Abstract  A convenient procedure for the synthesis of aliphatic alkylglycidyl ether has been studied. It has been found that the improved preparation of the alkylglycidyl ether can be achieved by using fatty alcohol such as octanol and octadecanol with epichlorohydrin in the presence of phase-transfer catalyst (PTC) such as 1-alkyloxypropan-2-ol-3-trimethyl ammonium methylsulfate, 1-alkyloxypropan-2-ol-3-melhyldiethanolammonium methylsulfate, alkyloxy-2-hydroxypropyldimethylamine and alkyloxy-2-hydroxypropyldiethanolamine, tetrabutylammonium bromide, etc. without water and other organic solvents. This method, carried out in solid phase/organic phase (reactants and product themselves), has the following merits: (i) producing the solid by-products such as sodium chloride and sodium hydroxide which are easily removed by simple filtration, (ii) saving the amount of reactants used such as sodium chloride and phase-transfer catalyst, and (iii! increasing the yields of glycidyl ethers. The yields of octylglycidyl ether and octadecylglycidyl ether are 92.0 and 91.7%, respectively. The amount of sodium hydroxide used can be saved by from 1.5 to 0.7 molar ratio with respect to octanol in comparison with those in the conventional method using PTC.

Abstract  The structural phase transition from the hexagonal to a distorted-hexagonal (centered rectangular) phase (the LS-S transition) in Langmuir monolayers of octadecanol is studied in a grazing incidence x-ray diffraction experiment. We find algebraic decay of positional correlations, which suggests solid-like order in both phases at the distances accessible in the present x-ray diffraction experiment. The transition is accompanied by strong positional disorder, which is evident from the drastic increase of the exponent eta to values eta>2 close to the transition. Remarkably, on approaching the transition, the continuous increase of eta is apparent already at 20 degrees C above it. The positional disorder is attributed to elastic distortions around pretransitional fluctuations. [S1063-651X(99)10102-8].

Abstract  Absorption spectra in the terahertz (THz) region between 10 and 400 cm(-1) were measured for fatty acids and their analogues at room temperature. Saturated fatty acids such as palmitic and stearic acids had some sharp peaks, while unsaturated fatty acids such as oleic, linoleic and linolenic acids had two distinct peaks at 247 and 328 cm(-1). These peaks apparently derived from the carboxylic group because oleyl alcohol had no distinct peak. The THz absorption spectra of fatty acids may be affected by the crystalline as well as the chemical structure. The THz absorption spectra of oleic acid esters depended on ester types, although all oleic acid esters had some peaks due to the ester group. THz absorbance of fatty acids positively correlated with concentration. Based on these results, THz spectrometry may be a good analytical method for the non-destructive qualitative and quantitative evaluation of fatty acids and their analogues.

Abstract  Butanol is a precursor of many industrial chemicals, and a fuel that is more energetic, safer and easier to handle than ethanol. Fermentative biobutanol can be produced using renewable carbon sources such as agro-industrial residues and lignocellulosic biomass. Solventogenic clostridia are known as the most preeminent biobutanol producers. However, until now, solvent production through the fermentative routes is still not economically competitive compared to the petrochemical approaches, because the butanol is toxic to their own producer bacteria, and thus, the production capability is limited by the butanol tolerance of producing cells. In order to relieve butanol toxicity to the cells and improve the butanol production, many recovery strategies (either in situ or downstream of the fermentation) have been attempted by many researchers and varied success has been achieved. In this article, we summarize in situ recovery techniques that have been applied to butanol production through Clostridium fermentation, including liquid-liquid extraction, perstraction, reactive extraction, adsorption, pervaporation, vacuum fermentation, flash fermentation and gas stripping. We offer a prospective and an opinion about the past, present and the future of these techniques, such as the application of advanced membrane technology and use of recent extractants, including polymer solutions and ionic liquids, as well as the application of these techniques to assist the in situ synthesis of butanol derivatives.

