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General Introduction Some of these properties influence the amount and diffusivity of gases in PFCs (solubility, diffusion coefficients), others influence how the liquid PFC moves within the lung (vapor pressure, surface tension, spreading coefficient density, kinematic viscosity) and others influence the biodistribution of the PFC (partition coefficient (log P), lipid solubility) (Wolfson et al., 1998). Respiratory gas carrying capacity varies among fluids and is different for O2 (35–70 ml gas/dL @ 25°C; >3× that of blood) than CO2 (122–225 ml/dL @25°C; approximately 4×> that for O2) according to Table I.2. Although several hundreds of such compounds have been screened over the past twenty years, very few were found to meet the appropriate physicochemical and biological criteria for in vivo oxygen delivery. This includes high purity, rapid excretion, aptitude to forming stable emulsions, absence of clinically significant side-effects and large scale, cost-effective industrial feasibility (Riess, 2001). Fluorinated lipids and fluorinated surfactants can be used to promote the stability of various colloidal systems, including different types of emulsions, vesicles and tubules that also show promising for controlled release drug delivery due to the strong tendency that these molecules have to self-assemble. The potential of non-polar hydrocarbon-in- fluorocarbon emulsions, multiple emulsions and gel emulsions is a new field giving the first steps (Kraft, 2001). I.3.2. Industrial Purposes There are a large number of documented applications of perfluoroalkanes in the industry. Among others, perfluoroalkanes are been used 1) As co-solvents in supercritical extraction: improving the solubility of hydrophilic substances in supercritical reaction or extraction media (Raveendran and Wallen, 2002). In many supercritical fluid applications carbon dioxide is widely used as the near-critical solvent. As an example, the formation of water in CO2 microemulsions offers a new approach to biological processes, organic synthesis, nanoparticle chemistry and dry cleaning (Stone et al., 2003). Although CO2 has many advantages, its poor solvency with respect to polar compounds can be a problem. Until now, attempts to find suitable hydrocarbon-based surfactants have had a limited success. One strategy that has proven quite successful for overcoming this limitation is to make use of CO2-philic functional groups to behave as surfactants. It has been verified that the solubility of a compound in - 9 -
General Introduction carbon dioxide is increased if it contains a fluorinated alkyl segment, since CO2 is more soluble in fluorinated compounds than in their hydrocarbon counterparts (Hoefling et al., 1991). Non-polar perfluorocarbon species show increased solubility in supercritical CO2 and have been used in the design of CO2-philic surfactants, chelating agents and ligands in order to improve the solubility of polymers, metals and catalysts (Osswald et al., 2001). 2) As medium in two-phase reaction mixture: in a novel separation and purification technique that is attracting current interest in organic synthesis and process development, in the immobilization of expensive metal catalysts called “Fluorous Phase Organic Synthesis" (FPOS) (Horvath and Rabai, 1994). The hydrophobicity of fluorinated compounds that makes them immiscible with water and with many common organic solvents, their ability to form a homogenous solution at elevated temperatures with several of these solvents, their inertness, their solubility in supercritical CO2 and their ability to dissolve gases contributes to the increasing popularity of the "Fluorous Phase" in organic syntheses (Gladysz, 1994; Studer et al., 1997 and Betzemeier and Knochel, 1999). By introducing perfluorinated ligands, a catalyst is solubilized and simultaneously immobilized in the "Fluorous Phase". By increasing the temperature, the biphasic system forms a homogenous solution and the catalytic process can take place. Cooling down the reaction mixture leads to the reformation of two separate phases. Afterwards, easy product isolation and the recovery of the perfluoro-tagged metal catalyst can be achieved by simple phase separation. The isolation and recovery of perfluorinated components can be accomplished not only by a phase separation of immiscible liquid layers but also by solidliquid extraction using a perfluorinated non-polar stationary phase (Horvath and Rabai, 1994). 3) As refrigerants: short-chain halocarbons that are used as refrigerants, aerosol propellants and foam blowing agents. Initially, the chlorofluorocarbons (CFCs) were used for this purpose, but they were implicated in stratospheric ozone depletion (Molina and Rowland, 1974) and have subsequently been replaced by the hydrofluorocarbons (HFCs) (Wallington et al., 1994). The CFCs were typically fully halogenated methanes while the HFCs are generally partially fluorinated ethanes such as HFC 134a (1,1,1,2tetrafluoroethane), which is the most commonly used HFC. Other short chain perfluoroalkanes used as evaporative fluorocarbon cooling for the semiconductor pixel and - 10 -
Page 1 and 2: Ana Maria Antunes Dias Universidade
Page 3 and 4: o júri presidente Prof. Dr. Joaqui
Page 5 and 6: 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: General Introduction the numerous a
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 and 58: I.3.2. Apparatus and Procedure Expe
Page 59 and 60: I.3.3. Experimental Results and Dis
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 83 and 84:
Experimental Methods, Results and D
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
P / MPa 6 5 4 3 2 1 0 P / MPa 14 12
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II.6. Liquid - Liquid Equilibrium I
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
0 τ β Δ1 2Δ1 [ 1+ B τ + B τ +
Page 103 and 104:
References Experimental Methods, Re
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
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
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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
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( ) ( ) ∑∑∑ 3 2 2 2 2 qq 32π
Page 125 and 126:
Modeling HRT is a promising theory,
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( ρ) ρ , 0 ≤ ρ ( ρ) 2 Modelin
Page 129 and 130:
III.3. Application to Pure Compound
Page 131 and 132:
Modeling From the optimised paramet
Page 133 and 134:
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
Page 143 and 144:
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
Page 151 and 152:
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.
Page 181 and 182:
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
Page 187 and 188:
Modeling Hildebrand, J. H.; Fisher,
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Modeling McCabe, C.; Jackson, SAFT-
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Modeling Poling, B.; Prauznitz, J.;
Page 193 and 194:
Modeling Wertheim, M. S., Fluids wi
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