Mixture Of Decane Research Articles

Polyferrocenylsilane microspheres: synthesis, mechanism of formation, size and charge tunability, electrostatic self-assembly, and pyrolysis to spherical magnetic ceramic particles.

Pt(0)-catalyzed ring-opening precipitation copolymerization of [1]silaferrocenophanes fcSiMe(2) (3) and the spirocyclic cross-linker fcSi(CH(2))(3) (4) (fc = Fe(eta(5)-C(5)H(4))(2)) was used to prepare polyferrocenylsilane microspheres (PFSMSs) under mild conditions. By varying the reaction conditions, a wide variety of other morphologies was obtained. The effects of temperature, monomer ratio, solvent composition, catalyst concentration, and time on the observed morphology were investigated and interpreted in terms of a mechanism for microsphere formation. The most well-defined particles were formed using equimolar amounts of 3 and 4, in a 50:50 mixture of xylenes and decane at 60 degrees C with gentle agitation. Chemical oxidation of the polymeric microspheres led to positively charged particles (OPFSMSs) which underwent electrostatically driven self-assembly with negatively charged silica microspheres to form core-corona composite particles. Redox titration with controlled amounts of the one-electron oxidant [N(C(6)H(4)Br-p)(3)][PF(6)] in acetonitrile led to the oxidation of the outer 0.15 microm (ca. 32%) of the PFSMSs. The resulting OPFSMSs were reduced back to their neutral form by reaction with hydrazine in methanol. Pyrolysis of the PFSMSs led to spherical magnetic ceramic replicas with tunable magnetic properties that organize into ordered 2-D arrays at the air-water interface under the influence of a magnetic field.

Bilayer Reconstitution of Voltage-Dependent Ion Channels using a Microfabricated Silicon Chip

Painted bilayers containing reconstituted ion channels serve as a well defined model system for electrophysiological investigations of channel structure and function. Horizontally oriented bilayers with easy solution access to both sides were obtained by painting a phospholipid:decane mixture across a cylindrical pore etched into a 200- μm thick silicon wafer. Silanization of the SiO 2 layer produced a hydrophobic surface that promoted the adhesion of the lipid mixture. Standard lithographic techniques and anisotropic deep-reactive ion etching were used to create pores with diameters from 50 to 200 μm. The cylindrical structure of the pore in the partition and the surface treatment resulted in stable bilayers. These were used to reconstitute Maxi K channels in the 100- and 200- μm diameter pores. The electrophysiological characteristics of bilayers suspended in microchips were comparable with that of other bilayer preparations. The horizontal orientation and good voltage clamping properties make the microchip bilayer method an excellent system to study the electrical properties of reconstituted membrane proteins simultaneously with optical probes.

Volumetric Behavior of Decane + Carbon Dioxide at High Pressures. Measurement and Calculation

The volumetric behavior of carbon dioxide (1) + decane (2) mixtures has been investigated under the high pressures 20, 30, and 40 MPa in the temperature range [308.15 K to 368.15 K]. Densities have been measured for pure decane and for x1 = 0.15, 0.30, 0.51, 0.66, 0.78, and 0.84. Density variations show a peculiar behavior: a crossover phenomenon with the composition at a given pressure and temperature is observed. The measured fluid densities have been compared with values predicted by equations of state with various mixing rules. This comparative study has revealed models well adapted to these density estimations.

Densities, Viscosities, and Refractive Indices of Binary Liquid Mixtures of Hexane, Decane, Hexadecane, and Squalane with Benzene at 298.15 K

Densities, ρ, viscosities, η, and refractive indices, nD, for binary mixtures of hexane, decane, hexadecane, and squalane with benzene were measured over the whole composition range at 298.15 K and atmospheric pressure. The excess molar volumes, , and viscosity deviations, δη, were calculated from experimental measurements. These result were further fitted to the Redlich−Kister equation to estimate the binary coefficients and standard errors. The effects of chain length and branching of alkanes on and δη values have been discussed.

