not only by electrostatic attractions between DNA phosphate groups and [C(12)mim]Br headgroups but also by hydrophobic interactions among [C(12)mim]Br alkyl chains. Isothermal titration calorimetry analysis indicated that the [C(12)mim]Br aggregation in the presence and absence of DNA are both thermodynamically favored driven by enthalpy and entropy. DNA undergoes size transition and conformational change induced by [C(12)mim]Br, and the charges of DNA are neutralized by the added [C(12)mim]Br. Various microstructures were observed such as DNA with loose coil conformation in nature state, necklace-like structures, and compact spherical aggregates. MD simulation showed that the polyelectrolyte collapses upon the addition of oppositely charged surfactants and the aggregation of surfactants around the polyelectrolyte was reaffirmed. The simulation predicted the gradual neutralization of the negatively charged polyelectrolyte by the surfactant, consistent with the experimental results. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. 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.

  10. Small angle neutron scattering study of doxorubicin–surfactant ...

    Indian Academy of Sciences (India)

    The binding affinity of doxorubicin within the micelle carrier is enhanced through complex formation of drug and anionic surfactant, aerosol OT (AOT). Electrostatic binding of doxorubicin with negatively charged surfactants leads to the formation of hydrophobic drug–surfactant complexes. Surfactant-induced partitioning of ...

  11. 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.

  12. Composition driven monolayer to bilayer transformation in a surfactant intercalated Mg-Al layered double hydroxide.

    Science.gov (United States)

    Naik, Vikrant V; Chalasani, Rajesh; Vasudevan, S

    2011-03-15

    The structure and organization of dodecyl sulfate (DDS) surfactant chains intercalated in an Mg-Al layered double hydroxide (LDH), Mg(1-x)Alx(OH)2, with differing Al/Mg ratios has been investigated. The Mg-Al LDHs can be prepared over a range of compositions with x varying from 0.167 to 0.37 and therefore provides a simple system to study how the organization of the alkyl chains of the intercalated DDS anions change with packing density; the Al/Mg ratio or x providing a convenient handle to do so. Powder X-ray diffraction measurements showed that at high packing densities (x ≥ 0.3) the alkyl chains of the intercalated dodecyl sulfate ions are anchored on opposing LDH sheets and arranged as bilayers with an interlayer spacing of ∼27 Å. At lower packing densities (x flat in the galleries with an interlayer spacing of ∼8 Å. For the in between compositions, 0.2 ≤ x organization of the chains and the interlayer spacing. The simulations are able to reproduce the composition driven monolayer to bilayer transformation in the arrangement of the intercalated surfactant chains and in addition provide insights into the factors that decide the arrangement of the surfactant chains in the two situations. In the bilayer arrangement, it is the dispersive van der Waals interactions between chains in opposing layers of the anchored bilayer that is responsible for the cohesive energy of the solid whereas at lower packing densities, where a monolayer arrangement is favored, Coulomb interactions between the positively charged Mg-Al LDH sheets and the negatively charged headgroup of the DDS anion dominate.

  13. Thraustochytrid protists degrade hydrocarbons

    Digital Repository Service at National Institute of Oceanography (India)

    Raikar, M.T.; Raghukumar, S.; Vani, V.; David, J.J.; Chandramohan, D.

    isolation tubes with crude oil. Three isolates tested showed positive hydrophobicity of cell walls as judged by the Microbial Adhesion to Hydrocarbons (MATH) assay. Addition of Bombay High crude oil to nutrient broth slightly enhanced growth of the protists...

  14. 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.

  15. Purifying hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    Rostin, H

    1938-08-11

    A process is described for continuously purifying hydrocarbon oils consisting in conducting the vapors of the same at a temperature of 300 to 400/sup 0/C over the oelitic ore minette together with reducing gases in presence of steam the proportion of the reducing gases and steam being such that the sulfur of the hydrocarbons escapes from the reaction chamber in the form of sulfuretted hydrogen without permanent sulfide of iron being formed.

  16. Process for refining hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Risenfeld, E H

    1924-11-26

    A process is disclosed for the refining of hydrocarbons or other mixtures through treatment in vapor form with metal catalysts, characterized by such metals being used as catalysts, which are obtained by reduction of the oxide of minerals containing the iron group, and by the vapors of the hydrocarbons, in the presence of the water vapor, being led over these catalysts at temperatures from 200 to 300/sup 0/C.

  17. 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.

  18. Effect of a cationic surfactant on the volatilization of PAHs from soil.

    Science.gov (United States)

    Lu, Li; Zhu, Lizhong

    2012-06-01

    Cationic surfactants are common in soils because of their use in daily cosmetic and cleaning products, and their use as a soil amendment for the mitigation and remediation of organic contaminated soils has been proposed. Such surfactant may affect the transfer and fate of organic contaminants in the environment. This study investigated the effect of a cationic surfactant, dodecylpyridinium bromide (DDPB), on the volatilization of polycyclic aromatic hydrocarbons (PAHs) from a paddy soil. The volatilization of PAHs from moist soil amended with different concentrations of DDPB was tested in an open system. The specific effects of DDPB on the liquid-vapor and solid-vapor equilibriums of PAHs were separately investigated in closed systems by headspace analysis. DDPB affects both liquid-vapor and solid-vapor processes of PAHs in soil. At DDPB concentrations below the critical micelle concentration (CMC), movement of PAHs from the bulk solution to the gas-liquid interface appeared to be facilitated by interaction between PAHs and the surfactant monomers adsorbed at the gas-liquid interface, promoting the volatilization of PAHs from solution. However, when DDPB was greater than the CMC, volatilization was inhibited due to the solubilization of PAHs by micelles. On the other hand, the formation of sorbed surfactant significantly inhibited the solid-vapor volatilization of PAHs. The overall effect of the two simultaneous effects of DDPB on liquid-vapor and solid-vapor processes was a decreased volatilization loss of PAHs from soil. Inhibition of PAH volatilization was more significant for the soil with a lower moisture content.

  19. The Accelerated Late Adsorption of Pulmonary Surfactant

    OpenAIRE

    Loney, Ryan W.; Anyan, Walter R.; Biswas, Samares C.; Rananavare, Shankar B.; Hall, Stephen B.

    2011-01-01

    Adsorption of pulmonary surfactant to an air−water interface lowers surface tension (γ) at rates that initially decrease progressively, but which then accelerate close to the equilibrium γ. The studies here tested a series of hypotheses concerning mechanisms that might cause the late accelerated drop in γ. Experiments used captive bubbles and a Wilhelmy plate to measure γ during adsorption of vesicles containing constituents from extracted calf surfactant. The faster fall in γ reflects faster...

  20. Poly(ethylene oxide) surfactant polymers

    OpenAIRE

    VACHEETHASANEE, KATANCHALEE; WANG, SHUWU; QIU, YONGXING; MARCHANT, ROGER E.

    2004-01-01

    We report on a series of structurally well-defined surfactant polymers that undergo surface-induced self-assembly on hydrophobic biomaterial surfaces. The surfactant polymers consist of a poly(vinyl amine) backbone with poly(ethylene oxide) and hexanal pendant groups. The poly(vinyl amine) (PVAm) was synthesized by hydrolysis of poly(N-vinyl formamide) following free radical polymerization of N-vinyl formamide. Hexanal and aldehyde-terminated poly (ethyleneoxide) (PEO) were simultaneously att...

  1. Study of conformation and dynamic of surfactant molecules in graphite oxide via NMR

    Energy Technology Data Exchange (ETDEWEB)

    Ai, X.Q. [Jiangsu Second Normal University, College of Physics and Electronic Engineering, Nanjing (China); Ma, L.G. [Nanjing Xiaozhuang University, School of Electronic Engineering, Nanjing (China)

    2016-08-15

    The conformation and dynamic of surfactant in graphite oxide (GO) was investigated by solid-state {sup 13}C magic-angle-spinning NMR and {sup 1}H-{sup 13}C cross-polarization/magic-angle-spinning NMR spectra. The conformation ordering of the alkyl chains in the confined system shows strong dependence on its orientation. While the alkyl chains parallel to the GO layer in lateral monolayer arrangement are in gauche conformation in addition to a small amount of all-trans conformation, those with orientation radiating away from the GO in paraffin bilayer arrangement is in all-trans conformation in addition to some gauche conformation even though high-order diffraction peaks appears. NMR results suggest that the least mobile segment is located at the GO-surfactant interface corresponding to the N-methylene group. Further from it, the mobility of the alkyl chain increases. The terminal methyl and N-methyl carbon groups have the highest mobile. The chains in all-trans conformational state are characterized as more rigid than chains with gauche conformation; each segment of the confined alkyl chains with the lateral monolayer arrangement exhibits less mobility as compared to that with the paraffin bilayer arrangement. (orig.)

  2. Falling chains

    OpenAIRE

    Wong, Chun Wa; Yasui, Kosuke

    2005-01-01

    The one-dimensional fall of a folded chain with one end suspended from a rigid support and a chain falling from a resting heap on a table is studied. Because their Lagrangians contain no explicit time dependence, the falling chains are conservative systems. Their equations of motion are shown to contain a term that enforces energy conservation when masses are transferred between subchains. We show that Cayley's 1857 energy nonconserving solution for a chain falling from a resting heap is inco...

  3. Adsorption of diclofenac onto organoclays: Effects of surfactant and environmental (pH and temperature) conditions

    OpenAIRE

    De Oliveira , Tiago; Guégan , Régis; Thiebault , Thomas; Le Milbeau , Claude; Muller , Fabrice; Teixeira , Vinicius; Giovanela , Marcelo; Boussafir , Mohammed

    2017-01-01

    Accepted Manuscript; International audience; Among pharmaceutical products (PPs) recalcitrant to water treatments, diclofenac shows a high toxicity and remains at high concentration in natural aquatic environments. The aim of this study concerns the understanding of the adsorption mechanism of this anionic PP onto two organoclays prepared with two long-alkyl chains cationic surfactants showing different chemical nature for various experimental pH and temperature conditions. The experimental d...

  4. Spectroscopic investigation on the interaction of some surfactant-cobalt(III) complexes with serum albumins

    Energy Technology Data Exchange (ETDEWEB)

    Vignesh, Gopalaswamy; Nehru, Selvan; Manojkumar, Yesaiyan; Arunachalam, Sankaralingam, E-mail: arunasurf@yahoo.com

    2014-01-15

    The interaction of HSA/BSA with single and double chain surfactant-cobalt(III) complexes, cis-[Co(phen){sub 2}(UA)Cl](ClO{sub 4}){sub 2}·2H{sub 2}O (1), cis-[Co(phen){sub 2}(UA){sub 2}](ClO{sub 4}){sub 3}·2H{sub 2}O (2), cis-[Co(en){sub 2}(UA)Cl](ClO{sub 4}){sub 2}·2H{sub 2}O (3), cis-[Co(en){sub 2}(UA){sub 2}](ClO{sub 4}){sub 3}·2H{sub 2}O (4), were investigated by steady state fluorescence, UV–vis absorption, synchronous, three dimensional fluorescence and circular dichroism spectroscopy. The results reveal that the quenching of HSA/BSA by all the four complexes takes place through static mechanism. The binding constant, binding sites and thermodymamic parameter were calculated. The results illustrate that the double chain surfactant-cobalt(III) complexes bind more strongly than the corresponding single chain complexes. The distance between donor (HSA/BSA) and acceptor (surfactant-cobalt(III) complexes) was obtained according to FRET. The results of synchronous, three dimensional and circular dichroism spectroscopy studies show that all the complexes caused considerable amount of conformational and some amount of environment changes in HSA/BSA. -- Highlights: • Binding of single and double chain surfactant-cobalt(III) complexes with serum albumins. • Hydrophobic attraction plays a major role in the binding process. • Binding induces considerable amount of conformational changes in the protein.

  5. Aquatic toxicity and biodegradability of advanced cationic surfactant APA-22 compatible with the aquatic environment.

    Science.gov (United States)

    Yamane, Masayuki; Toyo, Takamasa; Inoue, Katsuhisa; Sakai, Takaya; Kaneko, Youhei; Nishiyama, Naohiro

    2008-01-01

    Cationic surfactant is a chemical substance used in hair conditioner, fabric softener and other household products. By investigating the relationship between the aquatic toxicity and the chemical structures of two types of mono alkyl cationic surfactants, alkyl trimethylammonium salts and alkyl dimethylamine salts, we have found that the C22 alkyl chain length is effective to reduce the toxicity. Besides, we have recognized that the amidopropyl functional group contributes to the enhanced biodegradability by investigating the biodegradation trend of (alkylamidopropyl)dimethylamine salt (alkyl chain length: C18). Based on these findings, we have developed mono alkyl cationic surfactant called APA-22, N-[3-(dimethylamino)propyl]docosanamide salt. APA-22 is formed by the C22 alkyl chain, amidopropyl functional group and di-methyltertiary amine group. We evaluated the aerobic and anaerobic biodegradability of APA-22 by two standard methods (OECD Test Guideline 301B and ECETOC technical document No.28) and found that this substance was degraded rapidly in both conditions. The toxicity to algae, invertebrate and fish of this substance are evaluated by using OECD Test Guideline 201, 202 and 203, respectively. All acute toxicity values are >1 mg/L, which indicates that environmental toxicity of this substance is relatively less toxic to aquatic organism. In addition, we estimated the biodegradation pathway of APA-22 and observed the complete disappearance of APA-22 and its intermediates during the test periods. Based on the environmental data provided above, we concluded that APA22 is more compatible with the aquatic environment compared to other cationic surfactants with mono long alkyl chain.

  6. Surfactant properties of human meibomian lipids.

    Science.gov (United States)

    Mudgil, Poonam; Millar, Thomas J

    2011-03-25

    Human meibomian lipids are the major part of the lipid layer of the tear film. Their surfactant properties enable their spread across the aqueous layer and help maintain a stable tear film. The purpose of this study was to investigate surfactant properties of human meibomian lipids in vitro and to determine effects of different physical conditions such as temperature and increased osmolarity, such as occur in dry eye, on these properties. Human meibomian lipids were spread on an artificial tear solution in a Langmuir trough. The lipid films were compressed and expanded to record the surface pressure-area (Π-A) isocycles. The isocycles were recorded under different physical conditions such as high pressure, increasing concentration and size of divalent cations, increasing osmolarity, and varying temperature. Π-A isocycles of meibomian lipids showed that they form liquid films that are compressible and multilayered. The isocycles were unaffected by increasing concentration or size of divalent cations and increasing osmolarity in the subphase. Temperature had a marked effect on the lipids. Increase in temperature caused lipid films to become fluid, an expected feature, but decrease in temperature unexpectedly caused expansion of lipids and an increase in pressure suggesting enhanced surfactant properties. Human meibomian lipids form highly compressible, non-collapsible, multilayered liquid films. These lipids have surfactants that allow them to spread across an aqueous subphase. Their surfactant properties are unaffected by increasing divalent cations or hyperosmolarity but are sensitive to temperature. Cooling of meibomian lipids enhances their surfactant properties.

  7. Conductive Supramolecular Architecture Constructed from Polyoxovanadate Cluster and Heterocyclic Surfactant

    Directory of Open Access Journals (Sweden)

    Toshiyuki Misawa

    2018-01-01

    Full Text Available Proton-conductive solid electrolytes are significant for fuel-cell battery technology. Especially for use in motor vehicles, proton conductors which work at intermediate temperatures (373–673 K under an anhydrous atmosphere are desired to improve the fuel cell stability and efficiency. Inorganic–organic hybrid supramolecular architectures are a promising option for the realization of highly conductive proton conductors. Here, a hybrid layered crystal was synthesized for the first time by using an proton-containing decavanadate (V10 anion and a heterocyclic surfactant cation. A simple ion-exchange reaction led to the formation of an inorganic–organic hybrid of V10 by using dodecylpyridazinium (C12pda as the heterocyclic surfactant. Single crystal X-ray analyses revealed that four C12pda cations were associated with one V10 anion, which was a diprotonated species forming a one-dimensional infinite chain structure through hydrogen bonds. Anhydrous proton conductivity was investigated by alternating current (AC impedance spectroscopy in the range of 313–393 K, exhibiting a maximum value of 1.7 × 10−5 S cm−1 at 373 K.

  8. Linear C32H66 hydrocarbon in the mixed state with C10H22 ...

    Indian Academy of Sciences (India)

    Unknown

    S R Research Laboratory for Studies in Crystallization Phenomena, 10-1-96, ... mixed state with certain shorter chain length homologues (SMOLLENCs), estimated ... Methods. Five hydrocarbons of even carbon numbers, C10, C12, C14, C16 ...

  9. Enabling the synthesis of medium chain alkanes and 1-alkenes in yeast

    DEFF Research Database (Denmark)

    Zhu, Zhiwei; Zhou, Yongjin J.; Kang, Min Kyoung

    2017-01-01

    Microbial synthesis of medium chain aliphatic hydrocarbons, attractive drop-in molecules to gasoline and jet fuels, is a promising way to reduce our reliance on petroleum-based fuels. In this study, we enabled the synthesis of straight chain hydrocarbons (C7–C13) by yeast Saccharomyces cerevisiae...

  10. Coagulation-flocculation process applied to wastewaters generated in hydrocarbon-contaminated soil washing

    International Nuclear Information System (INIS)

    Torres, L. g.; Belloc, C.; Iturbe, R.; Bandala, E.

    2009-01-01

    A wastewater produced in the contaminated soil washing was treated by means of coagulation-flocculation (CF) process. the wastewater treatment in this work continued petroleum hydrocarbons, a surfactant, i. e., sodium dodecyl sulphate (SDS) as well as salts, humic acids and other constituents that were lixiviated rom the soil during the washing process. The aim of this work was to develop a process for treating the wastewaters generated when washing hydrocarbon-contaminated soils in such a way that it could be recycled to the washing process, and at the end of the cleaning up, the waters could be disposed properly. (Author)

  11. Degradation of surfactants by sono-irradiation

    International Nuclear Information System (INIS)

    Ashokkumar, M.; Grieser, F.; Vinodgopal, K.

    2000-01-01

    Full text: The ultrasound induced decomposition of a commercially available polydisperse nonylphenol ethoxylate surfactant (Teric GN9) has been investigated. Nearly 90% mineralization and/or degradation into volatile products of the surfactant is achieved after sonication for 24 hours. Ultrasound has been found to be a useful tool to achieve a number of chemical processes. Linear and branched alkyl benzene sulfonates and alkyl nonylphenol ethoxylates are widely used surfactants which accumulated in the environment and contribute to a well-recognised pollution problem. We have investigated the use of ultrasound in the degradation of both types of surfactants with the aim of understanding the mechanism of degradation in order to optimise the decomposition process. In this presentation, we report on the sonochemical degradation of Teric GN9- polydisperse, a nonylphenol ethoxylate with an average of 9 ethylene oxide units. The ultrasound unit used for the degradation studies of the surfactant solutions was an Allied Signal (ELAC Nautik) RF generator and transducer with a plate diameter of 54.5 mm operated at 363 kHz in continuous wave mode at an intensity of 2 W/cm 2 . Ultrasound induced cavitation events generate primary radicals inside gas/vapour filled bubbles. Due to the extreme conditions (T ∼ 5000 K; P ∼ 100 atm) generated within the collapsing bubble, H and OH radicals are produced by the homolysis of water molecules, if water is the medium of sonication. These primary radicals attack the surfactant molecules adsorbed at the bubble/water interface. The initial rate of reaction of the surfactant was found to be dependent on the monomer concentration in solution below and above the critical micelle concentration of the surfactants. This result strongly suggests that the initial radical attack on the surfactants occurs at the cavitation bubble/solution interface, followed by oxidative decomposition and pyrolysis of volatile fragments of the surfactant within

  12. Surfactant nebulization versus instillation during high frequency ventilation in surfactant-deficient rabbits

    NARCIS (Netherlands)

    Dijk, Peter H.; Heikamp, A; Bambang Oetomo, Sidarto

    Surfactant nebulization improves lung function at low alveolar doses of surfactant. However, efficiency of nebulization is low, and lung deposition seems to depend on lung aeration. High frequency ventilation (HFV) has been shown to improve lung aeration. We hypothesize that the combination of HFV

  13. Open lung ventilation preserves the response to delayed surfactant treatment in surfactant-deficient newborn piglets

    NARCIS (Netherlands)

    van Veenendaal, Mariëtte B.; van Kaam, Anton H.; Haitsma, Jack J.; Lutter, René; Lachmann, Burkhard

    2006-01-01

    OBJECTIVE: Delayed surfactant treatment (>2 hrs after birth) is less effective than early treatment in conventionally ventilated preterm infants with respiratory distress syndrome. The objective of this study was to evaluate if this time-dependent efficacy of surfactant treatment is also present

  14. 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)

  15. Photoluminescence and self-assembly of cesium lead halide perovskite nanocrystals: Effects of chain length of organic amines and reaction temperature

    Science.gov (United States)

    Yuan, Yi; Liu, Zheming; Liu, Zhenyang; Peng, Lan; Li, Yongjie; Tang, Aiwei

    2017-05-01

    All-inorganic halide perovskites have become one of the most prospective materials for lightening and display technology due to their color-tunable and narrow-band emission. Herein, we have systematically studied the effects of organic amines with different hydrocarbon chain length on the optical properties and morphology as well as the crystal structure of colloidal CsPbBr3 nanocrystals (NCs), which were synthesized in the presence of oleic acid (OA) and organic amines by using a simple hot-injection approach. The hydrocarbon chain length has shown an independent correlation to the morphology and crystal structure of the as-obtained CsPbBr3 NCs at 160 °C, but their optical properties can be affected to some extent. The photoluminescence quantum yields (PLQYs) of the CsPbBr3 NCs synthesized in the presence of organic amines with long carbon chain length are generally in the range of 55-80% for different reaction time, but the PLQYs of less than 20% are obtained for the products synthesized in the presence of octylamine (OTAm) with short carbon chain length. The effects of the reaction temperature on the optical properties, size and crystal structure of the CsPbBr3 NCs synthesized in the presence of cetylamine (CTAm) are studied. Interestingly, some nanoplates also appear in these CsPbBr3 NCs obtained at relatively low temperatures (120 and 140 °C), which have a strong tendency to self-assemble into face-to-face nanostructures. Such a similar self-assembly behavior is also observed in the product synthesized in the presence of oleylamine (OLAm), but only flat nanoplates are observed in the products in the presence of OTAm at 120 °C. The results indicate that the lower reaction temperature and hydrocarbon chain length of the organic ligands play a significant role in the self-assembly of CsPbBr3 NCs. This work opens up an alternative approach to controllable-synthesis of perovskite NCs through varying the carbon chain length of organic surfactants, and enlightens

  16. Dilute Surfactant Methods for Carbonate Formations

    Energy Technology Data Exchange (ETDEWEB)

    Kishore K. Mohanty

    2006-02-01

    There are many fractured carbonate reservoirs in US (and the world) with light oil. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). The process of using dilute anionic surfactants in alkaline solutions has been investigated in this work for oil recovery from fractured oil-wet carbonate reservoirs both experimentally and numerically. This process is a surfactant-aided gravity drainage where surfactant diffuses into the matrix, lowers IFT and contact angle, which decrease capillary pressure and increase oil relative permeability enabling gravity to drain the oil up. Anionic surfactants have been identified which at dilute concentration of 0.05 wt% and optimal salinity can lower the interfacial tension and change the wettability of the calcite surface to intermediate/water-wet condition as well or better than the cationic surfactant DTAB with a West Texas crude oil. The force of adhesion in AFM of oil-wet regions changes after anionic surfactant treatment to values similar to those of water-wet regions. The AFM topography images showed that the oil-wetting material was removed from the surface by the anionic surfactant treatment. Adsorption studies indicate that the extent of adsorption for anionic surfactants on calcite minerals decreases with increase in pH and with decrease in salinity. Surfactant adsorption can be minimized in the presence of Na{sub 2}CO{sub 3}. Laboratory-scale surfactant brine imbibition experiments give high oil recovery (20-42% OOIP in 50 days; up to 60% in 200 days) for initially oil-wet cores through wettability alteration and IFT reduction. Small (<10%) initial gas saturation does not affect significantly the rate of oil recovery in the imbibition process, but larger gas saturation decreases the oil recovery rate. As the core permeability decreases, the rate of oil recovery reduces

  17. 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)

  18. Fundamental spectroscopic studies of carbenes and hydrocarbon radicals

    Energy Technology Data Exchange (ETDEWEB)

    Gottlieb, C.A.; Thaddeus, P. [Harvard Univ., Cambridge, MA (United States)

    1993-12-01

    Highly reactive carbenes and carbon-chain radicals are studied at millimeter wavelengths by observing their rotational spectra. The purpose is to provide definitive spectroscopic identification, accurate spectroscopic constants in the lowest vibrational states, and reliable structures of the key intermediates in reactions leading to aromatic hydrocarbons and soot particles in combustion.

  19. Process for desulfurizing hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    1937-04-12

    A process is described for the desulfurization of a mixture of hydrocarbons, and in particular hydrocarbons containing less than 7 atoms of carbon and sulfur compounds of the type of sulfur carbonyl, characterized by the fact that the mixture, preferably in the liquid phase, is brought in contact with a solution of caustic alkali, essentially anhydrous or preferably with a solution of alkali hydroxide in an organic hydroxy nonacid solvent, for example, an alcohol, or with an alkaline alcoholate, under conditions suitable to the formation of hydrogen sulfide which produces a hydrocarbon mixture free from sulfur compounds of the sulfur carbonyl type but containing hydrogen sulfide, and that it is treated, following mixing, having beem submitted to the first treatment, by means of aqueous alkaline hydroxide to eliminate the hydrogen sulfide.

  20. Recovery of hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    1941-02-10

    A process is disclosed for recovery of hydrocarbon oils, especially lubricating oils or diesel oils, through pressure hydrogenation of distillation, extraction of hydrogenation products from coal or coaly materials or from oils such as mineral oils or tars in liquid phase by use in a reaction vessel of fixed-bed catalysts, characterized in that as starting material is employed material which has been freed of asphaltic and resinous material by hydrogenation refining, vacuum-steam distillation, treatment with hydrogen-rich hydrocarbons (hydroforming), or sulfuric acid.

