{"title":"Adsorption of tetracycline using aspartic acid and polypyrrole-functionalized multiwalled carbon nanotubes: Kinetic, isotherm, and thermodynamic analysis","authors":"Amirhossein Khazaie , Amir Hessam Hassani , Elham Moniri , Mahsasadat Miralinaghi","doi":"10.1016/j.fluid.2025.114531","DOIUrl":"10.1016/j.fluid.2025.114531","url":null,"abstract":"<div><div>This study investigates the adsorption of tetracycline from aqueous solutions using a novel nanocomposite adsorbent composed of multi-walled carbon nanotubes functionalized with aspartic acid and poly-pyrrole. Batch adsorption experiments were conducted to evaluate the effects of pH, contact time, temperature, and initial concentration on adsorption efficiency. The maximum adsorption capacity was found to be 38.08 mg/g at pH 5, 25 °C, and an initial TC concentration of 100 mg/L. Kinetic data were best described by the pseudo-second-order model, indicating chemisorption, while equilibrium data fit well with the Langmuir isotherm model, confirming monolayer adsorption. Thermodynamic parameters revealed that the adsorption process is spontaneous and exothermic, with ΔG° values ranging from –11.9 to –11.11 kJ/mol and ΔH° = -21.34 kJ/mol. These findings suggest that MWCNT-Asp-PPy is an efficient, high-capacity adsorbent for TC removal, with promising applications in water treatment.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"599 ","pages":"Article 114531"},"PeriodicalIF":2.8,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144686010","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":"Molecular dynamics simulation study on the selective extraction of 1,3 propanediol from fermentation broth using imidazolium-based hydrophobic ionic liquids","authors":"Raj Akshat , Anand Bharti , Padmini Padmanabhan","doi":"10.1016/j.fluid.2025.114530","DOIUrl":"10.1016/j.fluid.2025.114530","url":null,"abstract":"<div><div>Selective extraction of dilute 1,3 propanediol (1,3-PDO) (<20 wt %) from the fermentation broth is challenging via conventional distillation as the process becomes energy-intensive. Liquid-liquid extraction (LLE) using solvents such as ionic liquids (ILs) may significantly reduce costs. Therefore, this study explored the potential of imidazolium-based hydrophobic ILs for the selective extraction of 1,3-PDO from a fermentation broth containing 1,3-PDO, 2,3-butanediol (2,3-BDO), glycerol (Gly), and water using molecular dynamics simulations. Three ILs, having the same cation, 1‑butyl‑3‑methylimidazolium ([Bmim]<sup>+</sup>), but different anions-hexafluorophosphate ([PF₆]⁻), bis(trifluoromethylsulfonyl)imide ([NTF₂]⁻), and trifluoromethanesulfonate ([TFO]⁻)-were investigated. The local mass density profiles confirmed a well-defined biphasic system for all ILs. [Bmim][PF<sub>6</sub>] and [Bmim][TFO] showed excellent results, with 1.3-PDO distribution coefficients ranging from 2.53 to 6.71 and 4.12 to 15.40, respectively. The selectivity towards 1.3-PDO relative to water ranged from 50.6 to 192.50, while selectivity relative to glycerol (2.88–13.83) and 2,3-BDO (4.59–25.67) was also notably high. [Bmim][TFO] exhibited the strongest affinity for 1,3-PDO, with the highest binding energies and more favorable hydrogen bonds. Furthermore, diffusion coefficient analysis indicated that PDO exhibited lower diffusion rates in the extraction phase. Radial distribution function (RDF), spatial distribution function (SDF), and coordination number (CN) analyses confirmed a compact solvation shell and higher 1,3-PDO density around [Bmim][TFO]. Supported by COSMO-SAC thermodynamic model predictions, the study demonstrated that the anion plays a critical role in IL performance. Overall, the results established the extraction performance trend as [Bmim][TFO] > [Bmim][PF₆] > [Bmim][NTF₂], highlighting [Bmim][TFO] as a promising candidate for selective PDO recovery.