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Experimental Methods, Results and Discussion The temperature of the glass sample cell was measured with a calibrated Pt100 temperature sensor, class 1/10 (L), using a 6 ½ dataloger system (H) (Agilent model 34401A) for continuously data acquisition with an uncertainty of ± 0.05 K. Beforehand, in accordance to the International Temperature Scale of 1990, IST-90, this sensor was calibrated against a SPRT (25 ohm; Tinsley, 5187A) temperature probe using an ASL bridge model F26. In pressure measurements, a high precision temperature compensated, quartz pressure tranducer (C) (ParoScientific Inc. model 2100A-101) was used. The accuracy of the pressure transducer is ± 0.01% in the working range (0 to 1.38) MPa. Two output frequency signs (corresponding to the sensor temperature and the quartz pressure sensor) were registered in the 6½ dataloger system (Agilent model 34401A) and the corresponding pressure was calculated using the calibration function that includes temperature compensation. In the glass vacuum line, all glass connections were assembled with greaseless spherical joints, teflon O-rings and high vacuum teflon valves. The vacuum line is connected to the rotatory vacuum pump (G) (BOC Edwards, model RV5) through a glass cold trap (D) filled with liquid nitrogen. The apparatus was designed to permit degassing of the solvent using the condenser (F). The solvent is refluxed to the sample cell (A) while non-condensable gases are pumped out. Previous experience with the degassing of fluorinated compounds for solubility measurements showed that they could be better and faster degassed through successive melting/freezing cycles while vacuum pumping non-condensable gases and that was the procedure used in this work. The sample cell with a volume of 10 cm 3 , containing the degassed solvent is then immersed in the thermostatic water bath. When the equilibrium temperature is reached, the apparatus is isolated from the vacuum source and the sample cell valve is opened to connect the sample container to the closed line and the quartz pressure sensor. After pressure stabilization, the pressure and time experimental data are recorded and the correct pressure value is obtained by extrapolation to the initial time of a pressure versus time relation. To avoid condensation, the apparatus from the sample cell to the pressure transducer is maintained at a higher temperature than the sample cell. This heating system, includes a hot water jacket protected tube (E) and a hotblock box (M) for the pressure transducer. - 39 -
I.3.3. Experimental Results and Discussion Experimental Methods, Results and Discussion To evaluate the accuracy and estimate the precision of the experimental apparatus, the vapor pressure of perfluorobenzene was measured. Perfluorobenzene was chosen as the reference fluid because the vapor pressures of the compounds studied in this work are of the same order of magnitude of perfluorobenzene in the temperature range studied. Also, perfluorobenzene is a compound included in the IUPAC recommendations of reference materials for pressure-volume-temperature relations (IUPAC, 1987), since agreement between normal boiling temperatures of perfluorobenzene measured by Counsell et al. (1965), Douslin et al. (1965) and Ambrose (1981) are within a range of 0.005 K. All the measurements were carried using comparative ebulliometric apparatus. More recently, Ambrose et al. (1990) re-measured the vapor pressure of perfluorobenzene using the same technique with an absolute deviation from the previous results lower then 0.015 kPa. Findlay et al. (1969) also measured the vapor pressure of perfluorobenzene but using a static method. A comparison between the experimental data measured in this work and literature data is presented in Table II.7. Literature data used were calculated with the equations reported by the authors as being the best fit to their experimental data. Absolute deviations between experimental and literature data are shown in Figure II.6. Data from Ambrose et al. (1990) are not included in the figure since they coincide with the ones from Ambrose (1981). From these results, an accuracy better than 0.1 kPa can be stated for the measurements performed in this work. The vapor pressures for the studied compounds are reported in Table II.8 along with values calculated with the Antoine equation, ln B /kPa = A − (II.7) ( P ) ( T/K) + C where P is the vapor pressure, T is the temperature and A, B and C are adjustable constants. The Antoine constants adjusted to the experimental data are reported in Table II.9. - 40 -
Page 1 and 2:
Ana Maria Antunes Dias Universidade
Page 3 and 4:
o júri presidente Prof. Dr. Joaqui
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palavras-chave resumo perfluoroalca
Page 7 and 8: Contents Notation List of Tables Li
Page 9 and 10: Notation Abbreviations AAD EoS LCST
Page 11 and 12: List of Tables Table I.1 Average Bo
Page 13 and 14: Table III.6 Adjusted Binary Paramet
Page 15 and 16: Figure II.9 Comparison between corr
Page 17 and 18: Figure III.8 Temperature-density di
Page 19 and 20: Figure III.25 Vapor-phase mole frac
Page 21 and 22: I.1. Fluorine Properties General In
Page 23 and 24: Table I.2. Physicochemical Properti
Page 25 and 26: General Introduction order to compa
Page 27 and 28: General Introduction the numerous a
Page 29 and 30: General Introduction carbon dioxide
Page 31 and 32: General Introduction animals. That
Page 33 and 34: General Introduction Table I.3. Lit
Page 35 and 36: References General Introduction Ban
Page 37 and 38: General Introduction Hildebrand, J.