  1. History of surfactant up to 1980.

    Science.gov (United States)

    Obladen, Michael

    2005-01-01

    Remarkable insight into disturbed lung mechanics of preterm infants was gained in the 18th and 19th century by the founders of obstetrics and neonatology who not only observed respiratory failure but also designed devices to treat it. Surfactant research followed a splendid and largely logical growth curve. Pathological changes in the immature lung were characterized in Germany by Virchow in 1854 and by Hochheim in 1903. The Swiss physiologist von Neergard fully understood surfactant function in 1929, but his paper was ignored for 25 years. The physical properties of surfactant were recognized in the early 1950s from research on warfare chemicals by Pattle in Britain and by Radford and Clements in the United States. The causal relationship of respiratory distress syndrome (RDS) and surfactant deficiency was established in the USA by Avery and Mead in 1959. The Australian obstetrician Liggins induced lung maturity with glucocorticoids in 1972, but his discovery was not fully believed for another 20 years. A century of basic research was rewarded when Fujiwara introduced surfactant substitution in Japan in 1980 for treatment and prevention of RDS. Copyright 2005 S. Karger AG, Basel

  2. Poly(ethylene oxide) surfactant polymers.

    Science.gov (United States)

    Vacheethasanee, Katanchalee; Wang, Shuwu; Qiu, Yongxing; Marchant, Roger E

    2004-01-01

    We report on a series of structurally well-defined surfactant polymers that undergo surface-induced self-assembly on hydrophobic biomaterial surfaces. The surfactant polymers consist of a poly(vinyl amine) backbone with poly(ethylene oxide) and hexanal pendant groups. The poly(vinyl amine) (PVAm) was synthesized by hydrolysis of poly(N-vinyl formamide) following free radical polymerization of N-vinyl formamide. Hexanal and aldehyde-terminated poly(ethylene oxide) (PEO) were simultaneously attached to PVAm via reductive amination. Surfactant polymers with different PEO:hexanal ratios and hydrophilic/hydrophobic balances were prepared, and characterized by FT-IR, 1H-NMR and XPS spectroscopies. Surface active properties at the air/water interface were determined by surface tension measurements. Surface activity at a solid surface/water interface was demonstrated by atomic force microscopy, showing epitaxially molecular alignment for surfactant polymers adsorbed on highly oriented pyrolytic graphite. The surfactant polymers described in this report can be adapted for simple non-covalent surface modification of biomaterials and hydrophobic surfaces to provide highly hydrated interfaces.

  3. 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

  4. Two sides of the coin. Part 1. Lipid and surfactant self-assembly revisited.

    Science.gov (United States)

    Ninham, Barry W; Larsson, Kåre; Lo Nostro, Pierandrea

    2017-04-01

    Hofmeister, specific ion effects, hydration and van der Waals forces at and between interfaces are factors that determine curvature and microstructure in self assembled aggregates of surfactants and lipids; and in microemulsions. Lipid and surfactant head group interactions and between aggregates vary enormously and are highly specific. They act on the hydrophilic side of a bilayer, micelle or other self assembled aggregate. It is only over the last three decades that the origin of Hofmeister effects has become generally understood. Knowledge of their systematics now provides much flexibility in designing nanostructured fluids. The other side of the coin involves equally specific forces. These (opposing) forces work on the hydrophobic side of amphiphilic interfaces. They are due to the interaction of hydrocarbons and other "oils" with hydrophobic tails of surfactants and lipids. The specificity of oleophilic solutes in microemulsions and lipid membranes provides a counterpoint to Hofmeister effects and hydration. Together with global packing constraints these effects determine microstructure. Another factor that has hardly been recognised is the role of dissolved gas. This introduces further, qualitative changes in forces that prescribe microstructure. The systematics of these effects and their interplay are elucidated. Awareness of these competing factors facilitates formulation of self assembled nanostructured fluids. New and predictable geometries that emerge naturally provide insights into a variety of biological phenomena like anaesthetic and pheromone action and transmission of the nervous impulse (see Part 2). Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Ultrathin nanofibrous films prepared from cadmium hydroxide nanostrands and anionic surfactants.

    Science.gov (United States)

    Peng, Xinsheng; Karan, Santanu; Ichinose, Izumi

    2009-08-04

    We developed a simple fabrication method of ultrathin nanofibrous films from the dispersion of cadmium hydroxide nanostrands and anionic surfactants. The nanostrands were prepared in a dilute aqueous solution of cadmium chloride by using 2-aminoethanol. They were highly positively charged and gave bundlelike fibers upon mixing an aqueous solution of anionic surfactant. The nanostrand/surfactant composite fibers were filtered on an inorganic membrane filter. The resultant nanofibrous film was very uniform in the area of a few centimeters square when the thickness was not less than 60 nm. The films obtained with sodium tetradecyl sulfate (STS) had a composition close to the electroneutral complex, [Cd37(OH)68(H2O)n] x 6(STS), as confirmed by energy dispersive X-ray analysis. They were water-repellent with a contact angle of 117 degrees, and the value slightly decreased with the alkyl chain length of anionic surfactants. Ultrathin nanofibrous films were stable enough to be used for ultrafiltration at pressure difference of 90 kPa. We could effectively separate Au nanoparticles of 40 nm at an extremely high filtration rate of 14000 L/(h m2 bar).

  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. 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.

  8. Synthesis of mesoporous nano-hydroxyapatite by using zwitterions surfactant

    Science.gov (United States)

    Mesoporous nano-hydroxyapatite (mn-HAP) was successfully synthesized via a novel micelle-templating method using lauryl dimethylaminoacetic acid as zwitterionic surfactant. The systematic use of such a surfactant in combination with microwave energy inputenables the precise contr...

  9. Early surfactant therapy and nasal continuous positive airways ...

    African Journals Online (AJOL)

    respiratory distress syndrome (RDS) receiving nasal continuous positive airways ... required FiO2 was allowed to rise above 0.4 before surfactant was administered. ... group received surfactant immediately and the high-threshold group ...

  10. 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 ...

  11. Fullerene surfactants and their use in polymer solar cells

    Science.gov (United States)

    Jen, Kwan-Yue; Yip, Hin-Lap; Li, Chang-Zhi

    2015-12-15

    Fullerene surfactant compounds useful as interfacial layer in polymer solar cells to enhance solar cell efficiency. Polymer solar cell including a fullerene surfactant-containing interfacial layer intermediate cathode and active layer.

  12. Characterization of hydrocarbon utilizing fungi from hydrocarbon ...

    African Journals Online (AJOL)

    Prof. Ogunji

    mineral salt) medium supplemented with 0.05% (v/v) of ... both plants and animals due to disruption in food chain, and death of plants and animal ... to grow under stressed environmental conditions (low nutrient, pH, and water activity), extension in.

  13. Optrode for sensing hydrocarbons

    Science.gov (United States)

    Miller, H.; Milanovich, F.P.; Hirschfeld, T.B.; Miller, F.S.

    1988-09-13

    A two-phase system employing the Fujiwara reaction is provided for the fluorometric detection of halogenated hydrocarbons. A fiber optic is utilized to illuminate a column of pyridine trapped in a capillary tube coaxially attached at one end to the illuminating end of the fiber optic. A strongly alkaline condition necessary for the reaction is maintained by providing a reservoir of alkali in contact with the column of pyridine, the surface of contact being adjacent to the illuminating end of the fiber optic. A semipermeable membrane caps the other end of the capillary tube, the membrane being preferentially permeable to the halogenated hydrocarbon and but preferentially impermeable to water and pyridine. As the halogenated hydrocarbon diffuses through the membrane and into the column of pyridine, fluorescent reaction products are formed. Light propagated by the fiber optic from a light source, excites the fluorescent products. Light from the fluorescence emission is also collected by the same fiber optic and transmitted to a detector. The intensity of the fluorescence gives a measure of the concentration of the halogenated hydrocarbons. 5 figs.

  14. Catalyst for hydrocarbon conversion

    International Nuclear Information System (INIS)

    Duhaut, P.; Miquel, J.

    1975-01-01

    A description is given for a catalyst and process for hydrocarbon conversions, e.g., reforming. The catalyst contains an alumina carrier, platinum, iridium, at least one metal selected from uranium, vanadium, and gallium, and optionally halogen in the form of metal halide of one of the aforesaid components. (U.S.)

  15. Surfactant therapy in late preterm infants

    Directory of Open Access Journals (Sweden)

    Murat Yurdakök

    2013-06-01

    Full Text Available Late preterm (LPT neonates are at a high risk for respiratory distress soon after birth due to respiratory distress syndrome (RDS, transient tachypnea of the newborn, persistent pulmonary hypertension, and pneumonia along with an increased need for surfactant replacement therapy, continuous positive airway pressure, and ventilator support when compared with the term neonates. In the past, studies on outcomes of infants with respiratory distress have primarily focused on extremely premature infants, leading to a gap in knowledge and understanding of the developmental biology and mechanism of pulmonary diseases in LPT neonates. Surfactant deficiency is the most frequent etiology of RDS in very preterm and moderately preterm infants, while cesarean section and lung infection play major roles in RDS development in LPT infants. The clinical presentation and the response to surfactant therapy in LPT infants may be different than that seen in very preterm infants. Incidence of pneumonia and occurrence of pneumothorax are significantly higher in LPT and term infants. High rates of pneumonia in these infants may result in direct injury to the type II alveolar cells of the lung with decreasing synthesis, release, and processing of surfactant. Increased permeability of the alveolar capillary membrane to both fluid and solutes is known to result in entry of plasma proteins into the alveolar hypophase, further inhibiting the surface properties of surfactant. However, the oxygenation index value do not change dramatically after ventilation or surfactant administration in LPT infants with RDS compared to very preterm infants. These finding may indicate a different pathogenesis of RDS in late preterm and term infants. In conclusion, surfactant therapy may be of significant benefit in LPT infants with serious respiratory failure secondary to a number of insults. However, optimal timing and dose of administration are not so clear in this group. Additional

  16. Surfactant-Polymer Interaction for Improved Oil Recovery; FINAL

    International Nuclear Information System (INIS)

    Gabitto, Jorge; Mohanty, Kishore K.

    2002-01-01

    The goal of this research was to use the interaction between a surfactant and a polymer for efficient displacement of tertiary oil by improving slug integrity, oil solubility in the displacing fluid and mobility control. Surfactant-polymer flooding has been shown to be highly effective in laboratory-scale linear floods. The focus of this proposal is to design an inexpensive surfactant-polymer mixture that can efficiently recover tertiary oil by avoiding surfactant slug degradation and viscous/heterogeneity fingering

  17. Preparation of mesoporous nanofibers by vapor phase synthesis: control of mesopore structures with the aid of co-surfactants

    International Nuclear Information System (INIS)

    Min, Sa Hoon; Jang, Jyongsik; Lee, Kyung Jin; Bae, Joonwon

    2013-01-01

    Mesoporous nanofibers (MSNFs) can be fabricated in the pores of anodic aluminum oxide (AAO) membrane using diverse methods. Among them vapor phase synthesis (VPS) provides several advantages over sol–gel or evaporation-induced self-assembly (EISA) based methods. One powerful advantage is that we can employ multiple surfactants as structural directing agents (SDAs) simultaneously. By adopting diverse pairs of SDAs, we can control the mesopore structures, i.e. pore size, surface area, and even the morphology of mesostructures. Here, we used F127 as a main SDA, which is relatively robust (thus, difficult to change the mesopore structures), and added a series of cationic co-surfactants to observe the systematical changes in their mesostructure with respect to the chain length of the co-surfactant. (paper)

  18. Preparation of mesoporous nanofibers by vapor phase synthesis: control of mesopore structures with the aid of co-surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Min, Sa Hoon; Jang, Jyongsik; Lee, Kyung Jin [School of Chemical and Biological Engineering, College of Engineering, Seoul National University, Shinlimdong 56-1, Seoul, 151-742 (Korea, Republic of); Bae, Joonwon [Department of Applied Chemistry, Dongduk Women' s University, Seoul 136-714 (Korea, Republic of)

    2013-06-28

    Mesoporous nanofibers (MSNFs) can be fabricated in the pores of anodic aluminum oxide (AAO) membrane using diverse methods. Among them vapor phase synthesis (VPS) provides several advantages over sol-gel or evaporation-induced self-assembly (EISA) based methods. One powerful advantage is that we can employ multiple surfactants as structural directing agents (SDAs) simultaneously. By adopting diverse pairs of SDAs, we can control the mesopore structures, i.e. pore size, surface area, and even the morphology of mesostructures. Here, we used F127 as a main SDA, which is relatively robust (thus, difficult to change the mesopore structures), and added a series of cationic co-surfactants to observe the systematical changes in their mesostructure with respect to the chain length of the co-surfactant. (paper)

  19. Preparation of mesoporous nanofibers by vapor phase synthesis: control of mesopore structures with the aid of co-surfactants

    Science.gov (United States)

    Min, Sa Hoon; Bae, Joonwon; Jang, Jyongsik; Lee, Kyung Jin

    2013-06-01

    Mesoporous nanofibers (MSNFs) can be fabricated in the pores of anodic aluminum oxide (AAO) membrane using diverse methods. Among them vapor phase synthesis (VPS) provides several advantages over sol-gel or evaporation-induced self-assembly (EISA) based methods. One powerful advantage is that we can employ multiple surfactants as structural directing agents (SDAs) simultaneously. By adopting diverse pairs of SDAs, we can control the mesopore structures, i.e. pore size, surface area, and even the morphology of mesostructures. Here, we used F127 as a main SDA, which is relatively robust (thus, difficult to change the mesopore structures), and added a series of cationic co-surfactants to observe the systematical changes in their mesostructure with respect to the chain length of the co-surfactant.

  20. Interactions between fluorinated cationic guar gum and surfactants in the dilute and semi-dilute solutions.

    Science.gov (United States)

    Wang, Chen; Li, Xiaorui; Li, Peizhi; Niu, Yuhua

    2014-01-01

    The interactions between the fluorinated cationic guar gum (FCGG) and ionic surfactants including cetyl trimethyl ammonium bromide (CTAB) and sodium lauryl sulfate (SDS) were studied by light scattering, fluorescence spectroscopy, UV-spectrophotometer, (19)F NMR and dynamic rheometer, respectively. The FCGG is prepared with cationic guar gum, isophorone diisocyanate and 2,2,3,4,4,4-hexafluoro-1-butanol. The results show that, with the addition of the surfactants, the stretching degree of the FCGG chains is increased in the FCGG/CTAB solutions, while the dramatical shrinking of FCGG chain, the phase separation and the re-stretched macromolecules appear successively because of the electricity neutralization reaction in the FCGG/SDS system. The mixed hydrophobic domains in all solutions will be reinforced and then dismantled. The solution elasticity shows up the maximum value accordingly. The surfactants can be embedded in the micro-domains and then hinder the fluorinated segmental motions. The interactions between FCGG and SDS are much stronger than those between FCGG and CTAB. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Adsorption of anionic surfactants in limestone medium during oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Canbolat, Serhat; Bagci, Suat [Middle East Technical Univ., Dept. of Petroleum and Natural Gas Engineering, Ankara (Turkey)

    2004-07-15

    Foam-forming surfactant performance was evaluated by several experimental methods (interfacial tension, foam stability, corefloods) using commercial surfactants. There is considerable interest in the use of foam-forming surfactants for mobility control in water flood. To provide effective mobility control, the injected surfactant must propagate from the injection well toward the production well. One of the important parameters affecting propagation of foam-forming surfactant through the reservoir is the retention of surfactant due to its adsorption on reservoir rock. The determination of the adsorption of foam-forming surfactants in limestone reservoirs is important for the residual oil recovery efficiency. Adsorption measurements, recovery efficiencies, and surfactant and alkaline flooding experiments carried out with the representative of the selected surfactants alkaline solutions, linear alkyl benzene sulphonic acid (LABSA), sodium lauryl ether sulfate (SLES), and NaOH in a limestone medium. These surfactants were selected with respect to their foaming ability. Calibration curves formed by pH measurements were used to determine the correct adsorption amount of the used surfactants and recovery efficiency of these surfactants compared with base waterflooding. The results showed that LABSA adsorbed more than SLES in limestone reservoirs. The recovery efficiency of SLES was higher than the recovery efficiency of LABSA, and they decreased the recovery efficiency with respect to only the water injection case. (Author)

  2. The Inhibiting or Accelerating Effect of Different Surfactants on ...

    African Journals Online (AJOL)

    The course of differential capacity curves of the electric double layer at the mercury electrode/surfactant solution interface was described for three different surfactants from different groups. Using square-wave voltammetry (SWV) it was found that the surfactants had a varying effect on the kinetics of electroreduction of Zn2+ ...

  3. Optimization of surfactant application for synthetic drilling fluid; Otimizacao da aplicacao de emulsificante em fluidos de perfuracao sinteticos

    Energy Technology Data Exchange (ETDEWEB)

    Arruda, Jefferson Teixeira [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Santos, Telma Pitanga; Medeiros, Ana Catarina da Rocha; Garcia, Rosangela Balaban [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Lab. de Pesquisa em Petroleo

    2008-07-01

    The most common synthetic drilling fluids are made of polymerized olefins, paraffin and esters, which have absence of aromatics hydrocarbons and biodegradability as advantages. These fluids have good performance during the drilling operations (high thermal stability) and have low toxicity. Nevertheless, their big disadvantage is the high cost, which limits their use. One of the biggest challenges in working with synthetic fluids is the control of water/oil emulsion stability, being the surfactant the main agent responsible for keeping this stability between both phases of the fluid. The water/oil and oil/water emulsion is defined by the chemical nature of the surfactant. The emulsions can be changed from oil/water to water/oil and vice versa by many mechanisms, such as temperature variation, addition of another surfactant and alteration of the disperse phase volumetric percentage. The aim of this work was the optimization of synthetic drilling fluids formulations by using commercial surfactants. The optimized formulations showed similar rheological properties. After aging at high temperature (300 deg F), some tendency to migration of oil phase in both fluids was observed. This result was associated to the fluid's viscosity. However, the formulations showed high electrical stability, indicating formation of stable emulsions. The HTHP filtration volumes were small. (author)

  4. Soil remediation: humic acids as natural surfactants in the washings of highly contaminated soils

    International Nuclear Information System (INIS)

    Conte, Pellegrino; Agretto, Anna; Spaccini, Riccardo; Piccolo, Alessandro

    2005-01-01

    The remediation of the highly contaminated site around the former chemical plant of ACNA (near Savona) in Northern Italy is a top priority in Italy. The aim of the present work was to contribute in finding innovative and environmental-friendly technology to remediate soils from the ACNA contaminated site. Two soils sampled from the ACNA site (A and B), differing in texture and amount and type of organic contaminants, were subjected to soil washings by comparing the removal efficiency of water, two synthetic surfactants, sodium dodecylsulphate (SDS) and Triton X-100 (TX100), and a solution of a natural surfactant, a humic acid (HA) at its critical micelle concentration (CMC). The extraction of pollutants by sonication and soxhlet was conducted before and after the soil washings. Soil A was richer in polycyclic aromatic hydrocarbons, whereas soil B had a larger content of thiophenes. Sonication resulted more analytically efficient in the fine-textured soil B. The coarse-textured soil A was extracted with a general equal efficiency also by soxhlet. Clean-up by water was unable to exhaustively remove contaminants from the two soils, whereas all the organic surfactants revealed very similar efficiencies (up to 90%) in the removal of the contaminants from the soils. Hence, the use of solutions of natural HAs appears as a better choice for soil washings of highly polluted soils due to their additional capacity to promote microbial activity, in contrast to synthetic surfactants, for a further natural attenuation in washed soils. - Solutions of natural humic acids appear to be a better choice for washing highly polluted soils

  5. Enhanced In Situ Chemical Oxidation Using Surfactants and Shear Thinning Fluids

    Science.gov (United States)

    Hauswirth, S.; Sadeghi, S.; Cerda, C. C.; Espinoza, I.; Schultz, P. B.; Miller, C. T.

    2017-12-01

    In situ chemical oxidation (ISCO) is an attractive approach for the remediation of recalcitrant contaminants, due to the fact that target compounds are degraded in place, precluding the need for ex situ treatment or disposal. However, field applications of ISCO approaches have been plagued by "rebound" of contaminant concentrations in groundwater weeks to months after treatment. The cause of rebound at a given site may vary, but is typically associated with back-diffusion from finer grained, low permeability units or the presence of non-aqueous phase liquids (NAPLs) that are incompletely degraded during treatment. Modifications to traditional ISCO methods have been proposed to overcome these challenges, including the use of shear-thinning polymers to improve delivery of oxidants to low permeability units and the addition of surfactants to improve dissolution of contaminants from NAPLs. In this work, we investigate the application of these approaches to the oxidation of manufactured gas plant (MGP) tars—NAPLs composed primarily of polycyclic aromatic hydrocarbons (PAHs). We conducted experiments to determine the mutual impact of each chemical component on the physical and chemical properties of the overall system. Specifically, experiments were designed to: determine the kinetics and overall effectiveness of contaminant-oxidant reactions for multiple oxidant-activator combinations; screen several common surfactants in terms of their ability to increase MGP tar solubility and their compatibility with oxidant systems; measure the impact of oxidants and surfactants on the rheology of several common polymer additives; and assess the effect of surfactants and polymers on the consumption of oxidants/activators and on the kinetics of contaminant-oxidant reactions. The results of this work provide insight into the chemical and physical mechanisms associated with enhanced ISCO approaches and an improved basis with which to model and design ISCO applications at both the lab

  6. Optimized mixed oils remarkably reduce the amount of surfactants in microemulsions without affecting oral bioavailability of ibuprofen by simultaneously enlarging microemulsion areas and enhancing drug solubility.

    Science.gov (United States)

    Chen, Yizhen; Tuo, Jue; Huang, Huizhi; Liu, Dan; You, Xiuhua; Mai, Jialuo; Song, Jiaqi; Xie, Yanqi; Wu, Chuanbin; Hu, Haiyan

    2015-06-20

    The toxicity and irritation associated with high amounts of surfactants restrict the extensive utilization of microemulsions. To address these shortcomings, employing mixed oils to enlarge microemulsion areas therefore reducing surfactant contents is a promising strategy. However, what kinds of mixed oils are more efficient in enlarging microemulsion areas still remains unclear. In this research, we found that the chain length and degree of unsaturation of oils play a key role in enlarging microemulsion areas. The combination of moderate chain saturated oil caprylic/capric triglyceride (GTCC) with long chain unsaturated oil glycerol trioleate significantly increased the microemulsion areas. Solubility of ibuprofen in the mixed oils was unexpectedly and remarkably increased (almost 300mg/mL) compared with that (around 100mg/mL) of the single oil (GTCC), which also resulted in greatly increased solubility of ibuprofen in mixed oils-containing microemulsions. By optimizing the mixed oil formulation, the absolute amount of surfactant in drug-loaded microemulsions was reduced but increased drug oral bioavailability in rats was maintained. It could be concluded that the combined use of moderate chain oils and long chain unsaturated oils could not only acquire enlarged microemulsion areas but also enhanced drug solubility, therefore doubly reducing surfactant amount, which is extremely beneficial for developing safe microemulsions. Copyright © 2015. Published by Elsevier B.V.

  7. Effects of surfactants on morphology in synthesis of α-Mn2O3 nanostructures

    International Nuclear Information System (INIS)

    Ramarajan, D.; Sivagurunathan, P.

    2011-01-01

    Cubic and chain-like structure of α-Mn 2 O 3 with a high surface area was prepared by air oxidation of manganese chloride through sol process by adding hexamine and mercaptosuccinic acid as wetting agent, respectively. The as-synthesized products were characterized with X-ray powder diffraction (XRD), Energy Dispersive X-ray spectroscopy (EDX), transmission electron microscope (TEM), and selected area electron diffraction (SAED). The possible formation mechanism of α-Mn 2 O 3 cubic and chain-like nanostructures has been proposed and discussed. -- Graphical abstract: Cubic and chain-like nanostructure of α-Mn 2 O 3 has been synthesized by air oxidation of manganese chloride as precursor, hexamine, and mercaptosuccinic acid as wetting agent, respectively. Display Omitted Research highlights: → Cubic nanostructure of α-Mn 2 O 3 is obtained using hexamine as surfactant. → Chain-like structure of α-Mn 2 O 3 is obtained using mercaptosuccinic acid as surfactant. → The linking nature of mercaptosuccinic acid is proved. → Mercaptosuccinic acid accelerates the growth of material.

  8. Chemical Kinetics of Hydrocarbon Ignition in Practical Combustion Systems

    International Nuclear Information System (INIS)

    Westbrook, C.K.

    2000-01-01

    Chemical kinetic factors of hydrocarbon oxidation are examined in a variety of ignition problems. Ignition is related to the presence of a dominant chain branching reaction mechanism that can drive a chemical system to completion in a very short period of time. Ignition in laboratory environments is studied for problems including shock tubes and rapid compression machines. Modeling of the laboratory systems are used to develop kinetic models that can be used to analyze ignition in practical systems. Two major chain branching regimes are identified, one consisting of high temperature ignition with a chain branching reaction mechanism based on the reaction between atomic hydrogen with molecular oxygen, and the second based on an intermediate temperature thermal decomposition of hydrogen peroxide. Kinetic models are then used to describe ignition in practical combustion environments, including detonations and pulse combustors for high temperature ignition, and engine knock and diesel ignition for intermediate temperature ignition. The final example of ignition in a practical environment is homogeneous charge, compression ignition (HCCI) which is shown to be a problem dominated by the kinetics intermediate temperature hydrocarbon ignition. Model results show why high hydrocarbon and CO emissions are inevitable in HCCI combustion. The conclusion of this study is that the kinetics of hydrocarbon ignition are actually quite simple, since only one or two elementary reactions are dominant. However, there are many combustion factors that can influence these two major reactions, and these are the features that vary from one practical system to another

  9. Monitoring the thinning dynamics of soap films by phase shift interferometry. The case of perfluoropolyether surfactants.