Turbulence effects on the combustion of single hydrocarbon droplets

An experimental facility was developed to study the effect of isotropic turbulence on single-droplet burning. The facility allows the generation of a zero mean velocity, isotropic, and homogeneous turbulence with variable turbulent kinetic energy. The turbulent field was characterized using laser Doppler anemometry. Turbulent integral length scale was determined directly using two-point velocity measurements. It was found to be constant and independent of the turbulence kinetic energy level. The study was conducted at normal ambient room temperature and pressure conditions by systematically varying the turbulence kinetic energy and the fuel type for mono- and bicomponent hydrocarbon ( n -alkane) droplets. The suspended droplet technique was used in this investigation with a quartz fiber of 0.2 mm diameter. Monocomponent hydrocarbon droplet burning was found to obey the D 2 law, as well as bicomponent droplet burning of n -heptane and n -decane mixtures, where only one sequence was observed. This is not surprising since at high temperature conditions the bicomponent droplet burning is controlled by the least volatile component. Furthermore, the study of isolated single mono- and bicomponent hydrocarbon droplet burning under isotropic turbulence and zero mean velocity conditions showed that a spatially fluctuating flame envelopes the droplet and its extinction takes place for a turbulent velocity of the order of the propagation velocity of the associated hydrocarbon/air laminar premixed flame. The turbulence effect on the monocomponent and bicomponent droplet combustion rates before extinction was found to be negligible compared with the stagnant case.

Experimental Three-Phase Flow in Porous Media: Development of Saturated Structures Dominated by Viscous Flow, Gravity, and Capillarity

Summary The motivation for this work is the need to understand the formation of oil banks during waterflooding operations as well counter-current gravity driven oil recovery mechanisms. The success of these operations depends on a combination of viscous, gravitational, and capillary forces. This paper focuses on the development of three-phase saturation structures driven by viscous flow, gravity, and capillarity. Three liquids: water, benzyl alcohol, and decane are flowed through glass bead packs. Dynamic water floods of cores saturated with mixtures of benzyl alcohol and decane are described. Saturation distributions in the core are determined using x-ray computer tomography (CT). The injection of water generates a benzyl alcohol bank that displaces most of the decane ahead of it. Benzyl alcohol and decane, driven by gravity, exchange places in the core. This gravity driven counter-current flow is rapid in the presence of low water saturation ahead of the benzyl alcohol bank and within the benzyl alcohol bank. The gravity exchange is slow in the presence of mobile water behind the benzyl alcohol bank. The water saturation structure is stable and is not significantly affected by the counter-current flow of benzyl alcohol and decane. The accumulation of decane at the top of the core triggers a backward migration of a decane tongue. The decane tongue disappears when water injection is resumed and the benzyl alcohol bank re-forms where the decane tongue existed. When mobile decane is not present, significant capillary driven longitudinal fluid transport is observed while the high gradient saturation structure in the transverse direction remains stable. Even high saturation gradients in the longitudinal direction are quite stable. Fluid flow patterns during the shut in periods and displacement mechanisms are proposed.

Experimental Liquid Viscosity of Pentane + Octane + Decane Mixtures from 298.15 to 373.15 K up to 25 MPa

We have measured the liquid viscosity of the ternary system n-pentane + octane + decane using a rolling-ball viscometer at temperatures from 298.15 to 373.15 K with pressures up to 25 MPa. These mixture measurements agree with calculated results from existing correlations within 6%.

The Effect of Temperature on the Bioventing of Soil Contaminated with Toluene and Decane

The effect of temperature on evaporation and biodegradation rates during soil bioventing (SBV) was studied for a mixture of toluene and decane in bench-scale soil columns at a continuous air flow and consecutively at two different flow rates. The effect of temperature on SBV was monitored by GC headspace analysis of contaminant, CO2 and O2 concentrations in the soil gas over time. Separation of evaporation and biodegradation processes into three different phases based on their rates was used together with Q10 and E10 (values that give the factor by which biodegradation and evaporation rates increase when the temperature is raised by 10 degrees) to compare quantitatively the removal kinetics at 10 and 20°C. Adsorption of toluene and decane onto soil (a phase partitioning process) at 20 and 10°C was described with linear Freundlich isotherms. A temperature decrease from 20 to 10°C resulted in an increase of soil-air partitioning coefficients by a factor of 1.8 and of 2.1 for toluene and decane, respectively. The mean Q10 value for the biodegradation of toluene was found to be 2.2 for a temperature rise from 10 to 20°C. A toluene content in the soil gas above 75% of the saturation concentration inhibited biodegradation at both temperatures. The SBV efficiency was dependent on temperature with respect to remediation time. SBV at 20°C resulted in a 99.8% and a 98.7% reduction of toluene and decane initial concentrations, respectively. To reach similar results at 10°C, about 1.6 times as much time and 1.4 times as much air were required; however, at both temperatures the total amounts of biodegraded hydrocarbons were approximately the same. The evaporation-to-biodegradation ratios at 20°C were 82.5:17.5 for toluene and 16:84 for decane, whereas at 10 °C they were 71:29 and 2:98, respectively. A comparison of Q10 values showed that, except during the initial phase of SBV, only a modest decrease in biodegradation rates should be expected after a decrease in temperature from 20 to 10°C. Flow rate reduction had a significant impact on the toluene evaporation rate at a higher temperature, whereas for decane this rate was only slightly affected by temperature. In contrast to decane, the ratio between toluene vapor pressures at 20 and 10°C may be used to predict the removal of toluene by evaporation during the above-mentioned phases of SBV, when evaporation is important.