Abstract  Reactive extractions of acrylic, propionic, and butyric acids using Aliquat 336 in oleyl alcohol were carried out to study the effects of temperature (305-333 K). The effects of temperature on the partition (P) and dimerization (D) coefficients were evaluated, and it was found that P decreases with increasing temperature, whereas the effects of temperature on D vary. Chemical extractions using Aliquat 336 in oleyl alcohol at temperatures ranging from 305 to 333 K show an increase in K(E(1:1)) values with temperature up to 313 K for acrylic and propionic acids but a decrease with increasing temperature for butyric acid over the range studied. Differences in the hydrophobicity and octanol-water partition coefficient are suggested as the reasons for the differences in extraction by the respective acids using Aliquat 336 in oleyl alcohol. The enthalpy (Delta H) and entropy (Delta S) of reaction were evaluated at different temperatures, and their difference was assessed in terms of different parameters.

Abstract  Lipid derived diesters display excellent thermodynamic characteristics suitable for applications in phase change materials (PCMs), making them potential renewable alternatives suitable for replacing traditional petrochemical derived PCMs such as paraffins. In order to evaluate their abilities to be used as PCMs, however, it is important to understand how their structures influence the high temperature behaviour under both thermal and thermo-oxidative conditions. This study analyzed the thermal stability of three template diester systems under both inert and oxidative environments using thermogravimetric analysis (TGA) under nitrogen and air, respectively. The lipid derived diesters, synthesized from dialcohols and either oleic (unsaturated) or stearic acid (saturated), and from oleyl alcohol and various diacids, all possessed the form 18-n-18, where n represented the length of the dialcohol or diacid moiety (n = 2,4, 6, 8, 9 or 10 carbon atoms) and 18 gave the length of the fatty acid moiety on the diol derived diesters, and the fatty alcohol moiety on the dibasic diesters. Under inert atmospheres, none of the diesters break down and are stable until they evaporate. The introduction of unsaturation raises the evaporation temperature of the reference diesters, especially at large diol chain lengths, while the reversal of the ester group lowers the evaporation temperatures with respect to the diol derived diesters. These results reveal that saturated and unsaturated diol derived diesters and saturated dibasic diesters are able to function in a wide range of applications as high as their evaporation point depending on the atmosphere present, and above similar to 240 degrees C in all instances. Specifically, the thermal and oxidative stabilities of these diesters indicate their suitability for use in thermal energy storage as phase change materials. (C) 2016 Elsevier B.V. All rights reserved.

Abstract  We isolated eight chlorosulfolipids (1-8) from the chrysophyta Ochromonas danica (IAM CS-2), including five new chlorosulfolipids (2-5, 8). The planar structures of all the compounds were elucidated by 1D and 2D NMR and ESI-MS/MS analyses. We determined the relative configuration of seven chlorosulfolipids (1-7), including the most commonly known chlorosulfolipid, 2,2,11,13,15,16-hexachlorodocosane-1,14-disulfate (1), by J-based configuration analysis (JBCA). The absolute configuration of each compound was determined using a modified Mosher's method after chemical degradation. 2,2,11,13,15,16-Hexachloro-14-docosanol-1-sulfate (2) was the most toxic to brine shrimp (Artemia salina) larvae (LC(50) 0.27 microg/mL). Compounds 1 and 4-8 were less toxic (LC(50) 2.2-6.9 microg/mL). Compound 3 was not toxic at 30 microg/mL.

Abstract  The leaf essential oil of Ajuga iva growing wild in Mascara region situated in the North West of Algeria, has been obtained by hydrodistillation and analyzed by GC and GC-MS. We proposed to determine the physicochemical, organoleptic and chemical identification of these components. Twenty two volatile compounds were identified which included: dienestrol (54.04%), eucalyptol (27%), o-xylene (7.98 %), 1-octadecanol (5.80%); 3-carene (4.46%), (E)-2,3,6- trimethoxypentafulvene-1-carbonitrile (4.34%), (-)-spathulenol (1.77%), nonanal (1.24%). The oil from Ajuga iva showed activities against Escherichia coli, Salmonella typhimurium, Staphylococcus aureus,Bacillus subtilis, and Pseudomonas aeroginosa.

