Dual-channel optical phase measurement system for improved precision

Developments and applications of a dual-channel phase measurement system are being proposed and experimentally studied by utilizing an optical homodyne technique. In this measurement system, the phase modulation was adopted by using a near-stable Zn-indiffused lithium niobate phase modulator. The proposed method was successfully applied on the simultaneous measurements of the phase-retardation difference between a transmitted light and a reflected light after passing through a nonpolarization beam splitter. The measured stability of the phase-retardation difference was approximately 0.0013 rad.     

Correlations for describing gas-to-ionic liquid partitioning at 323 K based on ion-specific equation coefficient and group contribution versions of the Abraham model

Chromatographic retention measurements were measured for a wide range of solutes on 1-methyl-3-ethylimidazolium tris(pentafluoroethyl)trifluorophosphate, ([MEIm]⁺[FAP]⁻), and 1-(3-hydroxypropyl)pyridinium tris(pentafluoroethyl)trifluorophosphate, ([1-PrOHPy]⁺[FAP]⁻), stationary phases at 323 K. The measured retention factors were combined with published infinite dilution activity coefficient, gas solubility data and retention factor data to yield gas-to-anhydrous ionic liquid (IL) partition coefficients at 323 K for 2349 different solute-IL combinations. The compiled partition coefficient data were analyzed using the ion-specific equation coefficient and the functional group contribution versions of the Abraham solvation parameter model. Ion-specific equation coefficients were calculated for 25 cations and 14 anions. In addition, values were calculated for 14 cation functional groups and 14 anions. The calculated ion-specific equation coefficients and calculated functional group values described the experimental 323 K partition coefficient data to within standard deviations of 0.10 and 0.13 log units, respectively.     

Correlation of the Solubilizing Abilities of Hexyl(trimethyl)ammonium <Emphasis Type="Italic">bis</Emphasis>((Trifluoromethyl)sulfonyl)imide, 1-Propyl-1-methylpiperidinium <Emphasis Type="Italic">bis</Emphasis>((Trifluoromethyl)sulfonyl)imide,and 1-Butyl-1-methyl-pyrrolidinium Thiocyanate

Chromatographic retention data were measured for a wide range of organic solutes on 1-butyl-1-methylpyrrolidinium thiocyanate ([BMPyrr]⁺[SCN]⁻), hexyl(trimethyl)ammonium bis((trifluoromethyl)sulfonyl)imide ([HexM₃Am]⁺[(Tf)₂N]⁻), and 1-propyl-1-methylpiperidinium bis((trifluoromethyl)sulfonyl)imide ([PMPip]⁺[(Tf)₂N]⁻) stationary phases at 323 and 353 K. The measured retention factors were combined with published infinite dilution activity coefficient and gas-to-water partition coefficient data to yield gas-to-anhydrous ionic liquid (IL) partition coefficients and water-to-anhydrous IL partition coefficients. Both sets of partition coefficients were analyzed using the Abraham model. The derived Abraham model correlations describe the observed gas-to-IL and water-to-IL partition coefficient data to within average standard deviations of 0.116 and 0.156 log₁₀ units, respectively.