Page 39 and 40: General Introduction Rowinsky EK. N
Page 41 and 42: II. Part EXPERIMENTAL METHODS, RESU
Page 43 and 44: Experimental Methods, Results and D
Page 49 and 50: Table II.3. (continued) T K ρexp g
Page 51 and 52: ρ / g.cm-3 1.750 1.730 1.710 1.690
Page 55 and 56: I. 3. Vapour pressure I.3.1. Biblio
Page 57: I.3.2. Apparatus and Procedure Expe
Page 63 and 64: Table II.8. (continued) T K Pexp kP
Page 67 and 68: ΔH vap = TΔS vap 2⎛ d ln P ⎞
Page 69 and 70: I.4. Solubility at atmospheric pres
Page 79 and 80: x2 (T,P2) 7.0E-03 6.0E-03 5.0E-03 4
Page 81 and 82: L 2,1 0.70 0.60 0.50 0.40 0.30 285
Page 93 and 94: P / MPa 6 5 4 3 2 1 0 P / MPa 14 12
Page 95 and 96: II.6. Liquid - Liquid Equilibrium I
Page 101 and 102: 0 τ β Δ1 2Δ1 [ 1+ B τ + B τ +
Page 103 and 104: References Experimental Methods, Re
Page 109 and 110:
Experimental Methods, Results and D
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III.1. Introduction Modeling Most c
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Modeling The pioneering work of Wer
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III.2. Soft-SAFT Model Modeling A S
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Modeling The equation of state is w
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Chain Term Modeling Originally Wert
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Modeling The model is easily extend
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( ) ( ) ∑∑∑ 3 2 2 2 2 qq 32π
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Modeling HRT is a promising theory,
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( ρ) ρ , 0 ≤ ρ ( ρ) 2 Modelin
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III.3. Application to Pure Compound
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Modeling From the optimised paramet
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T / K 400 350 300 250 200 150 100 5
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ln Pvap 1.0E+01 1.0E+00 1.0E-01 1.0
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Modeling Table III.2. Absolute Aver
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Modeling The correlation coefficien
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Pvap (MPa) 4.00 3.50 3.00 2.50 2.00
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Modeling The mixture parameters a a
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Modeling the assumptions made by th
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Modeling between oxygen and perfluo
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xSolute 5.5E-03 5.0E-03 4.5E-03 4.0
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Modeling previous work, dealing wit
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Modeling These results confirm that
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Modeling CO2 binary mixtures using
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Modeling average deviation (AAD) be
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P / MPa 14 12 10 8 6 4 2 0 0 0.2 0.
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Modeling Figures III.16, III.17 and
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Modeling calculations from the orig
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Table III.9. References for VLE exp
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P / MPa 20 18 16 14 12 10 8 6 4 2 0
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Modeling Finally, Figure III.24 pre
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III.4.4. VLE and LLE of Alkane and
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Modeling number of perfluro-n-alkan
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y C6F14 1.0 0.8 0.6 0.4 0.2 0.0 0.0
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P / MPa 0.08 0.07 0.06 0.05 0.04 0.
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P / MPa 0.12 0.10 0.08 0.06 0.04 0.
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Modeling approach based on the meth
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Modeling Blas, F. J.; Vega, L. F.,
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DIPPR, Thermophysical Properties Da
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Modeling Hildebrand, J. H.; Fisher,
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Modeling McCabe, C.; Jackson, SAFT-
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Modeling Poling, B.; Prauznitz, J.;
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Modeling Wertheim, M. S., Fluids wi
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