Enriqueta R. López

• University of Santiago de Compostela

This work is focused on the thermophysical and tribological study of eight nanolubricant compositions based on a polyalphaolefin (PAO 20) and two different nanoadditives: multi-walled carbon nanotubes (MWCNTs) and hexagonal boron nitride (h-BN). Regarding the thermophysical properties, density and dynamic viscosity of the base oil and the nanolubri...

This work presents the antifriction and antiwear properties of TiO2 nanoparticles coated with oleic acid, TiO2-OA, as additives of a low viscosity polyalphaolefin base oil, PAO8. To find the optimal concentration of nanoadditives that minimize friction and wear, four PAO8 based nanodispersions were formulated: PAO8 + 0.10 wt% TiO2-OA, PAO8 + 0.25 w...

This research reports the antifriction and antiwear properties of Mn3O4-Graphene nanocomposites (Mn3O4-G) as additives of a paraffinic base oil commonly used in the formulation of electric vehicles transmission oils, G-III base oil. Four G-III base oil nanodispersions have been designed, G-III base oil + 0.025 wt% Mn3O4-G, G-III base oil + 0.050 wt...

Lubrication usage is one of the most effective method of controlling friction and wear in mechanical equipment, and in order to improve the performance of such lubricants additives are added into them leading these oils to be able to meet the requirements of modern industry. Lubricant additives that mainly work as a multifunctional enhancer such as...

In this work, ZnO nanoparticles (NPs) were successfully synthesized and coated with oleic acid (OA). The mean diameter of these NPs (ZnO-OA) was around 10 nm, their core was characterized by XRD and their coating by FTIR and Raman. Homogeneous dispersions at different concentrations (0.10, 0.25, 0.50, 0.75 and 1.00 wt%) of ZnO-OA in polyalphaolefin...

Tribological performance of polyalphaolefin 32, PAO, is investigated by adding two nanomaterials (graphene nanoplatelets, GnP, and hexagonal boron nitride nanoparticles, h-BN) and an ionic liquid ([P6,6,6,14][DEHP], IL1, [P2,4,4,4][DEP], IL2, or [P6,6,6,14][(iC8)2PO2], IL3). Designed double hybrid nanodispersions are PAO/1 wt% ILX/0.05 wt% GnP/0.1...

This research is based on the investigation of the tribological properties of a biodegradable polymeric ester lubricant (BIOE) additivated with two different pristine graphene nanoplatelets (GnPs), named as GnP7 and GnP40. These GnPs have lateral sizes of 7 and 40 μm, and thickness of 3 and 10 nm, respectively. Four different nanoadditive loadings:...

In the present work, antifriction and antiwear synergies of two functionalized graphene oxides (reduced graphene oxide, rGO, and reduced graphene oxide modified with octadecylamine, [email protected]) with a phosphonium ionic liquid (IL) as additives of a biodegradable ester base oil, BIOE, were investigated. For this aim, four BIOE nanodispersions...

Antifriction synergies between an ionic liquid (IL) and nanopowders as additives of an ester base oil were analysed at rolling conditions. For this aim, two nanodispersions based on hybrid combinations of hexagonal boron nitride nanoparticles (h‐BN) or graphene nanoplatelets (GnP) with tri(butyl) ethylphosphonium diethylphosphate ionic liquid as ad...

Tribological performance of three ionic liquids (ILs), trihexyltetradecylphosphonium bis(2-ethylhexyl)phosphate (IL1), tributylethylphosphonium diethylphosphate (IL2) and trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl)phosphinate (IL3) combined with graphene nanoplatelets (GnP) as hybrid additives for a polyalphaolefin (PAO 32) base oil wa...

In this work, antifriction and antiwear capabilities of hexagonal boron nitride nanoparticles (h-BN) or graphene nanoplatelets (GnP) as additives of a polyalphaolefin neat oil (PAO 40) were studied at pure sliding conditions. For this purpose, eight PAO 40 nanodispersions were prepared: four nanodispersions with h-BN and four others based on GnP. T...

