Fluid Phase Equilibria最新文献

{"title":"Understanding the solubility behavior of 2,2′-bifuran-5,5′-dicarboxylic acid in different pure solvents","authors":"Samir F. Castilla-Acevedo ,&nbsp;Alvaro Pallais-Leclair ,&nbsp;Diego T. Melfi ,&nbsp;Pooja Bhalode ,&nbsp;Berlyn Mellein ,&nbsp;Aaron M. Scurto ,&nbsp;Dionisios G. Vlachos ,&nbsp;Alan M. Allgeier","doi":"10.1016/j.fluid.2025.114355","DOIUrl":"10.1016/j.fluid.2025.114355","url":null,"abstract":"<div><div>The molecule 2,2′-bifuran-5,5′-dicarboxylic acid (BFDCA) has attracted significant attention due to its potential as a building block to form biorenewable polymers. However, there is no information available on the solubility of BFDCA in pure solvents, hindering the effective design for reaction, separation, and crystallization processes. The present work evaluated the solubility of BFDCA in eight different solvents at temperatures from 298.15 K to 363.15 K. On a mole fraction basis, the BFDCA solubility from high to low at 298.15 K followed the order: DMAc &gt; DMSO &gt; MeOH &gt; 1-pentanol &gt; 2-propanol &gt; acetic acid &gt; acetonitrile &gt; H₂O. Additional solubility tests were performed in cyclohexane, acetone, and dichloromethane, but the equilibrium solute concentration was below the detection limit of the instrument in the range of temperatures studied. The sigma (σ) profile of BFDCA shows that this molecule is strongly polar and can behave as a donor and acceptor of hydrogen bonds. A higher screening charge density was found in the hydrogen bonding (HB) donor regions in BFDCA, which would favor the interaction with the solvents’ HB acceptor regions. Correlations between BFDCA solubility and solvent property parameters show that solvents’ HB acceptor propensity and total basicity play an important role in the solute solubility, which agrees with the findings from the σ profile of BFDCA and solvents and linear energy solvation relationships (LSER). However, the dipole moment, dielectric constant, cohesive energy density, and surface tension also influence the BFDCA solubility since the evaluated molecular descriptors are insufficient to explain the solubility behavior in some cases. The Apelblat equation and the NRTL activity coefficient model aptly described the experimentally observed solubility with model fitting, whereas the COnductor-like Screening MOdel for Real Solvents (COSMO-RS) method predicted qualitative trends.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"594 ","pages":"Article 114355"},"PeriodicalIF":2.8,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of pure and mixture thermodynamic properties and phase equilibria using an optimized equation of state - part 2: Vapor pressure modelling and extension to mixtures","authors":"Allan Paolo L. Almajose ,&nbsp;Maria Lourdes P. Dalida","doi":"10.1016/j.fluid.2025.114345","DOIUrl":"10.1016/j.fluid.2025.114345","url":null,"abstract":"<div><div>The Almajose–Dalida equation is used to develop thermodynamically consistent energy parameter coefficients using three established alpha functions in the literature. Specifically, the Twu function, the Heyen function, and the Mathias–Copeman alpha functions were applied to model the energy parameters of 100 compounds commonly used in process simulations. Thermodynamic consistency rules were applied to each function; however, since the Mathias–Copeman function is not inherently thermodynamically consistent, numerical boundary conditions were imposed to ensure its consistency up to 3000 K. Additionally, thermodynamically-consistent generalized correlations were developed for the Twu two-parameter and Heyen alpha functions, enabling the generalized Almajose–Dalida equation to extend to species with unavailable parameters.</div><div>Furthermore, the equation was applied to fluid mixtures using advanced mixing rules, including the van der Waals one-fluid (vdW1f) rule and the Huron–Vidal–Orbey–Sandler (HVOS) rule. Enhanced by the Panagiotopoulos cross-interaction model, the vdW1f rule provided accurate fits for nonideal systems, achieving precise phase equilibrium and volumetric behavior predictions. By integrating the modified HVOS mixing rule alongside the modified UNIFAC method, the equation attains fully predictive capabilities. This comprehensive approach advances the accuracy and reliability of thermodynamic modeling using the Almajose–Dalida equation, particularly in cases where access to experimental data is limited.