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Modeling Table III.1. Optimised Molecular Parameters for the Pure Components and References from where Experimental Vapour Pressure and Density Data Were Taken. Compound m σ (Å) Gases ε/kB (K) Reference O2 1.168 3.198 111.5 NIST Chemistry WebBook Xe 1.000 3.953 226.6 NIST Chemistry WebBook Rn 1.460 3.606 233.6 NIST Chemistry WebBook CO2 2.681 2.534 153.4 NIST Chemistry WebBook Linear saturated perfluoroalkanes CF4 1 4.217 190.1 Smith and Srivastava (1986) C2F6 1.392 4.342 204.5 Smith and Srivastava (1986) C3F8 1.776 4.399 214.7 Smith and Srivastava (1986) C4F10 2.134 4.433 223.0 Brown and Mears (1958) C5F12 2.497 4.449 230.2 C6F14 2.832 4.479 236.6 C7F16 3.169 4.512 242.7 C8F18 3.522 4.521 245.1 C9F20 3.901 4.526 246.8 Cyclic and substituted fluoroalkanes Barber and Cady (1956) Burguer and Cady (1951) This work; Dunlap et al. (1958); Crowder et al. (1967) and Mousa (1978) Oliver et al. (1951) ; Steele et al. (1997); Oliver and Grisard (1951); Milton and Oliver (1952) This work Kreglewski (1962) This work Piñeiro et al. (2004) C10F18 2.696 4.999 310.1 This work C7F14 3.463 4.150 228.6 C6F6 3.148 3.647 253.6 C7F8 3.538 3.764 253.0 Glew and Reeves (1956) Good et al. (1959) This work; Ambrose (1981); Hales and Townsend (1974) This work; Ambrose and Ellender (1981); Hales and Townsend (1974) 1Br-C8F17 3.522 4.652 268.9 This work 1H-C8F17 3.522 4.492 253.6 This work 1H,8H-C8F16 3.522 4.456 267.8 This work - 111 -
Modeling From the optimised parameters of the linear perfluoroalkanes from C1 to C9, a simple relationship of the molecular parameters with the carbon number, CN, was obtained: m = 0.3580 + 0.679 CN (III.31) mσ 3 = 35.49 + 42.38 CN (III.32) mε/kB B = 96.60 + 91.64 CN (III.33) Units of σ and ε/kB are Å and K, respectively. Parameters from these relationships deviate from the fitted parameters with an absolute averaged deviation (AAD) lower than 1%. One of the advantages of molecular theories compared to macroscopic models is that the former need fewer meaningful parameters. To provide additional evidence of this, optimised size and energy parameters are plotted in Figure III.2 with respect the carbon number CN for the linear perfluoroalkane chain. Because the model is homonuclear and the effect of the extreme CF3 groups weakens as the chain length increases, the LJ parameters should tend to an asymptotic value, as seen in Figure III.2. Furthermore, molecular simulation united-atom model (Cui et al., 1998; Hariharan and Harris, 1996) in which the LJ potential for the nonbonded interactions is used (without Coulombic interactions), employ optimised values for the size parameter in the range σCF2 = σCF3 = 4.65 ± 0.05 Å. These simulations give quantitative predictions for equilibrium properties of chains from n-perfluoropentane to n-perfluorohexadecane. The corresponding value from our model (equivalent to a chain of infinite number of carbons), straightforwardly calculated from Equations III.31-III.33, is 4.63 Å. The similarity among the parameters of different theories acts in favour of the physical meaning of them. Figures III.3-III.7 present equilibrium liquid densities and vapour pressures for the gases, linear perfluoroalkanes and cyclic and substituted fluoroalkanes under study. Results obtained with the soft-SAFT EoS were compared with the ones given by the original form of the Peng-Robinson EoS (Peng and Robinson, 1976). Full lines represent the soft-SAFT correlation using the parameters given in Table III.1 while dashed lines represent the results given by the Peng-Robinson EoS. Since no critical data were found for perfluorodecalin nor substituted fluoroalkanes, only the correlation from the soft-SAFT EoS is presented in these cases. - 112 -
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Ana Maria Antunes Dias Universidade
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o júri presidente Prof. Dr. Joaqui
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palavras-chave resumo perfluoroalca
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Contents Notation List of Tables Li
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Notation Abbreviations AAD EoS LCST
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List of Tables Table I.1 Average Bo
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Table III.6 Adjusted Binary Paramet
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Figure II.9 Comparison between corr
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Figure III.8 Temperature-density di
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Figure III.25 Vapor-phase mole frac
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I.1. Fluorine Properties General In
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Table I.2. Physicochemical Properti
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General Introduction order to compa
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General Introduction the numerous a
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General Introduction carbon dioxide
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General Introduction animals. That
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General Introduction Table I.3. Lit
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References General Introduction Ban
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General Introduction Hildebrand, J.