    Science.gov (United States)

    Gambi, Cecilia M C; Vannoni, Maurizio; Sordini, Andrea; Molesini, Giuseppe

    2014-02-01

    An interferometric method to monitor the thinning process of vertical soap films from a water solution of surfactant materials is reported. Raw data maps of optical path difference introduced by the film are obtained by conventional phase shift interferometry. Off-line re-processing of such raw data taking into account the layered structure of soap films leads to an accurate measurement of the geometrical thickness. As an example of data acquisition and processing, the measuring chain is demonstrated on perfluoropolyether surfactants; the section profile of vertical films is monitored from drawing to black film state, and quantitative data on the dynamics of the thinning process are presented. The interferometric method proves effective to the task, and lends itself to further investigate the physical properties of soap films.

  10. Surfactants, interfaces and pores : a theoretical study

    NARCIS (Netherlands)

    Huinink, H.

    1998-01-01

    The aim of this study was to investigate the behavior of surfactants in porous media by theoretical means. The influence of curvature of a surface on the adsorption has been studied with a mean field lattice (MFL) model, as developed by Scheutjens and Fleer. An analytical theory has been

  11. Influence of surfactant concentration on nanohydroxyapatite growth

    Indian Academy of Sciences (India)

    Nanohydroxyapatite particles with different morphologies were synthesized through a microwave coupled hydrothermal method using CTAB as a template. A successful synthesis of nanosized HAP spheres, rods and fibres is achieved through this method by controlling the concentration of the surfactant. The concentration ...

  12. of surfactant replacement therapy at Johannesburg Hospital ...

    African Journals Online (AJOL)

    To assess the impact of surfactant replacement therapy (SRl) on the outcome of ... oxygen requirements) was compared with that of a historical control group of ... The use of SRT added to the total cost of treating a patient ventilated for HMD.

  13. Surfactant protein D is proatherogenic in mice

    DEFF Research Database (Denmark)

    Sørensen, G. L.; Madsen, J.; Kejling, K.

    2006-01-01

    Surfactant protein D (SP-D) is an important innate immune defense molecule that mediates clearance of pathogens and modulates the inflammatory response. Moreover, SP-D is involved in lipid homeostasis, and pulmonary accumulation of phospholipids has previously been observed in SP-D-deficient (Spd...

  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. Surfactant enhanced non-classical extraction

    International Nuclear Information System (INIS)

    Szymanowski, J.

    2000-01-01

    Surfactant enhanced non-classical extractions are presented and discussed. They include micellar enhanced ultrafiltration and cloud point extraction. The ideas of the processes are given and the main features are presented. They are compared to the classical solvent extraction. The fundamental of micellar solutions and their solubilisation abilities are also discussed. (author)

  16. Lung Surfactant - The Indispensable Component of Respiratory ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 8. Lung Surfactant - The Indispensable Component of Respiratory Mechanics. Shweta Saxena. Research News Volume 10 Issue 8 August 2005 pp 91-96. Fulltext. Click here to view fulltext PDF. Permanent link:

  17. 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

  18. Surfactant enhanced non-classical extraction

    International Nuclear Information System (INIS)

    Szymanowski, J.

    1999-01-01

    Surfactant enhanced non-classical extractions are presented and discussed. They include micellar enhanced ultrafiltration and cloud point extraction. The ideas of the processes are given and the main features are presented. They are compared to the classical solvent extraction. The fundamental of micellar solutions and their solubilization abilities are also discussed. (author)

  19. Identifying future directions for subsurface hydrocarbon migration research

    Science.gov (United States)

    Leifer, I.; Clark, J. F.; Luyendyk, B.; Valentine, D.

    Subsurface hydrocarbon migration is important for understanding the input and impacts of natural hydrocarbon seepage on the environment. Great uncertainties remain in most aspects of hydrocarbon migration, including some basic mechanisms of this four-phase flow of tar, oil, water, and gas through the complex fracture-network geometry particularly since the phases span a wide range of properties. Academic, government, and industry representatives recently attended a workshop to identify the areas of greatest need for future research in shallow hydrocarbon migration.Novel approaches such as studying temporal and spatial seepage variations and analogous geofluid systems (e.g., geysers and trickle beds) allow deductions of subsurface processes and structures that remain largely unclear. Unique complexities exist in hydrocarbon migration due to its multiphase flow and complex geometry, including in-situ biological weathering. Furthermore, many aspects of the role of hydrocarbons (positive and negative) in the environment are poorly understood, including how they enter the food chain (respiration, consumption, etc.) and “percolate” to higher trophic levels. But understanding these ecological impacts requires knowledge of the emissions' temporal and spatial variability and trajectories.

  20. An experimental study on the bio-surfactant-assisted remediation of crude oil and salt contaminated soils.

    Science.gov (United States)

    Zhang, Wen; Li, Jianbing; Huang, Guohe; Song, Weikun; Huang, Yuefei

    2011-01-01

    The effect of bio-surfactant (rhamnolipid) on the remediation of crude oil and salt contaminated soil was investigated in this study. The experimental results indicated that there was a distinct decline of total petroleum hydrocarbon (TPH) concentration within the soil when using rhamnolipid during a remediation period of 30 days, with maximum TPH reduction of 86.97%. The most effective remediation that was observed was with rhamnolipid at a concentration of 2 CMC in soil solution, and a first-order TPH degradation rate constant of 0.0866 d(-1). The results also illustrated that salts in soil had a negative impact on TPH reduction, and the degradation rate was negatively correlated with NaCl concentration in soil solution. The analysis of soil TPH fractions indicated that there was a significant reduction of C13-C30 during the remediation process when using bio-surfactant.

  1. 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

  2. Dimeric Surfactants: Promising Ingredients of Cosmetics and Toiletries

    Directory of Open Access Journals (Sweden)

    Naveen Kumar

    2013-11-01

    Full Text Available Surfactants are an essential ingredient for cosmetic, toiletries and personal care products for enhancing their performance. Dimeric surfactants demonstrate superiority compared to conventional surfactants in all areas of application. Dimeric surfactants are extremely promising for utilization in various cosmetic formulations viz. shampoo, lotions, creams, conditioners etc. These surfactants possess extremely unique surface properties viz. lower surface tension, unique micellization, low critical micelle concentration (CMC and antimicrobial activity, higher solubilization etc. Dimerics enhance the performances of cosmetics in an extraordinary manner and provide eco-friendly preparations for human epidermis.

  3. 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.

  4. 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)

  5. Surfactant Sensors in Biotechnology; Part 1 – Electrochemical Sensors

    Directory of Open Access Journals (Sweden)

    Milan Sak-Bosnar

    2004-01-01

    Full Text Available An overview on electrochemical surfactant sensors is given with special attention to papers published since 1993. The importance of surfactants in modern biotechnology is stressed out. Electrochemical sensors are usually divided according to the measured physical quantity to potentiometric, amperometric, conductometric and impedimetric surfactant sensors. The last ones are very few. Potentiometric surfactant sensors are the most numerous due to their simplicity and versatility. They can be used either as end-point titration sensors or as direct EMF measurement sensors, in batch or flow-through mode. Some amperometric surfactant sensors are true biosensors that use microorganisms or living cells.

  6. Distilling hydrocarbons, etc

    Energy Technology Data Exchange (ETDEWEB)

    Turner, C

    1917-11-23

    In the fractional or destructive distillation of hydrocarbon oils or other liquids, the pressure in the still is raised and lowered alternately. The still is closed to raise the pressure, and is opened to lower the pressure rapidly solely by expansion of the vapors. The operation is effected without intermittent cooling, except such as may occur during the lowering of the pressure. In distilling hydrocarbon oil, pressure steam is blown into the oil until the pressure reaches 5 lb/in./sup 2/. The vapor outlet is then opened until the pressure falls to 2 lb/in./sup 2/, whereupon the vapor outlet is closed and steam is again admitted. The operation is continued until the steam, which is of 20 lb pressure, no longer effects distillation; after this stage, superheated steam is used.

  7. Distilling hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    Tausz, J

    1924-07-16

    Hydrocarbon oils such as petroleum, shale oils, lignite or coal tar oils are purified by distilling them and collecting the distillate in fractions within narrow limits so that all the impurities are contained in one or more of the narrow fractions. In distilling ligroin obtained by destructive distillation of brown coal, it is found that the coloring and resin-forming constituents are contained in the fractions distilling over at 62 to 86/sup 0/C and 108/sup 0/C. The ligroin is purified, therefore, by distillating in an apparatus provided with an efficient dephlegmotor and removing these two fractions. The distillation may be carried out wholly or in part under reduced pressure, and fractions separated under ordinary pressure may be subsequently distilled under reduced pressure. The hydrocarbons may be first separated into fractions over wider limits and the separate fractions be subjected to a further fractional distillation.

  8. Nuclear explosives and hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, P

    1971-10-01

    A nuclear explosive 12 in. in diam and producing very little tritium is feasible in France. Such a device would be well adapted for contained nuclear explosions set off for the purpose of hydrocarbon storage or stimulation. The different aspects of setting off the explosive are reviewed. In the particular case of gas storage in a nuclear cavity in granite, it is demonstrated that the dose of irradiation received is extremely small. (18 refs.)

  9. Treatment of hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    1936-02-22

    A process is described for refining a mixture of liquid hydrocarbons containing harmful substances, this process permitting the operation, which consists in treating the liquid mixture at a temperature higher than 200/sup 0/C with a solid catalyst of phosphoric acid, consisting of phosphoric acid deposited on a solid support of the type of metallurgical coke, for a time sufficient to convert the harmful components to inoffensive substances.

  10. Cracking hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    Seigle, A A.F.M.

    1922-12-20

    Hydrocarbon oils such as petroleum, peat, shale, or lignite oils, heavy tars, resin oils, naphthalene oils, etc., are vaporized by being fed from a tank through a preheater to the lower part of a vertical annular retort heated by a flame projected down the central cavity from a burner. The oil vapors rise through annular passages formed by disks, on which are placed chips of copper, iron, aluminum, etc., to act as catalysts.

  11. High boiling point hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Pier, M

    1929-04-29

    A process is given for the production of hydrocarbons of high boiling point, such as lubricating oils, from bituminous substances, such as varieties of coal, shale, or other solid distillable carbonaceous materials. The process consists of treating the initial materials with organic solvents and then subjecting the products extracted from the initial materials, preferably directly, to a reducing treatment in respect to temperature, pressure, and time. The reduction treatment is performed by means of hydrogen under pressure.

  12. Direct hydrocarbon fuel cells

    Science.gov (United States)

    Barnett, Scott A.; Lai, Tammy; Liu, Jiang

    2010-05-04

    The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

  13. Fatty acid sulphoalkyl amides and esters as cosmetic surfactants.

    Science.gov (United States)

    Petter, P J

    1984-10-01

    Synopsis A review is given of the manufacture, properties and applications of the anionic surfactants commonly known as taurates and isethionates (fatty acid sulphoalkyl amides and esters, respectively). Originally developed in the 1930s for textile processing, these surfactants are used increasingly in the cosmetic field, particularly those derived from coconut fatty acid. Both types are produced from sodium isethionate, HO degrees C(2)H(4)SO(3)Na. The acyl isethionate, R degrees COO degrees C(2)H(4)SO(3)Na, is obtained by reaction with a fatty acid ('direct process'). or fatty acid chloride ('indirect process'). The direct process is cheaper but requires extreme conditions which can lead to discoloration of the product and a loss of shorter chain fatty acid components. The N-methyl-N-acyltaurate, R degrees CON(R(1))C(2)H(4)SO(3)Na, is obtained by Schotten-Baumann reaction of a fatty acid chloride with N-methyltaurine, which is derived from sodium isethionate via methylamine. Taurates and isethionates retain the benefits of the soaps to which they are structurally similar, but chemical modifications have eliminated many undesirable features. Thus they combine good detergency and wetting with high foaming, and maintain their performance in hard or salt water. Taurates are stable to hydrolysis over the whole pH range. Isethionates are prone to hydrolysis at high (>8) or low (soap bars based on isethionate can be formulated at neutral pH ('Dove type'bars) instead of the alkaline pH of soap, and have been shown in various studies to be milder than soap and better tolerated by the young, the old and those with sensitive skins. Similarly, isethionates have been shown to be less irritating than other anionic or amphoteric surfactants used in cosmetics. The difference has been related to the negligible effect of isethionate on the water-binding capacity of stratum corneum. Other cosmetic applications besides toilet bars include shampoos (excellent cleaning, mild to scalp

  14. Effects of Surfactant on Geotechnical Characteristics of Silty Soil

    International Nuclear Information System (INIS)

    Rahman, Z.A.; Sahibin, A.R.; Lihan, T.; Idris, W.M.R.; Sakina, M.

    2013-01-01

    Surfactants are often used as a cleaning agent for restoration of oil-contaminated soil. However the effect of surfactant on the geotechnical properties of soil is not clearly understood. In this study, the effects of surfactant on silty soil were investigated for consistency index, compaction, permeability and shear strength. Sodium dodecyl sulfate (SDS) was used in this study to prepare the surfactant-treated soil. Our results showed that the soil with added surfactant exhibited a decrease in liquid and plastic limit values. Maximum dry densities increased and optimum moisture contents decreased as contents of added surfactant were increased. The presence of surfactant assists the soil to achieve maximum density at lower water content. The addition of surfactant decreased the permeability of soil from 6.29 x 10 -4 to 1.15 x 10 -4 ms -1 . The shear strength of soil with added surfactant was examined using the undrained unconsolidated triaxial tests. The results showed that the undrained shear strength, Cu was significantly affected, decreased from 319 kPa to 50 kPa for soil with 20 % of added surfactant. The results of this study showed that the presence of surfactant in soil can modify the mechanical behaviour of the soil. (author)

  15. 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.

  16. Chlorinated hydrocarbons in a pelagic community

    International Nuclear Information System (INIS)

    Elder, D.; Fowler, S.W.

    1976-01-01

    For several years data have been accruing on the distribution of chlorinated hydrocarbon pollutants in marine ecosystems. An overall picture of ambient levels in biota, water and sediments is now emerging however, despite the vast amount of data collected to date, questions still arise as to whether certain pollutants such as chlorinated hydrocarbons are indeed magnified through the marine food web. Evidence both for and against trophic concentration of PCB and DDT compounds has been cited. The answer to this question remains unclear due to lack of adequate knowledge on the relative importance of food and water in the uptake of these compounds as well as the fact that conclusions are often confounded by comparing pollutant concentrations in successive links in the food chain sampled at different geographical locations and/or at different points in time. The situation is further complicated by complex prey-predator relationships that exist in many marine communities. In the present study we have tried to eliminate some of these problems by examining PCB and DOT concentrations in species belonging to a relatively well-defined pelagic food chain sampled at one point in space and time

  17. Charging and Screening in Nonpolar Solutions of Nonionizable Surfactants

    Science.gov (United States)

    Behrens, Sven

    2010-03-01

    Nonpolar liquids do not easily accommodate electric charges, but surfactant additives are often found to dramatically increase the solution conductivity and promote surface charging of suspended colloid particles. Such surfactant-mediated electrostatic effects have been associated with equilibrium charge fluctuations among reverse surfactant micelles and in some cases with the statistically rare ionization of individual surfactant molecules. Here we present experimental evidence that even surfactants without any ionizable group can mediate charging and charge screening in nonpolar oils, and that they can do so at surfactant concentrations well below the critical micelle concentration (cmc). Precision conductometry, light scattering, and Karl-Fischer titration of sorbitan oleate solutions in hexane, paired with electrophoretic mobility measurements on suspended polymer particles, reveal a distinctly electrostatic action of the surfactant. We interpret our observations in terms of a charge fluctuation model and argue that the observed charging processes are likely facilitated, but not limited, by the presence of ionizable impurities.

  18. Status of surfactants as penetration enhancers in transdermal drug delivery

    Directory of Open Access Journals (Sweden)

    Iti Som

    2012-01-01

    Full Text Available Surfactants are found in many existing therapeutic, cosmetic, and agro-chemical preparations. In recent years, surfactants have been employed to enhance the permeation rates of several drugs via transdermal route. The application of transdermal route to a wider range of drugs is limited due to significant barrier to penetration across the skin which is associated with the outermost stratum corneum layer. Surfactants have effects on the permeability characteristics of several biological membranes including skin. They have the potential to solubilize lipids within the stratum corneum. The penetration of the surfactant molecule into the lipid lamellae of the stratum corneum is strongly dependent on the partitioning behavior and solubility of surfactant. Surfactants ranging from hydrophobic agents such as oleic acid to hydrophilic sodium lauryl sulfate have been tested as permeation enhancer to improve drug delivery. This article reviews the status of surfactants as permeation enhancer in transdermal drug delivery of various drugs.

  19. 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.

  20. Influence of stability of polymer surfactant on oil displacement mechanism

    Science.gov (United States)

    Liu, Li; Li, Chengliang; Pi, Yanming; Wu, Di; He, Ying; Geng, Liang

    2018-02-01

    At present, most of the oilfields of China have entered the late stage of high water-cut development, and three oil recovery technique has become the leading technology for improving oil recovery. With the improvement of three oil recovery techniques, the polymer surfactant flooding technology has been widely promoted in oil fields in recent years. But in the actual field experiment, it has been found that the polymer surfactant has chromatographic separation at the extraction end, which indicates that the property of the polymer surfactant has changed during the displacement process. At present, there was few literature about how the stability of polymer surfactant affects the oil displacement mechanism. This paper used HuaDing-I polymer surfactant to conduct a micro photolithography glass flooding experiment, and then compared the oil displacement law of polymer surfactant before and after static setting. Finally, the influence law of stability of polymer surfactant on the oil displacement mechanism is obtained by comprehensive analysis.

  1. Determination of trace quaternary ammonium surfactants in water by combining solid-phase extraction with surface-assisted laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Chen, Y C; Sun, M C

    2001-01-01

    This study demonstrates the feasibility of combining solid-phase extraction (SPE) with surface-assisted laser desorption/ionization (SALDI) mass spectrometry to determine trace quaternary ammonium surfactants in water. The trace surfactants in water were directly concentrated on the surface of activated carbon sorbent in SPE. The activated carbon sorbent was then mixed with the SALDI liquid for SALDI analysis. No SPE elution procedure was necessary. Experimental results indicate that the surfactants with longer chain alkyl groups exhibit higher sensitivities than those with shorter chain alkyl groups in SPE-SALDI analysis. The detection limit for hexadecyltrimethylammonium bromide is around 10 ppt in SPE-SALDI analysis by sampling 100 mL of aqueous solution, while that of tetradecyltrimethylammonium bromide is about 100 ppt. The detection limit for decyltrimethylammonium bromide and dodecyltrimethylammonium bromide is in the low-ppb range. Copyright 2001 John Wiley & Sons, Ltd.

  2. Isolation and Characterization of Hydrocarbon-Degrading Yeast Strains from Petroleum Contaminated Industrial Wastewater

    Directory of Open Access Journals (Sweden)

    Boutheina Gargouri

    2015-01-01

    Full Text Available Two yeast strains are enriched and isolated from industrial refinery wastewater. These strains were observed for their ability to utilize several classes of petroleum hydrocarbons substrates, such as n-alkanes and aromatic hydrocarbons as a sole carbon source. Phylogenetic analysis based on the D1/D2 variable domain and the ITS-region sequences indicated that strains HC1 and HC4 were members of the genera Candida and Trichosporon, respectively. The mechanism of hydrocarbon uptaking by yeast, Candida, and Trichosporon has been studied by means of the kinetic analysis of hydrocarbons-degrading yeasts growth and substrate assimilation. Biodegradation capacity and biomass quantity were daily measured during twelve days by gravimetric analysis and gas chromatography coupled with mass spectrometry techniques. Removal of n-alkanes indicated a strong ability of hydrocarbon biodegradation by the isolated yeast strains. These two strains grew on long-chain n-alkane, diesel oil, and crude oil but failed to grow on short-chain n-alkane and aromatic hydrocarbons. Growth measurement attributes of the isolates, using n-hexadecane, diesel oil, and crude oil as substrates, showed that strain HC1 had better degradation for hydrocarbon substrates than strain HC4. In conclusion, these yeast strains can be useful for the bioremediation process and decreasing petroleum pollution in wastewater contaminated with petroleum hydrocarbons.

  3. Isolation and Characterization of Hydrocarbon-Degrading Yeast Strains from Petroleum Contaminated Industrial Wastewater

    Science.gov (United States)

    Gargouri, Boutheina; Mhiri, Najla; Karray, Fatma; Aloui, Fathi; Sayadi, Sami

    2015-01-01

    Two yeast strains are enriched and isolated from industrial refinery wastewater. These strains were observed for their ability to utilize several classes of petroleum hydrocarbons substrates, such as n-alkanes and aromatic hydrocarbons as a sole carbon source. Phylogenetic analysis based on the D1/D2 variable domain and the ITS-region sequences indicated that strains HC1 and HC4 were members of the genera Candida and Trichosporon, respectively. The mechanism of hydrocarbon uptaking by yeast, Candida, and Trichosporon has been studied by means of the kinetic analysis of hydrocarbons-degrading yeasts growth and substrate assimilation. Biodegradation capacity and biomass quantity were daily measured during twelve days by gravimetric analysis and gas chromatography coupled with mass spectrometry techniques. Removal of n-alkanes indicated a strong ability of hydrocarbon biodegradation by the isolated yeast strains. These two strains grew on long-chain n-alkane, diesel oil, and crude oil but failed to grow on short-chain n-alkane and aromatic hydrocarbons. Growth measurement attributes of the isolates, using n-hexadecane, diesel oil, and crude oil as substrates, showed that strain HC1 had better degradation for hydrocarbon substrates than strain HC4. In conclusion, these yeast strains can be useful for the bioremediation process and decreasing petroleum pollution in wastewater contaminated with petroleum hydrocarbons. PMID:26339653

  4. CHAIN 2

    International Nuclear Information System (INIS)

    Bailey, D.

    1998-04-01

    The Second Processing Chain (CHAIN2) consists of a suite of ten programs which together provide a full local analysis of the bulk plasma physics within the JET Tokamak. In discussing these ten computational models this report is intended to fulfil two broad purposes. Firstly it is meant to be used as a reference source for any user of CHAIN2 data, and secondly it provides a basic User Manual sufficient to instruct anyone in running the CHAIN2 suite of codes. In the main report text each module is described in terms of its underlying physics and any associated assumptions or limitations, whilst deliberate emphasis is put on highlighting the physics and mathematics of the calculations required in deriving each individual datatype in the standard module PPF output. In fact each datatype of the CHAIN2 PPF output listed in Appendix D is cross referenced to the point in the main text where its evaluation is discussed. An effort is made not only to give the equation used to derive a particular data profile but also to explicitly define which external data sources are involved in the computational calculation

  5. Measuring Trace Hydrocarbons in Silanes

    Science.gov (United States)

    Lesser, L. A.

    1984-01-01

    Technique rapid and uses standard analytical equipment. Silane gas containing traces of hydrocarbons injected into carrier gas of moist nitrogen having about 0.2 percent water vapor. Carrier, water and silane pass through short column packed with powdered sodium hydroxide which combines moisture and silane to form nonvolatile sodium silicate. Carrier gas free of silane but containing nonreactive hydrocarbons, pass to silica-gel column where chromatographic separation takes place. Hydrocarbons measured by FID.

  6. Fractional separation of hydrocarbon vapours

    Energy Technology Data Exchange (ETDEWEB)

    1937-07-10

    A process is described for converting higher boiling hydrocarbons to lower boiling hydrocarbons by subjecting them at elevated temperatures to a conversion operation, then separating the higher and lower boiling fractions. The separation takes place while the reaction products are maintained in the vapor phase by contact with a mass of solid porous material which has little or no catalytic activity but does have a preferential absorption property for higher boiling hydrocarbons so that the lower boiling part of the reaction products pass through the separation zone while the heavier hydrocarbons are retained. The separation is accomplished without substantial loss of heat of these reaction products.

  7. Next Generation Surfactants for Improved Chemical Flooding Technology

    Energy Technology Data Exchange (ETDEWEB)

    Laura Wesson; Prapas Lohateeraparp; Jeffrey Harwell; Bor-Jier Shiau

    2012-05-31

    The principle objective of this project was to characterize and test current and next generation high performance surfactants for improved chemical flooding technology, focused on reservoirs in the Pennsylvanian-aged (Penn) sands. In order to meet this objective the characteristic curvatures (Cc) of twenty-eight anionic surfactants selected for evaluation for use in chemical flooding formulations were determined. The Cc values ranged from -6.90 to 2.55 with the majority having negative values. Crude oil samples from nine Penn sand reservoirs were analyzed for several properties pertinent to surfactant formulation for EOR application. These properties included equivalent alkane carbon numbers, total acid numbers, and viscosity. The brine samples from these same reservoirs were analyzed for several cations and for total dissolved solids. Surfactant formulations were successfully developed for eight reservoirs by the end of the project period. These formulations were comprised of a tertiary mixture of anionic surfactants. The identities of these surfactants are considered proprietary, but suffice to say the surfactants in each mixture were comprised of varying chemical structures. In addition to the successful development of surfactant formulations for EOR, there were also two successful single-well field tests conducted. There are many aspects that must be considered in the development and implementation of effective surfactant formulations. Taking into account these other aspects, there were four additional studies conducted during this project. These studies focused on the effect of the stability of surfactant formulations in the presence of polymers with an associated examination of polymer rheology, the effect of the presence of iron complexes in the brine on surfactant stability, the potential use of sacrificial agents in order to minimize the loss of surfactant to adsorption, and the effect of electrolytes on surfactant adsorption. In these last four studies

  8. Process for preparing hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Krauch, C; Anther, E; Pier, M

    1926-04-07

    A process is described for the conversion of coal of all kinds, wood, oil, shale, as well as other carbonaceous materials into liquid hydrocarbons in two steps, characterized by treatment of the coal and so forth with a stream of hydrogen or hydrogen-containing gases at raised temperatures and raised pressures and producing a tarry product which, after separation of the ashlike residue, is converted by a further treatment, in the presence of catalysts, with hydrogen or hydrogen-containing gases at raised temperature and pressure, largely into low-boiling products.