Abstract  Thermochromic composites of benzofluoran dye, bisphenol A developer and octadecanol solvent were investigated to analyse how different molar ratios of developer influences the structural, optical and thermal properties. Increasing the amount of developer gives stronger absorption in the visible region and larger colour contrast between coloured and discoloured states. The colour clearing temperature of all studied composites is well below their melting point and the phase transitions are influenced only little by the content of the developer. The crystalline structure is fully controlled by the solvent; it changes from the gamma phase to the liquid at heating and returns through the rotator phase into the gamma phase at cooling. Crystallinity of the composites diminishes with the content of the developer, causing increased scattering of light. The dye: developer molar ratio equal to 1:3 was determined to be large enough to open lactone ring in all dye molecules. Colour hysteresis of such composites shrinks to practically single sigmoidal curve whereas the colour contrast still increases with higher amount of the developer. This effect could be attributed to developer - solvent interactions in a composite with lower crystallinity. (C). 2014 Elsevier Ltd. All rights reserved.

Abstract  Using Brewster angle microscopy, it is demonstrated that extended L-2'-single liquid crystalline domains in an octadecanol monolayer grow by locally heating and cooling, Langmuir monolayers at the air/water-interface with a focused IR-laser. The effect of the cooling rate on the domain size is discussed. The behavior is explained as an isotensile reorientation transition.

Abstract  (Solid + liquid) equilibrium temperatures for mixtures containing quinoline and 1-dodecanol, 1-hexadecanol, or 1-octadecanol have been measured using a dynamic method. (Quinoline + benzene, +alkane, or +1-alkanol) systems were investigated using DISQUAC. The corresponding interaction parameters are reported. The model yields a good representation of molar excess Gibbs free energies, G(E), molar excess enthalpies, H(E), and of the (solid + liquid) equilibria, SLE. Interactional and structural effects were analysed comparing H(E) and the molar excess internal energy at constant volume, U(V)(E). It was encountered that structural effects are very important in systems involving alkanes or 1-alkanols. Interactions between amine molecules are stronger in mixtures with quinoline than in those containing pyridine, which was ascribed to the higher polarizability of quinoline. (C) 2008 Elsevier Ltd. All rights reserved.

Abstract  Maleic anhydride was grafted by long chain alcohol l-eicosanol to a novel sort of corresponding monoester, mono-eicosyl cis-butene dicarboxylate. Then the four novel ternary lanthanide (Eu3+, Tb3+, Dy3+, Gd3+) complexes with the as-derived long chain monoester and a second ligand 1,10-phenanthroline were synthesized and characterized by elemental analysis, IR spectra. The photophysical properties of these complexes were studied in detail with ultraviolet absorption spectra, low temperature phosphorescent spectra, fluorescent spectra and luminescent lifetimes, indicating that the intramolecular energy transfer mechanism runs smoothly within these ternary complexes in terms of sensitized functions of 1, 10-phenanthroline and strong characteristic green, red or blue emissions of Tb3+, Eu3+ or Dy3+ have been achieved. (c) 2005 Elsevier B.V. All rights reserved.

Abstract  Thirty-four sets of data on solid-liquid equilibria for the entitled mixtures are examined in terms of DISQUAC. On the basis of data for systems containing n-octane, new first dispersive interchange coefficients are given for the hydroxyl/aliphatic contacts involved. They are constant from 1-hexadecanol. The remainder interchange coefficients are kept the same as in our previous works. The relative standard deviations for the equilibrium temperatures are less than 0.025 for all the mixtures investigated. Results depend on the difference in size of the mixture compounds.

Abstract  A heterogeneous floating multilayer created from a 99 1 mole mixture of 1 octadecanol and BODIPY-HPC was characterized by fluorescence microscopy The monomer and the D dimer emission of the BODIPY moiety displayed a variety of structures including phase separated fluid-like regions (dimer rich) and more rigid solid like regions (monomer rich) These layers were deposited onto a Au(111) electrode surface and characterized using capacitance measurements and in situ fluorescence microscopy A direct comparison between the floating layer and the resulting deposited layer revealed an expansion of 1 3-2x with distortion in the fluorescent features due to the multilayer nature of the floating layer A similar variety of structures or phases were observed to exist on the electrode which displayed different potential dependent changes in fluorescence The monomer and dimer fluorescence intensity and their ratio were used to characterize the potential dependence of the various adsorbed phases An example is presented that illustrates the influence of the solid substrate on the characteristics of the adsorbed layer A region in the floating layer that appeared to be mixed in composition was transformed into a dimer rich region that had potential dependent characteristics of both This method is useful for probing the heterogeneity of organic layers adsorbed on electrode surfaces The phase characteristics of the adsorbed organic layer can be probed using these types of dimer forming fluorescent probes and FRET methods but are complicated by the influence of the solid substrate and the photobleaching that occurs (C) 2010 Elsevier B V All rights reserved