Effect of palmitic and lauric acids on the phospholipid bilayer membrane conductivity.

Palmitic acid increased the conductivity of BLM from mitochondrial phospholipids when they were dissolved in a mixture of decane and chlorodecane, and was ineffective when phospholipids were dissolved in decane. Lauric acid produced an increase in the membrane conductivity independently of the phospholipid type in the membrane-forming solutions (mitochondrial phospholipids, asolectin, lecithin with cholesterol) and their solvents (decane or decane with chlorodecane). The results show that discrepancies between published data concerning fatty acid effects on the BLM conductivity may be explained by differences in phospholipids, their solvents and fatty acid used.

Influence of adsorption on photoinduced electron transfer in supported liquid membranes: the case of C 60

Porous polymer membranes modified by the incorporation of a decane mixture of fullerene and phospholipids have photoconducting properties which depend on the nature of the polymer. We show that the mechanism of bilayer lipid membrane formation usually used to explain these photoconducting properties by electron transfer, is not pertinent when explaining the influence of the membrane surface properties on the measured photocurrents.

Vaporization of Binary Fuel Mixture Droplets in a Thermal Wind Tunnel

The authors present the study of vaporization, in forced convection, of two or three binary fuel mixture droplets. The droplets are situated one behind the other and are evaporated by forced convection in a thermal wind tunnel equipped with a video recording system. The image processing provides the radius regression of the droplets in accordance with the elapsed time, which is compared with results from a calculated model based on the concept of the gaseous e lm surrounding the droplets and the source of heat and mass transfer. During the period of suspension of the droplets, their vaporization begins in natural convection. From the opening of the obturator that allows the arrival of hot aire ow, the forced convection sequence begins, as does the interaction between droplets. Average Nusselt and Sherwood numbers used for the calculation of gaseous e lm thicknesses surrounding droplets come from established correlations in natural and forced convection. In the case of interaction, these Nusselt and Sherwood numbers are corrected. The experiments and calculations that are undertaken for several mixtures of heptane and decane, and for several distances between the droplets, are in good agreement. Numerical results of the validated model are analyzed using a systematic parametric study.

Interfacial tension and spreading coefficient under reservoir conditions

The variation of interfacial tension (IFT) with temperature and pressure strongly influences the transport of the fluid in a reservoir. This makes the IFT probably the most important of the factors that make one-third of the total oil in place (in reservoir rock) un-recoverable by gas drive or water flooding [H.Y. Jennings Jr., G.H. Newman, The effect of temperature and pressure on the interfacial tension of water against methane-normal decane mixtures. SPE 1971, pp. 171–175]. Several models and correlations were used to calculate the measured data presented here. We have studied the applicability of four most commonly used IFT-correlations, those of Katz et al. [D.L. Katz, R.R. Monroe, R.P. Trainer, Surface tension of crude oils containing dissolved gases. AIME. Technical publications No. 1624, pp. 285–294.], Hough and Stegemeier [E.W. Hough, G.L Stegemeier, Correlation of surface and interfacial tension of light hydrocarbons in the critical region. SPEJ, December 1961, pp. 259–263.], Lee and Chien [S.T. Lee, M.C.H. Chien, A new Multicomponent surface Tension correlation based on scaling theory. SPE/DOE 12643 fourth symposium on EOR/Tulsa, OK, April 15–18.], and Pedersen et al. [K.S. Pedersen, F. Aage, P. Tomassen, properties of oils and natural gases. Gulf publishing, 1989, pp. 196–207]. The experimental results from the three binary systems as well as the recombined crude oil system have shown that the IFT in the high pressure region (below saturation pressure) remains quite low despite large pressure decrements. This study was then extended to include measurements of the equilibrium interfacial for oil–brine, oil–gas and gas–brine at reservoir temperature and pressure over the range 250 to 3728 psia. The IFT were used to evaluate the spreading coefficient as a function of pressure at reservoir temperature. The viscosity and density of the oil and gas and brine phases were also measured over the same range of reservoir conditions.

