The Lorentz-Lorenz function of five gaseous and liquid saturated hydrocarbons

Hädrich, Jürgen

doi:10.1007/bf00936026

Cited by 15 publications

(8 citation statements)

References 25 publications

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“…The dilute solution refractive index is replaced with that of the pure solvent to determine q with little loss of accuracy. The Lorentz−Lorenz equation is used to account for the density dependence of the refractive index, − and the linearized Cauchy equation , is used to correct the refractive index for a λ 0 of 532 nm.…”

Section: Methodsmentioning

confidence: 99%

Density-Induced Phase Separation in Poly(ethylene-co-1-butene)−Dimethyl Ether Solutions

McHugh

Zanten

2005

Macromolecules

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Dynamic light scattering measurements are reported for poly(ethylene-co-20.2 mol % 1-butene) (PEB10) in dimethyl ether (DME) at 110-170°C and pressures to 2500 bar. The cloud-point curve for the PEB10-DME system exhibits both low-and high-pressure upper consolute solution temperature (UCST) branches. The polymer infinite dilution translational diffusion coefficient, D0, increases with increasing temperature and decreasing pressure as expected. The observed variation of D0 is inversely proportional to the solvent viscosity, indicating that the polymer coil hydrodynamic size is independent of temperature and pressure. The dynamic second virial coefficient, kD, which represents a balance between thermodynamic interactions and hydrodynamic forces, displays values that lie within the bounds expected for Θ and good solvent conditions. While the low-pressure UCST is classical in that the polymer-solvent interactions become unfavorable upon approach to this phase boundary, the highpressure UCST branch exhibits anomalous behavior wherein polymer-solvent interactions improve as this phase boundary is approached. Such behavior suggests that the phase separation is entropic in origin and is driven by unfavorable mixing effects.

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Section: Methodsmentioning

confidence: 99%

Density-Induced Phase Separation in Poly(ethylene-co-1-butene)−Dimethyl Ether Solutions

McHugh

Zanten

2005

Macromolecules

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“…31 and n values for mixtures of SCF ethane and liquid alkane cosolvent are determined from the pure-component values using the Lorentz-Lorenz mixing rule, eq 9, in association with eq 5. 32 and n for cosolvent liquids at 20 °C were obtained from the literature. 33 The negative trend of Φ vdW /k B T with decreasing separation distance seen in Figure 2 is typical of the increasing van der Waals attractive forces between spherical copper particles interacting through the bulk phase.…”

Section: Methodsmentioning

confidence: 99%

Copper Nanoparticle Synthesis in Compressed Liquid and Supercritical Fluid Reverse Micelle Systems

Kitchens

Roberts

2004

Ind. Eng. Chem. Res.

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Synthesis of copper nanoparticles within sodium bis(2-ethylhexyl)sulfosuccinate (AOT) reverse micelles was performed by implementing compressed liquid and supercritical fluid (SCF) alkanes as the bulk solvent of the microemulsion system. In this reverse micelle reaction media, the role of the anionic surfactant AOT is twofold. Initially, the AOT creates a thermodynamically stable microemulsion system consisting of water and metal ions encased within an AOT surfactant reverse micelle and dispersed within a bulk oil phase. The AOT surfactant also acts as a stabilizing ligand where the surfactant tails sterically stabilize the synthesized copper particles in solution. Our previous experimental and modeling studies have shown that the strength of the solvent interactions between the bulk liquid organic solvent and the surfactant tails affects the particle growth rate and the mean copper nanoparticle size synthesized within the microemulsion system. The thermophysical properties of compressed liquids and SCFs can be tuned through adjustments in temperature and pressure. This affords the unique ability to control particle synthesis within the reverse micelle systems by adjusting the strength of the interaction between the surfactant tails and the bulk solvent. Our results demonstrate that an increase in pressure or a decrease in temperature results in the ability to synthesize slightly larger particles. In compressed propane, the median particle diameter synthesized can be shifted from 5.4 to 9.0 nm with an increase in pressure from 241 to 345 bar. Synthesis in compressed and SCF ethane is achieved at a pressure of 517 bar and can be slightly adjusted with temperature and even more so with the addition of a liquid alkane cosolvent. A soft-sphere modeling approach was taken to model the total interaction energy of copper particles, stabilized by AOT surfactant and dispersed within the bulk fluid, and effectively support our experimental results.

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“…The viscosity at high pressures is also approximated by extrapolation utilizing the residual viscosity correlation proposed by Brebach and Thodos [19] and the extrapolated density data. The refractive index is calculated using the Lorentz-Lorenz correlation [20] of the refractive index and density. No such data are available for propylene yet.…”

Section: Methodsmentioning

confidence: 99%

Amorphous polystyrene-block-polybutadiene and crystallizable polystyrene-block-(hydrogenated polybutadiene) solutions in compressible near critical propane and propylene – Hydrogenation effects

Winoto

Radosz

Hong

et al. 2009

Journal of Non-Crystalline Solids

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The Lorentz-Lorenz function of five gaseous and liquid saturated hydrocarbons

Cited by 15 publications

References 25 publications

Density-Induced Phase Separation in Poly(ethylene-co-1-butene)−Dimethyl Ether Solutions

Density-Induced Phase Separation in Poly(ethylene-co-1-butene)−Dimethyl Ether Solutions

Copper Nanoparticle Synthesis in Compressed Liquid and Supercritical Fluid Reverse Micelle Systems

Amorphous polystyrene-block-polybutadiene and crystallizable polystyrene-block-(hydrogenated polybutadiene) solutions in compressible near critical propane and propylene – Hydrogenation effects

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