Solid lipid microparticles (SLMPs) are attractive carriers as delivery systems as they are stable, easy to manufacture and can provide controlled release of bioactive agents and increase their efficacy and/or safety. Particles from Gas-Saturated Solutions (PGSS®) technique is a solvent-free technology to produce SLMPs, which involves the use of sup...

Hybrid nanostructure combinations of ionic liquids (ILs) and hexagonal boron nitride (h-BN) nanosheets are proposed as additives to lubricants to enhance their tribological performance and their temporal stability. Trihexyltetradecylphosphonium bis(2-ethylhexyl)phosphate (IL1), tributylethylphosphonium diethylphosphate (IL2) and trihexyltetradecylp...

The main task of this work is to study the tribological performance of nanolubricants formed by trimethylolpropane trioleate (TMPTO) base oil with magnetic nanoparticles coated with oleic acid: Fe3O4 of two sizes 6.3 nm and 10 nm, and Nd alloy compound of 19 nm. Coated nanoparticles (NPs) were synthesized via chemical co-precipitation or thermal de...

In this work, the synergy between an ionic liquid (IL) and nanoparticles as additives of lubricants was studied. For this purpose, four dispersions based on graphene nanoplatelets, GnPs, or nanoparticles of hexagonal boron nitride, h-BN, with or without the IL tri(butyl) ethylphosphonium diethylphosphate in an ester type base oil, triisotridecyltri...

Dispersions based on hexagonal boron nitride, h-BN, nanoparticles, at 0.50, 0.75 and 1.0 wt.% mass concentrations, in an ester base oil composed mainly of trimethylolpropane trioleate, were investigated as potential nanolubricants. The stability of the dispersions was assessed to determine the reliability of the tribological, thermophysical and rhe...

This article presents an experimental investigation on the effects of concentration and morphology of nanoadditives on the thermophysical properties of nanolubricants (NLs) at different temperatures. A polyalphaolefin (PAO6) oil was used as base fluid. A two-step method was used to prepare the NLs. Zirconium oxide (ZrO2) and boron nitride (BN) nano...

The main goal of this work is to study the tribological properties of nanolubricants formed by trimethylolpropane trioleate (TMPTO) or a polyalphaolefin (PAO 40) base oils with reduced graphene oxide sheets (rGO). This reduction was carried out in order to have a good stability of the nanoadditives in the fluids. For this aim, rGO nanopowders were...

Solubility of individual light fullerenes (C60 and C70) in n-heptane was measured in the ranges of pressure from 0.1 up to 110 MPa and temperature from 298.3 to 358.3 K. At 0.1 MPa, the solubility diagrams of the C60 – n-heptane, C70 – n-heptane binary systems consist of only one branch corresponding to crystallization of mono-solvated fullerenes –...

The objective of this work is to study the tribological and thermophysical properties of nanolubricants composed by a trimethylolpropane trioleate (TMPTO) oil, and graphene nanoplatelets (GnP). For this aim, nanolubricants based on TMPTO with 0.05, 0.10, 0.25 and 0.50 wt% of graphene nanoplatelets were prepared. The dependence on temperature and co...

This article presents an experimental study on some thermophysical properties (density, viscosity and adiabatic bulk modulus) of six nanolubricants based on synthetic oils and ZrO2 nanoparticles. Two-step method with ultrasonic disruptor was used to prepare the nanodispersions. The morphology, crystalline degree and elemental composition of nanopar...

Using a Beckman thermometer, the concentration dependence of water crystallization temperatures was investigated for C60(OH)22–24 – H2O, C70(OH)12 – H2O, C70[C(COOH)2]3 – H2O, С60(C5H9NO3)2 - H2O, С60(C6H14N2O2)2 – H2O binary systems. The semi-empirical Virial Decomposition Asymmetric Model of virial expansion of the excess Gibbs energy of the ligh...