Theory of Multicontact Miscible Displacement with Nitrogen

Abstract Solutions obtained by the method of characteristics (MOC) for displacement of mixtures of methane, butane and decane by nitrogen or nitrogen/methane mixtures are used to explain conflicting experimental observations concerning the sensitivity of minimum miscibility pressures to changes in the compositions of an initial oil or the injection gas. The solutions presented show why some investigators have reported weak dependence of the minimum miscibility pressure (MMP) on methane concentrations while others have reported significant sensitivity. The analysis of displacement composition routes indicates that either observation can be correct for some ranges of initial and injection fluid compositions, and shows that the sensitivity behavior depends on the relative positions in composition space of three key tie lines (the initial, injection, and crossover tie lines) with respect to the critical locus.

Layer Compression Modulus of Electrostatically Stabilized Lyotropic Lamellar Phases Revisited: Application to the Quantitative Analysis of a Polymer Induced Critical SmA–SmA Phase Separation

We present a calculation of the smectic compression modulus B of a lyotropic lamellar phase stabilized by electrostatic interactions. This calculation, based on a numerical solution of the Poisson-Boltzmann equation, shows that the classical analytical expressions of B given in the literature in the two asymptotic limits (absence of added salt, or large added salt concentration) are valid under very restrictive conditions only. The motivation of this study lies in the understanding of the physical behavior of a doped amphiphilic lamellar phase formed from a mixture of non ionic surfactants (Triton X100/Triton X35), cationic surfactant (cetylpyridinium chloride), water, decane and water-soluble polymer (polyvynilpyrolidone). A critical lamellar/lamellar phase separation observed in our system is quantitatively well-explained by using both the present calculations and a recent model proposed by Ligoure et al. which predicts the polymer-mediated intermembrane interaction contribution to the smectic compression modulus.

Movement of liquid contaminants in partially saturated frozen granular soils

Understanding the migration of nonaqueous phase liquids in frozen subsurface soils is becoming increasingly important in permafrost regions and in temperate zones where frozen subsurface barriers have been proposed to confine contaminants. Tests were performed on 32 specimens of gravelly sands from the Hanford, Washington reservation to determine the relationship between degree of ice saturation and intrinsic permeability. Decane, a representative nonaqueous phase liquid, was employed as the permeant, and was infiltrated through the frozen specimens at −10°C. In addition to pure water, a NaCl brine and a mixture of water and decane were utilized as the pore liquids. For all specimens the intrinsic permeability correlated linearly with the ice saturation, varying from approximately 2.7× 10 −7 cm 2 at 0% saturation to negligible values at nearly 100% saturation. The different pore liquids did not affect the correlation significantly. Bentonite was added to some of the specimens prior to freezing, reducing the intrinsic permeability to negligible levels.

Comparison of High-Pressure Vapor−Liquid Equilibria of Mixtures of CO2 or Propane with Nonane and C9 Alkylbenzenes

Vapor−liquid equilibria were measured for (1) binary mixtures of carbon dioxide with nonane, cumene, propylbenzene, or mesitylene, (2) binary mixtures of propane with nonane, cumene, or mesitylene, and (3) ternary mixtures of carbon dioxide, nonane, and cumene. For the carbon dioxide mixtures, vapor−liquid equilibria were measured at 70 °C and at pressures ranging from 3.7 MPa to 12.1 MPa. For the propane mixtures, vapor−liquid equilibria were measured at 104 °C and at pressures ranging from 0.9 MPa to 3.7 MPa. It was found that differences in the phase equilibria of the mixtures could be explained primarily by the self-association of the C9 components. The composition of the C9 components in the vapor phase compositions were found to be directly related to the volatility (self-association) of the C9 component. Liquid phase compositions were found to be enriched in carbon dioxide or propane content in the mixtures containing C9 compounds having the weakest self-association. Also presented in this paper are comparisons of measurements of vapor−liquid equilibria of carbon dioxide + decane and propane + decane with literature data as validation of the two experimental methods used. These measurements were made at 71 °C for the carbon dioxide + decane mixtures and at temperatures ranging from 38 °C to 120 °C for the propane + decane mixtures.

Surface tension of binary liquid–vapor mixtures: A comparison of mean-field and scaling theories