  9. Recovering valuable liquid hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Pier, M

    1931-06-11

    A process for recovering valuable liquid hydrocarbons from coking coal, mineral coal, or oil shale through treatment with hydrogen under pressure at elevated temperature is described. Catalysts and grinding oil may be used in the process if necessary. The process provides for deashing the coal prior to hydrogenation and for preventing the coking and swelling of the deashed material. During the treatment with hydrogen, the coal is either mixed with coal low in bituminous material, such as lean coal or active coal, as a diluent or the bituminous constituents which cause the coking and swelling are removed by extraction with solvents. (BLM)

  10. Hydrogen production from hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Docekal, J

    1986-01-01

    Hydrogen is an important feed stock for chemical and petroleum industries, in addition to being considered as the energy carrier of the future. At the present time the feed stock hydrogen is mainly manufactured from hydrocarbons using steam reforming. In steam reforming two processes are employed, the conventional process and PSA (pressure swing adsorption) process. These two processes are described and compared. The results show that the total costs and the maintenance costs are lower for the PSA process, the capital outlay is lower for the conventional process, and the operating costs are similar for the two processes.

  11. Permaflood, formation in situ of surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Kapo, G

    1972-01-01

    The present paper described a new process to produce surfactants in situ in which advantage is taken of the chemical reaction of oxidation in the liquid phase. This process consists of injecting a front of oxidizing agents and reaction compounds, in order to avoid the precipitation of the reaction products and to avoid the interaction between the surfactants produced and the calcium and magnesium in the connate water. Many different types of oxidizing agents as sodium dichromate, hydrogen peroxide, potassium permanganate, sodium hypochlorite, etc., are used. Also, there is considered the use of catalyzers with these oxidizing agents and the variation of the pH of the oxidizing front (permanaganate was the first oxidant used to check the technical and economic possibilities of this process in the laboratory). The process is called Permaflood, so named because potassium permanganate was the first oxidant used to check the technical and economic possibilities of this process in the laboratory.

  12. Synthesis and Surface Activity of Cationic Amino Acid-Based Surfactants in Aqueous Solution.

    Science.gov (United States)

    Greber, Katarzyna E

    2017-01-01

    I studied the possibility of using amino acid-based surfactants as emulsifiers at the same time as preservatives. Fourteen lipopeptides were synthesized employing a solid phase peptide synthesis procedure. All compounds were designed to be positively charged from +1 to +4 and acylated with fatty acid chain-palmitic and miristic. The surface activity of the obtained lipopeptides was tested using a semi-automatic tensiometer to calculate parameters describing the behavior of lipopeptides in the air/water interface. Such parameters as CMC, surface tension at the CMC point ( σ CMC ), effectiveness ( π CMC ), and efficiency (pC20) were measured. Emulsifying properties of all lipopeptides were also examined. The studies reveal that the surface active properties of synthesized compounds strongly depend on the length of alkyl chains as well as on the composition of amino acid polar heads. The critical micelle concentration decreases with increasing alkyl chain length of lipopeptides with the same polar head. The effectiveness and efficiency decrease when the number of amino acids in the polar head increases. All lipopeptides established a very weak emulsification power and created unstable water/Miglyol 812 and water/paraffin oil emulsions. Results suggest that lipopeptides cannot be used as emulsifiers; nonetheless, it is possible to use them as auxiliary surfactants with disinfectant properties in combination with more potent emulsifiers.

  13. Polymorphism and mesomorphism of oligomeric surfactants: effect of the degree of oligomerization.

    Science.gov (United States)

    Jurašin, D; Pustak, A; Habuš, I; Šmit, I; Filipović-Vinceković, N

    2011-12-06

    A series of cationic oligomeric surfactants (quaternary dodecyldimethylammonium ions with two, three, or four chains connected by an ethylene spacer at the headgroup level, abbreviated as dimer, trimer, and tetramer) were synthesized and characterized. The influence of the degree of oligomerization on their polymorphic and mesomorphic properties was investigated by means of X-ray diffraction, polarizing optical microscopy, thermogravimetry, and differential scanning calorimetry. All compounds display layered arrangements with interdigitated dodecyl chains. The increase in the degree of oligomerization increases the interlayer distance and decreases the ordering in the solid phase; whereas the dimer sample is fully crystalline with well-developed 3D ordering and the trimer and tetramer crystallize as highly ordered crystal smectic phases. The number of thermal phase transitions and sequence of phases are markedly affected by the number of dodecyl chains. Anhydrous samples exhibit polymorphism and thermotropic mesomorphism of the smectic type, with the exception of the tetramer that displays only transitions at higher temperature associated with decomposition and melting. All hydrated compounds form lyotropic mesophases showing reversible phase transitions upon heating and cooling. The sequence of liquid-crystalline phases for the dimer, typical of concentrated ionic surfactant systems, comprises a hexagonal phase at lower temperatures and a smectic phase at higher temperatures. In contrast, the trimer and tetramer reveal textures of the hexagonal phase. © 2011 American Chemical Society

  14. 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.

  15. Microemulsion-based lycopene extraction: Effect of surfactants, co-surfactants and pretreatments.

    Science.gov (United States)

    Amiri-Rigi, Atefeh; Abbasi, Soleiman

    2016-04-15

    Lycopene is a potent antioxidant that has received extensive attention recently. Due to the challenges encountered with current methods of lycopene extraction using hazardous solvents, industry calls for a greener, safer and more efficient process. The main purpose of present study was application of microemulsion technique to extract lycopene from tomato pomace. In this respect, the effect of eight different surfactants, four different co-surfactants, and ultrasound and enzyme pretreatments on lycopene extraction efficiency was examined. Experimental results revealed that application of combined ultrasound and enzyme pretreatments, saponin as a natural surfactant, and glycerol as a co-surfactant, in the bicontinuous region of microemulsion was the optimal experimental conditions resulting in a microemulsion containing 409.68±0.68 μg/glycopene. The high lycopene concentration achieved, indicates that microemulsion technique, using a low-cost natural surfactant could be promising for a simple and safe separation of lycopene from tomato pomace and possibly from tomato industrial wastes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. The Equilibrium Spreading Tension of Pulmonary Surfactant

    OpenAIRE

    Dagan, Maayan P.; Hall, Stephen B.

    2015-01-01

    Monomolecular films at an air/water interface coexist at the equilibrium spreading tension (γe) with the bulk phase from which they form. For individual phospholipids, γe is single-valued, and separates conditions at which hydrated vesicles adsorb from tensions at which overcompressed monolayers collapse. With pulmonary surfactant, isotherms show that monolayers compressed on the surface of bubbles coexist with the three-dimensional collapsed phase over a range of surface tensions. γe therefo...

  17. PLUNC: a multifunctional surfactant of the airways

    OpenAIRE

    Bartlett, Jennifer; Gakhar, Lokesh; Penterman, Jon; Singh, Pradeep; Mallampalli, Rama K.; Porter, Edith; McCray, Paul B.

    2011-01-01

    PLUNC (palate, lung and nasal epithelium clone) protein is an abundant secretory product of epithelia throughout the mammalian conducting airways. Despite its homology with the innate immune defence molecules BPI (bactericidal/permeability-increasing protein) and LBP (lipopolysaccharide-binding protein), it has been difficult to define the functions of PLUNC. Based on its marked hydrophobicity and expression pattern, we hypothesized that PLUNC is an airway surfactant. We found that purified r...

  18. The Accelerated Late Adsorption of Pulmonary Surfactant

    Science.gov (United States)

    2011-01-01

    Adsorption of pulmonary surfactant to an air−water interface lowers surface tension (γ) at rates that initially decrease progressively, but which then accelerate close to the equilibrium γ. The studies here tested a series of hypotheses concerning mechanisms that might cause the late accelerated drop in γ. Experiments used captive bubbles and a Wilhelmy plate to measure γ during adsorption of vesicles containing constituents from extracted calf surfactant. The faster fall in γ reflects faster adsorption rather than any feature of the equation of state that relates γ to surface concentration (Γ). Adsorption accelerates when γ reaches a critical value rather than after an interval required to reach that γ. The hydrophobic surfactant proteins (SPs) represent key constituents, both for reaching the γ at which the acceleration occurs and for producing the acceleration itself. The γ at which rates of adsorption increase, however, is unaffected by the Γ of protein in the films. In the absence of the proteins, a phosphatidylethanolamine, which, like the SPs, induces fusion of the vesicles with the interfacial film, also causes adsorption to accelerate. Our results suggest that the late acceleration is characteristic of adsorption by fusion of vesicles with the nascent film, which proceeds more favorably when the Γ of the lipids exceeds a critical value. PMID:21417351

  19. Alveolar Thin Layer Flows and Surfactant Dynamics

    Science.gov (United States)

    Roumie, Ahmad; Jbaily, Abdulrahman; Szeri, Andrew J.

    2017-11-01

    Pulmonary surfactants play a vital role in everyday respiration. They regulate surface tension in the lungs by diffusing through the hypophase, a liquid layer that lines the interior surface of the alveoli, and adsorbing to the existing air-fluid interface. This decreases the equilibrium surface tension value by as much as a factor of 3, minimizing breathing effort and preventing lung collapse at the end of exhalation. Given that the hypophase thickness h lies within the range 0.1 μm < h <0.5 μm , and that the average alveolar radius R is 100 μm , for some purposes the hypophase may usefully be modeled as a fluid layer on a flat sheet representing the alveolar wall. Moreover, because of the large aspect ratio, the lubrication approximation can be applied. The aim of the present work is to study the interaction between the straining of the alveolar wall and the fluid flow in the hypophase. The analysis is governed by the relative magnitudes of the time scales of surfactant diffusion, adsorption, desorption, viscous dissipation and sheet straining. Cases of particular interest include non-uniform surfactant concentration at the interface, leading to Marangoni flows and a non-uniform hypophase thickness profile. The analytical formulation and numerical simulations are presented. This work is motivated by a need to understand alveolar deformation during breathing, and to do so in a way that derives from improved understanding of the fluid mechanics of the problem.

  20. Determination of polynuclear hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Lodge, Jr, J P

    1963-01-01

    At the present time, the method of choice for the determination of polynuclear hydrocarbons appears to be the following, (a) extraction of the benzene-soluble fraction from the gross collected particulate matter, (b) one pass through a chromatographic column of partially deactivated alumina, (c) spectral examination of the fractions and (d) the application of appropriate chemical tests as indicated by the previous step. Using this method, the presence of pyrene, fluoranthene, one of the benzofluorenes, chrysens, benz(a)anthracene, benzo(a)pyrene, benzo(e)pyrene, benzo(k)fluoranthene, anthanthrene, and coronene was demonstrated in the air of numerous American cities, and benzo(a)pyrene was measured at some 130 sites. Invaluable as such accurate determinations may be for research purposes, they are still too costly and time-consuming for routine survey purposes. While studies on the subject are by no means complete, they indicate the validity of piperonal chloride test as a general index of polycyclic hydrocarbons. This procedure is described in this paper. 7 references.

  1. Hydrocarbons: source of energy

    International Nuclear Information System (INIS)

    Imarisio, G.; Frias, M.; Bemtgen, J.M.

    1989-01-01

    Hydrocarbons are at present the single most important source of energy, since they are the most versatile and widely used. It is expected that their importance will extend well into the next century and therefore it is essential to provide for all those improvements which will extend their availability and usefulness. The sub-programme ''Optimization of the production and utilization of hydrocarbons'' (within the Non-Nuclear Energy R and D Programme of the European Communities) is pursuing a number of R and D topics aimed at the above-mentioned results. It is implemented by means of shared-cost R and D contracts. At this first Seminar held in Lyon (France) from 21-23 September, 1988, all contractors of the sub-programme presented the state of progress of their R and D projects. These proceedings comprise all the papers presented at the Seminar. The section on oilfield exploration includes a report of work on the interpretation of nuclear logs by means of mathematical models. (author)

  2. Surfactant producing TNT-degrading microorganisms for bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Vorobyov, A.; Marchenko, A.; Rudneva, O.; Borovick, R. [Research Center for Toxicology and Hygienic Regulation of Biopreparations, Serpukhov, Moscow region (Russian Federation); Radosevich, M. [Univ. of Delaware, Newark (United States). Dept. of Plant and Soil Sciences

    2003-07-01

    In general the biodegradation of nitroaromatic hydrocarbons is influenced by their bioavailability. 2,4,6-trinitrotoluene is very poorly soluble in water. TNT is easily adsorbed to clay or humus fractions in the soil, and pass very slowly to the aqueous phase, where microorganisms metabolize it. Biosurfactants that increase TNT solubility and improve its bioavailability can thereby accelerate degradation. Pure cultures of microorganisms-TNT degraders were isolated by the method of enrichment cultures from samples of different-type soil contaminated by TNT (soddy-podzol, black earth, and gray forest ones). From 28 soil samples 35 isolates of microorganisms degrading TNT were taken. The isolated soil samples had been tested for availability of microbial activity towards TNT. By10 g of air-dried soil, 10 ml of distilled water, and 2 mg of TNT were placed into 750 ml shaken flasks. The flasks were incubated at 150 rev/min and 24 C. Glucose, sodium succinate or sodium acetate had been used as co-substrates. The ability of the strains to produce surfactants was studied by drop collapsing test and direct measuring of surface tension of cultural liquid after cultivation with TNT. Cells of the strains were cultivated on solid and liquid nutrient media. For drop collapsing test the cells were cultivated on solid nutrient media; the separated colonies were suspended in distilled water. Drop sustainability test ws conducted on a standard 96-well plates coated with a thin layer of vaseline oil. Surface tension of cultural liquid ws measured after cultivation of strains in the presence of TNT with the use of a ring tensiometer. Before measuring of surface tension microbial cells were collected from liquid culture by centrifugation. (orig.)

  3. Solubilization properties of polycyclic aromatic hydrocarbons by saponin, a plant-derived biosurfactant

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Wenjun, E-mail: wenjunzhou@zju.edu.cn [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang 310028 (China); Yang Juanjuan; Lou Linjie [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhu Lizhong [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang 310028 (China)

    2011-05-15

    The enhanced solubilization of polycyclic aromatic hydrocarbons (PAHs) by saponin, a plant-derived non-ionic biosurfactant, was investigated. The results indicated that the solubilization capabilities of saponin for PAHs were greater than some representative synthetic non-ionic surfactants and showed strong dependence on solution pH and ionic strength. The molar solubilization ratio (MSR) of saponin for phenanthrene was about 3-6 times of those of the synthetic non-ionic surfactants, and decreased by about 70% with the increase of solution pH from 4.0 to 8.0, but increased by approximately 1 times with NaCl concentration increased from 0.01 to 1.0 M. Heavy metal ions can enhance saponin solubilization for phenanthrene and the corresponding MSR values increased by about 25% with the presence of 0.01 M of Cd{sup 2+} or Zn{sup 2+}. Saponin is more effective in enhancing PAHs solubilization than synthetic non-ionic surfactants and has potential application in removing organic pollutants from contaminated soils. - Highlights: > The enhanced solubilization of PAHs by saponin was investigated in this study. > Saponin showed great solubilization capability for PAHs. > Saponin is more effective in enhancing HOCs solubilization at lower solution pH. > Increasing ionic strength can enhance HOCs solubilization in saponin solution. > Heavy metal ions can also enhance phenanthrene solubilization in saponin solution. - Saponin showed different solubilization properties for PAHs from the synthetic non-ionic surfactants and anionic rhamnolipid biosurfactants.

  4. Solubilization properties of polycyclic aromatic hydrocarbons by saponin, a plant-derived biosurfactant

    International Nuclear Information System (INIS)

    Zhou Wenjun; Yang Juanjuan; Lou Linjie; Zhu Lizhong

    2011-01-01

    The enhanced solubilization of polycyclic aromatic hydrocarbons (PAHs) by saponin, a plant-derived non-ionic biosurfactant, was investigated. The results indicated that the solubilization capabilities of saponin for PAHs were greater than some representative synthetic non-ionic surfactants and showed strong dependence on solution pH and ionic strength. The molar solubilization ratio (MSR) of saponin for phenanthrene was about 3-6 times of those of the synthetic non-ionic surfactants, and decreased by about 70% with the increase of solution pH from 4.0 to 8.0, but increased by approximately 1 times with NaCl concentration increased from 0.01 to 1.0 M. Heavy metal ions can enhance saponin solubilization for phenanthrene and the corresponding MSR values increased by about 25% with the presence of 0.01 M of Cd 2+ or Zn 2+ . Saponin is more effective in enhancing PAHs solubilization than synthetic non-ionic surfactants and has potential application in removing organic pollutants from contaminated soils. - Highlights: → The enhanced solubilization of PAHs by saponin was investigated in this study. → Saponin showed great solubilization capability for PAHs. → Saponin is more effective in enhancing HOCs solubilization at lower solution pH. → Increasing ionic strength can enhance HOCs solubilization in saponin solution. → Heavy metal ions can also enhance phenanthrene solubilization in saponin solution. - Saponin showed different solubilization properties for PAHs from the synthetic non-ionic surfactants and anionic rhamnolipid biosurfactants.

  5. Surfactant protein A and surfactant protein D variation in pulmonary disease

    DEFF Research Database (Denmark)

    Sørensen, Grith Lykke; Husby, Steffen; Holmskov, Uffe

    2007-01-01

    Surfactant proteins A (SP-A) and D (SP-D) have been implicated in pulmonary innate immunity. The proteins are host defense lectins, belonging to the collectin family which also includes mannan-binding lectin (MBL). SP-A and SP-D are pattern-recognition molecules with the lectin domains binding...... lavage and blood have indicated associations with a multitude of pulmonary inflammatory diseases. In addition, accumulating evidence in mouse models of infection and inflammation indicates that recombinant forms of the surfactant proteins are biologically active in vivo and may have therapeutic potential...... in controlling pulmonary inflammatory disease. The presence of the surfactant collectins, especially SP-D, in non-pulmonary tissues, such as the gastrointestinal tract and genital organs, suggest additional actions located to other mucosal surfaces. The aim of this review is to summarize studies on genetic...

  6. Biosurfactant-enhanced bioremediation of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Cameotra, S.S.; Bollag, J.M. [Penn State University, University Park, PA (USA). Soil Biochemical Lab.

    2003-07-01

    Biosurfactants are surface-active compounds synthesized by it wide variety of micro-organisms. They are molecules that have both hydrophobic and hydrophilic domains and are capable of lowering the surface tension and the interfacial tension of the growth medium. Biosurfactants possess different chemical structures - lipopeptides, glycolipids, neutral lipids, and fatty acids. They are nontoxic biomolecules that are biodegradable. Biosurfactants also exhibit strong emulsification of hydrophobic compounds and form stable emulsions. Polycyclic aromatic hydrocarbons (PAHs) can be toxic, mutagenic, and carcinogenic compounds that pollute the environment. They are released to the environment its a result of spillage of oil and byproducts of coal treatment processes. The low water solubility of PAHs limits their availability to microorganisms, which is a potential problem for bioremediation of PAH-contaminated sites. Microbially produced surfactants enhance the bioavailability of these hydrophobic compounds for bioremediation. Therefore, biosurfactant-enhanced solubility of PAHs has potential applications in bioremediation.

  7. A novel viscoelastic surfactant suitable for use in high temperature carbonate reservoirs for diverted acidizing stimulation treatments

    Energy Technology Data Exchange (ETDEWEB)

    Holt, Stuart; Zhou, Jian; Gadberry, Fred [AkzoNobel Surface Chemistry, Forth Worth, TX (United States); Nasr-El-Din, Hisham; Wang, Guanqun [Texas A and M University, College Station, TX (United States). Dept. of Petroleum Engineering

    2012-07-01

    Due to the low permeability of many carbonate hydrocarbon-bearing reservoirs, it is difficult to achieve economic hydrocarbon recovery from a well without secondary stimulation. Bullheading of strong acids, such as HCl is practiced in low temperature reservoirs, but as the bottom hole temperature (BHT) rises, the acid becomes increasingly corrosive, causing facial dissolution and sub-optimal wormhole network development. In the last decade, viscoelastic surfactants (VES) have been added to HCl acid systems to improve the stimulation of HT carbonate reservoirs. The VES form 'living polymers' or worm-like micelles as electrolyte concentration rises in the acid due to reaction with the reservoir. This leads to viscosification of the stimulation fluid. The viscosification slows further acid reaction in the region already contacted by the acid, and forces the acid to take an alternate path into the rock, leading to diversion of the acids further down the well to the harder to access toe or lower permeability zones. Until recently, the maximum BHT that such VES-based diverting systems could be used was up to about 250 deg F/120 deg C. Above that temperature, all viscous properties of the fluid are lost, destroying the mechanism of acid diversion. A recently developed novel viscoelastic surfactant provides nearly 100 deg F/55 deg C extension in the BHT range in which diverted acid treatments can be used. These fluids are able to maintain both viscosity up to about 375 deg F/190 deg C, with the elastic modulus predominating up to 350 deg F/175 deg C. It is the elasticity which is particularly important in acid diversion. These fluids can have their viscosity readily broken by in-situ hydrocarbons, dilution with water or by using a mutual solvent. The broken fluids are readily removed from the near-well bore, leaving the newly created wormhole network to produce the target hydrocarbons. The new VES is significantly more environmentally benign compared with current

  8. Enhancing the Drag Reduction Phenomenon within a Rotating Disk Apparatus Using Polymer-Surfactant Additives

    Directory of Open Access Journals (Sweden)

    Musaab K. Rashed

    2016-12-01

    Full Text Available Pipelines and tubes play important roles in transporting economic liquids, such as water, petroleum derivatives, and crude oil. However, turbulence reduces the initial flow rate at which liquids are pumped, thereby making liquid transportation through pipelines inefficient. This study focuses on enhancing the drag reduction (DR phenomenon within a rotating disk apparatus (RDA using polymer-surfactant additives. The complex mixture of polyisobutylene (PIB and sodium dioctyl sulfosuccinate (SDS was used. These materials were tested individually and as a complex mixture in RDA at various concentrations and rotational speeds (rpm. The morphology of this complex was investigated using transmission electronic microscopy (TEM. The reduction of the degradation level caused by the continuous circulation of surfactant additives in RDA could improve the long-term DR level. Experimental result shows that the maximum %DR of the complex mixture was 21.455% at 3000 rpm, while the PIB and SDS were 19.197% and 8.03%, respectively. Therefore, the complex mixture had better performance than these substances alone and were highly dependent on the alkyl chain of the surfactant.

  9. Anaerobic digestion of amine-oxide-based surfactants: biodegradation kinetics and inhibitory effects.

    Science.gov (United States)

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

    2017-08-01

    Recently, anaerobic degradation has become a prevalent alternative for the treatment of wastewater and activated sludge. Consequently, the anaerobic biodegradability of recalcitrant compounds such as some surfactants require a thorough study to avoid their presence in the environment. In this work, the anaerobic biodegradation of amine-oxide-based surfactants, which are toxic to several organisms, was studied by measuring of the biogas production in digested sludge. Three amine-oxide-based surfactants with structural differences in their hydrophobic alkyl chain were tested: Lauramine oxide (AO-R 12 ), Myristamine oxide (AO-R 14 ) and Cocamidopropylamine oxide (AO-cocoamido). Results show that AO-R 12 and AO-R 14 inhibit biogas production, inhibition percentages were around 90%. AO-cocoamido did not cause inhibition and it was biodegraded until reaching a percentage of 60.8%. Otherwise, we fitted the production of biogas to two kinetic models, to a pseudo first-order model and to a logistic model. Production of biogas during the anaerobic biodegradation of AO-cocoamido was pretty good adjusted to the logistics model. Kinetic parameters were also determined. This modelling is useful to predict their behaviour in wastewater treatment plants and under anaerobic conditions in the environment.

  10. Polyurethane and polyurea nanoparticles based on polyoxyethylene castor oil derivative surfactant suitable for endovascular applications.

    Science.gov (United States)

    Morral-Ruíz, Genoveva; Melgar-Lesmes, Pedro; García, María Luísa; Solans, Conxita; García-Celma, María José

    2014-01-30

    The design of new, safe and effective nanotherapeutic systems is an important challenge for the researchers in the nanotechnology area. This study describes the formation of biocompatible polyurethane and polyurea nanoparticles based on polyoxyethylene castor oil derivative surfactant formed from O/W nano-emulsions by polymerization at the droplet interfaces in systems composed by aqueous solution/Kolliphor(®) ELP/medium chain triglyceride suitable for intravenous administration. Initial nano-emulsions incorporating highly hydrophilic materials were prepared by the phase inversion composition (PIC) method. After polymerization, nanoparticles with a small particle diameter (25-55 nm) and low polydispersity index were obtained. Parameters such as concentration of monomer, O/S weight ratio as well as the polymerization temperature were crucial to achieve a correct formation of these nanoparticles. Moreover, FT-IR studies showed the full conversion of the monomer to polyurethane and polyurea polymers. Likewise the involvement of the surfactant in the polymerization process through their nucleophilic groups to form the polymeric matrix was demonstrated. This could mean a first step in the development of biocompatible systems formulated with polyoxyethylene castor oil derivative surfactants. In addition, haemolysis and cell viability assays evidenced the good biocompatibility of KELP polyurethane and polyurea nanoparticles thus indicating the potential of these nanosystems as promising drug carriers. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. 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.

  12. 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.

  13. Heavy Chain Diseases

    Science.gov (United States)

    ... of heavy chain produced: Alpha Gamma Mu Alpha Heavy Chain Disease Alpha heavy chain disease (IgA heavy ... the disease or lead to a remission. Gamma Heavy Chain Disease Gamma heavy chain disease (IgG heavy ...

  14. Steam hydrocarbon cracking and reforming

    NARCIS (Netherlands)

    Golombok, M.

    2004-01-01

    Many industrial chemical processes are taught as distinct contrasting reactions when in fact the unifying comparisons are greater than the contrasts. We examine steam hydrocarbon reforming and steam hydrocarbon cracking as an example of two processes that operate under different chemical reactivity

  15. Laboratory bioremediation of diesel fuel contaminated soil using indigenous cultures and surfactants

    International Nuclear Information System (INIS)

    Mas, Z.; Morin, P.; Walter, D.

    1998-01-01

    To help verify soil and groundwater remediation techniques, an Environmental Testing Facility (ETF) was built in Argentia, Newfoundland. A laboratory program has been developed and the influence of various parameters such as temperature, pH, nutrients and bacterial seeding on the biodegradation of diesel fuel-contaminated soils by indigenous microorganisms has been evaluated. Two non-toxic surfactants, Triton X-100 and Tween-60, have also been tested to determine their leaching potential for possible use in hydrocarbon removal, alone, or in combination with bioremediation. The addition of Triton X-100 showed no significant effect on the biotreatment of diesel fuel, but improved markedly diesel fuel leaching by percolation, indicating good potential for global remediation of the test soil by a combination of leaching and biodegradation. Tween-60 appears to inhibit biological activity, causing the efficiency of bacterial growth to drop from 50 per cent to 35 per cent. 8 refs., 4 tabs., 6 figs

  16. 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.