Reliable equations of state (EoS) together with heat capacities at atmospheric pressure make possible to determine properties as the isobaric thermal expansivity, compressibility, both isothermal and isentropic, high pressure isobaric heat capacities or speed of sound. In this work, we have analysed the reliability of two density scaling based EoS,...

Characterization of Elastohydrodynamic Lubrication, EHL, contacts requires an appropriate EoS for the lubricant. Experimental viscosities and speeds of sound of six lubricants from 278.15 to 398.15 K at 0.1 MPa together with densities up to 120 MPa are reported. Tammann-Tait and the two EoSs based on the scaling concept describe the experimental de...

Solubility of light fullerenes (C60 and C70) in n-nonane was investigated in the ranges of pressure form 0.1 MPa up to 100 MPa and temperature from 298.3 K to 353.3 K. Under isothermal conditions, the solubility, expressed as weight fraction of the fullerene in the solution, increases monotonously with increasing pressure. At ambient pressure, we h...

This work analyzes the friction coefficients and the wear volumes obtained in probes made of AISI 420 stainless steel worn with AISI 52100 chrome steel balls under loads of 8, 18, and 30 N; the contact was lubricated with 1-ethyl-3-methylimidazolium ethyl sulfate or 1-ethyl-3-methylimidazolium hexyl sulfate. Under the two lowest loads, the results...

The tribological performance of three ionic liquids (ILs) containing the same cation, 1-butyl-1-methylpyrrolidinium [C4C1Pyrr]+, and the anions tetracyanoborate [B(CN)4]−, trifluoromethanesulphonate [CF3SO3]− and tris(pentafluoroethyl)trifluorophosphate [(C2F5)3PF3]−were analyzed. A reciprocating ball-on-plate tribometer was used at room temperatur...

After doing several miscibility essays with eight ionic liquids (ILs) and four base oils, the ILs tri(butyl)ethylphosphonium diethylphosphate [P4,4,4,2][C2C2PO4] and trihexyl(tetradecyl)phosphonium tris(pentafluoroethyl)trifluorophosphate [P6,6,6,14][(C2F5)3PF3] were selected to be studied as lubricant additives. The neat IL [P4,4,4,2][C2C2PO4], th...

A setup based on a static visual synthetic method for determining phase equilibria up to 100 MPa is presented. Solubilities of carbon dioxide (CO2) in a high-oleic sunflower oil (HOSO) and in an additivated vegetable lubricant (BIO-2T-05) were determined from 298 K to 363 K up to CO2 mass compositions of 0.42. The experimental device was verified c...

The ionic liquids 1-butyl-1-methylpyrrolidinium bis(tri-fluoromethylsulfonyl)imide, [C4C1Pyrr][Tf2N], and 1-butyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide, [C4C1C1Im][Tf2N], were evaluated as neat lubricants for steel–steel sliding contacts using a ball-on-plate reciprocating tribometer under loads of 8, 18, and 30 N at room temper...

The tribological behaviour was evaluated for two ionic liquids (ILs) as neat lubricants for the sliding pair stainless steel AISI420 and 100Cr6 under four loads (14, 18, 22 and 26 N). The ILs contain the same anion, tris(pentafluoroethyl)trifluorophosphate [(C2F5)3PF3]− (also known as [FAP]−), combined with the cations 1-butyl-2,3-dimethylimidazoli...

This chapter reviews recent advances in modelling and predicting some transport properties of dense fluids. We summarize the recent developments for transport in supercooled liquids, focussing on links between structural relaxation and viscosity and decoupling between viscosity and diffusion/mobility. Building on theoretical advances in the superco...

In this work, a general equation of state (EOS) recently derived by Grzybowski et al. [Phys. Rev. E 83, 041505 (2011)] is applied to 51 molecular and ionic liquids in order to perform density scaling of pVT data employing the scaling exponent γ(EOS). It is found that the scaling is excellent in most cases examined. γ(EOS) values range from 6.1 for...

