Addition Of Decane Research Articles

Addition of terpenoids to pear ester plus acetic acid increases catches of codling moth (Lepidoptera: Tortricidae)

AbstractField studies were conducted to evaluate new kairomone blends in combination with pear ester (E,Z)‐2,4‐ethyl decadienoate (PE) and acetic acid (AA) for their attraction of male and female codling moth, Cydia pomonella (L.), in apple, Malus domestica Borkhausen. The addition of decanal to either AA or PE alone significantly increased total and female moth catches. However, the addition of decanal did not improve the attraction of PE + AA. The addition of either the pyranoid (PyrLOX) or furanoid (FurLOX) linalool oxide but not linalool (LOL) increased moth catches with PE but did not increase catches with PE + AA. Similarly, the addition of PyrLOX plus decanal did not improve PE + AA. The addition of (E)‐4,8‐dimethyl‐1,3,7‐nonatriene (DMNT) to either AA, PE + AA or PE + AA+decanal did not significantly increase moth catches. However, the addition of PyrLOX to traps with PE + AA and DMNT (4‐component lure) significantly increased moth catches compared with PE + AA alone or any of the ternary blends of these volatiles. Females accounted for 60%–80% of the total catch with this 4‐component lure. The 4‐component blend with PyrLOX was a more attractive lure than similar blends that substituted LOL, or a binary blend of LOL and FurLOX for PyrLOX. The 4‐component blend caught nearly fourfold more total and female moths than the purported attractant N‐butyl sulphide when it was used in combination with PE + AA. These results indicate that significant improvements in monitoring, mating disruption and mass trapping of codling moth are possible. Further studies are needed to assess the new attractive blend's effectiveness in combination with sex pheromone lures and to evaluate whether other host plant volatiles can be added or substitute for DMNT or LOX when used in combination with PE + AA.

A facile method for preparation of hollow mesoporous silica sphere and its application

Hollow mesoporous silica spheres (HMSS) were facilely synthesized by the Stöber method, in which decane was first used to form the hollow structure. The pore diameter of the mesoporous shell and the porous volume of the HMSS become higher with addition of decane. The average diameter of the HMSS is about 1100nm, the thickness of the shell is about 190nm. The mesoporous channels are perpendicular throughout the shell to the center of the HMSS. The HMSS shows an excellent adsorption property for cationic organic dye (methylene blue, MB) from aqueous solutions, such as higher adsorption rate and capacity than those reported.

Aqueous Mixtures of a Trisiloxane Surfactant and Oil Studied by SANS and NMR Self-diffusion: Effect of Temperature and Oil Concentration

Samples of a poly(ethylene oxide) trisiloxane surfactant, water, and decane have been investigated using pulsed field gradient NMR (PGSE NMR) and small-angle neutron scattering (SANS) to determine the solution structure. The surfactant/water weight ratio has been kept constant at a value of 3/2, with variation of the oil (decane) content. In the neutron scattering measurements the temperature was varied from 23 °C up to the phase separation limit for these systems. The combined NMR and SANS data show that on addition of decane, the system exists as a hexagonal phase of cylindrical decane-containing micelles at all temperatures investigated. The addition of decane changes significantly the values for the structure parameters in the system, inducing an increase in periodicity of 12–15 A. By substitution of decane with its deuterated equivalent, decane-d22, it was possible to obtain detailed information on the structural organization of the oil component in this ternary mixture.

Effect of hydrocarbon incorporation in the R H12A(EO) 9 system: Preparation of porous materials

We have investigated the preparation, in a direct one-step reaction, of mesoporous and/or macroporous silica materials from the R H 12A(EO) 9 surfactant-based system. We have to look at the phase behavior of the R H 12A(EO) 9 surfactant in water as well as the effect of the solubilization of various hydrocarbons in this system. The phase diagram proved that hexadecane, decane and cyclohexane can be incorporated into the micelles (L 1). Results also show that whatever the liquid crystal phases [direct hexagonal (H 1) and lamellar (L α)] both the swelling and the penetration effects take place upon addition of decane, while only the swelling effect occurs with hexadecane. Moreover, for these two hydrocarbons, at high oil concentration, oil-in-water concentrated emulsion is formulated. The stability of the emulsion is enhanced from days to several weeks with the addition of oil. Starting from the various systems, porous silica materials were then synthesized. The present work shows that in contrary to cyclohexane, hexadecane and decane are effective expanders for the mesopore size enlargement. This suggests that in the micelles hexane and decane form a core of oil, whereas cyclohexane is incorporated between the hydrophobic chains of the surfactant. The variations of the pore diameter upon the addition of oil have been related to the solubilization properties of the oil in the surfactant. Our study also reveals that hydrogenated systems behave as the fluorinated ones, i.e., the formation of macroporous materials templated by emulsions is favored with systems, which exhibit a high value of the PIT.