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"599 ","pages":"Article 114530"},"PeriodicalIF":2.8,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144633706","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":"Experimental determination and correlation of solubility for R1234ze(E) in POE, PVE, and PAG base oils","authors":"Tao Jia , Jinpeng Yang , Jia Yu","doi":"10.1016/j.fluid.2025.114529","DOIUrl":"10.1016/j.fluid.2025.114529","url":null,"abstract":"<div><div>Detailed knowledge about the solubility of refrigerant in oil is essential for the design, operation, and long-term reliability of HVAC and refrigeration systems. Herein, as the leading candidates, the solubilities of R1234ze(E) in polyol ester (POE), polyvinylether (PVE), and polyalkylene glycol (PAG) base oils were investigated using the isochoric saturation method at temperatures from 283 K to 353 K. The viscosity grade of the three base oils is ISO VG 68. Additionally, the Peng-Robinson (PR) + Wilson model was successfully applied to correlate the experimental data. The absolute average relative deviations between the experimental and calculated pressures for R1234ze(E) in POE, PVE, and PAG base oils were 1.56 %, 0.91 %, and 1.46 %, respectively. These results provide valuable physical property data for the selection of suitable oils in vapor compression refrigeration systems.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"599 ","pages":"Article 114529"},"PeriodicalIF":2.8,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144633707","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}
Lihang Bai , Yulong Ji , Haifeng Ma , Bohao Wu , Maogang He , Wenze Zhu
{"title":"A novel cubic equation of state of a flexible Zc","authors":"Lihang Bai , Yulong Ji , Haifeng Ma , Bohao Wu , Maogang He , Wenze Zhu","doi":"10.1016/j.fluid.2025.114527","DOIUrl":"10.1016/j.fluid.2025.114527","url":null,"abstract":"<div><div>Classical cubic equations of state (EoSs) cannot produce satisfactory predictions for dense-state fluids because of the missing molecular repulsion effect. This work introduces a newly developed cubic EoS of a flexible critical compressibility Z<sub>c</sub> by incorporating a repulsion term. Its <em>α</em>-function is redefined and capable of reliable extrapolation throughout the entire temperature range. As straightforward as the Soave-Redlich-Kwong (SRK) EoS, all the necessary parameters of the new EoS can be determined using the critical properties (<em>T</em><sub>c</sub>, <em>p</em><sub>c</sub>, <em>v</em><sub>c</sub>) and acentric factors. Tested upon pure and multi-component fluids, the new EoS demonstrates superior robustness and accuracy compared to the SRK EoS.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"599 ","pages":"Article 114527"},"PeriodicalIF":2.8,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144632860","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":"Corrigendum to “Using Physical Property Models and Artificial Intelligence to Design Chemical Products in the journal Fluid Phase Equilibria” [Fluid Phase Equilibria 596 (2025) 114441]","authors":"Kevin G. Joback","doi":"10.1016/j.fluid.2025.114505","DOIUrl":"10.1016/j.fluid.2025.114505","url":null,"abstract":"","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"598 ","pages":"Article 114505"},"PeriodicalIF":2.8,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144713757","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}
Larissa F. Torres , Antonin Chapoy , Rod Burgass , Cláudio Dariva , Papa M. Ndiaye , Frederico W. Tavares