The solubilities of carbon dioxide, CO2, in a reference semi-synthetic oil and in a developed vegetable sunflower-based oil for two stroke engines have been measured from 283 K to 348 K and pressures up to 9 MPa in a high pressure gas solubility apparatus that works in isochoric conditions. The densities of the developed vegetable oil from 293 K to...

To perform an appropriate selection of the lubricants in air conditioned systems working with carbon dioxide as refrigerant, the thermodynamic behavior of the CO2+lubricant systems must be well known. In this work we present a new setup to prepare compressed gas–liquid mixtures and to determine the high pressure density by using an automated densim...

Casalini and Roland [Phys. Rev. E 69, 062501 (2004); J. Non-Cryst. Solids 353, 3936 (2007)] and other authors have found that both the dielectric relaxation times and the viscosity, η, of liquids can be expressed solely as functions of the group (TV γ), where T is the temperature, V is the molar volume, and γ a state-independent scaling exponent. H...

The use of biodegradable lubricants based on vegetable oils is receiving increasing attention, being an important area of research, in order to promote products with a reduced environmental impact during their entire life cycle. Compressibility is one of the key properties that should be taken into account to develop efficient hydraulic fluids and...

In this work we report several excess thermodynamic properties for the dimethyl carbonate + n-octane system in an effort to better understand their behavior over wide temperature and pressure ranges. From previous experimental pVTx data for this system, the changes in the excess molar Gibbs energies, in the excess molar entropies, and in the excess...

In this work we report several derived thermodynamic properties, the isothermal compressibility (κT), the isobaric thermal expansion coefficient (αp), and the internal pressure (π), and their excess functions (κTE, αpE, and πE) for the refrigerant + lubricant mixtures HFC-134a + triethylene glycol dimethyl ether and HFC-134a + tetraethylene glycol...

In this work, the solubility of carbon dioxide, CO2, in pentaerythritol tetraheptanoate (PEC7) and in pentaerythritol tetranonanoate (PEC9) has been performed from 283 to 348K and pressures up to 7.5MPa in an isochoric high-pressure gas solubility apparatus. The solubility values are very similar in terms of mole fractions of CO2 in both pentaeryth...

The solubility of carbon dioxide, CO2, in dipentaerythritol hexaheptanoate (DiPEC7) and a polypropylene glycol dimethyl ether (PAG1) was measured at 283.15 K, 298.15 K, 323.15 K, and 348.15 K, and pressures up to 7 MPa in a high-pressure gas solubility apparatus. A total of 42 pTx values were measured with an isochoric technique, having a mole frac...

In this work, an experimental study for the determination of the density of two dipentaerythritol esters, dipentaerythritol hexapentanoate (DiPEC5) and dipentaerythritol hexaheptanoate (DiPEC7) has been performed for temperatures ranging from 283.15K to 398.15K and pressures up to 70MPa. The heart of the automatic assembly is an Anton Paar DMA HPM...

The densities at high pressures of two dimethoxy end-capped poly(propylene glycols), CH3–O–[CH2–CH(CH3)–O]m–CH3, with average molar masses higher than 1300g·mol−1, were measured in the range (0.1 to 60)MPa at five different temperatures from (298.15 to 398.15)K. The measurements were performed in a high-pressure vibrating tube densimeter. A correct...

This paper analyzes one of the most important properties in the refrigeration field: the solubility of the refrigerants in lubricants. The experimental solubilities of 1,1,1,2-tetrafluorethane (HFC134a) in dimethyl carbonate and diethyl carbonate are reported and discussed for a temperature range from (263.15 to 308.15) K and 101.33 kPa partial pre...

In this work, we present the automatization of a densimetric system for pVT measurements of compressed fluids, operating over the temperature range from 283.15 K to 398.15 K and pressures up to 70 MPa. The heart of the automatic assembly is a commercial Anton Paar DMA HPM vibrating-tube densimeter. The densimeter was calibrated using the method dev...