We use two different methods to estimate surface tension of binary liquid–vapor mixtures of CO2 and a hydrocarbon near a critical point. The first method is based on the gradient theory, which is essentially a mean-field approximation to the problem that reduces the determination of the interface’s structure and the surface tension to a boundary value problem. The theory’s input is an equation of state of homogeneous fluid and the influence parameters of inhomogeneous fluid. The Peng–Robinson equation and a modification of it are used as the equation of state of homogeneous fluid. The second method is based on the concept of two-scale-factor universality which can predict the surface tension from the singularity in the thermodynamic properties of the bulk fluid. The inputs of the method are an equation of state and certain universal amplitude ratios near the critical point. As the equation of state, we use a modification of a model first proposed by Leung and Griffiths, and further developed by Moldover, Rainwater, and co-workers. We use the two models to examine in detail CO2+n -butane and CO2+n -decane mixtures. While both models provide accurate estimates of surface tension of CO2+n -butane mixtures, only the gradient theory can predict accurately surface tension of CO2+n -decane mixtures. Moreover, while the gradient theory and the Peng–Robinson equation of state use very few adjustable parameters (at most three parameters), calculation of surface tension based on two-scale-factor universality and the corresponding equation of state requires many adjustable parameters whose number has to be increased dramatically as the fluid mixture becomes more complex. We then use the gradient theory to predict surface tension of binary liquid–vapor mixtures of CO2 and benzene, cyclohexane, and n-hexadecane. In all cases, the predictions of the gradient theory are in good agreement with the available experimental data.

Enthalpies of mixing of ternary alkane mixtures with branched chain components

Measurements at 25 °C are reported for the enthalpies of mixing of 2-methyl pentane with n-dodecane and with each of three pseudo n-dodecanes prepared from equimolar mixtures of n-undecane + n-tridecane, n-decane + n-tetradecane, and n-octane + n-hexadecane respectively. Measurements for mixtures of the equimolar decane + tetradecane mixture with each of the other three branched hexane isomers are also reported. The results are compared with the work of Benson and co-workers for binary mixtures of n-dodecane with the same hexanes. The deviations of 1–2% from the principle of congruence are similar to those reported previously for the ternary n-alkane mixtures.

Effect of salinity and alcohol partitioning on phase behavior and oil displacement efficiency in surfactant‐polymer flooding

AbstractThe equivalent alkane carbon number (EACN) of a crude oil, namely Ankleshwar crude, is successfully modeled by a mixture of pure alkanes. The EACN of the crude oil is found to be 9.3, and an appropriate mixture of nonane and decane exhibited phase behavior similar to that of the crude oil. A surfactant system for a water flooded reservoir at 80 C and having a salinity in the range of 2% to 3% NaCl is formulated by blending a phosphated ester with a petroleum sulfonate in the weight ratio of 2/5. The addition of phosphate ester not only increases the salt tolerance of the petroleum sulfonate system, it also broadens the IFT minimum. The oil displacement tests at 80 C in sandpacks and Berea cores showed that the surfactant formulation containing tertiary amyl alcohol (TAA) displaced 92% oil in sandpacks and 79% crude oil in Berea cores. The oil recovery efficiency was poor when formulations contained other alcohols. From the effluent surfactant concentration, it is shown that there is a correlation between the tertiary oil recovery, surfactant breakthrough and surfactant retention in porous media. It is proposed that, because alcohols such as isopropyl alcohol (IPA), isobutyl alcohol (IBA) and secondary butyl alcohol (SBA) partition significantly in the equilibrated excess brine phase, the alcohol‐depleted surfactant slug forms stable emulsions resulting in faster breakthrough of surfactant in the effluent and lower oil displacement efficiency. In the case of TAA‐containing formulation, there is a partitioning of TAA in the oil phase. Therefore, there is a mass transfer of alcohol from surfactant slug to the oil ganglia in porous media. This produces a transient ultralow IFT between residual oil and the surfactant solution which mobilizes oil, resulting in higher oil displacement efficiency.

Selective hydrogen atom abstraction by tritium and deuterium atoms in radiolysis of tritiated decane at 77 K. Mass effect on solid-state reaction

The relative yields of five isotopic compounds of hydrogen produced in the radiolysis of partially tritiated deuteriodecane (n-C/sub 10/D/sub 22/(T))-protiated decane (n-C/sub 10/H/sub 22/) mixtures at 77 K were measured by conventional radiogas chromatography. The HT/DT ratio in hydrogen yields is much lower than the HD/D/sub 2/ ratio. Though D atoms react selectively with n-C/sub 10/H/sub 22/, T atoms do not react as selectively with n-C/sub 10/H/sub 22/ as D atoms do. The ratio ((p/sub C/sub 10/H/sub 22///p/sub C/sub 10/D/sub 22//)/sub T) of the reaction probability of the T atoms with n-C/sub 10/H/sub 22/ to that with n-C/sub 10/D/sub 22/ is 4.5-6.3, which is much lower than the ratio ((p/sub C/sub 10/H/sub 22///p/sub C/sub 10/D/sub 22//)/sub D/ = 30) for the D atoms. The ratio for the T atoms in the radiolysis is rather close to the ratio (2.3) for the recoil T atoms. The mass effect on the selective hydrogen atom abstraction reaction in the decane mixtures is discussed. 16 references, 3 figures, 1 table.