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"594 ","pages":"Article 114345"},"PeriodicalIF":2.8,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adsorption-desorption hysteresis of gas mixtures/graphite system through molecular simulation: Implications for gas separation membrane technology","authors":"Arshad Raza","doi":"10.1016/j.fluid.2025.114352","DOIUrl":"10.1016/j.fluid.2025.114352","url":null,"abstract":"<div><div>Graphite could potentially serve as a membrane for enhanced gas separation in the petroleum sector. The extraction of in-situ hydrogen (H₂) in natural gas reservoirs will be challenging due to the presence of methane (CH₄) and carbon dioxide (CO₂). A downhole wellbore membrane to selectively produce hydrogen while prohibiting the flow of CO₂ and other gases would improve economic viability. However, investigations on graphite for gas transport of CO₂, H₂, and CH₄ in terms of hysteresis have received little attention. For this paper, we used molecular dynamics simulation to investigate H₂, CO₂ and CH₄ adsorption/desorption behavior on graphite under various pressures (2.75–41.37 MPa) and temperatures (350 K). By combining Grand Canonical Monte Carlo with molecular dynamics, the simulation not only investigates sorption but also examines the interaction between graphite and gases. Our results indicate that the adsorption capacity is directly correlated to pressure and the adsorption curve reaches the maximum at a high pressure of 41.37 MPa. At extreme pressures, the rate of adsorption increases, but at a lower pressure indicating limited availability of adsorbent pores. The sorption capacity non-linearly with pressure limits both the adsorption and desorption process with a maximum sorption capacity of about 11.3 mmol/g for H₂, 17 mmol/g for CH₄ and 43 mmol/g for CO₂ at a pressure of about 40 MPa. The desorption curve slightly overlaps the adsorption curve and marks the hysteresis effect <em>between the two processes of adsorption and desorption</em>. The effect of hydrogen on the graphite is less than carbon dioxide or methane. The discrepancy among adsorbent preferences for carbon dioxide arises from size, polarizability or interaction energy. In terms of diffusion coefficients, hydrogen can be said to have a higher diffusion coefficient than that of carbon dioxide while carbon dioxide has a higher one when compared to methane, probably due to its lighter molecular weight and weaker adsorption.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"593 ","pages":"Article 114352"},"PeriodicalIF":2.8,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A robust setup for efficient characterization of multicomponent vapor-liquid equilibria using Raman spectroscopy","authors":"Marvin Kasterke,&nbsp;Leo Bahr,&nbsp;Hans-Jürgen Koß,&nbsp;Thorsten Brands","doi":"10.1016/j.fluid.2025.114344","DOIUrl":"10.1016/j.fluid.2025.114344","url":null,"abstract":"<div><div>Vapor-liquid equilibrium (VLE), a crucial thermodynamic property in diverse industrial processes, assumes paramount significance in the development, optimization, and operation of separation processes and various applications. Despite their central role, large sample volumes, long measurement times and the handling of the apparatus are a challenge for the precise determination of VLE data. In response to these challenges, we present an innovative Raman spectroscopy-based measurement setup that enables fast, accurate and user-friendly characterization of VLE. The application of Raman spectroscopy enables non-invasive analysis of vapor and liquid-phases in small sample volumes (&lt;3 ml) for multiple VLE data points. The usage of a compact isothermal VLE measurement cell ensures rapid and reliable VLE control. The combination of the equilibrium cell with a highly confocal fiber-coupled Raman probe in backscattering configuration and a high-throughput spectrometer establishes an efficient setup for quantifying VLE data in a broad range of conditions. The setup has been validated for vapor pressure curves of methyl tert‑butyl ether (MTBE), isooctane (2,2,4-trimethylpentane) and cyclohexane for a temperature range of 283.15 K to 333.15 K and the measurement of the binary VLE MTBE-isooctane at 318 .15K. the setup allows a highly efficient access to VLE data of industrial relevance.