In this work, the solubility of carbon dioxide, CO2, in pentaerythritol tetrapentanoate (PEC5) and in pentaerythritol tetra(2-ethylhexanoate) (PEBE8) has been performed from (283 to 333) K and pressures up to 7 MPa in a new high-pressure gas solubility apparatus. The results show that in the present analyzed range CO2 is highly soluble in these oil...

Most of the industrial applications of ester-based synthetic lubricants are performed at medium and high pressures, but in the case of viscosity and density, the existing studies are carried out mainly at atmospheric pressure. Lubricants are normally composed by several compounds; hence, it is interesting to know how the pressure and the temperatur...

New densities are reported over the whole composition range for 1-iodoperfluorohexane+n-octane system at temperatures from 288.15 to 308.15 K at atmospheric pressure. These data have been used to compute the excess molar volumes, V m E. Large positive V m E values have been obtained over the entire range of composition, which increases when the tem...

In this work, the speed of sound was measured in monoglyme (monoethylene glycol dimethyl ether or MEGDME) and diglyme (diethylene glycol dimethyl ether or DEGDME) in the temperature range 293.15 \leqslant T/K \leqslant 353.15293.15 \leqslant T/K \leqslant 353.15 at pressures up to 100MPa using a pulse echo technique operating at 3MHz; several the...

New experimental densities in the compressed liquid state are reported for pentaerythritol tetrapentanoate (PEC5) over the temperature range of 278.15−353.15 K and for pressures up to 45 MPa. Density values (99 experimental data) have been measured with a high-pressure vibrating tube densimeter. A correction factor that was due to the viscosity of...

Knowledge of proper lubricant selection and its handling can substantially influence the reliability of a refrigeration system. In this sense the awareness of several thermophysical properties of refrigerants, lubricants, and their mixtures under different conditions of pressure and temperature is highly important for designing refrigeration system...

New experimental densities in the compressed liquid state are reported for diethylene glycol monobutyl ether and propylene glycol propyl ether over the temperature range (283.15 to 353.15) K and for pressures up to 25 MPa. Density values (144 experimental data points) have been measured with a high-pressure vibrating tube densimeter. These data wer...

In this work we analyze the ability of the Nitta–Chao model for the prediction of the pressure dependence of different thermodynamic properties, such as density, isobaric thermal expansivity coefficient, isothermal compressibility coefficient and internal pressure of the pure components (dimethyl carbonate and diethyl carbonate). We also study phas...

Experimental solubilities were determined for 1,1,1,2-tetrafluoroethane (HFC134a) in triethylene glycol dimethyl ether and in tetraethylene glycol dimethyl ether at 101.33 kPa refrigerant partial pressure in the low-temperature range (258.15−298.15 K). The experimental device was adapted from an apparatus commonly used to measure slightly soluble g...

In this work, 144 new experimental density values are reported for diethylene glycol monomethyl ether (DEGME) and diethylene glycol monoethyl ether (DEGEE) in the compressed liquid phase between 283.15 K and 353.15 K for pressures up to 25 MPa. The density measurements were performed with an Anton Paar DMA 60/512P vibrating tube densimeter and then...

The speeds of sound in two poly(alkylene glycol) derivatives (triethylene glycol dimethyl ether and tetraethylene glycol dimethyl ether) were measured, at temperatures from 293.15 to 353.15 K and pressures from atmospheric up to 100 MPa, using a pulse technique operating at 3 MHz, with an estimated error of less than ±0.2%. From these measurements,...

Data available in the literature for vapor–liquid equilibria, activity coefficients at infinite dilution, and enthalpies of mixing for binary mixtures of 1-chloroalkanes or dichloroalkanes with alkanes are used to determine interaction parameters for three versions of the UNIFAC model – the Tassios et al., Larsen et al., and Gmehling et al. version...

In this work, we report excess molar volumes of organic carbonate+p-xylene systems and dynamic viscosities of organic carbonate+n-octane, n-dodecane or p-xylene systems. The excess molar volumes at 298.15K were calculated from density measurements made by using an Anton-Paar DMA 60/602HP densimeter. All the VmE values were positive for dimethyl car...