Investigation of the C 16(EO) 10/decane/water system for the design of porous silica materials

We have investigated the phase behavior of the C 16(EO) 10/decane/water system. Micellar phase (L 1), direct hexagonal (H 1), cubic (I 1) and lamellar liquid crystals were identified. Phase behavior proved that only a weak fraction of oil can be incorporated into the hydrophobic core of micelles (L 1). Results also show that whatever the liquid crystal phases both the swelling and the penetration effects take place upon addition of decane. Moreover, at high oil amount, oil-in-water emulsions are formulated. The stability of the emulsion is enhanced from few hours to several months with the addition of oil. Starting from this system, porous silica materials were then synthesized. The present work shows that as long as the decane loading is lower than 7 wt.%, decane is an effective expander to enlarge the pore size of mesoporous materials obtained through a CTM-type mechanism. The pore size expansion occurs via the swelling of the surfactant-silica hybrid mesophase. If the concentration of oil is further increased no mesoporous material is recovered anymore, but hollow silica spheres, templated by the oil droplet, are obtained. However, if the amount of oil is too high (>70 wt.%) the structure of the hollow spheres collapses and only their fingerprints is still observed.

Oil‐Induced Structural Change of Wormlike Micelles in Sugar Surfactant Systems

Sucrose monofatty acid esters form spherical or short‐rod micelles in water. By combining the sugar surfactant with lipophilic monoglyceride or short‐EO‐chain, poly (oxyethylene) alkyl ether (CmEOn) one‐dimensional growth of micelles takes place, and the viscosity of the aqueous mixed nonionic surfactant solution dramatically increases due to the entanglement of elongated wormlike micelles. Upon addition of oil (decane or m‐xylene), the viscosity changes in the opposite way. With a slightly polar m‐xylene, the viscosity increases, but the viscosity is sharply decreased upon addition of the saturated hydrocarbon decane. It was confirmed by SAXS results that long wormlike micelles are more extended by m‐xylene because the m‐xylene molecules are solubilized in the surfactant palisade layer, whereas decane is solubilized in the core of micelles and makes an oil pool inside. Consequently, upon addition of decane, wormlike micelles become shortened and change to short fat micelles. The oil‐induced structural change in the micellar shape is highly related to the solubilized site of oil in the aggregates.

Effect of organic solvents on oxygen mass transfer in multiphase systems: Application to bioreactors in environmental protection

The absorption of oxygen in aqueous–organic solvent emulsions was studied in a laboratory-scale bubble reactor at a constant gas flow rate. The organic and the gas phases were dispersed in the continuous aqueous phase. Volumetric mass transfer coefficients ( k L a) of oxygen between air and water were measured experimentally using a dynamic method. It was assumed that the gas phase contacts preferentially the water phase. It was found that addition of silicone oils hinders oxygen mass transfer compared to air–water systems whereas the addition of decane, hexadecane and perfluorocarbon PFC40 has no significant influence. By and large, the results show that, for experimental conditions (organic liquid hold-up ≤10% and solubility ratio ≤10), the k L a values of oxygen determined in binary air–water systems can be used for multiphase (gas–liquid–liquid) reactor design with applications in environmental protection (water and air treatment processes).

Development of a biosensor for the detection of tributyltin.