  17. Residual diesel measurement in sand columns after surfactant/alcohol washing

    International Nuclear Information System (INIS)

    Martel, R.; Gelinas, P.J.

    1996-01-01

    A new simple gravimetric technique has been designed to determine residual oil saturation of complex hydrocarbon mixtures (e.g., diesel) in sand column experiments because reliable methods are lacking. The He/N 2 technique is based on drying of sand columns by circulating helium gas to drag oil droplets in a cold trap (liquid nitrogen). With this technique, residual diesel measurement can be performed easily immediately after alcohol/surfactant washing and in the same lab. For high residual diesel content in Ottawa sand (25 to 30 g/kg), the technique is much more accurate (± 2% or 600 mg/kg) than the standard analytical methods for the determination of mineral oil and grease. The average relative error on partial diesel dissolution in sand column estimated after alcohol/surfactant flooding (residual saturation of 10 to 15 g/kg) is as low as 5%. The precision of the He/N 2 technique is adequate to compare relative efficiency of washing solutions when partial extraction of residual oil in Ottawa sand columns is performed. However, this technique is not adapted for determination of traces of oil in sediment or for environmental control of contaminated soils. Each diesel determination by the He/N 2 technique costs less than $8 in chemical products (helium and liquid nitrogen). A simple laboratory drying setup can be built for less than $400 which makes this technique valuable for diesel analyses when a large number of tests are required

  18. 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

  19. Canada's hydrocarbon processing evolution

    International Nuclear Information System (INIS)

    Wise, T.H.; Horton, R.

    2000-01-01

    The development of petroleum refining, petrochemicals and natural gas industries in Canada are discussed together with future issues and prospects. Figures give data on (a) refined products trade 1998; (b) refining capacity; (c) product demand 1980-1999; (d) refinery crude runs and capacity; (e) refining and marketing, historical returns 1993-1999; (f) processing power index for Canada and USA; (g) ethylene capacity; (eye) Montreal petrochemical capacities; (j) Sarnia petrochemical capacities in 2000; (k) Alberta petrochemicals capacities 2001; (l) ethylene net equivalent trade; (m) ethylene costs 1999 for W. Canada and other countries. It was concluded that the hydrocarbon processing business continues to expand in Canada and natural gas processing is likely to increase. Petrochemicals may expand in W. Canada, possibly using feed stock from the Far North. Offshore developments may stimulate new processing on the E. Coast

  20. Hydrogenating gaseous hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Nicolardot, P L.F.

    1930-08-06

    Gaseous hydrocarbons obtained by the destructive distillation of carbonaceous materials are simultaneously desulfurized and hydrogenated by passing them at 350 to 500/sup 0/C, mixed with carbon monoxide and water vapor over lime mixed with metallic oxides present in sufficient amount to absorb the carbon dioxide as it is formed. Oxides of iron, copper, silver, cobalt, and metals of the rare earths may be used and are mixed with the lime to form a filling material of small pieces filling the reaction vessel which may have walls metallized with copper and zinc dust. The products are condensed and fixed with absorbents, e.g. oils, activated carbon, silica gels. The metallic masses may be regenerated by a hot air stream and by heating in inert gases.

  1. Treating hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    Scott, R; MacIvor, W

    1869-09-01

    The treatment of hydrocarbon oils, such as coal or shale oils, paraffin oils, and petroleum, either in the crude or more or less refined state has the object of reducing the specific gravity and otherwise improving the qualities of such oils. The oil to be treated is put into any ordinary still and distilled. The vapor escaping during the distillation is passed through one or more heating vessels or chambers and exposed to the heat necessary to produce the change. The heating vessels or chambers may be made of metal, clay, or any other material adapted to endure heat, and they may be made of any desired form, or they may be constituted of a coil of metal pipes or a series of tubes such as are used for heating air for blast furnaces.

  2. Efficiency of lipopeptide biosurfactants in removal of petroleum hydrocarbons and heavy metals from contaminated soil.

    Science.gov (United States)

    Singh, Anil Kumar; Cameotra, Swaranjit Singh

    2013-10-01

    This study describes the potential application of lipopeptide biosurfactants in removal of petroleum hydrocarbons and heavy metals from the soil samples collected from industrial dumping site. High concentrations of heavy metals (like iron, lead, nickel, cadmium, copper, cobalt and zinc) and petroleum hydrocarbons were present in the contaminated soil samples. Lipopeptide biosurfactant, consisting of surfactin and fengycin was obtained from Bacillus subtilis A21. Soil washing with biosurfactant solution removed significant amount of petroleum hydrocarbon (64.5 %) and metals namely cadmium (44.2 %), cobalt (35.4 %), lead (40.3 %), nickel (32.2 %), copper (26.2 %) and zinc (32.07 %). Parameters like surfactant concentration, temperature, agitation condition and pH of the washing solution influenced the pollutant removing ability of biosurfactant mixture. Biosurfactant exhibited substantial hydrocarbon solubility above its critical micelle concentration. During washing, 50 % of biosurfactant was sorbed to the soil particles decreasing effective concentration during washing process. Biosurfactant washed soil exhibited 100 % mustard seed germination contradictory to water washed soil where no germination was observed. The results indicate that the soil washing with mixture of lipopeptide biosurfactants at concentrations above its critical micelle concentration can be an efficient and environment friendly approach for removing pollutants (petroleum hydrocarbon and heavy metals) from contaminated soil.

  3. Hydrocarbon degradation potential in reference soils and soils contaminated with jet fuel

    International Nuclear Information System (INIS)

    Lee, R.F.; Hoeppel, R.

    1991-01-01

    Petroleum degradation in surface and subsurface soils is affected by such factors as moisture content, pH, soil type, soil organics, temperature, and oxygen concentrations. In this paper, the authors determine the degradation rates of 14 C-labeled hydrocarbons added to soils collected from a contaminated surface site, contaminated subsurface sites, and a clean reference site. The radiolabeled hydrocarbons used include benzene, toluene, naphthalene, 1-methynaphthalene, phenanthrene, fluorene, anthracene, chrysene, and hexadecane. Microbial degradation rates were based on determination of mineralization rates (production of 14 CO 2 ) of hydrocarbons that were added to soil samples. Since water was added and oxygen was not limiting, the hydrocarbon rates determined are likely to be higher than those occurring in situ. Using radiolabeled hydrocarbons, information can be provided on differences in the degradation rates of various petroleum compounds in different types of soils at a site, on possible production of petroleum metabolites in the soil, and on the importance of anaerobic petroleum degradation and the effects of nutrient, water, and surfactant addition on biodegradation rates

  4. Formation of Monocrystalline 1D and 2D Architectures via Epitaxial Attachment: Bottom-Up Routes through Surfactant-Mediated Arrays of Oriented Nanocrystals.

    Science.gov (United States)

    Nakagawa, Yoshitaka; Kageyama, Hiroyuki; Oaki, Yuya; Imai, Hiroaki

    2015-06-09

    Monocrystalline architectures with well-defined shapes were achieved by bottom-up routes through epitaxial attachment of Mn3O4 nanocrystals. The crystallographically continuous 1D chains elongated in the a axis and 2D panels having large a or c faces were obtained by removal of the organic mediator from surfactant-mediated 1D and 2D arrays of Mn3O4 nanocrystals, respectively. Our basal approach indicates that the epitaxial attachment through the surfactant-mediated arrays is utilized for fabrication of a wide variety of micrometric architectures from nanometric crystalline units.

  5. TOXICITY COMPARISON OF BIOSURFACTANTS AND SYNTHETIC SURFACTANTS USED IN OIL SPILL REMEDIATION TO TWO ESTUARINE SPECIES

    Science.gov (United States)

    The relative environmental toxicities of synthetic and biogenic surfactants used in oil spill remediation efforts are not well understood. Acute and chronic toxicities of three synthetic surfactants and three microbially produced surfactants were determined and compared in this s...

  6. Influence of pulmonary surfactant on in vitro bactericidal activities of amoxicillin, ceftazidime, and tobramycin

    NARCIS (Netherlands)

    A. van 't Veen (Annemarie); J.W. Mouton (Johan); D.A.M.P.J. Gommers (Diederik); J.A.J.W. Kluytmans (Jan); P. Dekkers; B.F. Lachmann (Burkhard)

    1995-01-01

    textabstractThe influence of a natural pulmonary surfactant on antibiotic activity was investigated to assess the possible use of exogenous surfactant as a vehicle for antibiotic delivery to the lung. The influence of surfactant on the bactericidal activity of

  7. Remediation of soils contaminated by PAHs using a sequential method: desorption with surfactant-electro-chemical degradation

    International Nuclear Information System (INIS)

    Alcantara, M. T.; Gomez, J.; Pazos, M.; Longo, M. A.; Sanroman, M. A.

    2009-01-01

    Polycyclic aromatic hydrocarbons (PAHs) cause a high environmental impact when released into the environment. Many PAHs can have detrimental effects on both the flora and fauna of affected habitats through uptake and accumulation in food chains, and in some instances, pose serious health problems and/or genetic defects in humans. (Author)

  8. Remediation of soils contaminated by PAHs using a sequential method: desorption with surfactant-electro-chemical degradation

    Energy Technology Data Exchange (ETDEWEB)

    Alcantara, M. T.; Gomez, J.; Pazos, M.; Longo, M. A.; Sanroman, M. A.

    2009-07-01

    Polycyclic aromatic hydrocarbons (PAHs) cause a high environmental impact when released into the environment. Many PAHs can have detrimental effects on both the flora and fauna of affected habitats through uptake and accumulation in food chains, and in some instances, pose serious health problems and/or genetic defects in humans. (Author)

  9. Enhancement of surfactant efficacy during the cleanup of engine oil contaminated soil using salt and multi-walled carbon nanotubes.

    Science.gov (United States)

    Bonal, Niteesh Singh; Paramkusam, Bala Ramudu; Basudhar, Prabir Kumar

    2018-06-05

    The study aims to enhance the efficacy of surfactants using salt and multi-walled carbon nanotubes (MWCNT) for washing used engine oil (UEO) contaminated soil and compare the geotechnical properties of contaminated soil before and after washing (batch washing and soil washing). From batch washing of the contaminated soil the efficacy of the cleaning process is established. Contamination of soil with hydrocarbons present in UEO significantly affects its' engineering properties manifesting in no plasticity and low specific gravity; the corresponding optimum moisture content value is 6.42% while maximum dry density is 1.770 g/cc, which are considerably lower than those of the uncontaminated soil. The result also showed decrease in the values of cohesion intercept and increase in the friction angle values. The adopted soil washing technique resulted increase in specific gravity from 1.85 to 2.13 and cohesion from 0.443 to 1.04 kg/cm 2 and substantial decrease in the friction angle from 31.16° to 17.14° when washed with most efficient combination of SDS surfactant along with sodium meta-silicate (salt) and MWCNT. Effectiveness of the washing of contaminated soil by batch processing and soil washing techniques has been established qualitatively. The efficiency of surfactant treatment has been observed to be increased significantly by the addition of salt and MWCNT. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Polycyclic aromatic hydrocarbons in Saccoglossus kowalewskyi (Agassiz)

    Science.gov (United States)

    Carey, D. A.; Farrington, J. W.

    1989-08-01

    Hydrocarbon extracts were analyzed from Saccoglossus kowalewskyi, a deposit-feeding enteropneust worm, and from surface sediments from Cape Cod, MA. Worms were held in experimental aquaria in sieved sediments and flowing seawater for four months and then fed sediments mixed with creosote, lampblack or clean sediment for two weeks as analogues of sediments containing degraded oil and pyrogenic compounds. Worms from all treatments contained polyaromatic hydrocarbons (PAHs) in amounts and composition that indicate that the worms were contaminated with weathered No. 2 fuel oil before our experimental treatment and that the contamination persisted for four months in clean conditions. The contamination was not detected in the clean sediments used in the experiment. The worms accumulated steroid transformation products in greater abundance than the odd chain n-alkanes that dominated the sediment extractions. This may indicate selective assimilation of algal detritus and microbial products over salt marsh detritus. Worms, actively feeding during the experiment, contained 1-3 × 10 -6 g g -1 dry weight of unknown brominated compounds which were not detected in the sediments. These compounds are similar to bromopyrroles found elsewhere in enteropneusts, polychaetes and bacteria and may cause substantial interference in analyses for some industrial pollutants.

  11. 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

  12. Identifying the Imprint of Surfactant Stabilisation in Whitecap Foam Evolution

    Science.gov (United States)

    Callaghan, A. H.; Deane, G. B.; Stokes, D.

    2016-02-01

    Surfactants are ubiquitous in the world's oceans and can affect climatically-relevant processes such as air-sea gas exchange, sea spray aerosol (SSA) flux, and air-sea momentum transfer. Surfactants are amphiphilic and help form the physically and chemically distinct ocean surface microlayer (SML), however, the spatial distribution, concentration and composition of the SML is not well understood, especially under conditions of vigorous wave breaking. Like the SML, breaking waves also influence physical exchange processes at the air-sea interface, and oceanic whitecap foam coverage is commonly used to quantify bubble-mediated exchange processes. However, surfactants can increase the lifetime of foam over clean water conditions, potentially complicating the use of whitecap coverage to parameterise air-sea gas exchange and SSA production flux. A better understanding of how surfactants affect the evolution of whitecap foam is needed to improve whitecap parameterisations of bubble-mediated processes, and may also provide a remote sensing approach to map the spatial distribution of surfactants at the water surface. Here we present results from a laboratory study that looked at whitecap foam evolution in "clean" and "surfactant-added" seawater regimes. We find that the whitecap foam area growth timescale is largely insensitive to the presence of surfactants, but that surfactant stabilization of whitecap foam becomes important during the whitecap foam area decay phase. The timescale at which this occurs appears to be consistent for breaking waves of different scale and intensity. A simple method is then used to isolate the surfactant signal and derive an equivalent "clean" seawater foam decay time for the whitecaps in the "surfactant-added" regime. The method is applied to oceanic whitecaps and results compared to the laboratory whitecaps from the "clean" and "surfactant-added" regimes.

  13. Surfactant-enhanced control of track-etch pore morphology

    International Nuclear Information System (INIS)

    Apel', P.Yu.; Blonskaya, I.V.; Didyk, A.Yu.; Dmitriev, S.N.; Orelovich, O.L.; Samojlova, L.I.; Vutsadakis, V.A.; Root, D.

    2000-01-01

    The influence of surfactants on the process of chemical development of ion tracks in polymers is studied. Based on the experimental data, a mechanism of the surfactant effect on the track-etch pore morphology is proposed. In the beginning of etching the surfactant is adsorbed on the surface and creates a layer that is quasi-solid and partially protects the surface from the etching agent. However, some etchant molecules diffuse through the barrier and react with the polymer surface. This results in the formation of a small hole at the entrance to the ion track. After the hole has attained a few annometers in diameter, the surfactant molecules penetrate into the track and cover its walls. Further diffusion of the surfactant into the growing pore is hindered. The adsorbed surfactant layer is not permeable for large molecules. In contrast, small alkali molecules and water molecules diffuse into the track and provide the etching process enlarging the pore. At this stage the transport of the surfactant into the pore channel can proceed only due to the lateral diffusion in the adsorbed layer. The volume inside the pore is free of surfactant molecules and grows at a higher rate than pore entrance. After a more prolonged etching the bottle-like (or 'cigar-like') pore channels are formed. The bottle-like shape of the pore channels depends on the etching conditions such as alkali and surfactant concentration, temperature, and type of the surfactant. The use of surfactants enables one to produce track-etch membranes with improved flow rate characteristics compared with those having cylindrical pores with the same nominal pore diameters

  14. Neonatal varicella pneumonia, surfactant replacement therapy

    Directory of Open Access Journals (Sweden)

    Mousa Ahmadpour-kacho

    2015-12-01

    Full Text Available Background: Chickenpox is a very contagious viral disease that caused by varicella-zoster virus, which appears in the first week of life secondary to transplacental transmission of infection from the affected mother. When mother catches the disease five days before and up to two days after the delivery, the chance of varicella in neonate in first week of life is 17%. A generalized papulovesicular lesion is the most common clinical feature. Respiratory involvement may lead to giant cell pneumonia and respiratory failure. The mortality rate is up to 30% in the case of no treatment, often due to pneumonia. Treatment includes hospitalization, isolation and administration of intravenous acyclovir. The aim of this case report is to introduce the exogenous surfactant replacement therapy after intubation and mechanical ventilation for respiratory failure in neonatal chickenpox pneumonia and respiratory distress. Case Presentation: A seven-day-old neonate boy was admitted to the Neonatal Intensive Care Unit at Amirkola Children’s Hospital, Babol, north of Iran, with generalized papulovesicular lesions and respiratory distress. His mother has had a history of Varicella 4 days before delivery. He was isolated and given supportive care, intravenous acyclovir and antibiotics. On the second day, he was intubated and connected to mechanical ventilator due to severe pneumonia and respiratory failure. Because of sever pulmonary involvement evidenced by Chest X-Ray and high ventilators set-up requirement, intratracheal surfactant was administered in two doses separated by 12 hours. He was discharged after 14 days without any complication with good general condition. Conclusion: Exogenous surfactant replacement therapy can be useful as an adjunctive therapy for the treatment of respiratory failure due to neonatal chickenpox.

  15. Molecular dynamics of surfactant protein C

    DEFF Research Database (Denmark)

    Ramírez, Eunice; Santana, Alberto; Cruz, Anthony

    2006-01-01

    Surfactant protein C (SP-C) is a membrane-associated protein essential for normal respiration. It has been found that the alpha-helix form of SP-C can undergo, under certain conditions, a transformation from an alpha-helix to a beta-strand conformation that closely resembles amyloid fibrils, which...... are possible contributors to the pathogenesis of pulmonary alveolar proteinosis. Molecular dynamics simulations using the NAMD2 package were performed for systems containing from one to seven SP-C molecules to study their behavior in water. The results of our simulations show that unfolding of the protein...

  16. High Pressure Preignition Chemistry of Hydrocarbons and Hydrocarbon Mixtures

    National Research Council Canada - National Science Library

    Cernansky, N.P

    1998-01-01

    .... The research program entailed mechanistic studies examining the oxidation chemistry of single-component hydrocarbons and ignition studies examining the overall ignition of pure single component fuels and fuel blends...

  17. Microfluidic processing of concentrated surfactant mixtures: online SAXS, microscopy and rheology.

    Science.gov (United States)

    Martin, Hazel P; Brooks, Nicholas J; Seddon, John M; Luckham, Paul F; Terrill, Nick J; Kowalski, Adam J; Cabral, João T

    2016-02-14

    We investigate the effect of microfluidic flow on the microstructure and dynamics of a model surfactant mixture, combining synchrotron Small Angle X-ray Scattering (SAXS), microscopy and rheology. A system comprising a single-chain cationic surfactant, hexadecyl trimethyl ammonium chloride (C16TAC), a short-chain alcohol (1-pentanol) and water was selected for the study due to its flow responsiveness and industrial relevance. Model flow fields, including sequential contraction-expansion (extensional) and rotational flows, were investigated and the fluid response in terms of the lamellar d-spacing, orientation and birefringence was monitored in situ, as well as the recovery processes after cessation of flow. Extensional flows are found to result in considerable d-spacing increase (from approx 59 Å to 65 Å). However, under continuous flow, swelling decreases with increasing flow velocity, eventually approaching the equilibrium values at velocities ≃2 cm s(-1). Through individual constrictions we observe the alignment of lamellae along the flow velocity, accompanied by increasing birefringence, followed by an orientation flip whereby lamellae exit perpendicularly to the flow direction. The resulting microstructures are mapped quantitatively onto the flow field in 2D with 200 μm spatial resolution. Rotational flows alone do not result in appreciable changes in lamellar spacing and flow type and magnitude evidently impact the fluid microstructure under flow, as well as upon relaxation. The findings are correlated with rheological properties measured ex situ to provide a mechanistic understanding of the effect of flow imposed by tubular processing units in the phase behavior and performance of a model surfactant system with ubiquitous applications in personal care and coating industries.

  18. Radiation induced solid-state polymerization of long-chain acrylates containing fluorocarbon chain

    International Nuclear Information System (INIS)

    Shibasaki, Y.; Zhu, Zhi-Qin

    1995-01-01

    γ-Ray irradiation post-polymerizations of long-chain acrylates containing fluorocarbon chain, H(CF 2 ) 10 CH 2 OCOCH=CH 2 and H(CF 2 ) 8 CH 2 OCOCH=CH 2 , were investigated and also the structures and thermal properties of comb-like polymers obtained were studied. It was found that these monomers exhibited very high polymerizability at wide temperature ranges around the melting points. Because the fluorocarbon chains are less flexible and thicker than the hydrocarbon chains, it can be expected that the aggregation force among the monomer molecules is strong and the conformational freedom of functional group for polymerization is large. According to the DSC and the X-ray diffraction measurements of the comb-like polymers obtained, the fluorocarbon chains are aggregated in a mode of hexagonal packing in the lamellar crystals. This situation can be considered as an optimum condition for the γ-ray irradiation post-polymerization. (author)

  19. Evaluation of synthetic hydrocarbons for mark-recapture studies on the red milkweed beetle.

    Science.gov (United States)

    Ginzel, Matthew D; Hanks, Lawrence M

    2002-05-01

    This study evaluates the potential for using blends of synthetic hydrocarbons in mark-recapture studies of insects. To test the durability of hydrocarbons, we applied a blend of five straight-chain hydrocarbons (C24, C21, C26. C28, C30) to detached elytra of the red milkweed beetle, Tetraopes tetrophthalmus (Forster) (Coleoptera: Cerambycidae), mounted the elytra on pins, and placed them in an exposed location outdoors. The amount of hydrocarbons on the elytra did not change over time, even after two months of exposure to sun and rain. Synthetic hydrocarbons applied to the elytra of living beetles did not significantly influence their longevity or mating success in a laboratory study. and the amounts of hydrocarbons did not change with age. The invariability of hydrocarbon ratios over time suggests that blends could provide a nearly infinite variety of ratios to mark individual insects uniquely and indelibly with a hydrocarbon "fingerprint." This technique offers a convenient, safe, and durable means of individually marking insects and may find application in field studies of larger bodied insects that are long-lived and sedentary.

  20. Calculating in situ degradation rates of hydrocarbon compounds in deep waters of the Gulf of Mexico.

    Science.gov (United States)

    Thessen, Anne E; North, Elizabeth W

    2017-09-15

    Biodegradation is an important process for hydrocarbon weathering that influences its fate and transport, yet little is known about in situ biodegradation rates of specific hydrocarbon compounds in the deep ocean. Using data collected in the Gulf of Mexico below 700m during and after the Deepwater Horizon oil spill, we calculated first-order degradation rate constants for 49 hydrocarbons and inferred degradation rate constants for an additional 5 data-deficient hydrocarbons. Resulting calculated (not inferred) half-lives of the hydrocarbons ranged from 0.4 to 36.5days. The fastest degrading hydrocarbons were toluene (k=-1.716), methylcyclohexane (k=-1.538), benzene (k=-1.333), and C1-naphthalene (k=-1.305). The slowest degrading hydrocarbons were the large straight-chain alkanes, C-26 through C-33 (k=-0.0494 through k=-0.007). Ratios of C-18 to phytane supported the hypothesis that the primary means of degradation in the subsurface was microbial biodegradation. These degradation rate constants can be used to improve models describing the fate and transport of hydrocarbons in the event of an accidental deep ocean oil spill. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. The Effect of Surfactants on Gas-Liquid Pipe Flows

    NARCIS (Netherlands)

    Van Nimwegen, A.T.

    2015-01-01

    Liquid loading is a major problem in the natural gas industry, in which gas production is limited by the accumulation of liquids in the well tubing. Liquid loading can be prevented by the injection of surfactants at the bottom of the well. The surfactants cause the liquid in the well to foam,

  2. 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.,

  3. Surfactant induced flows in thin liquid films : an experimental study

    NARCIS (Netherlands)

    Sinz, D.K.N.

    2012-01-01

    The topic of the experimental work summarized in my thesis is the flow in thin liquid films induced by non-uniformly distributed surfactants. The flow dynamics as a consequence of the deposition of a droplet of an insoluble surfactant onto a thin liquid film covering a solid substrate where

  4. 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

  5. Marangoni flows induced by non-uniform surfactant distributions

    NARCIS (Netherlands)

    Hanyak, M.

    2012-01-01

    The spreading dynamics of surfactants is of crucial importance for numerous technological applications ranging from printing and coating processes, pulmonary drug delivery to crude oil recovery. In the area of inkjet printing surfactants are necessary for lowering surface tension of water-based ink

  6. 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.

  7. Binding of alkylpyridinium chloride surfactants to sodium polystyrene sulfonate

    NARCIS (Netherlands)

    Ishiguro, M.; Koopal, L.K.

    2009-01-01

    Binding of cationic surfactants to anionic polymers is well studied. However, the surfactant binding characteristics at very low concentration near the start of binding and at high concentration, where charge compensation may Occur. are less well known. Therefore, the binding characteristics of

  8. Adsorption and intercalation of anionic surfactants onto layered ...

    Indian Academy of Sciences (India)

    Layered double hydroxides (LDH) with brucite like structure was modified with various anionic surfactants containing sulfonate, carboxyl, phosphonate and sulfate end group through ion-exchange method. XRD reports indicated that the sulfonate group containing surfactants led to an adsorption process whereas the sulfate ...

  9. 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 ...

  10. Photoisomerization of merocyanine 540 in polymer-surfactant ...

    Indian Academy of Sciences (India)

    Photoisomerization of merocyanine 540 (MC540) in a polymer-surfactant aggregate is studied using picosecond time resolved emission spectroscopy. The aggregate consists of the polymer, poly(vinylpyrrolidone) (PVP) and the surfactant, sodium dodecyl sulphate (SDS). With increase in the concentration of SDS in an ...