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"594 ","pages":"Article 114344"},"PeriodicalIF":2.8,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurement for the critical temperatures, pressures, and thermal diffusivities of monoethanolamine, diethanolamine, and 2-amino-2-methyl-1-propanol","authors":"Nataliya S. Bogatishcheva,&nbsp;Alexander P. Popov,&nbsp;Dmitriy A. Galkin,&nbsp;Eugene D. Nikitin","doi":"10.1016/j.fluid.2025.114343","DOIUrl":"10.1016/j.fluid.2025.114343","url":null,"abstract":"<div><div>The critical pressures, critical temperatures, and thermal diffusivities have been measured for monoethanolamine (MEA), diethanolamine (DEA), and 2-amino-2-methyl-1-propanol (AMP). These compounds are the components of mixtures used for the capture of various greenhouse gases, mainly CO₂. The pulse-heating method applicable to highly thermally unstable compounds has been used to measure the critical properties. The combined relative expanded uncertainties at 0.95 level of confidence are 0.015 for the critical temperatures and from 0.036 to 0.047 for the critical pressures. The acentric factors of the alkanolamines under study have been calculated. The critical properties of the alkanolamines measured in this work have been compared with the literature data as well as with the values estimated by the group contribution methods of Wilson and Jasperson, Nannoolal et al., and Hukkerikar et al. All the group-contribution methods underestimate both the critical temperatures and pressures of the alkanolamines with one exception: the critical pressure of DEA estimated by the method of Nannoolal et al. is higher than the experimental value. In addition, such a comparison has been made with the critical properties of alkanolamines obtained using three versions of the SAFT equation of state (PρT-SAFT-HR, PC-SAFT, and SAFT-HR). These models of the SAFT EoS overestimate the critical temperature of the MEA and AMP and the critical pressure of the MEA but underestimate the critical pressure of the AMP.</div><div>The thermal diffusivities of MEA, DEA and AMP have been measured by the laser flash method using a LFA 457 MicroFlash system (Netzsch, Germany) at atmospheric pressure; the temperature range covered has been from 303.15 to 373.15 K. Linear polynomials have been used to describe the dependences of the thermal diffusivity on temperature. The thermal conductivities of the alkanolamines have been calculated from the experimental data on thermal diffusivity and the literature data on density and heat capacity. The combined relative expanded uncertainties are 0.05 and 0.06 for thermal diffusivity and thermal conductivity, respectively. The equations for calculating the thermal conductivities of MEA, DEA, and AMP have been obtained using the experimental data obtained in this work and taken from the literature. The comparison of the experimental values of thermal conductivity and those calculated by the method of Govender et al. has been performed. The technique of Govender and co-workers significantly overestimates the thermal conductivity of the alkanolamines.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"593 ","pages":"Article 114343"},"PeriodicalIF":2.8,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermophysical properties and isobaric vapor-liquid equilibria for 3,4-difluoronitrobenzene and 2,5-difluoronitrobenzene","authors":"Xueqiang Shao ,&nbsp;Shucui Han ,&nbsp;Lin Lin ,&nbsp;Jinyi Chen ,&nbsp;Jinbei Yang","doi":"10.1016/j.fluid.2025.114341","DOIUrl":"10.1016/j.fluid.2025.114341","url":null,"abstract":"<div><div>3,4-Difluoronitrobenzene and 2,5-difluoronitrobenzene are significant fine chemical intermediates, widely applied in the fields of medicine, pesticides, and liquid crystal materials, particularly in pharmaceutical production. The available literature on their thermodynamic properties is scarce. Thermophysical property measurements for pure 3,4-difluoronitrobenzene and 2,5-difluoronitrobenzene liquids were performed in relation to temperature: density (293.15 to 353.15) K, viscosity (293.15 to 353.15) K, saturated vapor pressure (366 to 478) K. Isobaric vapor-liquid equilibria (VLE) data for the 3,4-difluoronitrobenzene and 2,5-difluoronitrobenzene binary system were experimentally determined at 101.2 kPa. The correspondence between density and temperature was successfully modeled utilizing the DIPPR equation. Meanwhile, viscosity data were analyzed using four selected equations, with VFT equation yielding the most precise results. Furthermore, the correlation between saturated vapor pressure and temperature can be precisely established using Antoine and Riedel equations. The binary VLE data were modeled using NRTL and Wilson equations, yielding binary interaction parameters. These parameter-derived predictions closely aligned with experimental findings, revealing the absence of azeotropic behavior in the binary system. The thermophysical properties of these pure components, along with VLE data provided, are significant for the separation process of 3,4-difluoronitrobenzene and 2,5-difluoronitrobenzene.