VUV absorbing vapours in n-perfluorocarbons

Abstract

The optical transparency of perfluorocarbons used as Cherenkov media is of prime importance to many Ring Imaging Cherenkov detectors. We will in this paper show that the main photon absorbers in these fluids are hydrocarbons with double or triple bonds. We will moreover discuss a process which can eliminate these pollutants and restore the intrinsic excellent optical transparency of these fluids in the VUV range.

Water Solubility in Linear Fluoroalkanes Used in Blood Substitute Formulations

“…The chemicals used for the measurements were n-perfluorohexane (C 6 F 14 ), n-perfluorooctane (C 8 F 18 ), and nperfluorononane (C 9 F 20 ) from Fluorochem with purities verified by gas chromatography (GC) of 99.11, 98.36, and 99.18 wt %, respectively, and perfluoroheptane (C 7 F 16 ) from Apollo Scientific with a purity of 99.92 wt % (mixture of isomers). The substituted fluorocompounds 1Br-perfluorooctane (C 8 F 17 Br), 1H-perfluorooctane (C 8 F 17 H), 1H,8H-perfluorooctane (C 8 F 16 H 2 ), and 1Cl,8Cl-perfluorooctane (C 8 F 16 Cl 2 ) were acquired at Apollo Scientific presenting purities of 99.90, 97.05, 99.05, and 99.99 wt %, respectively. The 1I-perfluorooctane (C 8 F 17 I) was ac-quired at ABCR with a stated purity of 98.56 wt %.…”

“…The solubility of water in the C 6 -C 9 n-perfluroalkanes and in the substituted n-fluoroalkanes (C 8 F 17 H, C 8 F 16 H 2 , C 8 F 16 Cl 2 , C 8 F 17 Br, and C 8 F 17 I) was measured from 288 to 318 K at atmospheric pressure. Experimental values for the solubility of water in the studied n-perfluoroalkanes and substituted nfluorooctanes and the respective standard deviations are reported in Table 1 and presented in Figures 1 and 2, respectively.…”

“…[10][11][12][13][14] There are minimal data covering solubility and phase equilibrium of fluorinated compounds. 8,[10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] The study of water solubility is of particular interest, since the solvation properties and the molecular interactions of fluorocompounds with water are important to understand the FC-in-water or reversed emulsions formation and aging. 9,[25][26][27][28] The objective of the present work is to provide experimental and theoretical information about the unlike water-FC compound molecular interactions and to evaluate the effect of R-(ω-)fluorine substitution by H, Cl, Br, and I on this interaction.…”

Long term experience and performance of COMPASS RICH-1

“…A specific cleaning procedure needs to be applied before usage to the commercially available C 4 F 10 , which is full of impurities [10]: a system in which the C 4 F 10 circulates in closed loop through activated carbon and 3A molecular sieves and condenses in a cold section where the gas component is vented out has been built for this purpose; the typical fraction of material lost in this cleaning operation varies between 0.1 and 0.3.…”

THE 217.5 nm BAND, INFRARED ABSORPTION, AND INFRARED EMISSION FEATURES IN HYDROGENATED AMORPHOUS CARBON NANOPARTICLES

“…Substitution at the periphery of these molecules will tend to reduce these energies to some extent. Small alkane and alkene chains such as propane, C 3 H 8 , and propene, C 3 H 6 , have their absorption bands at ∼8 and ∼7 eV, respectively (Albrecht et al 2003), while 1,3-butadiene has a strong absorption band at ∼5.7 eV (Saltiel et al 2001). It is important to note that polyynes, C n H 2 , also absorb strongly in the UV, and there is evidence that these groups are present under certain conditions ).…”