  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. Polymeric surfactants for enhanced oil recovery : A review

    NARCIS (Netherlands)

    Raffa, Patrizio; Broekhuis, Antonius A.; Picchioni, Francesco

    Chemical enhanced oil recovery (EOR) is surely a topic of interest, as conventional oil resources become more scarce and the necessity of exploiting heavy and unconventional oils increases. EOR methods based on polymer flooding, surfactant-polymer flooding and alkali-surfactant-polymer flooding are

  13. 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 ...

  14. Growth of hydrocarbon utilizing microorganisms

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Mavinkurve, S.

    Two isolates from marine mud having broad spectrum hydrocarbon utilizing profile were identified as Arthrobacter simplex and Candida tropicalis.Both the organisms grew exponentially on crude oil. The cell yield of the organisms was influenced...

  15. Process for treating hydrocarbons, etc

    Energy Technology Data Exchange (ETDEWEB)

    1933-09-15

    A process is described for treating simultaneously bituminous substances and hydrocarbon oils for the production of low-boiling hydrocarbons and volatilization of the bituminous substances, characterized by the fact that it consists of heating a current of charge constituted by a mixture of the bituminous substances and hydrocarbon oils, to a high temperature, passing the heated current into a zone of extended reaction where the vapors are separated from the liquid or solid residue to favor transformation of the liquid hydrocarbons and volatilization of the bituminous substances, owing to the utilization of a heating agent carried to a high temperature being brought in contact with the heated charge in order to communicate its heat to the charge, while this later presents itself as relatively fine pellet or in the condition of distinct particles, particularly separated from one another.

  16. Pulmonary Surfactants for Acute and Chronic Lung Diseases (Part II

    Directory of Open Access Journals (Sweden)

    O. A. Rozenberg

    2014-01-01

    Full Text Available Part 2 of the review considers the problem of surfactant therapy for acute respiratory distress syndrome (ARDS in adults and young and old children. It gives information on the results of surfactant therapy and prevention of ARDS in patients with severe concurrent trauma, inhalation injuries, complications due to complex expanded chest surgery, or severe pneumonias, including bilateral pneumonia in the presence of A/H1N1 influenza. There are data on the use of a surfactant in obstetric care and prevention of primary graft dysfunction during lung transplantation. The results of longterm use of surfactant therapy in Russia, suggesting that death rates from ARDS may be substantially reduced (to 20% are discussed. Examples of surfactant therapy for other noncritical lung diseases, such as permanent athelectasis, chronic obstructive pulmonary diseases, and asthma, as well tuberculosis, are also considered.

  17. Des surfactants « verts » préparés à partir de fractions protéiques industrielles de colza

    Directory of Open Access Journals (Sweden)

    Larré Colette

    2003-09-01

    Full Text Available Edible surfactants were prepared from rapeseed meal by functionalization of two types of products: proteins or peptide fractions obtained by enzymatical hydrolysis. Functionalization aimed to enhance the amphophilic characteristics of the products by grafting hydrophobic chains\\; it was based on acylation or sulfamidation of proteins and acylation of peptides. The interfacial properties of these “green” surfactants measured by lowering the surface tension, and increasing the stability of foams and emulsions, were improved, depending on the chemical reagent used. For example, peptides modified by C1 4 acyl chlorides exhibited the better emulsifying properties, whereas the better foaming properties were obtained with peptides modified by C 10 and C 12 acyl chlorides. These surfactants could diversify the uses of rapeseed derivatives, particularly in non food industries.

  18. Investigations into surfactant/gas hydrate relationship

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, Rudy; Zhang, Guochang; Dearman, Jennifer; Woods, Charles [Swalm School of Chemical Engineering, Mississippi State University, Mississippi State, MS 39762 (United States)

    2007-03-15

    Gas hydrates have unique physical properties portending useful industrial applications of gas storage, gas separation, or water desalination. When gas hydrates were found in the early 1990s to occur naturally and abundantly in seafloors, three other primary interests and concerns emerged: potential new energy source, climate threat from their greenhouse gases, and seafloor instabilities. This paper presents research showing how anionic synthetic surfactants helped develop an industrial gas hydrate storage process for natural gas and how naturally-occurring in-situ anionic biosurfactants influence the formation and placement of gas hydrates in ocean sediments. The catalytic effects, mechanisms, and surface specificities imparted by synthetic surfactants in the gas storage process and imparted by biosurfactants in porous media are discussed. The Bacillus subtilis bacterium that is indigenous to gas hydrate mounds in the Gulf of Mexico was cultured in the laboratory. Its biosurfactant was separated and found to catalyze gas hydrates in porous media. The experiments indicate that seafloor-biosurfactants can be produced rapidly in-situ to achieve threshold concentrations whereby hydrates are promoted. The biosurfactants accumulate and promote hydrate formation on specific mineral surfaces such as sodium montmorillonite. (author)

  19. Reversal of multidrug resistance by surfactants.

    Science.gov (United States)

    Woodcock, D. M.; Linsenmeyer, M. E.; Chojnowski, G.; Kriegler, A. B.; Nink, V.; Webster, L. K.; Sawyer, W. H.

    1992-01-01

    Cremophor EL, a pharmacologically inactive solubilising agent, has been shown to reverse multidrug resistance (MDR). Using flow cytometric evaluation of equilibrium intracellular levels of daunorubicin (DNR), we found that eight other surface active agents will also reverse MDR. All the active detergents contain polyethoxylated moieties but have no similarities in their hydrophobic components. The properties of three polyethoxylated surfactants that showed the lowest toxicities, Cremophor, Tween 80 and Solutol HS15, were examined in more detail. The concentrations of Tween 80 and Solutol required to reverse DNR exclusion were 10-fold lower than for Cremophor. However while concentrations greater than or equal to 1:10(2) of the former two surfactants resulted in breakdown of cells, even 1:10 of Cremophor did not lyse cells. Studies of the effects of Cremophor on the uptake and efflux of DNR in normal and MDR cell types showed that Cremophor increases intracellular DNR primarily by locking the rapid efflux from the cells. This blockage of drug efflux may be mediated by a substantial alteration in the fluidity of cell membranes induced by Cremophor, as shown by decreased fluorescence anisotropy of a membrane probe. Consistent with these data, coinjection of adriamycin plus Cremophor into mice carrying a multidrug resistant P388 transplantable tumour significantly increased the survival time of the mice compared with adriamycin treatment alone. PMID:1637678

  20. 3D Model of Surfactant Replacement Therapy

    Science.gov (United States)

    Grotberg, James; Tai, Cheng-Feng; Filoche, Marcel

    2015-11-01

    Surfactant Replacement Therapy (SRT) involves instillation of a liquid-surfactant mixture directly into the lung airway tree. Though successful in neonatal applications, its use in adults had early success followed by failure. We present the first mathematical model of 3D SRT where a liquid plug propagates through the tree from forced inspiration. In two separate modeling steps, the plug first deposits a coating film on the airway wall which subtracts from its volume, a ``coating cost''. Then the plug splits unevenly at the airway bifurcation due to gravity. The steps are repeated until a plug ruptures or reaches the tree endpoint alveoli/acinus. The model generates 3D images of the resulting acinar distribution and calculates two global indexes, efficiency and homogeneity. Simulating published literature, the earlier successful adult SRT studies show comparatively good index values, while the later failed studies do not. Those unsuccessful studies used smaller dose volumes with higher concentration mixtures, apparently assuming a well mixed compartment. The model shows that adult lungs are not well mixed in SRT due to the coating cost and gravity effects. Returning to the higher dose volume protocols could save many thousands of lives annually in the US. Supported by NIH Grants HL85156, HL84370 and Agence Nationale de la Recherche, ANR no. 2010-BLAN-1119-05.

  1. Surfactant secretion and clearance in the newborn

    International Nuclear Information System (INIS)

    Stevens, P.A.; Wright, J.R.; Clements, J.A.

    1989-01-01

    Pregnant rabbits (30 days) were injected intravenously with [3H]choline 8 h before delivery. The fetuses were delivered, and lung lavage and lamellar body phospholipids (PL) were analyzed. Some newborns also received radioactively labeled surfactant intratracheally on delivery and were permitted to breathe. With time, intratracheal label decreased in lavage and appeared in the lamellar body fraction, and intravenous label accumulated in both pools. Using a tracer analysis for non-steady state, we calculated surfactant secretion and clearance rates for the newborn period. Before birth, both rates rose slightly from 1.8 micrograms PL.g body wt-1.h-1 at 6 h before birth to 7.3 at birth. Immediately after birth, secretion rate rose to 37.7 micrograms PL.g body wt-1.h-1. Between 1.5 and 2 h after birth it fell to a minimum of 1.8 micrograms PL.g body wt-1.h-1 and then rose slowly to 6.0 at 12 h. After birth, clearance rate increased less than secretion rate (maximum 24.7 micrograms PL.g body wt-1.h-1 shortly after birth) then followed the same pattern but did not balance secretion rate in the 1st day

  2. Predicting hydrocarbon release from soil

    International Nuclear Information System (INIS)

    Poppendieck, D.; Loehr, R.C.

    2002-01-01

    'Full text:' The remediation of hazardous chemicals from soils can be a lengthy and costly process. As a result, recent regulatory initiatives have focused on risk-based corrective action (RBCA) approaches. Such approaches attempt to identify the amount of chemical that can be left at a site with contaminated soil and still be protective of human health and the environment. For hydrocarbons in soils to pose risk to human heath and the environment, the hydrocarbons must be released from the soil and accessible to microorganisms, earthworms, or other higher level organisms. The sorption of hydrocarbons to soil can reduce the availability of the hydrocarbon to receptors. Typically in soils and sediments, there is an initial fast release of a hydrocarbon from the soil to the aqueous phase followed by a slower release of the remaining hydrocarbon to the aqueous phase. The rate and extent of slow release can influence aqueous hydrocarbon concentrations and the fate and transport of hydrocarbons in the subsurface. Once the fast fraction of the chemical has been removed from the soil, the remaining fraction of a chemical may desorb at a rate that natural mechanisms can attenuate the released hydrocarbon. Hence, active remediation may be needed only until the fast fraction has been removed. However, the fast fraction is a soil and chemical specific parameter. This presentation will present a tier I type protocol that has been developed to quickly estimate the fraction of hydrocarbons that are readily released from the soil matrix to the aqueous phase. Previous research in our laboratory and elsewhere has used long-term desorption (four months) studies to determine the readily released fraction. This research shows that a single short-term (less than two weeks) batch extraction procedure provides a good estimate of the fast released fraction derived from long-term experiments. This procedure can be used as a tool to rapidly evaluate the release and bioavailability of

  3. Characterization of cyanobacterial hydrocarbon composition and distribution of biosynthetic pathways.

    Directory of Open Access Journals (Sweden)

    R Cameron Coates

    Full Text Available Cyanobacteria possess the unique capacity to naturally produce hydrocarbons from fatty acids. Hydrocarbon compositions of thirty-two strains of cyanobacteria were characterized to reveal novel structural features and insights into hydrocarbon biosynthesis in cyanobacteria. This investigation revealed new double bond (2- and 3-heptadecene and methyl group positions (3-, 4- and 5-methylheptadecane for a variety of strains. Additionally, results from this study and literature reports indicate that hydrocarbon production is a universal phenomenon in cyanobacteria. All cyanobacteria possess the capacity to produce hydrocarbons from fatty acids yet not all accomplish this through the same metabolic pathway. One pathway comprises a two-step conversion of fatty acids first to fatty aldehydes and then alkanes that involves a fatty acyl ACP reductase (FAAR and aldehyde deformylating oxygenase (ADO. The second involves a polyketide synthase (PKS pathway that first elongates the acyl chain followed by decarboxylation to produce a terminal alkene (olefin synthase, OLS. Sixty-one strains possessing the FAAR/ADO pathway and twelve strains possessing the OLS pathway were newly identified through bioinformatic analyses. Strains possessing the OLS pathway formed a cohesive phylogenetic clade with the exception of three Moorea strains and Leptolyngbya sp. PCC 6406 which may have acquired the OLS pathway via horizontal gene transfer. Hydrocarbon pathways were identified in one-hundred-forty-two strains of cyanobacteria over a broad phylogenetic range and there were no instances where both the FAAR/ADO and the OLS pathways were found together in the same genome, suggesting an unknown selective pressure maintains one or the other pathway, but not both.

  4. Hydrocarbon removal with constructed wetlands

    OpenAIRE

    Eke, Paul Emeka

    2008-01-01

    Wetlands have long played a significant role as natural purification systems, and have been effectively used to treat domestic, agricultural and industrial wastewater. However, very little is known about the biochemical processes involved, and the use of constructed treatment wetlands in the removal of petroleum aromatic hydrocarbons from produced and/or processed water. Wastewaters from the oil industry contain aromatic hydrocarbons such as benzene, toluene, ethylbenzene and x...

  5. Bioassay of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Van Kirk, E.A.

    1980-08-01

    A positive relationship was found between the photodynamic activity of 24 polycyclic aromatic hydrocarbons versus published results on the mutagenicity, carcinogenicity, and initiation of unscheduled DNA synthesis. Metabolic activation of benzo(a)pyrene resulted in detection of increased mutagenesis in Paramecium tetraurelia as found also in the Ames Salmonella assay. The utility of P. tetraurelia as a biological detector of hazardous polycyclic aromatic hydrocarbons is discussed.

  6. Surfactant-enhanced bioremediation of PAH- and PCB-contaminated soils

    International Nuclear Information System (INIS)

    Ghosh, M.M.; Yeom, I.T.; Shi, Z.; Cox, C.D.; Robinson, K.G.

    1995-01-01

    The role of surfactants in the desorption of soil-bound polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) was investigated. The solubilization of individual PAHs in an extract of a weathered, coal tar-contaminated soil containing a mixture of PAHs and other petroleum derivatives was found to be significantly less than that for pure compounds. Batch soil washing with Triton X-100 (a commercial, nonionic alkyl phenol ethoxylate) was found to increase the effective diffusion rate of PAHs from the contaminated soil by four orders of magnitude compared to that obtained by gas purging when the results were analyzed using a radial diffusion model. At concentrations of up to 24 times its critical micelle concentration (CMC), Triton X-100 did not seem to enhance hydrocarbon degradation in the coal tar-contaminated soil; however, the biosurfactant rhamnolipid R1, at a concentration of 50x CMC, increased the rate of mineralization of 4,4'-chlorinated biphenyl mobilized from a laboratory-contaminated soil by more than 60 times

  7. Electrostatically atomised hydrocarbon sprays

    Energy Technology Data Exchange (ETDEWEB)

    Yule, A.J.; Shrimpton, J.S.; Watkins, A.P.; Balachandran, W.; Hu, D. [UMIST, Manchester (United Kingdom). Thermofluids Division, Dept. of Mechanical Engineering

    1995-07-01

    A burner using an electrostatic method to produce and control a fuel spray is investigated for non-burning sprays. The burner has a charge injection nozzle and the liquid flow rate and charge injection rate are varied using hydrocarbon liquids of differing viscosities, surface tensions and electrical conductivities (kerosene, white spirit and diesel oil). Droplet size distributions are measured and it is shown how the dropsize, spray pattern, breakup mechanism and breakup length depend on the above variables, and in particular on the specific charge achieved in the spray. The data are valuable for validating two computer models under development. One predicts the electric field and flow field inside the nozzle as a function of emitter potential, geometry and flow rate. The other predicts the effect of charge on spray dispersion, with a view to optimizing spray combustion. It is shown that electrostatic disruptive forces can be used to atomize oils at flow rates commensurate with practical combustion systems and that the charge injection technique is particularly suitable for highly resistive liquids. Possible limitations requiring further research include the need to control the wide spray angle, which may provide fuel-air mixtures too lean near the nozzle, and the need to design for maximum charge injection rate, which is thought to be limited by corona breakdown in the gas near the nozzle orifice. 30 refs., 15 figs., 1 tab.

  8. HYDROCARBONS RESERVES IN VENEZUELA

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Cruz, D.J.

    2007-07-01

    Venezuela is an important player in the energy world, because of its hydrocarbons reserves. The process for calculating oil and associated gas reserves is described bearing in mind that 90% of the gas reserves of Venezuela are associated to oil. Likewise, an analysis is made of the oil reserves figures from 1975 to 2003. Reference is also made to inconsistencies found by international experts and the explanations offered in this respect by the Ministry of Energy and Petroleum (MENPET) and Petroleos de Venezuela (PDVSA) regarding the changes that took place in the 1980s. In turn, Hubbert's Law is explained to determine peak production of conventional oil that a reservoir or field will reach, as well as its relationship with remaining reserves. Emphasis is placed on the interest of the United Nations on this topic. The reserves of associated gas are presented along with their relationship with the different crude oils that are produced and with injected gas, as well as with respect to the possible changes that would take place in the latter if oil reserves are revised. Some recommendations are submitted so that the MENPET starts preparing the pertinent policies ruling reserves. (auth)

  9. Evaluation of hydrocarbon potential

    International Nuclear Information System (INIS)

    Cashman, P.H.; Trexler, J.H. Jr.

    1992-01-01

    Task 8 is responsible for assessing the hydrocarbon potential of the Yucca Mountain vincinity. Our main focus is source rock stratigraphy in the NTS area in southern Nevada. (In addition, Trexler continues to work on a parallel study of source rock stratigraphy in the oil-producing region of east central Nevada, but this work is not funded by Task 8.) As a supplement to the stratigraphic studies, we are studying the geometry and kinematics of deformation at NTS, particularly as these pertain to reconstructing Paleozoic stratigraphy and to predicting the nature of the Late Paleozoic rocks under Yucca Mountain. Our stratigraphic studies continue to support the interpretation that rocks mapped as the open-quotes Eleana Formationclose quotes are in fact parts of two different Mississippian units. We have made significant progress in determining the basin histories of both units. These place important constraints on regional paleogeographic and tectonic reconstructions. In addition to continued work on the Eleana, we plan to look at the overlying Tippipah Limestone. Preliminary TOC and maturation data indicate that this may be another potential source rock

  10. 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.

  11. A multicenter, randomized trial comparing synthetic surfactant with modified bovine surfactant extract in the treatment of neonatal respiratory distress syndrome

    NARCIS (Netherlands)

    Adams, E; Vollman, J; Giebner, D; Maurer, M; Dreyer, G; Bailey, L; Anderson, M; Mefford, L; Beaumont, E; Sutton, D; Puppala, B; Mangurten, HH; Secrest, J; Lewis, WJ; Carteaux, P; Bednarek, F; Welsberger, S; Gosselin, R; Pantoja, AF; Belenky, A; Campbell, P; Patole, S; Duenas, M; Kelly, M; Alejo, W; Lewallen, P; DeanLieber, S; Hanft, M; Ferlauto, J; Newell, RW; Bagwell, J; Levine, D; Lipp, RW; Harkavy, K; Vasa, R; Birenbaum, H; Broderick, KA; Santos, AQ; Long, BA; Gulrajani, M; Stern, M; Hopgood, G; Hegyi, T; Alba, J; Christmas, L; McQueen, M; Nichols, N; Brown, M; Quissell, BJ; Rusk, C; Marks, K; Gifford, K; Hoehn, G; Pathak, A; Marino, B; Hunt, P; Fox, [No Value; Sharpstein, C; Feldman, B; Johnson, N; Beecham, J; Balcom, R; Helmuth, W; Boylan, D; Frakes, C; Magoon, M; Reese, K; Schwersenski, J; Schutzman, D; Soll, R; Horbar, JD; Leahy, K; Troyer, W; Juzwicki, C; Anderson, P; Dworsky, M; Reynolds, L; Urrutia, J; Gupta, U; Adray, C

    Objective. To compare the efficacy of a synthetic surfactant (Exosurf Neonatal, Burroughs-Wellcome Co) and a modified bovine surfactant extract (Survanta, Ross Laboratories) in the treatment of neonatal respiratory distress syndrome (RDS). Design. Multicenter, randomized trial. Setting. Thirty-eight

  12. APPLICATION OF FENTON’S REAGENT ON REMEDIATION OF POLYCYCLIC AROMATIC HYDROCARBONs (PAHs IN SPIKED SOIL

    Directory of Open Access Journals (Sweden)

    Nursiah La Nafie

    2010-06-01

    Full Text Available Problem associated with Polycyclic Aromatic Hydrocarbons (PAHs contaminated site in environmental media have received increasing attention. To resolve such problems, innovative in situ methods are urgently required. This work investigated the feasibility of using Fenton's Reagent to remediate PAHs in spiked soil. PAHs were spiked into soil to simulate contaminated soil. Fenton's Reagent (H2O2 + Fe2+ and surfactant were very efficient in destruction of PAHs including naphthalene, anthracene, fluoranthene, pyrene, and benzo(apyrene from spiked soil. It was indicated by the fact that more than 96% of PAHs were degraded in the solution and the spiked soil.   Keywords: Environmental, Fenton's Reagent, Polycyclic Aromatic Hydrocarbons, and Spiked soil.

  13. Modification of reduced-charge montmorillonites by a series of Gemini surfactants: Characterization and application in methyl orange removal

    International Nuclear Information System (INIS)

    Luo, Zhongxin; Gao, Manglai; Ye, Yage; Yang, Senfeng

    2015-01-01

    Highlights: • RCMs were modified by three Gemini surfactants with different spacer length. • The adsorption kinetics and thermodynamics of MO on organoclays were investigated. • Both the spacer length and clay layer charge have significant effects on the removal of MO. • The removal efficiency of MO increased with increasing clay layer charge. • Gemini surfactants modified RCMs were low-cost and high efficient adsorbents for the uptake of MO. - Abstract: The influences that the spacer chain length of Gemini surfactants and clay layer charge have on the structures and sorption characteristics of organoclays have been investigated. Organoclays were obtained by modifying a series of reduced charge montmorillonites (RCMs) using three Gemini surfactants with different spacer length. And their structures and sorption characteristics for methyl orange (MO) were examined. It was suggested that the amount, spacer length of Gemini surfactant and clay layer charge had significant effects on the microstructure of the organoclays. The adsorption experiments results claimed that the uptake of MO onto organoclays was in the order: 16-4-16-Mt > 16-8-16-Mt > 16-6-16-Mt, while it increased with increasing clay layer charge. The adsorption isotherms of MO onto the organoclays could be best described by Langmuir equation, and the adsorption kinetic was in good agreement with the pseudo-second-order model. Thermodynamic parameters demonstrated that the sorption process was spontaneous and endothermic in nature. This work will provide a deep insight into the interaction of Gemini-modified clays and MO, which pave the way for their practical applications in anionic dye adsorption

  14. Modification of reduced-charge montmorillonites by a series of Gemini surfactants: Characterization and application in methyl orange removal

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Zhongxin; Gao, Manglai, E-mail: mlgao@cup.edu.cn; Ye, Yage; Yang, Senfeng

    2015-01-01

    Highlights: • RCMs were modified by three Gemini surfactants with different spacer length. • The adsorption kinetics and thermodynamics of MO on organoclays were investigated. • Both the spacer length and clay layer charge have significant effects on the removal of MO. • The removal efficiency of MO increased with increasing clay layer charge. • Gemini surfactants modified RCMs were low-cost and high efficient adsorbents for the uptake of MO. - Abstract: The influences that the spacer chain length of Gemini surfactants and clay layer charge have on the structures and sorption characteristics of organoclays have been investigated. Organoclays were obtained by modifying a series of reduced charge montmorillonites (RCMs) using three Gemini surfactants with different spacer length. And their structures and sorption characteristics for methyl orange (MO) were examined. It was suggested that the amount, spacer length of Gemini surfactant and clay layer charge had significant effects on the microstructure of the organoclays. The adsorption experiments results claimed that the uptake of MO onto organoclays was in the order: 16-4-16-Mt > 16-8-16-Mt > 16-6-16-Mt, while it increased with increasing clay layer charge. The adsorption isotherms of MO onto the organoclays could be best described by Langmuir equation, and the adsorption kinetic was in good agreement with the pseudo-second-order model. Thermodynamic parameters demonstrated that the sorption process was spontaneous and endothermic in nature. This work will provide a deep insight into the interaction of Gemini-modified clays and MO, which pave the way for their practical applications in anionic dye adsorption.

  15. Surfactant protein B deficiency and gene mutations for neonatal respiratory distress syndrome in China Han ethnic population

    Science.gov (United States)

    Yin, Xiaojuan; Meng, Fanping; wang, Yan; Xie, Lu; Kong, Xiangyong; Feng, Zhichun

    2013-01-01

    Objective: To determine whether the SP-B deficiency and gene mutations in exon 4 is associated with neonatal RDS in China Han ethnic population. Methods: The study population consisted of 40 neonates with RDS and 40 neonates with other diseases as control in China Han ethnic population. We Compared SP-B expression in lung tissue and bronchoalveolar lavage fluid with immunoblotting, and analyzed mutations in the SP-B gene with polymerase chain reaction (PCR) and gene sequencing. Results: In RDS group, low mature Surfactant protein B was found in both lung tissue and bronchoalveolar lavage fluid in 8 neonates. In control group, only 4 neonates with low mature Surfactant protein B in both lung tissue and bronchoalveolar lavage fluid. In RDS group, 20 neonates were found to have mutations in exon 4, 12 homozygous mutations with C/C genotype and 8 heterozygous mutations with C/T genotype in surfactant protein B gene+1580 polymorphism. There were 8 cases mutations in control group, 1 in C/C and 7 in C/T genotype. The frequency of homozygotes with C/C genotype was 0.3 and frequency of heterozygotes with C/T genotype was 0.02 in RDS group. In control group, frequency of homozygotes with C/C genotype was 0.025 and frequency of heterozygote with C/T genotype was 0.175. Conclusion: Low mature Surfactant protein B is associated with the pathogenesis of neonatal respiratory distress syndrome (RDS) in China Han ethnic population. Mutations in exon 4 of the surfactant protein B gene demonstrate an association between homozygous mutations with C/C genotype in SP-B gene and neonatal RDS. PMID:23330012

  16. Application of positron annihilation techniques to the study of micels and microemulsions

    International Nuclear Information System (INIS)

    Olea C, O.