Abstract  Novel silver-doped nickel titanate nanoparticles (Ag-NiTiO3) were successfully prepared via a sol-gel method in the presence of stearyl alcohol as the capping agent and solvent. The formation of pure crystallized nickel titanate and silver-doped nickel titanate was occurred when the precursor was heat-treated at 700 degrees C in air for 150 and 60 min, respectively. The structural, morphological, and optical properties of obtained products were characterized by techniques such as X-ray diffraction (XRD), Fourier transforminfrared (FT-IR) spectroscopy, Energy dispersive X-ray microanalysis (EDX), ultraviolet-visible (UV-vis), and scanning electron microscopy (SEM). The magnetic property of the prepared Ag-NiTiO3 nanoparticles was also investigated with vibrating sample magnetometer (VSM). To fabricate a FTO/TiO2/Ag-NiTiO3/Pt-FTO solar cell, Ag-NiTiO3 film was directly deposited on top of the TiO2 prepared by electrophoresis deposition method. Furthermore, solar cell result indicates that an inexpensive solar cell could be developed by the synthesized Ag-NiTiO3 nanoparticles.

Abstract  Experimental data on the partitioning of amino acids (tryptophan, phenylalanine) and dipeptides (tryptophan-leucine, phenylalanine-leucine) between the aqueous feed phase and the organic solvent phase are presented. The organic solvent phase consists of a carrier, sodium di-2-ethylhexyl sulfosuccinate/quaternary ammonium salt/dioleyl phosphoric acid, dissolved in (Z)-9-octadecen-1-ol (an organic solvent). The equilibrium distribution coefficient for extractions is determined by varying the following experimental conditions: feed solution pH, initial feed phase concentration, and composition of organic phase. The partition coefficient for the stripping process is also determined by varying the stripping agent (sodium hydroxide, sodium chloride, sodium carbonate), the concentration, and the pH of the stripping solution. The extraction and stripping reaction coefficients are calculated by combining the experimental data and the kinetic expressions for interfacial reactions. The variation of the values of the coefficients with the solute type (i.e. amino acid or dipeptide) and with the operating conditions of the system di-2-ethylhexyl sulfosuccinate in (Z)-9-octadecen-1-ol is presented.

Abstract  Seven chemically designed monolayer compounds were synthesized and investigated with comparison to the properties and water evaporation suppression ability of 1-hexadecanol and 1-octadecanol. Increasing the molecular weight and polarity of the compound headgroup drastically altered the characteristics and performance of the monolayer at the air/water interface. Contrary to the common expectation the monolayer's lifetime on the water surface decreased with increasing number of ethylene oxy moieties, thus optimal performance for water evaporation suppression was achieved when only one ethylene oxy moiety was used. Replacing the hydroxyl headgroup with a methyl group and with multiple ethylene oxy moieties resulted in a loss of suppression capability, while an additional hydroxyl group provided a molecule with limited performance against water evaporation. Theoretical molecular simulation demonstrated that for exceptional performance, a candidate needs to possess a high equilibrium spreading pressure, the ability to sustain a highly ordered monolayer with a stable isotherm curve, and low tilt angle over the full studied range of surface pressures by simultaneously maintaining H-bonding to the water surface and between the monolayer chains. (C) 2012 Elsevier B.V. All rights reserved.