Excess molar volume, VmE has been calculated from experimental density data for liquid mixtures of dimethyl carbonate with octane over the temperature range from 278.15 to 353.15 K and for pressures up to the lowest of either near the appearance of liquid–liquid equilibrium (LLE) of this mixture or 25 MPa. We propose a new fitting equation of the e...

Excess molar volume, VmE has been calculated from experimental density data for liquid mixtures of dimethyl carbonate with octane over the temperature range from 278.15 to 353.15K and for pressures up to the lowest of either near the appearance of liquid–liquid equilibrium (LLE) of this mixture or 25MPa. We propose a new fitting equation of the exc...

Experimental densities for the compressed liquid phase are reported for dimethyl carbonate and octane, and nine of their mixtures over the composition range (0.1≤x≤0.9), the temperature range 278.15–353.15 K and for pressures up to 25 MPa. Density values (725 experimental data) of this system have been measured with a high-pressure vibrating tube d...

The experimental data available in the literature for the binary systems 1-iodoalkane and α,ω-diiodoalkane with alkanes are used to determine the interaction parameters of the iodine and methyl or methylene groups of the Nitta–Chao equation-of-state group contribution model and of three versions of the UNIFAC model due to Tassios et al., Larsen et...

The experimental densities ρ and excess molar volumesVmE of (dimethyl carbonate + toluene) at the temperatures (278.15, 288.15, 298.15, 308.15, 318.15, and 323.15) K and of (diethyl carbonate + toluene) at the temperatures (288.15, 298.15, 308.15, 318.15, and 323.15) K were determined using an Anton-Paar DMA602HP densimeter. For (dimethyl carbonate...

The Nitta–Chao EOS group-contribution model, based on cell theory, is used to study the interactions of the organic anhydride+n-alkane binary mixtures. A database of excess enthalpies, excess Gibbs energies and excess volumes for this kind of mixtures, together with molar volumes and vaporization enthalpies of pure organic anhydrides, were used to...

In this paper we present a new experimental apparatus designed to measure pressure–density–temperature (pT ) properties with a high-pressure vibrating tube densimeter. Data reliability has been verified by comparing our experimental results for methanol, n-heptane, toluene, and HFC-134a with literature data. In this work we also report new experime...

The excess molar enthalpies at 323.15 K, 373.15 K, and 423.15 K, at 8 MPa, are reported for the binary mixtures methanol + tetraethylene glycol dimethyl ether (TEGDME) and methanol + poly(ethylene glycol) dimethyl ether 250 (PEGDME 250). Excess molar enthalpies were determined with a Setaram C-80 calorimeter equipped with a flow mixing cell. For bo...

Excess molar volumes at 298.15 K for the binary mixtures of a I-bromoalkane with a n-alkane are reported. The VE values were obtained from measurements of the density with an Anton Paar densimeter. Literature data of excess Gibbs energies, excess enthalpies, excess volumes, and activity coefficients at infinite dilution for this kind of mixtures to...

Excess molar volumes at 298.15 K for the binary mixtures of a 1-bromoalkane with a n-alkane are reported. The V E values were obtained from measurements of the density with an Anton Paar densimeter. Literature data of excess Gibbs energies, excess enthalpies, excess volumes, and activity coefficients at infinite dilution for this kind of mixtures t...

Excess enthalpies and excess volumes of the binary systems methanol + N-formylmorpholine, methanol + N-methyl-2-pyrrolidine, and methanol + 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone at 298.15 K and atmospheric pressure have been measured. Excess enthalpies HE were measured in a Calvet microcalorimeter and excess volume VE in a vibrating-tu...

The characteristic parameters for the Tassios et al. (Ind. Eng. Chem. Process Des. Dev. 23 (1984) 391; 24 (1985) 701; 25 (1986) 22), Larsen et al. (Ind. Eng. Chem. Res. 26 (1987) 2274), and Gmehling et al. (Ibid. 32 (1993) 178) versions of UNIFAC model for organic anhydrides + n-alkane systems have been calculated. For the first time, published dat...