    1981-01-01

    The molecular auto-association mechanisms in sodium-oleate-alcohol-alkane-water systems were studied, applying positron and positronium annihilation techniques. The effects of the different component structures of these systems and of their concentrations on the swelled micel formation process which eventually produce microemulsions, were also investigated. The influences studied were: a) co-surfactant (alcohol) hydrocarbon chain lengths, b) alkane (oil) hydrocarbon chain lengths, c) surfactant concentrations, and d) surfactant double link alkylic chains. (author)

  17. Relative abundance of 'Bacillus' spp., surfactant-associated bacterium present in a natural sea slick observed by satellite SAR imagery over the Gulf of Mexico

    Directory of Open Access Journals (Sweden)

    Kathryn Lynn Howe

    2018-01-01

    Full Text Available The damping of short gravity-capillary waves (Bragg waves due to surfactant accumulation under low wind speed conditions results in the formation of natural sea slicks. These slicks are detectable visually and in synthetic aperture radar satellite imagery. Surfactants are produced by natural life processes of many marine organisms, including bacteria, phytoplankton, seaweed, and zooplankton. In this work, samples were collected in the Gulf of Mexico during a research cruise on the R/V 'F.G. Walton Smith' to evaluate the relative abundance of 'Bacillus' spp., surfactant-associated bacteria, in the sea surface microlayer compared to the subsurface water at 0.2 m depth. A method to reduce potential contamination of microlayer samples during their collection on polycarbonate filters was implemented and advanced, including increasing the number of successive samples per location and changing sample storage procedures. By using DNA analysis (real-time polymerase chain reaction to target 'Bacillus' spp., we found that in the slick areas, these surfactant-associated bacteria tended to reside mostly in subsurface waters, lending support to the concept that the surfactants they may produce move to the surface where they accumulate under calm conditions and enrich the sea surface microlayer.

  18. Lowering of the critical concentration for micelle formation in aqueous soap solutions by action of truly dissolved hydrocarbon at various temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Markina, Z.N.; Kostova, N.Z.; Rebinder, P.A.

    1970-03-01

    The effect of dissolved hydrocarbons (octane, benzene, and ethylbenzene) on critical micelle concentration of aqueous solutions of sodium salts of fatty acids from caproate to sodium myristate at various temperatures was studied. Experimental results showed that formation of micelles is promoted by presence of hydrocarbons dissolved in the water phase. Such solutions have below normal critical micelle concentration. The change in critical micelle concentration decreases with increase in length of hydrocarbon chain in the soap molecule and with decrease of hydrocarbon solubility in pure water. The nature of the hydrocarbon also affects the forms and dimension of the micelle. Aromatic hydrocarbons increase micelle volume and greatly decrease C.M.C., while aliphatic hydrocarbons decrease C.M.C. slightly. (12 refs.)

  19. Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Salama, Farid

    2010-01-01

    Carbonaceous materials play an important role in space. Polycyclic Aromatic Hydrocarbons (PAHs) are a ubiquitous component of the carbonaceous materials. PAHs are the best-known candidates to account for the IR emission bands. They are also thought to be among the carriers of the diffuse interstellar absorption bands (DIBs). PAH ionization states reflect the ionization balance of the medium while PAH size, composition, and structure reflect the energetic and chemical history of the medium. A major challenge is to reproduce in the laboratory the physical conditions that exist in the emission and absorption interstellar zones. The harsh physical conditions of the ISM -low temperature, collisionless, strong UV radiation fields- are simulated in the laboratory by associating a molecular beam with an ionizing discharge to generate a cold plasma expansion. PAH ions and radicals are formed from the neutral precursors in an isolated environment at low temperature and probed with high-sensitivity cavity ringdown spectroscopy in the NUV-NIR range. Carbon nanoparticles are also formed during the short residence time of the precursors in the plasma and are characterized with time-offlight mass spectrometry. These experiments provide unique information on the spectra of large carbonaceous molecules and ions in the gas phase that can now be directly compared to interstellar and circumstellar observations (IR emission bands, DIBs, extinction curve). These findings also hold great potential for understanding the formation process of interstellar carbonaceous grains. We will review recent progress in the experimental and theoretical studies of PAHs, compare the laboratory data with astronomical observations and discuss the global implications.

  20. Adsorption of small hydrocarbons on rutile TiO2(110)

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Long; Smith, R. Scott; Kay, Bruce D.; Dohnalek, Zdenek

    2016-08-01

    Temperature programmed desorption and molecular beam scattering were used to study the adsorption and desorption of small hydrocarbons (n-alkanes, 1-alkenes and 1-alkynes with 1 - 4 carbon atoms of C1-C4) on rutile TiO2(110). We show that the sticking coefficients for all the hydrocarbons are close to unity (> 0.95) at an adsorption temperature of 60 K. The desorption energies for hydrocarbons of the same chain length increase from n-alkanes to 1-alkenes and to 1-alkynes. This trend is likely a consequence of an additional dative bonding of the alkene and alkyne π system to the coordinatively unsaturated Ti5c sites. Similar to previous studies on the adsorption of n-alkanes on metal and metal oxide surfaces, we find the desorption energies within each group (n-alkanes vs. 1-alkenes vs. 1-alkynes) from Ti5c sites increase linearly with the chain length. The absolute saturation coverages of each hydrocarbon on Ti5c sites were also determined. The saturation coverage of CH4, is found to be ~ 2/3 monolayer (ML). The saturation coverages of C2-C4 hydrocarbons are found nearly independent of the chain length with values of ~1/2 ML for n-alkanes and 1-alkenes and 2/3 ML for 1-alkynes. This result is surprising considering their similar sizes.

  1. The effect of surfactant on pollutant biosorption of Trametes versicolor

    Science.gov (United States)

    Gül, Ülküye Dudu; Silah, Hülya; Akbaş, Halide; Has, Merve

    2016-04-01

    The major problem concerning industrial wastewater is treatment of dye and heavy metal containing effluents. Industrial effluents are also contained surfactants that are used as levelling, dispersing and wetting agents. The purpose of this study was to investigate the effect of surfactant on textile dye biosorption properties of a white rot fungus named Trametes versicolor. Reactive dyes are commonly used in textile industry because of their advantages such as brightness and excellent color fastness. A recative textile dye, called Everzol Black, was used in this study. The low-cost mollasses medium is used for fungal growth. The usage of mollases, the sugar refinery effluent as a source of energy and nutrients, gained importance because of reducing the cost and also reusing another waste. In biosorption process the effect of surfactant on dye removal properties of T. versicolor was examined as a function of pH, dye consentration and surfactant concentration. The results of this study showed that the surfactant enhanced the dye removal capacity of Trametes versicolor. The dye and surfactant molecules were interacted electrostatically and these electrostatic interactions improved dye removal properties of filamentous fungus T. versicolor. The results of this study recommended the use of surfactants as an inducer in textile wastewater treatment technologies.

  2. Contribution of Seawater Surfactants to Generated Primary Marine Aerosol Particles

    Science.gov (United States)

    Frossard, A. A.; Gerard, V.; Duplessis, P.; Kinsey, J. D.; Lu, X.; Zhu, Y.; Bisgrove, J.; Maben, J. R.; Long, M. S.; Chang, R.; Beaupre, S. R.; Kieber, D. J.; Keene, W. C.; Noziere, B.; Cohen, R. C.

    2017-12-01

    Surfactants account for minor fractions of total organic carbon in the ocean but may have major impacts on the surface tension of bursting bubbles at the sea surface that drive the production of primary marine aerosol particles (PMA). Surfactants associated with marine aerosol may also significantly reduce the surface tension of water thereby increasing the potential for cloud droplet activation and growth. During September and October 2016, PMA were produced from bursting bubbles in seawater using a high capacity generator at two biologically productive and two oligotrophic stations in the western North Atlantic, as part of a cruise on the R/V Endeavor. Surfactants were extracted from paired PMA and seawater samples, and their ionic compositions, total concentrations, and critical micelle concentrations (CMC) were quantified and compared for the four hydrographic stations. Higher surfactant concentrations were determined in the aerosol produced from biologically productive seawater compared to oligotrophic seawater, and the surfactants extracted from productive seawater were stronger (had lower CMCs) than those in the oligotrophic seawater. Surfactants associated with PMA and seawater in productive regions also varied over diel cycles, whereas those in the oligotrophic regions did not. This work demonstrates a direct link between surfactants in seawater and those in PMA.

  3. A simplified treatment of surfactant effects on cloud drop activation

    Directory of Open Access Journals (Sweden)

    T. Raatikainen

    2011-02-01

    Full Text Available Dissolved surface active species, or surfactants, have a tendency to partition to solution surface and thereby decrease solution surface tension. Activating cloud droplets have large surface-to-volume ratios, and the amount of surfactant molecules in them is limited. Therefore, unlike with macroscopic solutions, partitioning to the surface can effectively deplete the droplet interior of surfactant molecules.

    Surfactant partitioning equilibrium for activating cloud droplets has so far been solved numerically from a group of non-linear equations containing the Gibbs adsorption equation coupled with a surface tension model and an optional activity coefficient model. This can be a problem when surfactant effects are examined by using large-scale cloud models. Namely, computing time increases significantly due to the partitioning calculations done in the lowest levels of nested iterations.

    Our purpose is to reduce the group of non-linear equations to simple polynomial equations with well known analytical solutions. In order to do that, we describe surface tension lowering using the Szyskowski equation, and ignore all droplet solution non-idealities. It is assumed that there is only one surfactant exhibiting bulk-surface partitioning, but the number of non-surfactant solutes is unlimited. It is shown that the simplifications cause only minor errors to predicted bulk solution concentrations and cloud droplet activation. In addition, computing time is decreased at least by an order of magnitude when using the analytical solutions.

  4. Adsorption kinetics of surfactants on activated carbon

    Science.gov (United States)

    Arnelli; Aditama, WP; Fikriani, Z.; Astuti, Y.

    2018-04-01

    A study on the adsorption of both cationic and anionic surfactants using activated carbon as well as the investigation of the adsorption isotherms and adsorption kinetics has been conducted. The results showed that the adsorption of sodium lauryl sulfate (SLS) by activated carbon was Langmuir’s adsorption isotherm while its adsorption kinetics showed pseudo-second order with an adsorption rate constant of 2.23 x 103 g mg-1 hour-1. Meanwhile, the adsorption of HDTMA-Br by activated carbon showed that the isotherm adsorption tended to follow Freundlich’s isotherm and was pseudo-second order with an adsorption rate constant of 89.39 g mg-1 hour-1.

  5. Salt effects in surfactant-free microemulsions

    Science.gov (United States)

    Schöttl, Sebastian; Horinek, Dominik

    2018-06-01

    The weakly associated micellar aggregates found in the so-called "pre-ouzo region" of the surfactant-free microemulsion water/ethanol/1-octanol are sensitive to changes in the system composition and also to the presence of additives like salt. In this work, we study the influence of two salts, sodium iodide and lithium chloride, on aggregates in water/ethanol/1-octanol by molecular dynamics simulations. In both cases, ethanol concentration in the nonpolar phase and at the interface is increased due to a salting out effect on ethanol in the aqueous pseudo-phase. In addition, minor charging of the interface as a consequence of differential adsorption of anions and cations occurs. However, this charge separation is overall weakened by the erratic surface of octanol aggregates, where polar hydroxyl groups and hydrophobic patches are both present. Furthermore, ethanol at the interface shields hydrophobic patches and reduces the preferential adsorption of iodide and lithium.

  6. Surfactant protein D is proatherogenic in mice

    DEFF Research Database (Denmark)

    Sorensen, Grith L; Madsen, Jens; Kejling, Karin

    2006-01-01

    Surfactant protein D (SP-D) is an important innate immune defense molecule that mediates clearance of pathogens and modulates the inflammatory response. Moreover, SP-D is involved in lipid homeostasis, and pulmonary accumulation of phospholipids has previously been observed in SP-D-deficient (Spd......-/-) mice. Atherogenesis involves both inflammation and lipid deposition, and we investigated the role of SP-D in the development of atherosclerosis. SP-D synthesis was localized to vascular endothelial cells. Atherosclerotic lesion areas were 5.6-fold smaller in the aortic roots in Spd-/- mice compared...... with wild-type C57BL/6N mice on an atherogenic diet. HDL cholesterol (HDL-C) was significantly elevated in Spd-/- mice. Treatment of Spd-/- mice with a recombinant fragment of human SP-D resulted in decreases of HDL-C (21%) as well as total cholesterol (26%), and LDL cholesterol (28%). Plasma TNF...

  7. 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.

  8. 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

  9. Serum and sputum surfactants -A and -D in multidrug-resistant and ...

    African Journals Online (AJOL)

    Abnormal production and function of surfactants are associated with pulmonary diseases. Also, pulmonary infections alter surfactant metabolism. Due to lack of information on the levels of surfactants A (SP-A) and D (SP-D) in Nigerian tuberculosis (TB) patients, this study assessed these surfactants in both sputum and ...

  10. 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

  11. Cold pearl surfactant-based blends.

    Science.gov (United States)

    Crombie, R L

    1997-10-01

    Pearlizing agents have been used for many years in cosmetic formulations to add a pearlescent effect. Cold pearl surfactant-based blends are mixtures of glycol stearates and surfactants which can be blended in the cold into a wide range of personal-care formulations to create a pearlescent lustre effect. Under controlled manufacturing conditions constant viscosities and crystalline characteristics can be obtained. The development of these blends has been driven by efforts to improve the economics of adding solid pearlizing agents directly into a hot mix formulation. This paper summarizes the history of pearlizers, describes their advantages and physical chemistry of the manufacturing process. Finally some suggestions for applications are given. Les agents nacrants sont utilises depuis de nombreuses annees dans les formulations cosmetiques pour ajouter un effet nacre. Les melanges a froid a base de tensioactif nacre sont des melanges de stearates de glycol et de tensioactifs qui peuvent etre melanges a froid dans une large gamme de formulations d'hygiene personnelle pour creer un effet de lustre nacre. On peut obtenir des viscosites et des proprietes cristallines constantes avec des conditions de fabrication maitrisees. Le developpement de ces melanges a ete porte par les efforts pour ameliorer les couts de l'ajout d'agents nacrants solides directement dans une formulation melangee de l'ajout d'agents nacrants solides directement dans une formulation melangee a chaud. Cet article resume l'histoire des agents nacrants, decrit leurs avantages et al physico-chimie du procede de fabrication. On emet a la fin cetaines suggestions d'applications.

  12. Decontamination by cleaning with fluorocarbon surfactant solutions

    International Nuclear Information System (INIS)

    Kaiser, R.; Benson, C.E.; Meyers, E.S.; Vaughen, V.C.A.

    1994-02-01

    In the nuclear industry, facilities and their components inevitably become contaminated with radioactive materials. This report documents the application of a novel particle-removal process developed by Entropic Systems, Inc. (ESI), to decontaminate critical instruments and parts that are contaminated with small radioactive particles that adhere to equipment surfaces. The tests were performed as a cooperative effort between ESI and the Chemical Technology Division of the Oak Ridge National Laboratory (ORNL). ESI developed a new, environmentally compatible process to remove small particles from solid surfaces that is more effective than spraying or sonicating with CFC-113. This process uses inert perfluorinated liquids as working media; the liquids have zero ozone-depleting potential, are nontoxic and nonflammnable, and are generally recognized as nonhazardous materials. In the ESI process, parts to be cleaned are first sprayed or sonicated with a dilute solution of a high-molecular-weight fluorocarbon surfactant in an inert perfluorinated liquid to effect particle removal. The parts are then rinsed with the perfluorinated liquid to remove the fluorocarbon surfactant applied in the first step, and the residual rinse liquid is then evaporated from the parts into an air or nitrogen stream from which it is recovered. Nuclear contamination is inherently a surface phenomenon. The presence of radioactive particles is responsible for all ''smearable'' contamination and, if the radioactive particles are small enough, for some of the fixed contamination. Because radioactivity does not influence the physical chemistry of particle adhesion, the ESI process should be just as effective in removing radioactive particles as it is in removing nonradioactive particles

  13. Diesel-related hydrocarbons can dominate gas phase reactive carbon in megacities

    Directory of Open Access Journals (Sweden)

    R. E. Dunmore

    2015-09-01

    Full Text Available Hydrocarbons are key precursors to two priority air pollutants, ozone and particulate matter. Those with two to seven carbons have historically been straightforward to observe and have been successfully reduced in many developed cities through air quality policy interventions. Longer chain hydrocarbons released from diesel vehicles are not considered explicitly as part of air quality strategies and there are few direct measurements of their gaseous abundance in the atmosphere. This study describes the chemically comprehensive and continuous measurements of organic compounds in a developed megacity (London, which demonstrate that on a seasonal median basis, diesel-related hydrocarbons represent only 20–30 % of the total hydrocarbon mixing ratio but comprise more than 50 % of the atmospheric hydrocarbon mass and are a dominant local source of secondary organic aerosols. This study shows for the first time that 60 % of the winter primary hydrocarbon hydroxyl radical reactivity is from diesel-related hydrocarbons and using the maximum incremental reactivity scale, we predict that they contribute up to 50 % of the ozone production potential in London. Comparing real-world urban composition with regulatory emissions inventories in the UK and US highlights a previously unaccounted for, but very significant, under-reporting of diesel-related hydrocarbons; an underestimation of a factor ~4 for C9 species rising to a factor of over 70 for C12 during winter. These observations show that hydrocarbons from diesel vehicles can dominate gas phase reactive carbon in cities with high diesel fleet fractions. Future control of urban particulate matter and ozone in such locations requires a shift in policy focus onto gas phase hydrocarbons released from diesels as this vehicle type continues to displace gasoline world-wide.

  14. Chain reaction

    International Nuclear Information System (INIS)

    Balogh, Brian.

    1991-01-01

    Chain Reaction is a work of recent American political history. It seeks to explain how and why America came to depend so heavily on its experts after World War II, how those experts translated that authority into political clout, and why that authority and political discretion declined in the 1970s. The author's research into the internal memoranda of the Atomic Energy Commission substantiates his argument in historical detail. It was not the ravages of American anti-intellectualism, as so many scholars have argued, that brought the experts back down to earth. Rather, their decline can be traced to the very roots of their success after World War II. The need to over-state anticipated results in order to garner public support, incessant professional and bureaucratic specialization, and the sheer proliferation of expertise pushed arcane and insulated debates between experts into public forums at the same time that a broad cross section of political participants found it easier to gain access to their own expertise. These tendencies ultimately undermined the political influence of all experts. (author)

  15. 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...

  16. 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.

  17. Syntrophic biodegradation of hydrocarbon contaminants.

    Science.gov (United States)

    Gieg, Lisa M; Fowler, S Jane; Berdugo-Clavijo, Carolina

    2014-06-01

    Anaerobic environments are crucial to global carbon cycling wherein the microbial metabolism of organic matter occurs under a variety of redox conditions. In many anaerobic ecosystems, syntrophy plays a key role wherein microbial species must cooperate, essentially as a single catalytic unit, to metabolize substrates in a mutually beneficial manner. Hydrocarbon-contaminated environments such as groundwater aquifers are typically anaerobic, and often methanogenic. Syntrophic processes are needed to biodegrade hydrocarbons to methane, and recent studies suggest that syntrophic hydrocarbon metabolism can also occur in the presence of electron acceptors. The elucidation of key features of syntrophic processes in defined co-cultures has benefited greatly from advances in 'omics' based tools. Such tools, along with approaches like stable isotope probing, are now being used to monitor carbon flow within an increasing number of hydrocarbon-degrading consortia to pinpoint the key microbial players involved in the degradative pathways. The metagenomic sequencing of hydrocarbon-utilizing consortia should help to further identify key syntrophic features and define microbial interactions in these complex communities. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Production of light hydrocarbons, etc. [from heavy hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    1937-10-07

    A process is given for the production of light hydrocarbons of the gasoline type and, if desired, of the middle-oil type, from liquid or fusible heavy or medium heavy hydrocarbon materials. The process comprises subjecting the said initial materials in the first stage to catalytic hydrofining, separating the lower boiling constituents and the hydrogenating gas from the resulting products and then subjecting the higher boiling constituents in a second stage to a splitting destructive hydrogenation and then recycling substantially the entire reaction mixture obtained in the second stage to the frst stage.

  19. Two-step processing of oil shale to linear hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Eliseev, O.L.; Ryzhov, A.N.; Latypova, D.Zh.; Lapidus, A.L. [Russian Academy of Sciences, Moscow (Russian Federation). N.D. Zelinsky Institute of Organic Chemistry; Avakyan, T.A. [Gubkin Russian State University of Oil and Gas, Moscow (Russian Federation)

    2013-11-01

    Thermal and catalytic steam reforming of oil shale mined from Leningrad and Kashpir deposits was studied. Experiments were performed in fixed bed reactor by varying temperature and steam flow rate. Data obtained were approximated by empirical formulas containing some parameters calculated by least-squares method. Thus predicting amount of hydrogen, carbon monoxide and methane in producer gas is possible for given particular kind of oil shale, temperature and steam flow rate. Adding Ni catalyst enriches hydrogen and depletes CO content in effluent gas at low gasification temperatures. Modeling gas simulating steam reforming gases (H{sub 2}, CO, CO{sub 2}, and N{sub 2} mixture) was tested in hydrocarbon synthesis over Co-containing supported catalyst. Selectivity of CO conversion into C{sub 5+} hydrocarbons reaches 84% while selectivity to methane is 7%. Molecular weight distribution of synthesized alkanes obeys Anderson-Schulz-Flory equation and chain growth probability 0.84. (orig.)

  20. Selection of bacteria with hydrocarbon degrading capacity isolated from Colombian Caribbean sediments

    International Nuclear Information System (INIS)

    Narvaez Florez, Silvia; Gomez, Martha L; Martinez Maria M

    2008-01-01

    Thirty one bacterial isolations in minimal salts supplemented medium with hydrocarbons (ACPM or crude oil) as sole carbon source were isolated from sediment samples from the Colombian Caribbean. Bacterial strains underwent selection tests in different concentrations of hydrocarbons; 11 tolerant crude oil and ACPM strains in a range of 1-8%v/v were chosen. A mixed bacterial culture was created and assessed its ability to degrade hydrocarbons in a laboratory-scale test, with a concentration of 2% v/v of ACPM over a period of 21 days. Measurements of biomass in Colony Forming Units (CFU)/mL were used to develop the growth curve of the mixed culture. Hydrocarbons remotion was measured by mass chromatography. The mixed culture was able to degrade the 68.6% of aliphatic hydrocarbons in preference of long chain n- alkenes (C12- C31), reaching a maximum growth of 3.13 x 10 9 UFC / mL. Degradation of aromatic hydrocarbons was not evidenced under the observation time. Nine of the eleven strains were identified using the biochemical systems BBL and API 50 CHB/E; they belonged to the genus Klebsiella, Chromobacterium, Flavimonas, Enterobacter,Pseudomonas, and Bacillus. The evaluated strains have enzymatic potential to degrade hydrocarbons and it is necessary to characterize them at molecular level in order to develop and effective consortium for field application

  1. Production of hydrocarbons, especially ethylene

    Energy Technology Data Exchange (ETDEWEB)

    1952-01-17

    The invention has for its object a process for the production of gaseous nonsaturated hydrocarbons, particularly ethylene and aromatic hydrocarbons, by starting with hydrocarbon oils entirely of paraffinic nature or their fractions, which consists in putting the separated products in contact with solid inert material especially with porous nonmetallic inert material or of heavy metals or their alloys, maybe in a finely divided state or in the form, of pieces or chips, at a temperature above 500/sup 0/C, or better between 600 and 700/sup 0/C at a velocity per hour of 0.6 to 3.0, and preferably 0.75 to 1.5 parts per volume of products per each part of space volume of catalyst.

  2. Enrichment of light hydrocarbon mixture

    Science.gov (United States)

    Yang,; Dali, [Los Alamos, NM; Devlin, David [Santa Fe, NM; Barbero, Robert S [Santa Cruz, NM; Carrera, Martin E [Naperville, IL; Colling, Craig W [Warrenville, IL

    2010-08-10

    Light hydrocarbon enrichment is accomplished using a vertically oriented distillation column having a plurality of vertically oriented, nonselective micro/mesoporous hollow fibers. Vapor having, for example, both propylene and propane is sent upward through the distillation column in between the hollow fibers. Vapor exits neat the top of the column and is condensed to form a liquid phase that is directed back downward through the lumen of the hollow fibers. As vapor continues to ascend and liquid continues to countercurrently descend, the liquid at the bottom of the column becomes enriched in a higher boiling point, light hydrocarbon (propane, for example) and the vapor at the top becomes enriched in a lower boiling point light hydrocarbon (propylene, for example). The hollow fiber becomes wetted with liquid during the process.

  3. Production of hydrocarbons of value

    Energy Technology Data Exchange (ETDEWEB)

    1931-06-16

    A process is described for the production of hydrocarbons of great value by treating with heat and pressure carbonaceous materials such as coals, tars, mineral oils, and products of distillation and transformation of these materials, also for the refining with heat and pressure of mixed liquid hydrocarbons by means of hydrogen gas, preferably in the presence of catalysts, consisting in using as the hydrogenating gas that obtained by gasification of combustible solids after partial or complete cleaning at atmospheric or elevated pressures, by means of solid adsorbents, chemical agents or catalysts, or mixtures of these agents, the hydrocarbons being characterized by strong unsaturation, and the presence of oxygen, sulfur compounds, and oxides of nitrogen.

  4. Process of distilling heavy hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    1929-12-03

    This invention has for its object the distillation of heavy liquid hydrocarbons for the purpose of obtaining lighter hydrocarbons stable and immediately salable for fuels in combustion motors. The process is distinguished by the fact that the heavy hydrocarbon is distilled by means of heating to a temperature in keeping with the nature of the material to be treated up to 350/sup 0/C under pressure or without pressure the distillation being carried out on catalysts containing successively nickel, copper, and iron (3 parts of nickel, 1 part of copper, and 1 part of iron), the vapors produced by this distillation being exposed in turn to the action of catalysts of the same nature and in the same proportion.