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"593 ","pages":"Article 114341"},"PeriodicalIF":2.8,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Contributions to ionic activity coefficients: A review and comparison of equations of state with molecular simulations","authors":"Nefeli Novak ,&nbsp;Fufang Yang ,&nbsp;Martin Due Olsen ,&nbsp;Xiaodong Liang ,&nbsp;Nicolas von Solms ,&nbsp;Ioannis G. Economou ,&nbsp;Marcelo Castier ,&nbsp;Jean-Charles de Hemptinne ,&nbsp;Athanassios Z. Panagiotopoulos ,&nbsp;Georgios M. Kontogeorgis","doi":"10.1016/j.fluid.2025.114339","DOIUrl":"10.1016/j.fluid.2025.114339","url":null,"abstract":"<div><div>Advanced Equations of State for electrolyte solutions (e-EoS) consist of many contributions stemming from different intermolecular forces, e.g. repulsion, dispersion, hydrogen bonding, as well as ionic interactions between ions, ion solvation and possibly others. It is difficult to establish a priori which is the correct balance of the various contributions, and different parameter estimation strategies may result in similar performance of models having entirely different trends with respect to the contribution of the various terms. The first part of this work is a literature review on the balance of forces exhibited by existing electrolyte models, both activity coefficient models and e-EoS. In the second part of this work, the activity coefficients and the contributions of the various terms calculated by molecular simulation (MS) based on the recent studies by Saravi and Panagiotopoulos are analyzed and compared to their e-EoS counterparts at 25 °C and 1 bar. We have considered three e-EoS from literature, namely the eSAFT-VR Mie, ePPC-SAFT and e-CPA. MS studies have been presented in literature both using the so-called implicit and explicit simulations, but only the latter are considered here where water is treated as a molecule, as these are in closer agreement to experimental data. Although correspondence between MS contributions and e-EoS terms is not fully established, some conclusions related to the performance of e-EoS are obtained.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"594 ","pages":"Article 114339"},"PeriodicalIF":2.8,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of gas hydrates phase equilibrium in porous media – Pore size effect and thermodynamics approach","authors":"Sara Kishan Roodbari,&nbsp;Vahid Mohebbi,&nbsp;Reza Mosayebi Behbahani","doi":"10.1016/j.fluid.2025.114330","DOIUrl":"10.1016/j.fluid.2025.114330","url":null,"abstract":"<div><div>Rapid growth in conventional energy consumption has drawn attention to renewable resources and unconventional fossil energy sources, such as Natural Gas Hydrates (NGHs). Comprehensive knowledge of the NGH accumulation conditions is the basis of exploration and exploitation. The mechanisms and factors, related with sediments and their matrix characteristics, and thermodynamic conditions affect the formation and dissociation of NGHs in sediments. Thermodynamic data on hydrate formation in porous media is limited due to the time-consuming and complex nature of obtaining experimental data. The use of thermodynamic models capable of predicting hydrate formation conditions is highly beneficial for studying gas extraction from hydrate reservoirs. In this research, previously published experimental data and modeling were analyzed. The impact of pore size on the formation of natural gas hydrates (NGHs) was modeled using two different thermodynamic approaches (fugacity and activity models), and their adaptation to experimental data was studied. The outcomes of the thermodynamic models revealed that the fugacity and activity model exhibited overall average absolute percent deviation (AAD%) 2.89 and 4.6 %, respectively. Minimum and maximum percentages of the average absolute deviation (AAD%) in fugacity model at 1.05 % and 5.5 %, respectively. Meanwhile, the activity model showed a minimum deviation of 1.67 % and a maximum deviation of 9.22 %. Additionally, it was observed that as the pore size diameter approaches approximately 100 nm, the equilibrium hydrate pressure in porous media and the equilibrium pressure in pure water become close. The surface tension of 0.039(J/m²) proposed by Uchida et al. leads to accurate modeling of methane hydrate in porous media.