Excess volumes at 298.15 K and atmospheric pressure of some organic carbonate+alkane binary systems have been measured using an Anton Paar 602 HP densimeter. For the first time, published data on excess enthalpies, excess volumes, excess Gibbs energies of the above-mentioned binary systems together with the vaporisation enthalpies and the molar vol...

We have estimated the interaction parameters for ether and hydroxyl groups using an extensive experimental database of vapour-liquid equilibria, activity coefficients at infinite dilution, enthalpies of mixing and volumes of mixing of linear monoether + 1-alkanol binary systems. The theoretical results obtained with the parameters proposed are sign...

In this work we report the excess molar enthalpies at 298.15 K and atmospheric pressure of the mixtures 2,2,2-trifluoroethanol (TFE)+poly(ethylene glycol) dimethyl ether 250 (PEGDME 250), methanol + tetraethylene glycol dimethyl ether (TEGDME) and methanol + PEGDME 250. In the case of mixtures with methanol, the UNIFAC and DISQUAC group contributio...

Published data of the enthalpies of 1-fluoroalkane + alkane mixtures were examined on the basis of the Tassios et al and Larsen et al versions of the UNIFAC model. Interaction parameters were determined for the first time for these versions of UNIFAC model. The 1-fluoroalkane + alkane mixtures were characterised by the following types of groups: fl...

Literature data on enthalpies of mixing and vapor-liquid equilibria of organic linear carbonates + n-alkanes mixtures examined on the basis of the unifac model (in its original version as well as in those of Tassios et al., Larsen et al. and Gmehling et al.). For the four versions of the unifac model, the interaction parameters for the carbonate gr...

Literature data for vapor liquid equilibria, activity coefficients at infinite dilution, enthalpies of mixing, volumes of mixing of α,ω-dichloroalkane (ClCH2(CH2)m−2CH2Cl, from m=1 to 6) + − alkane mixtures together with vaporization enthalpies and molar volumes of pure dichloroalkanes were examined on the basis of the Nitta-Chao model. In this p...

In this work we have estimated the structural and interactional parameters of the ether- group for the group-contribution model of Nitta-Chao using a extensive experimental database of thermodynamic properties of ethers (monoethers, polyethers and acetals) and ether + n-alkane and ether + ether mixtures. The results obtained by Nitta-Chao model wit...

Excess enthalpies of the ternary mixture 2,2,2-trifluoroethanol–water–tetraethylene glycol dimethyl ether and the corresponding binary mixtures at 298.15 K have been measured using a standard Calvet microcalorimeter. Wilson, NRTL, UNIQUAC and Wang et al. models have been used to correlate the binary excess enthalpies and, using the parameters obtai...

Excess molar enthalpies HEm for [xCH2Cl(CH2)3CH2Cl + (1 - x )(CH3CO(CH2)v-3CH3 for v = 3, 4, 5, 6, or 7}] and [xCH2Cl(CH2)4CH2Cl + (1 - x ){CH3CO(CH2)v-3CH3- for v = 3, 6, or 7}] have been measured using a Calvet microcalorimeter at the temperature T = 298.15 K and normal atmospheric pressure. In all the composition range, excess enthalpies are pos...

Experimental excess enthalpies HEm at the temperature 298.15 and normal atmospheric pressure were obtained for (1,1-dichloropropane + hexan-2-one or heptan-2-one), (1,3-dichloropropane + propan-2-one, or hexan-2-one or heptan-2-one), and (1,4-dichlorobutane + propan-2-one or hexan-2-one or heptan-2-one) using a Calvet microcalorimeter. All the HEm...

1 The knowledge of the solubility of different gases such us O2, N2, and CO2 in lubricants used for two stroke engines is important because these gases are involved in the combustion process together with the lubricant and the gasoline in the combustion chamber, and the developed vegetable oil should have a similar behaviour than the reference synt...