A biosensor (LUMISENS I), based on the inducible bioluminescence of the Escherichia coli strain TBT3 (Ec::luxAB TBT3), was developed for the detection of the biocide tributyltin. LUMISENS I was set up with a minibioreactor and additional equipment for growth monitoring and light acquisition. The 100-mL minibioreactor has allowed us to establish a stable and reproducible environment for the bacteria (regulation of the growth rate, temperature, pH, and oxygenation), as well as for in situ contact with the xenobiotic. The optical components of the transducer were chosen according to the spectral emission of the strain being studied using a highly sensitive spectrophotometer that was initially devoted to Raman scattering. LUMISENS I was patented according to the in situ, automatic, and simultaneous measurement of the cell density and bioluminescence in the bioreactor. The first results showed that cells cultivated in a synthetic glucose medium provided a better detection limit than did those cultivated in a complex Luria-Bertani (LB) medium (0.02 and 1.5 microM of tributyltin, respectively). Cells maintained at a high growth rate (0.9 h(-1)) led to maximum bioluminescence. Moreover, air bubbling was efficient enough to provide suitable quantities of oxygen for both growth and light emission. When the TBT3 strain used the luxAB genes on its own, decanal, a long-chain aldehyde, had to be added to obtain the bioluminescence reaction. We found that the continuous addition of decanal was the most effective means of obtaining this reaction. The monitoring of the bioluminescence after tributyltin induction showed that the aldehyde was not toxic up to 300 microM during a 7-day experiment. Measurement of tributyltin with LUMISENS I was performed, which showed significant response up to 0.125 microM without any effect on optical density. Even though optimization of the performance of LUMISENS I is still under development, because of its original design, this biosensor is already in use as a warning system for the online monitoring of tributyltin.

Development of a biosensor for on-line detection of tributyltin with a recombinant bioluminescent Escherichia coli strain.

A biosensor was developed for the detection of tributyltin (TBT), using a bioluminescent recombinant Escherichia coli:: luxAB strain. Dedicated devices allowed the on-line measurement of bioluminescence, pH and dissolved oxygen values and the feed-back regulation of temperature. Bacterial physiology was monitored by the measurement of the cellular density, respiratory activity and the intracellular level of ATP, glucose and acetate levels. Our results showed that a synthetic glucose medium gave a better TBT detection limit than LB medium (respectively 0.02 micro M and 1.5 micro M TBT). High growth and dilution rates ( D=0.9 h(-1)) allowed maximum light emission from the bacterium. Moreover, simple atmospheric air bubbling was sufficient to provide oxygen for growth and the bioluminescence reaction. Real-time monitoring of bioluminescence after TBT induction occurred with continuous addition of decanal up to 300 micro M, which was not toxic throughout a 7-day experiment. The design of our biosensor and the optimization of the main parameters that influence microbial activity led to the capacity for the detection of TBT.

Improvement in the bioconversion of penicillin G to deacetoxycephalosporin G by elimination of agitation and addition of decane.

The bioconversion of penicillin G to deacetoxycephalosporin G (DAOG) using resting cells of Streptomyces clavuligerus could be a very valuable step in the economical production of semisynthetic cephalosporin antibiotics. The extent of the reaction, however, is very low due to inactivation of the ring expansion enzyme deacetoxycephalosporin C synthetase ("expandase") by reaction components. We show that elimination of agitation during the reaction lowers the rate but increases the amount of DAOG produced, presumably because the inactivation requires high levels of oxygen. Many additives to the medium were examined for their effect on the reaction. Clearly, the most effective compound was the organic solvent, decane.

Induction of a lamellar phase by the addition of a hydrocarbon to an isotropic ternary surfactant system

The effect of solubilization of the hydrocarbon decane into a ternary surfactant system composed of tetradecyldimethylamine oxide (TDMAO)/benzyl alcohol/water has been investigated. Studies along the isotropic L-phase region connecting the aqueous corner of the phase diagram with the benzyl alcohol side show an increasing concentration of the cosurfactant benzyl alcohol at first only leads to a moderate increase of the solubilization capacity and for intermediate amounts even to a minimum whereas for larger concentrations of benzyl alcohol large amounts of decane can become solubilized. The most interesting effect is that for compositions of the minimum solubility one finds upon further addition of decane the formation of a lamellar phase instead of a microemulsion phase. A SANS study not only confirmed the phase progression from L-phase to the lamellar phase but also showed that in the range of higher benzyl alcohol still a similar trend is observed, i.e. the addition of decane to the surfactant system enhances its amphiphilic strength. Evidently the incorporation of the decane molecules into the amphiphilic bilayer increases its rigidity thereby stabilizing the formation of liquid crystalline lamellar phases. As an effect the combination of the short chain alcohol and the hydrocarbon has a similar influence on the phase behavior as addition of a longer chain alcohol would have.

Highly Concentrated Cubic-Phase Emulsions: Basic Study on D-Phase Emulsification using Isotropic Gels.