  5. Cationic gemini surfactant-assisted synthesis of hollow Au nanostructures by stepwise reductions.

    Science.gov (United States)

    Wang, Wentao; Han, Yuchun; Tian, Maozhang; Fan, Yaxun; Tang, Yongqiang; Gao, Mingyuan; Wang, Yilin

    2013-06-26

    A novel synthetic approach was developed for creating versatile hollow Au nanostructures by stepwise reductions of Au(III) upon the use of cationic gemini surfactant hexamethylene-1,6-bis(dodecyl dimethylammonium bromide) (C12C6C12Br2) as a template agent. It was observed that the Au(I) ions obtained from the reduction of Au(III) by ascorbic acid can assist the gemini surfactant to form vesicles, capsule-like, and tube-like aggregates that subsequently act as soft templates for hollow Au nanostructures upon further reduction of Au(I) to Au(0) by NaBH4. It was demonstrated that the combination of C12C6C12Br2 and Au(I) plays a key role in regulating the structure of the hollow precursors not only because C12C6C12Br2 has a stronger aggregation ability in comparison with its single chain counterpart but also because the electrostatic repulsion between head groups of C12C6C12Br2 is greatly weakened after Au(III) is converted to Au(I), which is in favor of the construction of vesicles, capsule-like, and tube-like aggregates. Compared with solid Au nanospheres, the resultant hollow nanostructures exhibit enhanced electrocatalytic activities in methanol oxidation, following the order of elongated nanocapsule > nanocapsule > nanosphere. Benefiting from balanced interactions between the gemini surfactant and Au(I), this soft-template method may present a facile and versatile approach for the controlled synthesis of Au nanostructures potentially useful for fuel cells and other Au nanodevices.

  6. Environmental Safety of the Use of Major Surfactant Classes in North America

    Science.gov (United States)

    Cowan-Ellsberry, Christina; Belanger, Scott; Dorn, Philip; Dyer, Scott; McAvoy, Drew; Sanderson, Hans; Versteeg, Donald; Ferrer, Darci

    2014-01-01

    This paper brings together over 250 published and unpublished studies on the environmental properties, fate, and toxicity of the four major, high-volume surfactant classes and relevant feedstocks. The surfactants and feedstocks covered include alcohol sulfate or alcohol sulfate (AS), alcohol ethoxysulfate (AES), linear alkylbenzene sulfonate (LAS), alcohol ethoxylate (AE), and long-chain alcohol (LCOH). These chemicals are used in a wide range of personal care and cleaning products. To date, this is the most comprehensive report on these substance's chemical structures, use, and volume information, physical/chemical properties, environmental fate properties such as biodegradation and sorption, monitoring studies through sewers, wastewater treatment plants and eventual release to the environment, aquatic and sediment toxicity, and bioaccumulation information. These data are used to illustrate the process for conducting both prospective and retrospective risk assessments for large-volume chemicals and categories of chemicals with wide dispersive use. Prospective risk assessments of AS, AES, AE, LAS, and LCOH demonstrate that these substances, although used in very high volume and widely released to the aquatic environment, have no adverse impact on the aquatic or sediment environments at current levels of use. The retrospective risk assessments of these same substances have clearly demonstrated that the conclusions of the prospective risk assessments are valid and confirm that these substances do not pose a risk to the aquatic or sediment environments. This paper also highlights the many years of research that the surfactant and cleaning products industry has supported, as part of their environmental sustainability commitment, to improve environmental tools, approaches, and develop innovative methods appropriate to address environmental properties of personal care and cleaning product chemicals, many of which have become approved international standard methods. PMID

  7. Preparing valuable hydrocarbons by hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Pier, M

    1930-08-22

    A process is described for the preparation of valuable hydrocarbons by treatment of carbonaceous materials, like coal, tars, minerals oils, and their distillation and conversion products, and for refining of liquid hydrocarbon mixture obtained at raised temperature and under pressure, preferably in the presence of catalysts, by the use of hydrogen-containing gases, purified and obtained by distilling solid combustibles, characterized by the purification of the hydrogen-containing gases being accomplished for the purpose of practically complete removal of the oxygen by heating at ordinary or higher pressure in the presence of a catalyst containing silver and oxides of metals of group VI of the periodic system.

  8. Purifying and regenerating hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    1931-11-19

    Hydrocarbons are freed from sulfur-containing compounds, colloidal asphaltic bodies and unstable unsaturated substances by treatment with a small amount of dilute sulfuric acid and a salt of a trivalent cation, such as ferric chloride or sulfate. Hydrocarbons specified are petroleum, crude benzol, low temperature tars, shale oil or vapor-phase cracked spirit. Motor spirit or lubricating oil distillates are refined and finally distilled. The acid reagent may be regenerated by filtering through sand or asbestos. Used lubricating oils may be treated similarly and after removal of refining agent, the oil is heated with an adsorbent and decolorizing material and then filtered.

  9. Hydrocarbons cocktails of the future

    International Nuclear Information System (INIS)

    Anon.

    2004-01-01

    This publication of the Areva Group, a world nuclear industry leader, provides information on the energy in many domains. This issue deals with the CO 2 pollution exchange, the carbon sinks to compensate the CO 2 , the green coal as an innovative solution, an outsize dam in China, the solar energy progresses in France and the french medicine academy in favor of Nuclear. A special chapter is devoted to the hydrocarbons of the future, artificial chemical combination created from constituents of hydrocarbons and derived from various sources. (A.L.B.)

  10. Nanocomposites of PP and bentonite clay modified with different surfactants

    International Nuclear Information System (INIS)

    Rodrigues, Andre W.B.; Agrawal, Pankaj; Araujo, Edcleide M.; Melo, Tomas J.A.; Ueki, Marcelo M.

    2009-01-01

    The aim of this work was the development of nano composites of polypropylene (PP) and national bentonite clay modified with different surfactants. The results of X-Ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) showed that the organophilization process was effective. The surfactants led to a significant increase in the basal spacing of Brasgel PA clay. XRD results of the mixture PP/Brasgel PA clay modified with Praepagem WB surfactant indicated that a nanocomposite with intercalated structure was formed. When the Brasgel PA clay was modified with Praepagem HY surfactant, DRX results indicated that a micro composite was formed. Screw speed, clay content and PP viscosity had no influence on the XRD pattern of the obtained materials. (author)

  11. 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 ...

  12. MICROEMULSION OF MIXED CHLORINATED SOLVENTS USING FOOD GRADE (EDIBLE) SURFACTANTS

    Science.gov (United States)

    Ground water contamination frequently consists of mixed chlorinated solvents [e.g., tetrachloroethylene (PCE), trichloroethylene (TCE), and trans-1,2- dichloroethylene (DCE)]. In this research, mixtures of the food grade (edible) surfactants bis(2-ethylhexyl) sodium sulfosuccinat...

  13. Surfactant-assisted sacrificial template-mediated synthesis

    Indian Academy of Sciences (India)

    ... spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopyand photoluminescence studies. Influence of surfactant and solvents on morphology and luminescence of the final product in sacrificial template-assisted method has been investigated in detail.

  14. Use of surfactants in cleaning paraffin from oil wells

    Energy Technology Data Exchange (ETDEWEB)

    Liebold, G; Rehberg, W

    1969-05-01

    The use of surfactants is described especially oxethylated alkylphenols, in the cleaning of oil wells from paraffin. Aqueous 1 or 10% solutions of the surfactant were injected into the well through the annulus, partially in combination with demulsifiers (for example Separol-brands of BASF). Injection was accomplished continuously or in intervals; in the beginning of 50 ppm surfactant, afterward 15 to 30 ppm as related to the wet crude was necessary. Efficiency of the treatment could be proved by the decrease of pressure in the pipes, the loosening of paraffin shells, and considerably prolonged operation periods in wells which otherwise would have come to a standstill. In quite a number of wells, treatment with hot oil and electric heating could be completely replaced by injection of surfactants. (11 refs.)

  15. Mathematical Modelling of Surfactant Self-assembly at Interfaces

    KAUST Repository

    Morgan, C. E.; Breward, C. J. W.; Griffiths, I. M.; Howell, P. D.

    2015-01-01

    © 2015 Society for Industrial and Applied Mathematics. We present a mathematical model to describe the distribution of surfactant pairs in a multilayer structure beneath an adsorbed monolayer. A mesoscopic model comprising a set of ordinary

  16. Kinetics of Surfactant Desorption at an Air–Solution Interface

    KAUST Repository

    Morgan, C. E.; Breward, C. J. W.; Griffiths, I. M.; Howell, P. D.; Penfold, J.; Thomas, R. K.; Tucker, I.; Petkov, J. T.; Webster, J. R. P.

    2012-01-01

    The kinetics of re-equilibration of the anionic surfactant sodium dodecylbenzene sulfonate at the air-solution interface have been studied using neutron reflectivity. The experimental arrangement incorporates a novel flow cell in which the subphase

  17. 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.

  18. 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,.

  19. The cost and effectiveness of surfactant replacement therapy at ...

    African Journals Online (AJOL)

    S Atr Med J 1995; 85; 646-649. Department of Paediatrics and Child Health, Johannesburg Hospital ..... infants is small - of the order of 1% - as in this study. ... effects of surfactant therapy for neonatal respiratory distress syndrome. J Pediatr.

  20. Surfactant nebulisation prevents the adverse effects of surfactant therapy on blood pressure and cerebral blood flow in rabbits with severe respiratory failure

    NARCIS (Netherlands)

    Dijk, Peter H.; Heikamp, A; Bambang Oetomo, Sidarto

    1997-01-01

    Objective: Surfactant replacement therapy for the neonatal respiratory distress syndrome has shown beneficial effects on lung function and survival. Recently, rapid fluctuations of haemodynamics and cerebral perfusion following surfactant instillation have beer, described and an association with the

  1. 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

  2. Effects of Surfactants on the Rate of Chemical Reactions

    Directory of Open Access Journals (Sweden)

    B. Samiey

    2014-01-01

    Full Text Available Surfactants are self-assembled compounds that depend on their structure and electric charge can interact as monomer or micelle with other compounds (substrates. These interactions which may catalyze or inhibit the reaction rates are studied with pseudophase, cooperativity, and stoichiometric (classical models. In this review, we discuss applying these models to study surfactant-substrate interactions and their effects on Diels-Alder, redox, photochemical, decomposition, enzymatic, isomerization, ligand exchange, radical, and nucleophilic reactions.

  3. 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.

  4. Use of surfactants to control island size and density

    Science.gov (United States)

    Merrell, Jason; Liu, Feng; Stringfellow, Gerald B.

    2017-08-15

    Methods of controlling island size and density on an OMVPE growth film may comprise adding a surfactant at a critical concentration level, allowing a growth phase for a first period of time, and ending the growth phase when desired island size and density are achieved. For example, the island size and density of an OMVPE grown InGaN thin film may be controlled by adding an antimony surfactant at a critical concentration level.

  5. Liquid crystalline states of surfactant solutions of isotropic micelles

    International Nuclear Information System (INIS)

    Bagdassarian, C.; Gelbart, W.M.; Ben-Shaul, A.

    1988-01-01

    We consider micellar solutions whose surfactant molecules prefer strongly to form small, globular aggregates in the absence of intermicellar interactions. At sufficiently high volume fraction of surfactant, the isotropic phase of essentially spherical micelles is shown to be unstable with respect to an orientationally ordered (nematic) state of rodlike aggregates. This behavior is relevant to the phase diagrams reported for important classes of aqueous amphiphilic solutions

  6. BIOREMEDIATION OF A PETROLEUM-HYDROCARBON

    African Journals Online (AJOL)

    ES OBE

    under field conditions in the bioremediation of a petroleum- hydrocarbon polluted ... an accelerated biodegradation of petroleum hydrocarbons in a polluted agricultural soil ..... 12) Jackson, M.L. Soil chemical analysis. ... biological assay. 3 rd.

  7. Total Petroleum Hydrocarbons (TPH): ToxFAQs

    Science.gov (United States)

    ... a state: This map displays locations where Total Petroleum Hydrocarbons (TPH) is known to be present. On ... I get more information? ToxFAQs TM for Total Petroleum Hydrocarbons (TPH) ( Hidrocarburos Totales de Petróleo (TPH) ) August ...

  8. Predicting the environmental fate properties of petroleum hydrocarbon mixtures

    International Nuclear Information System (INIS)

    Pisigan, R.A. Jr.; Tucker, W.A.

    1995-01-01

    The environmental fate and transport of petroleum products for risk assessment can be evaluated based on the physico-chemical properties of an indicator chemical or a surrogate compound, or the whole mixture. A study was conducted to develop a simple representation of the hydrocarbon mixture as if it contained only few constituents, each of which represents a large number of compounds. The products considered are gasoline, diesel fuel, and jet fuel (JP4). Each petroleum hydrocarbon was characterized as a mixture of six constituents: short chain alkanes, long chain alkanes, short chain cycloalkanes and alkenes, long chain cycloalkanes and alkenes, BTEX, and other aromatics. The carbon number used as a cut-off between short and long chain alkanes, alkenes, and cycloalkanes varies with the type of product. Each mixture has different average molecular weight, water solubility, vapor pressure, organic carbon partition coefficient, and air diffusivity. The properties of each constituent of gasoline were derived from the weighted average of all compounds belonging to each constituent group. For diesel fuel and JP4, the properties of each constituent were generated from the properties of the component most representative of the group. Any property that is missing or not available from common literature sources was derived from regression equations developed from the data base for gasoline. These regression equations express the property as function of the number of carbon atoms. The R 2 values of the regression equations range from 0.82--0.92. Some case studies involving petroleum product contamination in which the estimated properties were applied are presented

  9. Physicochemical treatments of anionic surfactants wastewater: Effect on aerobic biodegradability.

    Science.gov (United States)

    Aloui, Fathi; Kchaou, Sonia; Sayadi, Sami

    2009-05-15

    The effect of different physicochemical treatments on the aerobic biodegradability of an industrial wastewater resulting from a cosmetic industry has been investigated. This industrial wastewater contains 11423 and 3148mgL(-1) of chemical oxygen demand (COD) and anionic surfactants, respectively. The concentration of COD and anionic surfactants were followed throughout the diverse physicochemical treatments and biodegradation experiments. Different pretreatments of this industrial wastewater using chemical flocculation process with lime and aluminium sulphate (alum), and also advanced oxidation process (electro-coagulation (Fe and Al) and electro-Fenton) led to important COD and anionic surfactants removals. The best results were obtained using electro-Fenton process, exceeding 98 and 80% of anionic surfactants and COD removals, respectively. The biological treatment by an isolated strain Citrobacter braakii of the surfactant wastewater, as well as the pretreated wastewater by the various physicochemical processes used in this study showed that the best results were obtained with electro-Fenton pretreated wastewater. The characterization of the treated surfactant wastewater by the integrated process (electro-coagulation or electro-Fenton)-biological showed that it respects Tunisian discharge standards.

  10. 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.

  11. Surfactant Effect on the Average Flow Generation Near Curved Interface

    Science.gov (United States)

    Klimenko, Lyudmila; Lyubimov, Dmitry

    2018-02-01

    The present work is devoted to the average flow generation near curved interface with a surfactant adsorbed on the surface layer. The investigation was carried out for a liquid drop embedded in a viscous liquid with a different density. The liquid flows inside and outside the drop are generated by small amplitude and high frequency vibrations. Surfactant exchange between the drop surface and the surrounding liquid is limited by the process of adsorption-desorption. It was assumed that the surfactant is soluble in the surrounding liquid, but not soluble in the liquid drop. Surrounding liquid and the liquid in the drop are considered incompressible. Normal and shear viscous stresses balance at the interface is performed under the condition that the film thickness of the adsorbed surfactant is negligible. The problem is solved under assumption that the shape of the drop in the presence of adsorbed surfactant remains spherical symmetry. The effective boundary conditions for the tangential velocity jump and shear stress jump, describing the above generation have been obtained by matched asymptotic expansions method. The conditions under which the drop surface can be considered as a quasi-solid are determined. It is shown that in the case of the significant effect of surfactant on the surface tension, the dominant mechanism for the generation is the Schlichting mechanisms under vibrations.

  12. Separation of oil and grease from oil sludge using surfactant

    International Nuclear Information System (INIS)

    Ainon Abdul Aziz; Syed Hakimi Sakuma Syed Ahmad; Zalina Laili

    2005-01-01

    The objective of the experiments was to observe the efficiency of the surfactant to remove oil and grease from oil sludges using various surfactant concentration ranging from 10 %, 15 %, 20 % and 30 %. The surfactant solution consists of two mixtures of Aqua 2000 and D Bond. The oil sludge were subjected to heating and surfactant treatment process. Remaining oil and grease concentration were observed on the oil sludges after treatment. Small scale experiments were conducted by heating process, without heating process and heating process with addition of sodium chloride. Surfactant solution was added in each process. Results shows that there is separation of oil and grease from the oil sludges. There were formation of mini emulsions (oil in water). The higher the concentration of surfactant used, the higher the concentrations of mini emulsion formed as observed. Solid remains after the treatment process were found to contain lesser oil concentration with presence of bitumen, sediment, organic and inorganic materials. After a washing process using distilled water, the solid was still black but less oily than before the treatment. There is no separation of oil occurred in aqueous solution for the control experiment. (Author)

  13. 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.

  14. Biocatalytic synthesis of polymeric nanowires by micellar templates of ionic surfactants

    International Nuclear Information System (INIS)

    Nazari, K.; Adhami, F.; Najjar-Safari, A.; Salmani, S.; Mahmoudi, A.

    2011-01-01

    Highlights: → Soft-template production of polyguaiacol nanowire was done by peroxidase enzyme. → Main advantage of this simple method is producing soluble encapsulated nanowires. → Nanowire can be easily precipitated and separated by dilution with distilled water. → Size tuned templates of sodium decyl sulfate (d = 2.7 nm) gave nanowires with d = 2-4 nm. → Dried surfactant-coated wires recover freshly on specified and desired applications. -- Abstract: Micelle-templated polyguaiacol nanowires were successfully prepared via polymerization oxidation of guaiacol (o-methoxy phenol) by peroxidase enzyme in the presence of hydrogen peroxide at mild reaction conditions. The dimensions of the prepared nanowires were controlled by tuning the size and shape of the micelle structure via changing and controlling the type, chain length and molar concentrations of the ionic surfactant. The progress of the reaction and estimation of the size of soft micellar templates were followed by UV-Vis spectroscopy and dynamic light scattering (DLS). The resulting micelle encapsulated or purified polyguaiacol nanowires were characterized using transmission electron microscopy (TEM).

  15. Novel epoxy-benzoxazine water-based emulsions with reactive benzoxazine surfactants for coatings

    Directory of Open Access Journals (Sweden)

    M. Krajnc

    2014-08-01

    Full Text Available Novel epoxy-benzoxazine emulsions designed for water-based coatings were prepared and investigated. Bisphenol A-based epoxy resins with molar weights of 340, 377 and 1750 g/mol along with epoxidized soybean oil were emulsified using mono- and bi-functional benzoxazine surfactants, which are able to react with epoxy resins at their cure temperature. The structure of synthesized surfactants carrying one or two polyether chains was confirmed using Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance and differential scanning calorimetry. Stability of emulsions was verified by particle diameters measurements. Coatings, made directly from emulsions, were dried and cured at elevated temperature using 3,3'-dimetoxybenzidine as curing agent to ensure a highly cross-linked structure of thermosetting films. Curing process, thermal properties and hardness of cured films were investigated. It was found that benzoxazine molecules were well incorporated into the epoxy network upon curing, which ensures no void structure of cured copolymer and enhanced coating properties.

  16. Biocatalytic synthesis of polymeric nanowires by micellar templates of ionic surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Nazari, K., E-mail: nazarikh@ripi.ir [Research Institute of Petroleum Industry, NIOC, P.O. Box 14665-137, Tehran (Iran, Islamic Republic of); Chemistry Dept., Shahr Rey Islamic Azad University, P.O. Box 18735-334, Tehran (Iran, Islamic Republic of); Adhami, F.; Najjar-Safari, A.; Salmani, S. [Chemistry Dept., Shahr Rey Islamic Azad University, P.O. Box 18735-334, Tehran (Iran, Islamic Republic of); Mahmoudi, A. [Chemistry Dept., Karaj Islamic Azad University, Karaj (Iran, Islamic Republic of)

    2011-07-15

    Highlights: {yields} Soft-template production of polyguaiacol nanowire was done by peroxidase enzyme. {yields} Main advantage of this simple method is producing soluble encapsulated nanowires. {yields} Nanowire can be easily precipitated and separated by dilution with distilled water. {yields} Size tuned templates of sodium decyl sulfate (d = 2.7 nm) gave nanowires with d = 2-4 nm. {yields} Dried surfactant-coated wires recover freshly on specified and desired applications. -- Abstract: Micelle-templated polyguaiacol nanowires were successfully prepared via polymerization oxidation of guaiacol (o-methoxy phenol) by peroxidase enzyme in the presence of hydrogen peroxide at mild reaction conditions. The dimensions of the prepared nanowires were controlled by tuning the size and shape of the micelle structure via changing and controlling the type, chain length and molar concentrations of the ionic surfactant. The progress of the reaction and estimation of the size of soft micellar templates were followed by UV-Vis spectroscopy and dynamic light scattering (DLS). The resulting micelle encapsulated or purified polyguaiacol nanowires were characterized using transmission electron microscopy (TEM).

  17. Experimental and QSAR study on the surface activities of alkyl imidazoline surfactants

    Science.gov (United States)

    Kong, Xiangjun; Qian, Chengduo; Fan, Weiyu; Liang, Zupei

    2018-03-01

    15 alkyl imidazoline surfactants with different structures were synthesized and their critical micelle concentration (CMC) and surface tension under the CMC (σcmc) in aqueous solution were measured at 298 K. 54 kinds of molecular structure descriptors were selected as independent variables and the quantitative structure-activity relationship (QSAR) between surface activities of alkyl imidazoline and molecular structure were built through the genetic function approximation (GFA) method. Experimental results showed that the maximum surface excess of alkyl imidazoline molecules at the gas-liquid interface increased and the area occupied by each surfactant molecule and the free energies of micellization ΔGm decreased with increasing carbon number (NC) of the hydrophobic chain or decreasing hydrophilicity of counterions, which resulted in a CMC and σcmc decrease, while the log CMC and NC had a linear relationship and a negative correlation. The GFA-QSAR model, which was generated by a training set composed of 13 kinds of alkyl imidazoline though GFA method regression analysis, was highly correlated with predicted values and experimental values of the CMC. The correlation coefficient R was 0.9991, which means high prediction accuracy. The prediction error of 2 kinds of alkyl imidazoline CMCs in the Validation Set that quantitatively analyzed the influence of the alkyl imidazoline molecular structure on the CMC was less than 4%.

  18. Remediation of Nitrobenzene Contaminated Soil by Combining Surfactant Enhanced Soil Washing and Effluent Oxidation with Persulfate

    Science.gov (United States)

    Yan, Jingchun; Gao, Weiguo; Qian, Linbo; Han, Lu; Chen, Yun; Chen, Mengfang

    2015-01-01

    The combination of surfactant enhanced soil washing and degradation of nitrobenzene (NB) in effluent with persulfate was investigated to remediate NB contaminated soil. Aqueous solution of sodium dodecylbenzenesulfonate (SDBS, 24.0 mmol L-1) was used at a given mass ratio of solution to soil (20:1) to extract NB contaminated soil (47.3 mg kg-1), resulting in NB desorption removal efficient of 76.8%. The washing effluent was treated in Fe2+/persulfate and Fe2+/H2O2 systems successively. The degradation removal of NB was 97.9%, being much higher than that of SDBS (51.6%) with addition of 40.0 mmol L-1 Fe2+ and 40.0 mmol L-1 persulfate after 15 min reaction. The preferential degradation was related to the lone pair electron of generated SO4•−, which preferably removes electrons from aromatic parts of NB over long alkyl chains of SDBS through hydrogen abstraction reactions. No preferential degradation was observed in •OH based oxidation because of its hydrogen abstraction or addition mechanism. The sustained SDBS could be reused for washing the contaminated soil. The combination of the effective surfactant-enhanced washing and the preferential degradation of NB with Fe2+/persulfate provide a useful option to remediate NB contaminated soil. PMID:26266532

  19. Insights into hydrocarbon formation by nitrogenase cofactor homologs.

    Science.gov (United States)

    Lee, Chi Chung; Hu, Yilin; Ribbe, Markus W

    2015-04-14

    The L-cluster is an all-iron homolog of nitrogenase cofactors. Driven by europium(II) diethylenetriaminepentaacetate [Eu(II)-DTPA], the isolated L-cluster is capable of ATP-independent reduction of CO and CN(-) to C1 to C4 and C1 to C6 hydrocarbons, respectively. Compared to its cofactor homologs, the L-cluster generates considerably more CH4 from the reduction of CO and CN(-), which could be explained by the presence of a "free" Fe atom that is "unmasked" by homocitrate as an additional site for methanation. Moreover, the elevated CH4 formation is accompanied by a decrease in the amount of longer hydrocarbons and/or the lengths of the hydrocarbon products, illustrating a competition between CH4 formation/release and C-C coupling/chain extension. These observations suggest the possibility of designing simpler synthetic clusters for hydrocarbon formation while establishing the L-cluster as a platform for mechanistic investigations of CO and CN(-) reduction without complications originating from the heterometal and homocitrate components. Nitrogenase is a metalloenzyme that is highly complex in structure and uniquely versatile in function. It catalyzes two reactions that parallel two important industrial processes: the reduction of nitrogen to ammonia, which parallels the Haber-Bosch process in ammonia production, and the reduction of carbon monoxide to hydrocarbons, which parallels the Fischer-Tropsch process in fuel production. Thus, the significance of nitrogenase can be appreciated from the perspective of the useful products it generates: (i) ammonia, the "fixed" nitrogen that is essential for the existence of the entire human population; and (ii) hydrocarbons, the "recycled" carbon fuel that could be used to directly address the worldwide energy shortage. This article provides initial insights into the catalytic characteristics of various nitrogenase cofactors in hydrocarbon formation. The reported assay system provides a useful tool for mechanistic

  20. Effective viscosity of confined hydrocarbons

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, V.N.; Persson, B.N.J.

    2012-01-01

    We present molecular dynamics friction calculations for confined hydrocarbon films with molecular lengths from 20 to 1400 carbon atoms. We find that the logarithm of the effective viscosity ηeff for nanometer-thin films depends linearly on the logarithm of the shear rate: log ηeff=C-nlog γ̇, where...