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1.
Ibrahim Kayali Mohammad Karaein Khawla Qamhieh Salam Wadaah Wisam Ahmad Ulf Olsson 《Journal of Dispersion Science and Technology》2013,34(1):10-17
Bicontinuous and water-in-diesel microemulsions were formulated using single nonionic alkyl poly glycol ethers combined with hydrophilic alcohol ethoxylates. The phase behavior at temperatures ranging from 0°C to 50°C was investigated. Visual inspection as well as cross-polarizers were used to detect anisotropy. The fish phase diagrams were determined. The presence of the hydrophilic alcohol ethoxylates was necessary to initiate both types of microemulsions. Increasing the hydrophobic chain length of the surfactant led to a wider range of temperature stability at lower surfactant concentration. Meanwhile, increasing the ethylene oxide units in the headgroup by two units led to a phase diagram that is dominated by lyotropic liquid crystal. The formulated water in diesel microemulsions were tested experimentally in a 4-cylinder diesel engine. From this it is observed that the emissions of NOx, soot, and CO2 were reduced substantially compared to neat diesel, while for the CO the reduction occurs just at low load. 相似文献
2.
Khawla Qamhieh Mirfit Amleh Mai Khaleel 《Journal of Dispersion Science and Technology》2013,34(11):1517-1525
The effect of replacing the conventional uniform macroion surface charge density with discrete macroion charge distributions on the structure of electric double layer (EDL) of a spherical macroion has been investigated by Monte Carlo (MC) simulations. Two discrete models have been investigated in addition to the central macroion charge: point charges localized on the macroion surface and finite-sized charges protruding into the solution. Both models have been studied with fixed and mobile macroion charges. The radial functions of local densities and electrostatic potential in EDL, are calculated and compared to the results obtained for the central macroion charge distribution. It is concluded that the model of charge distribution significantly affects the EDL structure close to the macroion, while the effect is much weaker at larger distances. With point charges localized on the macroion surface, counterions become stronger accumulated to the macroion, as a result the absolute values of surface potential ?0 and zeta ξ potential are decreased. With protruding charges, the excluded volume effect dominates over the increased correlation ability; hence the counterions are less accumulated near the macroions and the absolute values of ?0 and ξ potentials are increased. 相似文献
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G. Marx D. Ackermann J. Dilling F.P. Hessberger S. Hoffmann H.-J. Kluge R. Mann G. Münzenberg Z. Qamhieh W. Quint D. Rodriguez M. Schädel J. Schönfelder G. Sikler C. Toader C. Weber O. Engels D. Habs P. Thirolf H. Backe A. Dretzke W. Lauth W. Ludolphs M. Sewtz 《Hyperfine Interactions》2001,132(1-4):459-464
The ion trap facility SHIPTRAP is being set up to deliver very clean and cool beams of singly-charged recoil ions produced
at the SHIP velocity filter at GSI Darmstadt. SHIPTRAP consists of a gas cell for stopping and thermalizing high-energy recoil
ions from SHIP, an rf ion guide for extraction of the ions from the gas cell, a linear rf trap for accumulation and bunching
of the ions, and a Penning trap for isobaric purification. The progress in testing the rf ion guide is reported. A transmission
of about 93(5)% was achieved.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
5.
The effect of replacing the conventional uniform macroion surface charge density with discrete macroion charge distributions on structural properties of aqueous solutions of like-charged macroions has been investigated by Monte Carlo simulations. Two discrete charge distributions have been considered: point charges localized on the macroion surface and finite-sized charges protruding into the solution. Both discrete charge distributions have been examined with fixed and mobile macroion charges. Different boundary conditions have been applied to examine various properties. With point charges localized on the macroion surface, counterions become stronger accumulated to the macroion and the effect increases with counterion valence. As a consequence, with mono- and divalent counterions the potential of mean force between two macroions becomes less repulsive and with trivalent counterions more attractive. With protruding charges, the excluded volume effect dominates over the increased correlation ability; hence the counterions are less accumulated near the macroions and the potential of mean force between two macroions becomes more repulsive/less attractive. 相似文献
6.
Ibrahim Kayali Khawla Qamhieh Ulf Olsson 《Journal of Dispersion Science and Technology》2013,34(1):41-46
The phase behavior of systems containing sodium alkyl polypropylene oxide sulfate with equimolar ratio of polypropylene oxide ammonium chloride was determined as a function of salt concentration and alkane carbon number at ambient temperature. Visual inspection as well as cross polarizers were used to detect anisotropy. Solubilization ratios for oil and brine in the middle phases were measured and used to calculate the interfacial tension (IFT) between the microemulsion and oil or brine. The fish diagram is presented showing a minimum amount of 0.20 wt% surfactant needed to form the middle phase. Swelling increases with decreasing the alkane carbon number of the oil. Ultra low IFT values were predicted for the systems investigated. 相似文献
7.
Ibrahim Kayali Khawla Qamhieh Ulf Olsson Lada Bemert Reinhard Strey 《Journal of Dispersion Science and Technology》2013,34(4):516-520
Alcohol-free microemulsions were formulated using mixtures of extended surfactant (C12-14-PO14-EO2SO4Na), sodium dodecyl benzene sulfonic acid and cationic hydrotropes with equal amounts of water and diesel. The cationic hydrotropes had short hydrocarbon or propylene oxide chain. The formulation included sodium carbonate to convert naphthenic acids in diesel to soaps. The phase behavior at ambient temperature of oil-free mixtures as a function of NaCl concentration was investigated. Visual inspection as well as cross polarizers were used to detect anisotropy. The microemulsion fish phase diagram and solubilization ratios for diesel and brine in the middle phases were determined. The minimum surfactant concentration needed to initiate middle phase formation was 0.10 wt%. Salinity scans revealed that optimal salinity can be adjusted according to the hydrophilic/lipophilic nature of the hydrotrope used. Interfacial tension measurements using a spinning drop tensiometer showed a minimum value of 0.0015 mN/m between middle phase microemulsion and excess brine and a value of 0.032 mN/m between diesel and brine. 相似文献
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Ibrahim Kayali Khawla Qamhieh Bjorn Lindman 《Journal of Dispersion Science and Technology》2013,34(8):1151-1155
Three fragrances, limonene, benzaldehyde, and phenethylalcohol (that differ in their polarities), were solubilized in hexagonal liquid crystal using the polyethylene oxide‐polypropylene oxide‐polyethylene oxide, (EO27 PO61 EO27), P104 triblock copolymer, and water. The interlayer spacing of the hexagonal liquid crystals were established using small‐angle x‐ray scattering (SAXS). The SAXS data are used to calculate the interfacial area per polyethylene oxide (PEO) block and the radius of the apolar domain in order to determine the location of each fragrance in the association structure. The results show the presence of limonene inside the core of the apolar domain while benzaldehyde is only partially located inside the core with the other part contributing to the interface. The third fragrance, phenethylalcohol, is present between the polar heads, thus, contributing entirely to the interface. 相似文献
10.
The reagent 5,5-dimethyl-1,2,3-cyclohexanetrione 1,2-dioxime 3-thiosemicarbazone (DCDT) has been used for the spectrophotometrie determination of cobalt (II). Various factors affecting the sensitivity of this determination have been studied. These factors include wavelength, standing time and pH. The range of applicability of Beer's law on this determination has been concluded and its sensitivity has been calculated and compared with other reagents used for 相似文献