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General Introduction Rowinsky EK. N
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II. Part EXPERIMENTAL METHODS, RESU
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Experimental Methods, Results and D
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Table II.3. (continued) T K ρexp g
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ρ / g.cm-3 1.750 1.730 1.710 1.690
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I. 3. Vapour pressure I.3.1. Biblio
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I.3.2. Apparatus and Procedure Expe
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I.3.3. Experimental Results and Dis
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Table II.8. (continued) T K Pexp kP
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ΔH vap = TΔS vap 2⎛ d ln P ⎞
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I.4. Solubility at atmospheric pres
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Page 77 and 78:
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 83 and 84: Experimental Methods, Results and D
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 111 and 112: III.1. Introduction Modeling Most c
Page 113 and 114: Modeling The pioneering work of Wer
Page 115 and 116: III.2. Soft-SAFT Model Modeling A S
Page 117 and 118: Modeling The equation of state is w
Page 119 and 120: Chain Term Modeling Originally Wert
Page 121 and 122: Modeling The model is easily extend
Page 123 and 124: ( ) ( ) ∑∑∑ 3 2 2 2 2 qq 32π
Page 125 and 126: Modeling HRT is a promising theory,
Page 127 and 128: ( ρ) ρ , 0 ≤ ρ ( ρ) 2 Modelin
Page 129: III.3. Application to Pure Compound
Page 133 and 134: T / K 400 350 300 250 200 150 100 5
Page 135 and 136: ln Pvap 1.0E+01 1.0E+00 1.0E-01 1.0
Page 137 and 138: Modeling Table III.2. Absolute Aver
Page 139 and 140: Modeling The correlation coefficien
Page 141 and 142: Pvap (MPa) 4.00 3.50 3.00 2.50 2.00
Page 143 and 144: Modeling The mixture parameters a a
Page 145 and 146: Modeling the assumptions made by th
Page 147 and 148: Modeling between oxygen and perfluo
Page 149 and 150: xSolute 5.5E-03 5.0E-03 4.5E-03 4.0
Page 151 and 152: Modeling previous work, dealing wit
Page 153 and 154: Modeling These results confirm that
Page 155 and 156: Modeling CO2 binary mixtures using
Page 157 and 158: Modeling average deviation (AAD) be
Page 159 and 160: P / MPa 14 12 10 8 6 4 2 0 0 0.2 0.
Page 161 and 162: Modeling Figures III.16, III.17 and
Page 163 and 164: Modeling calculations from the orig
Page 165 and 166: Table III.9. References for VLE exp
Page 167 and 168: P / MPa 20 18 16 14 12 10 8 6 4 2 0
Page 169 and 170: Modeling Finally, Figure III.24 pre
Page 171 and 172: III.4.4. VLE and LLE of Alkane and
Page 173 and 174: Modeling number of perfluro-n-alkan
Page 175 and 176: y C6F14 1.0 0.8 0.6 0.4 0.2 0.0 0.0
Page 177 and 178: P / MPa 0.08 0.07 0.06 0.05 0.04 0.
Page 179 and 180: 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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