{"title":"Water content in pure CO2 and CO2-rich mixtures using the DSH analytical technique","authors":"Larissa F. Torres , Antonin Chapoy , Rod Burgass , Cláudio Dariva , Papa M. Ndiaye , Frederico W. Tavares","doi":"10.1016/j.fluid.2025.114523","DOIUrl":"10.1016/j.fluid.2025.114523","url":null,"abstract":"<div><div>The accurate determination of water content in equilibrium with hydrates helps to prevent operational problems related to flow assurance, and it is essential for the emerging Carbon Capture and Storage (CCS) processes for decarbonization. However, the experimental challenges associated with these measurements cause a scarcity of data. The development of the Differential Scanning Hygrometer (DSH) method has increased the number of water content reports for CO<sub>2</sub>-rich systems in equilibrium with hydrates. It monitors not absolute values but fluctuations in the water content due to the formation of ice or dew inside a temperature-controlled tube. Here, we provide experimental and modeling investigation for water content on pure CO<sub>2</sub> and two CO<sub>2</sub>-rich mixtures (CO<sub>2</sub>+CH<sub>4</sub> and CO<sub>2</sub>+CH<sub>4</sub>+N<sub>2</sub>) in equilibrium with hydrates: the sCPA and the SRK+EMS equations of state were used to model the obtained experimental data, both using the van der Waals-Platteeuw (vdW-P) model for the hydrate phase.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"599 ","pages":"Article 114523"},"PeriodicalIF":2.8,"publicationDate":"2025-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144595438","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":"Phase equilibria of carbon dioxide + sulfur hexafluoride mixed gas hydrate as fundamental data toward improving the mechanical properties of marine sediments","authors":"Tasuku Ishikawa , Takeshi Sugahara , Takayuki Hirai , Norimasa Yoshimoto","doi":"10.1016/j.fluid.2025.114525","DOIUrl":"10.1016/j.fluid.2025.114525","url":null,"abstract":"<div><div>Isothermal phase equilibria of carbon dioxide (CO<sub>2</sub>) + sulfur hexafluoride (SF<sub>6</sub>) mixed gas hydrate at temperatures of 281.85 K, 284.05 K, 288.05 K, 291.05 K, 291.74 K, and 292.20 K were measured so as to improve the mechanical properties of marine sediment by hydrate cementation. The addition of SF<sub>6</sub> significantly reduces the equilibrium pressure of CO<sub>2</sub>-containing mixed gas hydrate at each temperature. At temperatures above the quadruple point Q<sub>2</sub> (pure CO<sub>2</sub> hydrate + aqueous + CO<sub>2</sub>-rich liquid + vapor phases) of 283.22 K, the four-phase (mixed gas hydrate + aqueous + guest-rich liquid + vapor phases) equilibrium point(s) exists(exist) on the isotherms of the CO<sub>2</sub>+SF<sub>6</sub> mixed gas hydrate system. The four-phase equilibrium curve was connected from the quadruple point Q<sub>2</sub> of pure CO<sub>2</sub> hydrate to that of pure SF<sub>6</sub> hydrate and had a maximum temperature point at 292.0 ± 0.2 K, which is higher than both the Q<sub>2</sub> temperatures of pure CO<sub>2</sub> hydrate and pure SF<sub>6</sub> hydrate. Therefore, the addition of SF<sub>6</sub> to CO<sub>2</sub> brings a significant effect to expand the thermodynamically stable region of CO<sub>2</sub>-containing mixed gas hydrate in order for simultaneous CO<sub>2</sub> storage and sediment improvement to be realized at marine sediment.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"599 ","pages":"Article 114525"},"PeriodicalIF":2.8,"publicationDate":"2025-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144579991","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}
Pengshuai Zhang , Binbin Wu , Ranran Feng , Jiaxuan Xu , Jiaqi Li , Shuoye Yang , Peng Li