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"593 ","pages":"Article 114330"},"PeriodicalIF":2.8,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An NMR study of hydrofluorocarbon mixed-gas solubility and self-diffusivity in the ionic liquid 1-ethyl-3-methylimidazolium dicyanamide","authors":"Miguel Viar ,&nbsp;Fernando Pardo ,&nbsp;Gabriel Zarca ,&nbsp;Leoncio Garrido ,&nbsp;Ane Urtiaga","doi":"10.1016/j.fluid.2025.114340","DOIUrl":"10.1016/j.fluid.2025.114340","url":null,"abstract":"<div><div>To date, the design of advanced separation processes, such as the extractive distillation with ionic liquids (ILs), for the separation of common close-boiling refrigerant blends relies almost exclusively on binary equilibrium data obtained for single-gas/solvent systems, thus neglecting the influence of possible mixture effects. In this work, Nuclear Magnetic Resonance (NMR) spectroscopy and pulsed gradient spin echo (PGSE) NMR are proposed for the sequential assessment of the single and mixed-gas vapor-liquid equilibrium and self-diffusivity of two fluorinated refrigerants, difluoromethane (R-32) and pentafluoroethane (R-125), in the IL 1-ethyl-3-methylimidazolium dicyanamide at 303.1 K and pressures up to 4 bar, either as pure R-32 or using the commercial refrigerant blend R-410A. The results confirmed that the mixed-gas solubility and self-diffusivities were essentially equal to those obtained with pure feed gas, thus significant mixing effects were not observed for this particular system. However, an increase in the self-diffusion coefficients was observed with the concentration of absorbed gas, which was more significant for the smallest hydrofluorocarbon (R-32) than for R-125. This technique also allowed evaluating the mobility of the IL moieties, which was slightly higher for the IL anion. Moreover, the self-diffusion coefficients of the IL ions also increased with the amount of gas absorbed, yet less markedly than for the refrigerants. Overall, the NMR technique proved to be an accurate method for the rapid screening of possible mixture effects in equilibrium and transport properties of refrigerant and IL systems, thus providing essential information for designing novel advanced separation processes.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"593 ","pages":"Article 114340"},"PeriodicalIF":2.8,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrophobic interactions described using hetero-segmented PC-SAFT: 2. Surfactants and their aqueous solutions","authors":"Marius Rother,&nbsp;Gabriele Sadowski","doi":"10.1016/j.fluid.2025.114342","DOIUrl":"10.1016/j.fluid.2025.114342","url":null,"abstract":"<div><div>Despite their importance for industry and pharmaceuticals applications, description of aqueous solutions that contain surfactants is still a challenging task in thermodynamic modeling. As a first step towards a holistic modeling approach, which is also applicable for concentrated surfactant solutions, this work aimed to model the intrinsic behavior of surfactant molecules. For this purpose, we applied hetero-segmented PC-SAFT as a group contribution method to build surfactant molecules from different groups, which separately characterize the hydrophobic tail and the hydrophilic head of the surfactant. While the hydrophobic tail is modeled by the parameterization developed in the first part of this paper series (M. Rother, G. Sadowski, Fluid Phase Equilibria 582 (2024)), this work focuses on extending the parameter matrix to model the hydrophilic head. We considered the surfactant classes C_iG₁, C_iE_j and MEGA-i. The parameters for the surfactant head groups were adjusted to sorption data of surfactant/alcohol systems and to partition coefficients of the surfactants in n-alkane/water systems and n-alcohol/water systems. As a benchmark of the new parameterization, we modeled the critical micelle concentration as a function of temperature for these three surfactant classes using a newly developed, explicit equation for calculating this quantity. The results are in even quantitative agreement with the experimental data.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"593 ","pages":"Article 114342"},"PeriodicalIF":2.8,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}