In a hydrophilic octaethylene glycol dodecyl ether (C12EO8)-water system, a micellar cubic phase is formed below 20°C. Upon addition of decane, the maximum temperature of micellar cubic phase (I1) is increased, and, moreover, the hexagonal liquid crystal region changes to the I1 phase. Beyond the solubilization limit of decane in the I1 phase, highly viscous and gel-like O/I1-emulsions are formed in the two-phase region of I1+O. In the case of a surfactant mixture (C12EO4.8) containing C12EO8+C12EO3, a single I1 phase region is not present in a pseudo ternary phase diagram of water/C12EO4.8/decane system, but an I1+O region appears in the oil-rich region. C12EO4.8 forms lamellar liquid crystal in the aqueous system but C12EO3 in the mixture is dissolved in oil and the mixing fraction of C12EO8 in the surfactant aggregate increases as oil is added. Finally, a two-phase region of I1+O appears. It is considered that the O/I1-emulsion or gel based on the cubic phase corresponds to the gel appeared in the so-called D-phase emulsification process. Upon addition of alkyl polyol such as glycerol or 1,3-butanediol, the transparency of the emulsion in the I1+O region increases because the difference in refractive index between the cubic phase and excess oil is decreased. The maximum temperature of the I1 phase decreases with increasing polyol content. Consequently, the addition of alky polyols is not crucial to form O/I1 gels in an oil-rich region.

Interactions in Colloidal Mixtures: Partial Structure Factors in Mixtures of Colloidal Silica and an Anionic Oil-in-Water Microemulsion

We have investigated the colloidal stability and interactions in a mixture of colloidal silica (LudoxTM) and an oil-in-water microemulsion (AOT/decane/brine). Stable silica–microemulsion mixtures containing large fractions of dispersed phase (φoil+ φLudox> 0.36) can be prepared. For fixed silica and AOT concentrations, the addition of decane increases the size of the microemulsion droplets. Since the surfactant concentration remains constant, this droplet growth is balanced by a decrease in the number density of droplets. Partial structure factors for the mixture are extracted from sets of small-angle neutron scattering (SANS) data using a solvent contrast variation technique. The extracted partial structure factors are compared qualitatively to model calculations for a multicomponent sticky hard sphere (SHS) fluid. A shallow contact potential (approximately 2.6kT) between the Ludox particles is necessary to obtain agreement between model and experiment in the low-qregion of the partial structure factors. The magnitude of this contact potential does not change with decane concentration, in agreement with the macroscopic observation that there is no observable change in the stability of these silica–microemulsion mixtures.

Effect of Oil on the Surfactant Molecular Curvatures in Liquid Crystals

The effect of added decane, m-xylene, or squalane on the phase behavior of the polyoxyethylene dodecyl ether (C12EOn) −water system was investigated as a function of polyoxyethylene (EO) chain length at 25 °C. When the surfactant is relatively lipophilic (more lipophilic than the balanced state), the type of liquid crystal is changed to the more lipophilic one upon addition of decane. The lamellar (Lα) to lipophilic reverse hexagonal (H2) transition takes place in the C12EO3 system. On the other hand, the hexagonal (H1) to hydrophilic discrete cubic (I1) liquid crystal transition occurs in the hydrophilic C12EO7 system. There are two kinds of effects of oil on the self-organizing structures. One is the “penetration effect”, in which oil molecules penetrate into the surfactant palisade layer and expand the effective cross-sectional area, aS. The other is “swelling effect”, in which oil molecules are solubilized in the core of aggregates and expand the volume of aggregates. In this case, the aS is almost co...

Dielectric Spectroscopy of Liquid Lamellar Phases

Four lamellar based phases in the lecithin/water/oil phase system have been prepared and examined by low-frequency dielectric spectroscopy in the frequency range 3 × 10−5to 3 × 10+5Hz. The dielectric properties of the lamellar and liquid crystal phases have been determined over ranges of temperature, and measurements are reported for mixed phase systems. From this information the physical basis for the observed responses has been determined and is reported. Two broad patterns of dielectric response have been found. The ordered micellar and liquid crystal phases do not support dc conductances, even at the lowest frequencies used. The dispersions in these well-defined phases are of the fractional power law form, (iω)−s, in frequency with 1 >s> 0.5 at the lowest frequencies and 0.5 >s> 0 in the hertz and kilohertz ranges. On the addition of decane, or by using a formulation that lies close to the lamellar/liquid crystal phase boundary, dc conduction is observed, but in both cases the charge transport is blocked by electrode barrier layers and the generalized Maxwell–Wagner response is found. When the conductance is brought about by the addition of the oil, a large dipolar-like dispersion is observed in the frequency range below the inverse of the bulk relaxation time of the system. This dispersion has been associated with the discrete oil globules within the lamellar structure.