{"title":"Investigating the dissolution behavior and revealing the thermodynamic mechanism of Ethyl L-phenylalaninate hydrochloride in several neat and binary solvents","authors":"Pengshuai Zhang , Binbin Wu , Ranran Feng , Jiaxuan Xu , Jiaqi Li , Shuoye Yang , Peng Li","doi":"10.1016/j.fluid.2025.114524","DOIUrl":"10.1016/j.fluid.2025.114524","url":null,"abstract":"<div><div>This study investigated the solubility of ethyl l-phenylalaninate hydrochloride (H-Phe-OEt.HCl) in seven neat solvents (1-Propanol, 1,4-Dioxane, 2-Butoxyethanol, 2-Propoxyethanol, Isopropyl alcohol, 1-Butanol, THF) and two binary (2-Propoxyethanol + THF, 2-Butoxyethanol + 1-Propanol) solvent mixtures from 283.15 K to 323.15 K under atmospheric pressure. The solubility of H-Phe-OEt.HCl in the neat solvents was correlated by the NRTL, Buchowski-Ksiazczak λh, Margules, NRTL-SAC, Jouyban and van't Hoff model. For the binary solvent mixtures (2-Propoxyethanol + THF, 2-Butoxyethanol + 1-Propanol), the NRTL, van't Hoff, Jouyban-Acree van't Hoff and Ma model were employed to correlate the obtained solubility. Hansen solubility parameters (HSPs) was used to evaluate the dissolution trend of H-Phe-OEt.HCl in the selected solvents. In addition, the apparent thermodynamic parameters such as Δ<sub>sol</sub><em>H</em>° (apparent standard enthalpy change), Δ<sub>sol</sub><em>S</em>° (apparent standard entropy change) and Δ<sub>sol</sub><em>G</em>° (apparent standard Gibbs energy change) was calculated to evaluate the dissolution mechanism, all the positive values of Δ<sub>sol</sub><em>H</em>°, Δ<sub>sol</sub><em>S</em>° and Δ<sub>sol</sub><em>G</em>° illustrated that the dissolution of H-Phe-OEt.HCl was an endothermic and entropy-increase process. The current study could provide critical insights for optimizing industrial crystallization, purification, and separation processes of H-Phe-OEt.HCl.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"599 ","pages":"Article 114524"},"PeriodicalIF":2.8,"publicationDate":"2025-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144595439","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}
Fatemeh Ghadimi, Mohammad Amin Sobati, Mahdieh Amereh
{"title":"Predictive QSPR modeling of pyridine extraction from fuels using deep eutectic solvents: Structural descriptors and neural network insights","authors":"Fatemeh Ghadimi, Mohammad Amin Sobati, Mahdieh Amereh","doi":"10.1016/j.fluid.2025.114522","DOIUrl":"10.1016/j.fluid.2025.114522","url":null,"abstract":"<div><div>This study employs the Quantitative-Structure-Property-Relationship (QSPR) method to investigate the extractive denitrogenation process of fuels employing deep eutectic solvents (DESs). In this regard, the distribution of pyridine (PY) as a typical nitrogen compound between the hydrocarbon and DES-rich phases was predicted. A comprehensive dataset, covering liquid-liquid equilibrium (LLE) data for 43 ternary systems was collected from various hydrocarbons and DESs containing different hydrogen bond donors (HBDs) and hydrogen bond acceptors (HBAs), enabled an extensive investigation of structural effects on PY distribution. Predictive linear model employing multiple linear regression (MLR) and non-linear models employing multi-layer perceptron (MLP), Radial Basis Function (RBF), Support Vector Machine (SVM), and Random Forest (RF) were developed. The linear model achieved statistical values of R² = 0.8025 and Average Absolute Relative Deviation (AARD) = 21.52 %, while among the non-linear models, the MLP model demonstrated the best performance with R² = 0.9581 and AARD = 9.30 %. The examination of molecular descriptors in the QSPR model demonstrated that PY distribution between the DES and hydrocarbon-rich phases is strongly affected by the average molecular weight of the HBA component and the hydrophilic characteristics of the HBD structure. These observations offer benefical insights for selecting and fine-tuning of molecular structure of DESs in the extractive denitrogenation applications.</div></div>","PeriodicalId":12170,"journal":{"name":"Fluid Phase Equilibria","volume":"599 ","pages":"Article 114522"},"PeriodicalIF":2.8,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144655478","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}