Abstract  The adsorption behavior of 1,1,2,2,-tetrahydroheptadecafluorodecanol (FC10OH), 1-eicosanol (C20OH), and their mixtures at the hexane solution/water interface is summarized briefly and examined from the viewpoints of interfacial tensions in the presence of domains, domain formation, and the correlation between the phase transition and the miscibility of film forming substances in the adsorbed films. The two-dimensional analogue of the Laplace equation showed that the interfacial tension is always higher in the presence of domains than that in the absence of them. The higher tendency of domain formation of FC10OH compared to C20OH is mainly ascribed to the excess Gibbs energy of mixing of fluorocarbon chains and hydrocarbon solvent being positive and to the interaction energy between domains being more stable against cohesion for FC10OH than for C20OH. The thermodynamic equations derived here suggested the heteroazeotropy in the phase diagram of adsorption and the temperature dependence of interfacial tension at the phase transition points, which are in accord with the experimental findings qualitatively.

Abstract  The interfacial tension gamma of a hexane solution of 1,1,2,2-tetrahydroheptadecafluorodecanol CF3(CF2)(7)(CH2)(2)-OH (FC10OH) against water was measured as a function of temperature T and molality m(1) under atmospheric pressure. By the calculation of the interfacial density Gamma(1)(H) and then drawing the interfacial pressure pi vs area per adsorbed molecule A curves, it was concluded that two types of first-order phase transitions take place from the gaseous to the expanded state and from the expanded to the condensed one in the adsorbed film of FC10OH. The partial molar entropy (s) over bar(1)(H) - s(1)(O) and energy changes (u) over bar(1)(H) - u(1)(O) associated with the adsorption were estimated and compared with those of 1,1,2,2-tetrahydrohenicosafluorododecanol CF3(CF2)(9)(CH2)(2)OH (FC12OH). It was found that these values of FC10OH are negative and larger than those of FC12OH. It was suggested that, although both (s) over bar(1)(H) and s(1)(O) values increase, the increment in s(1)(O) is larger than that in (s) over bar(1)(H) when the fluorocarbon chain is lengthened from FC10OH to FC12OH. Furthermore, it was realized that the energetical stabilization of the FC10OH molecule accompanied by adsorption is less than that of the FC12OH molecule. Furthermore, it was shown that the temperature and pressure dependencies of the pi vs A curve are related to the partial molar entropy and volume changes of adsorption, respectively. By estimation of the temperature and pressure coefficients of A at constant pi, it is found that a temperature increase of only 1 K is sufficient to keep pi and A constant upon a decrease of the pressure by 1 MPa.

Abstract  New type of triazolium Gemini surfactants were synthesized by reaction of epichlorohydrine with long-chain fatty alcohols namely cetyl alcohol and oleyl alcohol furnishing product 2-(alkoxymethyl) oxirane followed by the their subsequent treatment with triazole resulting in the formation of 1-(1,2,4-triazole)-3-alokoxypropane-2-ol which on reaction with 1,6-dibromohexane resulted in the formation of triazolium-based cationic Gemini surfactant. Their formation was confirmed by IR spectroscopy. Surface tension values were used to determine the critical micelle concentration (CMC), minimum area per molecule (A(min)) at air-water interface, Gibbs free energy of adsorption (Delta G(ads)), the maximum surface excess concentration (Gamma(max)), and other parameters. The inhibition behavior of dimeric surfactant on the corrosion of carbon steel (CS) in 1N H2SO4 aqueous medium was studied at 30 degrees C. Performance tests like dispersion capability, foaming power and stability, emulsifying power, and wetting ability were determined. The obtained results show that dispersion capability, foaming power, foaming stability, and emulsifying ability are very good. The wetting power of synthesized surfactants is quite better.

Abstract  Solid-liquid equilibrium temperatures for tert-butanol + n-alkanes (C-18, C-19, C-20, C-21, C-22, C-23, C-24, C-25, C-26, C-28) systems have been measured by a dynamic method from 298.15 K to the melting point of the alkane. All the systems present an eutectic point at very low concentration of the alcohol. A first-order transition was observed for many of the n-alkanes considered. The experimental values are compared with those given by the DISQUAC model using the interaction parameters previously determined on the basis of vapor-liquid equilibria, VLE, and molar excess enthalpies, H-E, of systems containing the lower n-alkanes (n-C-6, n-C-7). Calculations were developed taking into account the solid-solid transition of the alkanes. The mean relative standard deviation for the equilibrium temperatures is 0.0073. Differences between experimental data and calculated results for SLE and H-E are analysed in terms of the Patterson effect. The possibility of improving predictions by modifying only the third dispersive interchange coefficient is discussed. Two values for this parameter are proposed depending on n, hereafter the number of C atoms in the n-alkane (n less than or equal to 8 and n greater than or equal to 9). In this way, the variation with the temperature of HE is better represented by the model for those systems including the longer n-alkanes. Predictions on SLE remain unchanged, because they depend essentially on the first interchange coefficients when the range of temperature considered, as in this case, is rather narrow. (C) 1998 Elsevier Science B.V. All rights reserved.

Abstract  In the present study, focused the antimicrobial compound production by the marine actinobacteria isolated from the mangrove sediments of Andaman Island. Streptomyces sp. DOSMB-A107 isolated from mangrove sediments of Andaman Island was identified by morphological, chemistry of cell wall and molecular characterization. Bioactive compounds were extracted with five different solvents and were identified using GC-MS analysis. Among the five different solvents ethyl acetate extract showed maximum activity against eleven bacteria and six fungal pathogens than other solvents. Twelve compounds were identified, off the following eight compounds such as 2-Butanol, 2-nitroso-, acetate(ester), Phenylethyl Alcohol, Phenol, 2,4-bis(1,1- dimethylethyl)-, 1-Hexadecanol, Pyrrolo[1,2a]pyrazine-1,4-dione, hexahydro-3- (2-methylpropy1)-, 1Hentetracontanol, 1-Eicosanol, Ergotaman-3',6',18-trione, 12'-hydroxy-2'-methyl-5' (phenylmethyl)-, (5'a)- were identified as anti-infective agent. Ethyl acetate would be a suitable solvent for the extraction of antimicrobial agents from Streptomyces.

Abstract  The properties of jojoba oil make it uniquely suited as a raw material for the cosmetics industry. Water-based, thermodynamically stable preparations of jojoba oil are essential in many formulations. New microemulsions were prepared based on jojoba oil and different nonionic surfactants, namely poly-oxyethylene-(ethylene oxide)(10)-oleyl alcohol (Brij 96V) and ethoxylated sorbitan esters (Tweens). The effects of the surfactants and of primary alcohols as cosurfactants on the isotropic regions of the phase diagram were elucidated. It was found that, up to a certain cosurfactant chain length, the isotropic region expanded considerably as chain length increased. The size of the isotropic region also increased as a function of the ethylene glycol content of the aqueous phase in microemulsions based on ethoxylated alcohol but shrank when ethylene glycol was included in microemulsions prepared with ethoxylated sorbitan esters. Secondary structural phase transitions from water-in-oil to bicontinuous and to oil-in-water structures (as determined by measuring conductivity and viscosity) were found to be related to jojoba oil content. Dynamic light scattering and small angle X-ray scattering studies established that incorporation of jojoba oil into Brij 96V micelles caused micellar transformation from elongated to spherical droplets and a decrease in the aggregation number.

Abstract  This paper presents the effect of adding different amounts of zinc into the composition of Zn-Mn/oleylamine core/shell ferrite nanoparticles (NPs). For this purpose, acetylacetonate as a main precursor, oleylamine as a surfactant and surface modifier, and stearyl alcohol as a co-surfactant were used for thermal decomposition synthesis of this ferrite. Monodispersed core/shell ferrite NPs synthesized with several compositions. The X-ray diffraction (XRD) patterns and transmission electron microscopy (TEM) images showed single-phase nanoparticles around 10 nm without any impurities. Fourier Transform Infrared Spectroscopy (FTIR) confirmed single-phase spinel with ultra-thin layers of oleylamine on the surfaces that make the particles separated from each other. Thermogravimetric studies could also measure the amount of surfactant around the NPs. Moreover, the DC magnetic properties of the samples were studied using the vibrating sample magnetometer (VSM). The M-H curves for all the samples showed negligible hysteresis loops indicating the superparamagnetic behaviour of the NPs. Furthermore, maximum saturation magnetization was measured for the sample with Mn0.6Zn0.4Fe2O4 with 45 amu.gr(-1), suggesting that this composition could be an excellent candidate for biomedical applications such as hyperthermia and imaging. (C) 2016 Elsevier B.V. All rights reserved.